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3789 lines
96 KiB
3789 lines
96 KiB
/* |
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* linux/kernel/printk.c |
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* |
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* Copyright (C) 1991, 1992 Linus Torvalds |
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* |
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* Modified to make sys_syslog() more flexible: added commands to |
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* return the last 4k of kernel messages, regardless of whether |
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* they've been read or not. Added option to suppress kernel printk's |
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* to the console. Added hook for sending the console messages |
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* elsewhere, in preparation for a serial line console (someday). |
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* Ted Ts'o, 2/11/93. |
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* Modified for sysctl support, 1/8/97, Chris Horn. |
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* Fixed SMP synchronization, 08/08/99, Manfred Spraul |
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* manfred@colorfullife.com |
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* Rewrote bits to get rid of console_lock |
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* 01Mar01 Andrew Morton |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/tty.h> |
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#include <linux/tty_driver.h> |
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#include <linux/console.h> |
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#include <linux/init.h> |
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#include <linux/jiffies.h> |
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#include <linux/nmi.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/delay.h> |
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#include <linux/smp.h> |
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#include <linux/security.h> |
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#include <linux/bootmem.h> |
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#include <linux/memblock.h> |
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#include <linux/syscalls.h> |
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#include <linux/crash_core.h> |
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#include <linux/kdb.h> |
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#include <linux/ratelimit.h> |
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#include <linux/kmsg_dump.h> |
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#include <linux/syslog.h> |
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#include <linux/cpu.h> |
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#include <linux/notifier.h> |
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#include <linux/rculist.h> |
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#include <linux/poll.h> |
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#include <linux/irq_work.h> |
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#include <linux/utsname.h> |
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#include <linux/ctype.h> |
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#include <linux/uio.h> |
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#include <linux/sched/clock.h> |
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#include <linux/sched/debug.h> |
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#include <linux/sched/task_stack.h> |
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#include <mt-plat/aee.h> |
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#include <linux/proc_fs.h> |
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|
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#include <linux/uaccess.h> |
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#include <asm/sections.h> |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/printk.h> |
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|
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#include "console_cmdline.h" |
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#include "braille.h" |
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#include "internal.h" |
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|
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/* |
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* 0: uart printk enable |
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* 1: uart printk disable |
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* 2: uart printk always enable |
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*/ |
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int printk_disable_uart; |
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#ifdef CONFIG_PRINTK_MT_PREFIX |
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/* declare a variable for save the status of irqs_disabled() */ |
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static int isIrqsDisabled; |
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#endif |
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module_param_named(disable_uart, printk_disable_uart, int, 0644); |
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|
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bool mt_get_uartlog_status(void) |
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{ |
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if (printk_disable_uart == 1) |
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return false; |
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else if ((printk_disable_uart == 0) || (printk_disable_uart == 2)) |
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return true; |
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return true; |
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} |
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|
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void set_uartlog_status(bool value) |
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{ |
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#ifdef CONFIG_MTK_ENG_BUILD |
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printk_disable_uart = value ? 0 : 1; |
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pr_info("set uart log status %d.\n", value); |
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#endif |
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} |
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|
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#ifdef CONFIG_MTK_PRINTK_UART_CONSOLE |
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void mt_disable_uart(void) |
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{ |
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/* uart print not always enable */ |
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if ((mt_need_uart_console != 1) && (printk_disable_uart != 2)) |
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printk_disable_uart = 1; |
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} |
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void mt_enable_uart(void) |
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{ |
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printk_disable_uart = 0; |
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} |
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#endif |
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|
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#ifdef CONFIG_PRINTK_MT_PREFIX |
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static DEFINE_PER_CPU(char, printk_state); |
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#endif |
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|
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int console_printk[4] = { |
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CONSOLE_LOGLEVEL_DEFAULT, /* console_loglevel */ |
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MESSAGE_LOGLEVEL_DEFAULT, /* default_message_loglevel */ |
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CONSOLE_LOGLEVEL_MIN, /* minimum_console_loglevel */ |
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CONSOLE_LOGLEVEL_DEFAULT, /* default_console_loglevel */ |
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}; |
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|
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/* |
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* Low level drivers may need that to know if they can schedule in |
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* their unblank() callback or not. So let's export it. |
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*/ |
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int oops_in_progress; |
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EXPORT_SYMBOL(oops_in_progress); |
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|
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/* |
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* console_sem protects the console_drivers list, and also |
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* provides serialisation for access to the entire console |
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* driver system. |
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*/ |
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static DEFINE_SEMAPHORE(console_sem); |
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struct console *console_drivers; |
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EXPORT_SYMBOL_GPL(console_drivers); |
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|
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#ifdef CONFIG_LOCKDEP |
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static struct lockdep_map console_lock_dep_map = { |
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.name = "console_lock" |
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}; |
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#endif |
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|
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enum devkmsg_log_bits { |
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__DEVKMSG_LOG_BIT_ON = 0, |
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__DEVKMSG_LOG_BIT_OFF, |
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__DEVKMSG_LOG_BIT_LOCK, |
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}; |
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|
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enum devkmsg_log_masks { |
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DEVKMSG_LOG_MASK_ON = BIT(__DEVKMSG_LOG_BIT_ON), |
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DEVKMSG_LOG_MASK_OFF = BIT(__DEVKMSG_LOG_BIT_OFF), |
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DEVKMSG_LOG_MASK_LOCK = BIT(__DEVKMSG_LOG_BIT_LOCK), |
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}; |
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|
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/* Keep both the 'on' and 'off' bits clear, i.e. ratelimit by default: */ |
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#define DEVKMSG_LOG_MASK_DEFAULT 0 |
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|
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static unsigned int __read_mostly devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT; |
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|
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static int __control_devkmsg(char *str) |
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{ |
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if (!str) |
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return -EINVAL; |
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|
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if (!strncmp(str, "on", 2)) { |
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devkmsg_log = DEVKMSG_LOG_MASK_ON; |
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return 2; |
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} else if (!strncmp(str, "off", 3)) { |
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devkmsg_log = DEVKMSG_LOG_MASK_OFF; |
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return 3; |
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} else if (!strncmp(str, "ratelimit", 9)) { |
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devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT; |
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return 9; |
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} |
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return -EINVAL; |
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} |
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|
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static int __init control_devkmsg(char *str) |
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{ |
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if (__control_devkmsg(str) < 0) |
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return 1; |
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|
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/* |
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* Set sysctl string accordingly: |
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*/ |
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if (devkmsg_log == DEVKMSG_LOG_MASK_ON) { |
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memset(devkmsg_log_str, 0, DEVKMSG_STR_MAX_SIZE); |
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strncpy(devkmsg_log_str, "on", 2); |
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} else if (devkmsg_log == DEVKMSG_LOG_MASK_OFF) { |
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memset(devkmsg_log_str, 0, DEVKMSG_STR_MAX_SIZE); |
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strncpy(devkmsg_log_str, "off", 3); |
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} |
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/* else "ratelimit" which is set by default. */ |
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|
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/* |
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* Sysctl cannot change it anymore. The kernel command line setting of |
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* this parameter is to force the setting to be permanent throughout the |
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* runtime of the system. This is a precation measure against userspace |
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* trying to be a smarta** and attempting to change it up on us. |
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*/ |
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devkmsg_log |= DEVKMSG_LOG_MASK_LOCK; |
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|
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return 0; |
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} |
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__setup("printk.devkmsg=", control_devkmsg); |
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|
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char devkmsg_log_str[DEVKMSG_STR_MAX_SIZE] = "ratelimit"; |
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|
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int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, |
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void __user *buffer, size_t *lenp, loff_t *ppos) |
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{ |
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char old_str[DEVKMSG_STR_MAX_SIZE]; |
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unsigned int old; |
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int err; |
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|
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if (write) { |
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if (devkmsg_log & DEVKMSG_LOG_MASK_LOCK) |
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return -EINVAL; |
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|
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old = devkmsg_log; |
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strncpy(old_str, devkmsg_log_str, DEVKMSG_STR_MAX_SIZE); |
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} |
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err = proc_dostring(table, write, buffer, lenp, ppos); |
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if (err) |
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return err; |
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|
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if (write) { |
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err = __control_devkmsg(devkmsg_log_str); |
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|
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/* |
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* Do not accept an unknown string OR a known string with |
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* trailing crap... |
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*/ |
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if (err < 0 || (err + 1 != *lenp)) { |
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|
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/* ... and restore old setting. */ |
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devkmsg_log = old; |
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strncpy(devkmsg_log_str, old_str, DEVKMSG_STR_MAX_SIZE); |
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|
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return -EINVAL; |
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} |
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} |
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|
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return 0; |
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} |
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|
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/* |
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* Number of registered extended console drivers. |
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* |
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* If extended consoles are present, in-kernel cont reassembly is disabled |
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* and each fragment is stored as a separate log entry with proper |
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* continuation flag so that every emitted message has full metadata. This |
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* doesn't change the result for regular consoles or /proc/kmsg. For |
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* /dev/kmsg, as long as the reader concatenates messages according to |
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* consecutive continuation flags, the end result should be the same too. |
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*/ |
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static int nr_ext_console_drivers; |
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|
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/* |
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* Helper macros to handle lockdep when locking/unlocking console_sem. We use |
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* macros instead of functions so that _RET_IP_ contains useful information. |
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*/ |
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#define down_console_sem() do { \ |
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down(&console_sem);\ |
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mutex_acquire(&console_lock_dep_map, 0, 0, _RET_IP_);\ |
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} while (0) |
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|
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static int __down_trylock_console_sem(unsigned long ip) |
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{ |
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int lock_failed; |
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unsigned long flags; |
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|
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/* |
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* Here and in __up_console_sem() we need to be in safe mode, |
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* because spindump/WARN/etc from under console ->lock will |
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* deadlock in printk()->down_trylock_console_sem() otherwise. |
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*/ |
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printk_safe_enter_irqsave(flags); |
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lock_failed = down_trylock(&console_sem); |
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printk_safe_exit_irqrestore(flags); |
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|
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if (lock_failed) |
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return 1; |
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mutex_acquire(&console_lock_dep_map, 0, 1, ip); |
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return 0; |
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} |
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#define down_trylock_console_sem() __down_trylock_console_sem(_RET_IP_) |
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|
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static void __up_console_sem(unsigned long ip) |
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{ |
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unsigned long flags; |
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|
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mutex_release(&console_lock_dep_map, 1, ip); |
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|
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printk_safe_enter_irqsave(flags); |
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up(&console_sem); |
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printk_safe_exit_irqrestore(flags); |
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} |
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#define up_console_sem() __up_console_sem(_RET_IP_) |
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|
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/* |
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* This is used for debugging the mess that is the VT code by |
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* keeping track if we have the console semaphore held. It's |
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* definitely not the perfect debug tool (we don't know if _WE_ |
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* hold it and are racing, but it helps tracking those weird code |
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* paths in the console code where we end up in places I want |
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* locked without the console sempahore held). |
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*/ |
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static int console_locked, console_suspended; |
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|
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/* |
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* If exclusive_console is non-NULL then only this console is to be printed to. |
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*/ |
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static struct console *exclusive_console; |
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|
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/* |
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* Array of consoles built from command line options (console=) |
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*/ |
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|
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#define MAX_CMDLINECONSOLES 8 |
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|
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static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES]; |
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|
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static int preferred_console = -1; |
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int console_set_on_cmdline; |
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EXPORT_SYMBOL(console_set_on_cmdline); |
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|
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/* Flag: console code may call schedule() */ |
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static int console_may_schedule; |
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|
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/* |
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* The printk log buffer consists of a chain of concatenated variable |
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* length records. Every record starts with a record header, containing |
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* the overall length of the record. |
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* |
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* The heads to the first and last entry in the buffer, as well as the |
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* sequence numbers of these entries are maintained when messages are |
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* stored. |
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* |
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* If the heads indicate available messages, the length in the header |
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* tells the start next message. A length == 0 for the next message |
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* indicates a wrap-around to the beginning of the buffer. |
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* |
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* Every record carries the monotonic timestamp in microseconds, as well as |
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* the standard userspace syslog level and syslog facility. The usual |
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* kernel messages use LOG_KERN; userspace-injected messages always carry |
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* a matching syslog facility, by default LOG_USER. The origin of every |
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* message can be reliably determined that way. |
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* |
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* The human readable log message directly follows the message header. The |
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* length of the message text is stored in the header, the stored message |
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* is not terminated. |
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* |
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* Optionally, a message can carry a dictionary of properties (key/value pairs), |
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* to provide userspace with a machine-readable message context. |
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* |
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* Examples for well-defined, commonly used property names are: |
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* DEVICE=b12:8 device identifier |
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* b12:8 block dev_t |
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* c127:3 char dev_t |
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* n8 netdev ifindex |
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* +sound:card0 subsystem:devname |
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* SUBSYSTEM=pci driver-core subsystem name |
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* |
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* Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value |
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* follows directly after a '=' character. Every property is terminated by |
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* a '\0' character. The last property is not terminated. |
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* |
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* Example of a message structure: |
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* 0000 ff 8f 00 00 00 00 00 00 monotonic time in nsec |
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* 0008 34 00 record is 52 bytes long |
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* 000a 0b 00 text is 11 bytes long |
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* 000c 1f 00 dictionary is 23 bytes long |
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* 000e 03 00 LOG_KERN (facility) LOG_ERR (level) |
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* 0010 69 74 27 73 20 61 20 6c "it's a l" |
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* 69 6e 65 "ine" |
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* 001b 44 45 56 49 43 "DEVIC" |
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* 45 3d 62 38 3a 32 00 44 "E=b8:2\0D" |
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* 52 49 56 45 52 3d 62 75 "RIVER=bu" |
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* 67 "g" |
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* 0032 00 00 00 padding to next message header |
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* |
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* The 'struct printk_log' buffer header must never be directly exported to |
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* userspace, it is a kernel-private implementation detail that might |
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* need to be changed in the future, when the requirements change. |
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* |
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* /dev/kmsg exports the structured data in the following line format: |
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* "<level>,<sequnum>,<timestamp>,<contflag>[,additional_values, ... ];<message text>\n" |
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* |
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* Users of the export format should ignore possible additional values |
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* separated by ',', and find the message after the ';' character. |
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* |
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* The optional key/value pairs are attached as continuation lines starting |
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* with a space character and terminated by a newline. All possible |
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* non-prinatable characters are escaped in the "\xff" notation. |
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*/ |
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|
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enum log_flags { |
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LOG_NOCONS = 1, /* already flushed, do not print to console */ |
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LOG_NEWLINE = 2, /* text ended with a newline */ |
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LOG_PREFIX = 4, /* text started with a prefix */ |
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LOG_CONT = 8, /* text is a fragment of a continuation line */ |
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}; |
|
|
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struct printk_log { |
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u64 ts_nsec; /* timestamp in nanoseconds */ |
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u16 len; /* length of entire record */ |
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u16 text_len; /* length of text buffer */ |
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u16 dict_len; /* length of dictionary buffer */ |
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u8 facility; /* syslog facility */ |
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u8 flags:5; /* internal record flags */ |
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u8 level:3; /* syslog level */ |
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} |
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#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS |
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__packed __aligned(4) |
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#endif |
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; |
|
|
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/* |
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* The logbuf_lock protects kmsg buffer, indices, counters. This can be taken |
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* within the scheduler's rq lock. It must be released before calling |
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* console_unlock() or anything else that might wake up a process. |
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*/ |
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DEFINE_RAW_SPINLOCK(logbuf_lock); |
|
|
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bool is_logbuf_lock(raw_spinlock_t *lock) |
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{ |
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if (lock == &logbuf_lock || lock == &console_sem.lock) |
|
return true; |
|
return false; |
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} |
|
|
|
/* |
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* Helper macros to lock/unlock logbuf_lock and switch between |
|
* printk-safe/unsafe modes. |
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*/ |
|
#define logbuf_lock_irq() \ |
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do { \ |
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printk_safe_enter_irq(); \ |
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raw_spin_lock(&logbuf_lock); \ |
|
} while (0) |
|
|
|
#define logbuf_unlock_irq() \ |
|
do { \ |
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raw_spin_unlock(&logbuf_lock); \ |
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printk_safe_exit_irq(); \ |
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} while (0) |
|
|
|
#define logbuf_lock_irqsave(flags) \ |
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do { \ |
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printk_safe_enter_irqsave(flags); \ |
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raw_spin_lock(&logbuf_lock); \ |
|
} while (0) |
|
|
|
#define logbuf_unlock_irqrestore(flags) \ |
|
do { \ |
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raw_spin_unlock(&logbuf_lock); \ |
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printk_safe_exit_irqrestore(flags); \ |
|
} while (0) |
|
|
|
#ifdef CONFIG_PRINTK |
|
DECLARE_WAIT_QUEUE_HEAD(log_wait); |
|
/* the next printk record to read by syslog(READ) or /proc/kmsg */ |
|
static u64 syslog_seq; |
|
static u32 syslog_idx; |
|
static size_t syslog_partial; |
|
|
|
/* index and sequence number of the first record stored in the buffer */ |
|
static u64 log_first_seq; |
|
static u32 log_first_idx; |
|
|
|
/* index and sequence number of the next record to store in the buffer */ |
|
static u64 log_next_seq; |
|
static u32 log_next_idx; |
|
|
|
/* the next printk record to write to the console */ |
|
static u64 console_seq; |
|
static u32 console_idx; |
|
|
|
/* the next printk record to read after the last 'clear' command */ |
|
static u64 clear_seq; |
|
static u32 clear_idx; |
|
|
|
#define PREFIX_MAX 32 |
|
#define LOG_LINE_MAX (1024 - PREFIX_MAX) |
|
|
|
#define LOG_LEVEL(v) ((v) & 0x07) |
|
#define LOG_FACILITY(v) ((v) >> 3 & 0xff) |
|
|
|
/* record buffer */ |
|
#define LOG_ALIGN __alignof__(struct printk_log) |
|
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT) |
|
static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); |
|
static char *log_buf = __log_buf; |
|
static u32 log_buf_len = __LOG_BUF_LEN; |
|
|
|
|
|
/* console duration detect */ |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
struct __conwrite_stat_struct { |
|
struct console *con; /* current console */ |
|
u64 time_before_conwrite; /* the last record before write */ |
|
u64 time_after_conwrite; /* the last record after write */ |
|
char con_write_statbuf[512]; /* con write status buf*/ |
|
}; |
|
u64 time_con_write_ttyS, time_con_write_pstore; |
|
u64 len_con_write_ttyS, len_con_write_pstore; |
|
static struct __conwrite_stat_struct conwrite_stat_struct = { |
|
.con = NULL, |
|
.time_before_conwrite = 0, |
|
.time_after_conwrite = 0 |
|
}; |
|
unsigned long rem_nsec_con_write_ttyS, rem_nsec_con_write_pstore; |
|
bool console_status_detected; |
|
#endif |
|
|
|
int printk_too_much_enable; |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
static int detect_count = |
|
/*Default max lines per second*/ |
|
CONFIG_LOG_TOO_MUCH_DETECT_COUNT; |
|
static bool detect_count_change; /* detect_count change flag*/ |
|
#define DETECT_COUNT_MIN 100 |
|
|
|
#define DETECT_TIME 1000000000ULL /* 1s = 1000000000ns */ |
|
#define DELAY_TIME (CONFIG_LOG_TOO_MUCH_DETECT_GAP*DETECT_TIME*60) |
|
|
|
static u64 delta_time; |
|
static u64 delta_count; |
|
static u64 t_base; |
|
static bool flag_toomuch; |
|
|
|
static char *log_much; |
|
static int log_count; |
|
static u32 start_idx; |
|
static u64 start_seq; |
|
#define LOG_MUCH_PLUS_LEN (1 << 17) |
|
|
|
static void log_much_do_check_and_delay(struct printk_log *msg); |
|
#endif |
|
|
|
void set_detect_count(int count) |
|
{ |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
if (count >= detect_count) |
|
detect_count = count; |
|
else { |
|
if (count < DETECT_COUNT_MIN) |
|
detect_count = DETECT_COUNT_MIN; |
|
else |
|
detect_count = count; |
|
detect_count_change = true; |
|
} |
|
pr_info("Printk too much criteria: %d delay_flag: %d\n", |
|
detect_count, detect_count_change); |
|
#endif |
|
} |
|
EXPORT_SYMBOL(set_detect_count); |
|
|
|
int get_detect_count(void) |
|
{ |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
return detect_count; |
|
#else |
|
return 0; |
|
#endif |
|
} |
|
EXPORT_SYMBOL(get_detect_count); |
|
|
|
void set_logtoomuch_enable(int value) |
|
{ |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
printk_too_much_enable = value; |
|
#endif |
|
} |
|
EXPORT_SYMBOL(set_logtoomuch_enable); |
|
|
|
int get_logtoomuch_enable(void) |
|
{ |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
return printk_too_much_enable; |
|
#else |
|
return 0; |
|
#endif |
|
} |
|
EXPORT_SYMBOL(get_logtoomuch_enable); |
|
|
|
/* Return log buffer address */ |
|
char *log_buf_addr_get(void) |
|
{ |
|
return log_buf; |
|
} |
|
|
|
/* Return log buffer size */ |
|
u32 log_buf_len_get(void) |
|
{ |
|
return log_buf_len; |
|
} |
|
|
|
/* human readable text of the record */ |
|
static char *log_text(const struct printk_log *msg) |
|
{ |
|
return (char *)msg + sizeof(struct printk_log); |
|
} |
|
|
|
/* optional key/value pair dictionary attached to the record */ |
|
static char *log_dict(const struct printk_log *msg) |
|
{ |
|
return (char *)msg + sizeof(struct printk_log) + msg->text_len; |
|
} |
|
|
|
/* get record by index; idx must point to valid msg */ |
|
static struct printk_log *log_from_idx(u32 idx) |
|
{ |
|
struct printk_log *msg = (struct printk_log *)(log_buf + idx); |
|
|
|
/* |
|
* A length == 0 record is the end of buffer marker. Wrap around and |
|
* read the message at the start of the buffer. |
|
*/ |
|
if (!msg->len) |
|
return (struct printk_log *)log_buf; |
|
return msg; |
|
} |
|
|
|
/* get next record; idx must point to valid msg */ |
|
static u32 log_next(u32 idx) |
|
{ |
|
struct printk_log *msg = (struct printk_log *)(log_buf + idx); |
|
|
|
/* length == 0 indicates the end of the buffer; wrap */ |
|
/* |
|
* A length == 0 record is the end of buffer marker. Wrap around and |
|
* read the message at the start of the buffer as *this* one, and |
|
* return the one after that. |
|
*/ |
|
if (!msg->len) { |
|
msg = (struct printk_log *)log_buf; |
|
return msg->len; |
|
} |
|
return idx + msg->len; |
|
} |
|
|
|
/* |
|
* Check whether there is enough free space for the given message. |
|
* |
|
* The same values of first_idx and next_idx mean that the buffer |
|
* is either empty or full. |
|
* |
|
* If the buffer is empty, we must respect the position of the indexes. |
|
* They cannot be reset to the beginning of the buffer. |
|
*/ |
|
static int logbuf_has_space(u32 msg_size, bool empty) |
|
{ |
|
u32 free; |
|
|
|
if (log_next_idx > log_first_idx || empty) |
|
free = max(log_buf_len - log_next_idx, log_first_idx); |
|
else |
|
free = log_first_idx - log_next_idx; |
|
|
|
/* |
|
* We need space also for an empty header that signalizes wrapping |
|
* of the buffer. |
|
*/ |
|
return free >= msg_size + sizeof(struct printk_log); |
|
} |
|
|
|
static int log_make_free_space(u32 msg_size) |
|
{ |
|
while (log_first_seq < log_next_seq && |
|
!logbuf_has_space(msg_size, false)) { |
|
/* drop old messages until we have enough contiguous space */ |
|
log_first_idx = log_next(log_first_idx); |
|
log_first_seq++; |
|
} |
|
|
|
if (clear_seq < log_first_seq) { |
|
clear_seq = log_first_seq; |
|
clear_idx = log_first_idx; |
|
} |
|
|
|
/* sequence numbers are equal, so the log buffer is empty */ |
|
if (logbuf_has_space(msg_size, log_first_seq == log_next_seq)) |
|
return 0; |
|
|
|
return -ENOMEM; |
|
} |
|
|
|
/* compute the message size including the padding bytes */ |
|
static u32 msg_used_size(u16 text_len, u16 dict_len, u32 *pad_len) |
|
{ |
|
u32 size; |
|
|
|
size = sizeof(struct printk_log) + text_len + dict_len; |
|
*pad_len = (-size) & (LOG_ALIGN - 1); |
|
size += *pad_len; |
|
|
|
return size; |
|
} |
|
|
|
/* |
|
* Define how much of the log buffer we could take at maximum. The value |
|
* must be greater than two. Note that only half of the buffer is available |
|
* when the index points to the middle. |
|
*/ |
|
#define MAX_LOG_TAKE_PART 4 |
|
static const char trunc_msg[] = "<truncated>"; |
|
|
|
static u32 truncate_msg(u16 *text_len, u16 *trunc_msg_len, |
|
u16 *dict_len, u32 *pad_len) |
|
{ |
|
/* |
|
* The message should not take the whole buffer. Otherwise, it might |
|
* get removed too soon. |
|
*/ |
|
u32 max_text_len = log_buf_len / MAX_LOG_TAKE_PART; |
|
if (*text_len > max_text_len) |
|
*text_len = max_text_len; |
|
/* enable the warning message */ |
|
*trunc_msg_len = strlen(trunc_msg); |
|
/* disable the "dict" completely */ |
|
*dict_len = 0; |
|
/* compute the size again, count also the warning message */ |
|
return msg_used_size(*text_len + *trunc_msg_len, 0, pad_len); |
|
} |
|
|
|
/* insert record into the buffer, discard old ones, update heads */ |
|
static int log_store(int facility, int level, |
|
enum log_flags flags, u64 ts_nsec, |
|
const char *dict, u16 dict_len, |
|
const char *text, u16 text_len) |
|
{ |
|
struct printk_log *msg; |
|
u32 size, pad_len; |
|
u16 trunc_msg_len = 0; |
|
|
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
int this_cpu = smp_processor_id(); |
|
char state = this_cpu_read(printk_state); |
|
char tbuf[50]; |
|
unsigned int tlen = 0; |
|
#endif |
|
|
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
static u64 start_ts_nsec; |
|
static bool initialized; |
|
#endif |
|
|
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
if (state == 0) { |
|
this_cpu_write(printk_state, ' '); |
|
state = ' '; |
|
} |
|
if (!(flags & LOG_CONT)) { |
|
if (console_suspended == 0) |
|
tlen = snprintf(tbuf, |
|
sizeof(tbuf), |
|
"%c(%x)[%d:%s]", |
|
state, this_cpu, |
|
current->pid, |
|
current->comm); |
|
else |
|
tlen = snprintf(tbuf, |
|
sizeof(tbuf), |
|
"%c(%x)", |
|
state, |
|
this_cpu); |
|
} |
|
#endif |
|
|
|
/* number of '\0' padding bytes to next message */ |
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
size = msg_used_size(text_len + tlen, dict_len, &pad_len); |
|
#else |
|
size = msg_used_size(text_len, dict_len, &pad_len); |
|
#endif |
|
|
|
if (log_make_free_space(size)) { |
|
/* truncate the message if it is too long for empty buffer */ |
|
size = truncate_msg(&text_len, &trunc_msg_len, |
|
&dict_len, &pad_len); |
|
/* survive when the log buffer is too small for trunc_msg */ |
|
if (log_make_free_space(size)) |
|
return 0; |
|
} |
|
|
|
if (log_next_idx + size + sizeof(struct printk_log) > log_buf_len) { |
|
/* |
|
* This message + an additional empty header does not fit |
|
* at the end of the buffer. Add an empty header with len == 0 |
|
* to signify a wrap around. |
|
*/ |
|
memset(log_buf + log_next_idx, 0, sizeof(struct printk_log)); |
|
log_next_idx = 0; |
|
} |
|
|
|
/* fill message */ |
|
msg = (struct printk_log *)(log_buf + log_next_idx); |
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
memcpy(log_text(msg), tbuf, tlen); |
|
if (tlen + text_len > LOG_LINE_MAX) |
|
text_len = LOG_LINE_MAX - tlen; |
|
|
|
memcpy(log_text(msg) + tlen, text, text_len); |
|
text_len += tlen; |
|
#else |
|
memcpy(log_text(msg), text, text_len); |
|
#endif |
|
msg->text_len = text_len; |
|
if (trunc_msg_len) { |
|
memcpy(log_text(msg) + text_len, trunc_msg, trunc_msg_len); |
|
msg->text_len += trunc_msg_len; |
|
} |
|
memcpy(log_dict(msg), dict, dict_len); |
|
msg->dict_len = dict_len; |
|
msg->facility = facility; |
|
msg->level = level & 7; |
|
msg->flags = flags & 0x1f; |
|
if (ts_nsec > 0) |
|
msg->ts_nsec = ts_nsec; |
|
else |
|
msg->ts_nsec = local_clock(); |
|
memset(log_dict(msg) + dict_len, 0, pad_len); |
|
msg->len = size; |
|
|
|
/* insert message */ |
|
log_next_idx += msg->len; |
|
log_next_seq++; |
|
|
|
/* printk too much detect */ |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
if (printk_too_much_enable == 1) { |
|
if (detect_count_change) { |
|
detect_count_change = false; |
|
t_base = msg->ts_nsec + DETECT_TIME*15; |
|
} |
|
if (flag_toomuch == false && t_base < msg->ts_nsec) { |
|
if (!initialized) { |
|
start_ts_nsec = msg->ts_nsec; |
|
start_idx = log_next_idx - msg->len; |
|
start_seq = log_next_seq - 1; |
|
initialized = true; |
|
} |
|
/* old messages were dropped */ |
|
if (start_seq < log_first_seq) { |
|
initialized = false; |
|
start_seq = log_first_seq; |
|
start_idx = log_first_idx; |
|
delta_time = msg->ts_nsec |
|
- log_from_idx(start_idx)->ts_nsec; |
|
delta_count = log_next_seq - start_seq; |
|
log_much_do_check_and_delay(msg); |
|
} else { |
|
delta_time = msg->ts_nsec - start_ts_nsec; |
|
delta_count = log_next_seq - start_seq; |
|
/* check every 5 seconds */ |
|
if (delta_time > DETECT_TIME * 5) { |
|
initialized = false; |
|
log_much_do_check_and_delay(msg); |
|
} |
|
} |
|
} |
|
} |
|
#endif |
|
|
|
return msg->text_len; |
|
} |
|
|
|
int dmesg_restrict = IS_ENABLED(CONFIG_SECURITY_DMESG_RESTRICT); |
|
|
|
static int syslog_action_restricted(int type) |
|
{ |
|
if (dmesg_restrict) |
|
return 1; |
|
/* |
|
* Unless restricted, we allow "read all" and "get buffer size" |
|
* for everybody. |
|
*/ |
|
return type != SYSLOG_ACTION_READ_ALL && |
|
type != SYSLOG_ACTION_SIZE_BUFFER; |
|
} |
|
|
|
static int check_syslog_permissions(int type, int source) |
|
{ |
|
/* |
|
* If this is from /proc/kmsg and we've already opened it, then we've |
|
* already done the capabilities checks at open time. |
|
*/ |
|
if (source == SYSLOG_FROM_PROC && type != SYSLOG_ACTION_OPEN) |
|
goto ok; |
|
|
|
if (syslog_action_restricted(type)) { |
|
if (capable(CAP_SYSLOG)) |
|
goto ok; |
|
/* |
|
* For historical reasons, accept CAP_SYS_ADMIN too, with |
|
* a warning. |
|
*/ |
|
if (capable(CAP_SYS_ADMIN)) { |
|
pr_warn_once("%s (%d): Attempt to access syslog with " |
|
"CAP_SYS_ADMIN but no CAP_SYSLOG " |
|
"(deprecated).\n", |
|
current->comm, task_pid_nr(current)); |
|
goto ok; |
|
} |
|
return -EPERM; |
|
} |
|
ok: |
|
return security_syslog(type); |
|
} |
|
|
|
static void append_char(char **pp, char *e, char c) |
|
{ |
|
if (*pp < e) |
|
*(*pp)++ = c; |
|
} |
|
|
|
static ssize_t msg_print_ext_header(char *buf, size_t size, |
|
struct printk_log *msg, u64 seq) |
|
{ |
|
u64 ts_usec = msg->ts_nsec; |
|
|
|
do_div(ts_usec, 1000); |
|
|
|
return scnprintf(buf, size, "%u,%llu,%llu,%c;", |
|
(msg->facility << 3) | msg->level, seq, ts_usec, |
|
msg->flags & LOG_CONT ? 'c' : '-'); |
|
} |
|
|
|
static ssize_t msg_print_ext_body(char *buf, size_t size, |
|
char *dict, size_t dict_len, |
|
char *text, size_t text_len) |
|
{ |
|
char *p = buf, *e = buf + size; |
|
size_t i; |
|
|
|
/* escape non-printable characters */ |
|
for (i = 0; i < text_len; i++) { |
|
unsigned char c = text[i]; |
|
|
|
if (c < ' ' || c >= 127 || c == '\\') |
|
p += scnprintf(p, e - p, "\\x%02x", c); |
|
else |
|
append_char(&p, e, c); |
|
} |
|
append_char(&p, e, '\n'); |
|
|
|
if (dict_len) { |
|
bool line = true; |
|
|
|
for (i = 0; i < dict_len; i++) { |
|
unsigned char c = dict[i]; |
|
|
|
if (line) { |
|
append_char(&p, e, ' '); |
|
line = false; |
|
} |
|
|
|
if (c == '\0') { |
|
append_char(&p, e, '\n'); |
|
line = true; |
|
continue; |
|
} |
|
|
|
if (c < ' ' || c >= 127 || c == '\\') { |
|
p += scnprintf(p, e - p, "\\x%02x", c); |
|
continue; |
|
} |
|
|
|
append_char(&p, e, c); |
|
} |
|
append_char(&p, e, '\n'); |
|
} |
|
|
|
return p - buf; |
|
} |
|
|
|
/* /dev/kmsg - userspace message inject/listen interface */ |
|
struct devkmsg_user { |
|
u64 seq; |
|
u32 idx; |
|
struct ratelimit_state rs; |
|
struct mutex lock; |
|
char buf[CONSOLE_EXT_LOG_MAX]; |
|
}; |
|
|
|
static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
char *buf, *line; |
|
int level = default_message_loglevel; |
|
int facility = 1; /* LOG_USER */ |
|
struct file *file = iocb->ki_filp; |
|
struct devkmsg_user *user = file->private_data; |
|
size_t len = iov_iter_count(from); |
|
ssize_t ret = len; |
|
|
|
if (!user || len > LOG_LINE_MAX) |
|
return -EINVAL; |
|
|
|
/* Ignore when user logging is disabled. */ |
|
if (devkmsg_log & DEVKMSG_LOG_MASK_OFF) |
|
return len; |
|
|
|
/* Ratelimit when not explicitly enabled. */ |
|
if (!(devkmsg_log & DEVKMSG_LOG_MASK_ON)) { |
|
if (!___ratelimit(&user->rs, current->comm)) |
|
return ret; |
|
} |
|
|
|
buf = kmalloc(len+1, GFP_KERNEL); |
|
if (buf == NULL) |
|
return -ENOMEM; |
|
|
|
buf[len] = '\0'; |
|
if (!copy_from_iter_full(buf, len, from)) { |
|
kfree(buf); |
|
return -EFAULT; |
|
} |
|
|
|
/* |
|
* Extract and skip the syslog prefix <[0-9]*>. Coming from userspace |
|
* the decimal value represents 32bit, the lower 3 bit are the log |
|
* level, the rest are the log facility. |
|
* |
|
* If no prefix or no userspace facility is specified, we |
|
* enforce LOG_USER, to be able to reliably distinguish |
|
* kernel-generated messages from userspace-injected ones. |
|
*/ |
|
line = buf; |
|
if (line[0] == '<') { |
|
char *endp = NULL; |
|
unsigned int u; |
|
|
|
u = simple_strtoul(line + 1, &endp, 10); |
|
if (endp && endp[0] == '>') { |
|
level = LOG_LEVEL(u); |
|
if (LOG_FACILITY(u) != 0) |
|
facility = LOG_FACILITY(u); |
|
endp++; |
|
len -= endp - line; |
|
line = endp; |
|
} |
|
} |
|
|
|
printk_emit(facility, level, NULL, 0, "%s", line); |
|
kfree(buf); |
|
return ret; |
|
} |
|
|
|
static ssize_t devkmsg_read(struct file *file, char __user *buf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct devkmsg_user *user = file->private_data; |
|
struct printk_log *msg; |
|
size_t len; |
|
ssize_t ret; |
|
|
|
if (!user) |
|
return -EBADF; |
|
|
|
ret = mutex_lock_interruptible(&user->lock); |
|
if (ret) |
|
return ret; |
|
|
|
logbuf_lock_irq(); |
|
while (user->seq == log_next_seq) { |
|
if (file->f_flags & O_NONBLOCK) { |
|
ret = -EAGAIN; |
|
logbuf_unlock_irq(); |
|
goto out; |
|
} |
|
|
|
logbuf_unlock_irq(); |
|
ret = wait_event_interruptible(log_wait, |
|
user->seq != log_next_seq); |
|
if (ret) |
|
goto out; |
|
logbuf_lock_irq(); |
|
} |
|
|
|
if (user->seq < log_first_seq) { |
|
/* our last seen message is gone, return error and reset */ |
|
user->idx = log_first_idx; |
|
user->seq = log_first_seq; |
|
ret = -EPIPE; |
|
logbuf_unlock_irq(); |
|
goto out; |
|
} |
|
|
|
msg = log_from_idx(user->idx); |
|
len = msg_print_ext_header(user->buf, sizeof(user->buf), |
|
msg, user->seq); |
|
len += msg_print_ext_body(user->buf + len, sizeof(user->buf) - len, |
|
log_dict(msg), msg->dict_len, |
|
log_text(msg), msg->text_len); |
|
|
|
user->idx = log_next(user->idx); |
|
user->seq++; |
|
logbuf_unlock_irq(); |
|
|
|
if (len > count) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (copy_to_user(buf, user->buf, len)) { |
|
ret = -EFAULT; |
|
goto out; |
|
} |
|
ret = len; |
|
out: |
|
mutex_unlock(&user->lock); |
|
return ret; |
|
} |
|
|
|
static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence) |
|
{ |
|
struct devkmsg_user *user = file->private_data; |
|
loff_t ret = 0; |
|
|
|
if (!user) |
|
return -EBADF; |
|
if (offset) |
|
return -ESPIPE; |
|
|
|
logbuf_lock_irq(); |
|
switch (whence) { |
|
case SEEK_SET: |
|
/* the first record */ |
|
user->idx = log_first_idx; |
|
user->seq = log_first_seq; |
|
break; |
|
case SEEK_DATA: |
|
/* |
|
* The first record after the last SYSLOG_ACTION_CLEAR, |
|
* like issued by 'dmesg -c'. Reading /dev/kmsg itself |
|
* changes no global state, and does not clear anything. |
|
*/ |
|
user->idx = clear_idx; |
|
user->seq = clear_seq; |
|
break; |
|
case SEEK_END: |
|
/* after the last record */ |
|
user->idx = log_next_idx; |
|
user->seq = log_next_seq; |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
} |
|
logbuf_unlock_irq(); |
|
return ret; |
|
} |
|
|
|
static unsigned int devkmsg_poll(struct file *file, poll_table *wait) |
|
{ |
|
struct devkmsg_user *user = file->private_data; |
|
int ret = 0; |
|
|
|
if (!user) |
|
return POLLERR|POLLNVAL; |
|
|
|
poll_wait(file, &log_wait, wait); |
|
|
|
logbuf_lock_irq(); |
|
if (user->seq < log_next_seq) { |
|
/* return error when data has vanished underneath us */ |
|
if (user->seq < log_first_seq) |
|
ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI; |
|
else |
|
ret = POLLIN|POLLRDNORM; |
|
} |
|
logbuf_unlock_irq(); |
|
|
|
return ret; |
|
} |
|
|
|
static int devkmsg_open(struct inode *inode, struct file *file) |
|
{ |
|
struct devkmsg_user *user; |
|
int err; |
|
|
|
if (devkmsg_log & DEVKMSG_LOG_MASK_OFF) |
|
return -EPERM; |
|
|
|
/* write-only does not need any file context */ |
|
if ((file->f_flags & O_ACCMODE) != O_WRONLY) { |
|
err = check_syslog_permissions(SYSLOG_ACTION_READ_ALL, |
|
SYSLOG_FROM_READER); |
|
if (err) |
|
return err; |
|
} |
|
|
|
user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL); |
|
if (!user) |
|
return -ENOMEM; |
|
|
|
ratelimit_default_init(&user->rs); |
|
ratelimit_set_flags(&user->rs, RATELIMIT_MSG_ON_RELEASE); |
|
|
|
mutex_init(&user->lock); |
|
|
|
logbuf_lock_irq(); |
|
user->idx = log_first_idx; |
|
user->seq = log_first_seq; |
|
logbuf_unlock_irq(); |
|
|
|
file->private_data = user; |
|
return 0; |
|
} |
|
|
|
static int devkmsg_release(struct inode *inode, struct file *file) |
|
{ |
|
struct devkmsg_user *user = file->private_data; |
|
|
|
if (!user) |
|
return 0; |
|
|
|
ratelimit_state_exit(&user->rs); |
|
|
|
mutex_destroy(&user->lock); |
|
kfree(user); |
|
return 0; |
|
} |
|
|
|
const struct file_operations kmsg_fops = { |
|
.open = devkmsg_open, |
|
.read = devkmsg_read, |
|
.write_iter = devkmsg_write, |
|
.llseek = devkmsg_llseek, |
|
.poll = devkmsg_poll, |
|
.release = devkmsg_release, |
|
}; |
|
|
|
#ifdef CONFIG_CRASH_CORE |
|
/* |
|
* This appends the listed symbols to /proc/vmcore |
|
* |
|
* /proc/vmcore is used by various utilities, like crash and makedumpfile to |
|
* obtain access to symbols that are otherwise very difficult to locate. These |
|
* symbols are specifically used so that utilities can access and extract the |
|
* dmesg log from a vmcore file after a crash. |
|
*/ |
|
void log_buf_vmcoreinfo_setup(void) |
|
{ |
|
VMCOREINFO_SYMBOL(log_buf); |
|
VMCOREINFO_SYMBOL(log_buf_len); |
|
VMCOREINFO_SYMBOL(log_first_idx); |
|
VMCOREINFO_SYMBOL(clear_idx); |
|
VMCOREINFO_SYMBOL(log_next_idx); |
|
/* |
|
* Export struct printk_log size and field offsets. User space tools can |
|
* parse it and detect any changes to structure down the line. |
|
*/ |
|
VMCOREINFO_STRUCT_SIZE(printk_log); |
|
VMCOREINFO_OFFSET(printk_log, ts_nsec); |
|
VMCOREINFO_OFFSET(printk_log, len); |
|
VMCOREINFO_OFFSET(printk_log, text_len); |
|
VMCOREINFO_OFFSET(printk_log, dict_len); |
|
} |
|
#endif |
|
|
|
/* requested log_buf_len from kernel cmdline */ |
|
static unsigned long __initdata new_log_buf_len; |
|
|
|
/* we practice scaling the ring buffer by powers of 2 */ |
|
static void __init log_buf_len_update(unsigned size) |
|
{ |
|
if (size) |
|
size = roundup_pow_of_two(size); |
|
if (size > log_buf_len) |
|
new_log_buf_len = size; |
|
} |
|
|
|
/* save requested log_buf_len since it's too early to process it */ |
|
static int __init log_buf_len_setup(char *str) |
|
{ |
|
unsigned int size = memparse(str, &str); |
|
|
|
log_buf_len_update(size); |
|
|
|
return 0; |
|
} |
|
early_param("log_buf_len", log_buf_len_setup); |
|
|
|
#ifdef CONFIG_SMP |
|
#define __LOG_CPU_MAX_BUF_LEN (1 << CONFIG_LOG_CPU_MAX_BUF_SHIFT) |
|
|
|
static void __init log_buf_add_cpu(void) |
|
{ |
|
unsigned int cpu_extra; |
|
|
|
/* |
|
* archs should set up cpu_possible_bits properly with |
|
* set_cpu_possible() after setup_arch() but just in |
|
* case lets ensure this is valid. |
|
*/ |
|
if (num_possible_cpus() == 1) |
|
return; |
|
|
|
cpu_extra = (num_possible_cpus() - 1) * __LOG_CPU_MAX_BUF_LEN; |
|
|
|
/* by default this will only continue through for large > 64 CPUs */ |
|
if (cpu_extra <= __LOG_BUF_LEN / 2) |
|
return; |
|
|
|
pr_info("log_buf_len individual max cpu contribution: %d bytes\n", |
|
__LOG_CPU_MAX_BUF_LEN); |
|
pr_info("log_buf_len total cpu_extra contributions: %d bytes\n", |
|
cpu_extra); |
|
pr_info("log_buf_len min size: %d bytes\n", __LOG_BUF_LEN); |
|
|
|
log_buf_len_update(cpu_extra + __LOG_BUF_LEN); |
|
} |
|
#else /* !CONFIG_SMP */ |
|
static inline void log_buf_add_cpu(void) {} |
|
#endif /* CONFIG_SMP */ |
|
|
|
void __init setup_log_buf(int early) |
|
{ |
|
unsigned long flags; |
|
char *new_log_buf; |
|
int free; |
|
|
|
if (log_buf != __log_buf) |
|
return; |
|
|
|
if (!early && !new_log_buf_len) |
|
log_buf_add_cpu(); |
|
|
|
if (!new_log_buf_len) |
|
return; |
|
|
|
if (early) { |
|
new_log_buf = |
|
memblock_virt_alloc(new_log_buf_len, LOG_ALIGN); |
|
} else { |
|
new_log_buf = memblock_virt_alloc_nopanic(new_log_buf_len, |
|
LOG_ALIGN); |
|
} |
|
|
|
if (unlikely(!new_log_buf)) { |
|
pr_err("log_buf_len: %ld bytes not available\n", |
|
new_log_buf_len); |
|
return; |
|
} |
|
|
|
logbuf_lock_irqsave(flags); |
|
log_buf_len = new_log_buf_len; |
|
log_buf = new_log_buf; |
|
new_log_buf_len = 0; |
|
free = __LOG_BUF_LEN - log_next_idx; |
|
memcpy(log_buf, __log_buf, __LOG_BUF_LEN); |
|
logbuf_unlock_irqrestore(flags); |
|
|
|
pr_info("log_buf_len: %d bytes\n", log_buf_len); |
|
pr_info("early log buf free: %d(%d%%)\n", |
|
free, (free * 100) / __LOG_BUF_LEN); |
|
} |
|
|
|
static bool __read_mostly ignore_loglevel; |
|
|
|
static int __init ignore_loglevel_setup(char *str) |
|
{ |
|
ignore_loglevel = true; |
|
pr_info("debug: ignoring loglevel setting.\n"); |
|
|
|
return 0; |
|
} |
|
|
|
early_param("ignore_loglevel", ignore_loglevel_setup); |
|
module_param(ignore_loglevel, bool, S_IRUGO | S_IWUSR); |
|
MODULE_PARM_DESC(ignore_loglevel, |
|
"ignore loglevel setting (prints all kernel messages to the console)"); |
|
|
|
static bool suppress_message_printing(int level) |
|
{ |
|
return (level >= console_loglevel && !ignore_loglevel); |
|
} |
|
|
|
#ifdef CONFIG_BOOT_PRINTK_DELAY |
|
|
|
static int boot_delay; /* msecs delay after each printk during bootup */ |
|
static unsigned long long loops_per_msec; /* based on boot_delay */ |
|
|
|
static int __init boot_delay_setup(char *str) |
|
{ |
|
unsigned long lpj; |
|
|
|
lpj = preset_lpj ? preset_lpj : 1000000; /* some guess */ |
|
loops_per_msec = (unsigned long long)lpj / 1000 * HZ; |
|
|
|
get_option(&str, &boot_delay); |
|
if (boot_delay > 10 * 1000) |
|
boot_delay = 0; |
|
|
|
pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, " |
|
"HZ: %d, loops_per_msec: %llu\n", |
|
boot_delay, preset_lpj, lpj, HZ, loops_per_msec); |
|
return 0; |
|
} |
|
early_param("boot_delay", boot_delay_setup); |
|
|
|
static void boot_delay_msec(int level) |
|
{ |
|
unsigned long long k; |
|
unsigned long timeout; |
|
|
|
if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING) |
|
|| suppress_message_printing(level)) { |
|
return; |
|
} |
|
|
|
k = (unsigned long long)loops_per_msec * boot_delay; |
|
|
|
timeout = jiffies + msecs_to_jiffies(boot_delay); |
|
while (k) { |
|
k--; |
|
cpu_relax(); |
|
/* |
|
* use (volatile) jiffies to prevent |
|
* compiler reduction; loop termination via jiffies |
|
* is secondary and may or may not happen. |
|
*/ |
|
if (time_after(jiffies, timeout)) |
|
break; |
|
touch_nmi_watchdog(); |
|
} |
|
} |
|
#else |
|
static inline void boot_delay_msec(int level) |
|
{ |
|
} |
|
#endif |
|
|
|
static bool printk_time = IS_ENABLED(CONFIG_PRINTK_TIME); |
|
module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR); |
|
|
|
static size_t print_time(u64 ts, char *buf) |
|
{ |
|
unsigned long rem_nsec; |
|
|
|
if (!printk_time) |
|
return 0; |
|
|
|
rem_nsec = do_div(ts, 1000000000); |
|
|
|
if (!buf) |
|
return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts); |
|
|
|
return sprintf(buf, "[%5lu.%06lu] ", |
|
(unsigned long)ts, rem_nsec / 1000); |
|
} |
|
|
|
static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf) |
|
{ |
|
size_t len = 0; |
|
unsigned int prefix = (msg->facility << 3) | msg->level; |
|
|
|
if (syslog) { |
|
if (buf) { |
|
len += sprintf(buf, "<%u>", prefix); |
|
} else { |
|
len += 3; |
|
if (prefix > 999) |
|
len += 3; |
|
else if (prefix > 99) |
|
len += 2; |
|
else if (prefix > 9) |
|
len++; |
|
} |
|
} |
|
|
|
len += print_time(msg->ts_nsec, buf ? buf + len : NULL); |
|
|
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
/* if uart printk enabled */ |
|
if (syslog == false && printk_disable_uart != 1) { |
|
if (buf) |
|
len += sprintf(buf+len, "<%d>", smp_processor_id()); |
|
else |
|
len += snprintf(NULL, 0, "<%d>", smp_processor_id()); |
|
} |
|
#endif |
|
|
|
return len; |
|
} |
|
|
|
static size_t msg_print_text(const struct printk_log *msg, bool syslog, char *buf, size_t size) |
|
{ |
|
const char *text = log_text(msg); |
|
size_t text_size = msg->text_len; |
|
size_t len = 0; |
|
|
|
do { |
|
const char *next = memchr(text, '\n', text_size); |
|
size_t text_len; |
|
|
|
if (next) { |
|
text_len = next - text; |
|
next++; |
|
text_size -= next - text; |
|
} else { |
|
text_len = text_size; |
|
} |
|
|
|
if (buf) { |
|
if (print_prefix(msg, syslog, NULL) + |
|
text_len + 1 >= size - len) |
|
break; |
|
|
|
len += print_prefix(msg, syslog, buf + len); |
|
memcpy(buf + len, text, text_len); |
|
len += text_len; |
|
buf[len++] = '\n'; |
|
} else { |
|
/* SYSLOG_ACTION_* buffer size only calculation */ |
|
len += print_prefix(msg, syslog, NULL); |
|
len += text_len; |
|
len++; |
|
} |
|
|
|
text = next; |
|
} while (text); |
|
|
|
return len; |
|
} |
|
|
|
static int syslog_print(char __user *buf, int size) |
|
{ |
|
char *text; |
|
struct printk_log *msg; |
|
int len = 0; |
|
|
|
text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); |
|
if (!text) |
|
return -ENOMEM; |
|
|
|
while (size > 0) { |
|
size_t n; |
|
size_t skip; |
|
|
|
logbuf_lock_irq(); |
|
if (syslog_seq < log_first_seq) { |
|
/* messages are gone, move to first one */ |
|
syslog_seq = log_first_seq; |
|
syslog_idx = log_first_idx; |
|
syslog_partial = 0; |
|
} |
|
if (syslog_seq == log_next_seq) { |
|
logbuf_unlock_irq(); |
|
break; |
|
} |
|
|
|
skip = syslog_partial; |
|
msg = log_from_idx(syslog_idx); |
|
n = msg_print_text(msg, true, text, LOG_LINE_MAX + PREFIX_MAX); |
|
if (n - syslog_partial <= size) { |
|
/* message fits into buffer, move forward */ |
|
syslog_idx = log_next(syslog_idx); |
|
syslog_seq++; |
|
n -= syslog_partial; |
|
syslog_partial = 0; |
|
} else if (!len){ |
|
/* partial read(), remember position */ |
|
n = size; |
|
syslog_partial += n; |
|
} else |
|
n = 0; |
|
logbuf_unlock_irq(); |
|
|
|
if (!n) |
|
break; |
|
|
|
if (copy_to_user(buf, text + skip, n)) { |
|
if (!len) |
|
len = -EFAULT; |
|
break; |
|
} |
|
|
|
len += n; |
|
size -= n; |
|
buf += n; |
|
} |
|
|
|
kfree(text); |
|
return len; |
|
} |
|
|
|
static int syslog_print_all(char __user *buf, int size, bool clear) |
|
{ |
|
char *text; |
|
int len = 0; |
|
|
|
text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); |
|
if (!text) |
|
return -ENOMEM; |
|
|
|
logbuf_lock_irq(); |
|
if (buf) { |
|
u64 next_seq; |
|
u64 seq; |
|
u32 idx; |
|
|
|
/* |
|
* Find first record that fits, including all following records, |
|
* into the user-provided buffer for this dump. |
|
*/ |
|
seq = clear_seq; |
|
idx = clear_idx; |
|
while (seq < log_next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
|
|
len += msg_print_text(msg, true, NULL, 0); |
|
idx = log_next(idx); |
|
seq++; |
|
} |
|
|
|
/* move first record forward until length fits into the buffer */ |
|
seq = clear_seq; |
|
idx = clear_idx; |
|
while (len > size && seq < log_next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
|
|
len -= msg_print_text(msg, true, NULL, 0); |
|
idx = log_next(idx); |
|
seq++; |
|
} |
|
|
|
/* last message fitting into this dump */ |
|
next_seq = log_next_seq; |
|
|
|
len = 0; |
|
while (len >= 0 && seq < next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
int textlen; |
|
|
|
textlen = msg_print_text(msg, true, text, |
|
LOG_LINE_MAX + PREFIX_MAX); |
|
if (textlen < 0) { |
|
len = textlen; |
|
break; |
|
} |
|
idx = log_next(idx); |
|
seq++; |
|
|
|
logbuf_unlock_irq(); |
|
if (copy_to_user(buf + len, text, textlen)) |
|
len = -EFAULT; |
|
else |
|
len += textlen; |
|
logbuf_lock_irq(); |
|
|
|
if (seq < log_first_seq) { |
|
/* messages are gone, move to next one */ |
|
seq = log_first_seq; |
|
idx = log_first_idx; |
|
} |
|
} |
|
} |
|
|
|
if (clear) { |
|
clear_seq = log_next_seq; |
|
clear_idx = log_next_idx; |
|
} |
|
logbuf_unlock_irq(); |
|
|
|
kfree(text); |
|
return len; |
|
} |
|
|
|
int do_syslog(int type, char __user *buf, int len, int source) |
|
{ |
|
bool clear = false; |
|
static int saved_console_loglevel = LOGLEVEL_DEFAULT; |
|
int error; |
|
|
|
error = check_syslog_permissions(type, source); |
|
if (error) |
|
return error; |
|
|
|
switch (type) { |
|
case SYSLOG_ACTION_CLOSE: /* Close log */ |
|
break; |
|
case SYSLOG_ACTION_OPEN: /* Open log */ |
|
break; |
|
case SYSLOG_ACTION_READ: /* Read from log */ |
|
if (!buf || len < 0) |
|
return -EINVAL; |
|
if (!len) |
|
return 0; |
|
if (!access_ok(VERIFY_WRITE, buf, len)) |
|
return -EFAULT; |
|
error = wait_event_interruptible(log_wait, |
|
syslog_seq != log_next_seq); |
|
if (error) |
|
return error; |
|
error = syslog_print(buf, len); |
|
break; |
|
/* Read/clear last kernel messages */ |
|
case SYSLOG_ACTION_READ_CLEAR: |
|
clear = true; |
|
/* FALL THRU */ |
|
/* Read last kernel messages */ |
|
case SYSLOG_ACTION_READ_ALL: |
|
if (!buf || len < 0) |
|
return -EINVAL; |
|
if (!len) |
|
return 0; |
|
if (!access_ok(VERIFY_WRITE, buf, len)) |
|
return -EFAULT; |
|
error = syslog_print_all(buf, len, clear); |
|
break; |
|
/* Clear ring buffer */ |
|
case SYSLOG_ACTION_CLEAR: |
|
syslog_print_all(NULL, 0, true); |
|
break; |
|
/* Disable logging to console */ |
|
case SYSLOG_ACTION_CONSOLE_OFF: |
|
if (saved_console_loglevel == LOGLEVEL_DEFAULT) |
|
saved_console_loglevel = console_loglevel; |
|
console_loglevel = minimum_console_loglevel; |
|
break; |
|
/* Enable logging to console */ |
|
case SYSLOG_ACTION_CONSOLE_ON: |
|
if (saved_console_loglevel != LOGLEVEL_DEFAULT) { |
|
console_loglevel = saved_console_loglevel; |
|
saved_console_loglevel = LOGLEVEL_DEFAULT; |
|
} |
|
break; |
|
/* Set level of messages printed to console */ |
|
case SYSLOG_ACTION_CONSOLE_LEVEL: |
|
if (len < 1 || len > 8) |
|
return -EINVAL; |
|
if (len < minimum_console_loglevel) |
|
len = minimum_console_loglevel; |
|
console_loglevel = len; |
|
/* Implicitly re-enable logging to console */ |
|
saved_console_loglevel = LOGLEVEL_DEFAULT; |
|
break; |
|
/* Number of chars in the log buffer */ |
|
case SYSLOG_ACTION_SIZE_UNREAD: |
|
logbuf_lock_irq(); |
|
if (syslog_seq < log_first_seq) { |
|
/* messages are gone, move to first one */ |
|
syslog_seq = log_first_seq; |
|
syslog_idx = log_first_idx; |
|
syslog_partial = 0; |
|
} |
|
if (source == SYSLOG_FROM_PROC) { |
|
/* |
|
* Short-cut for poll(/"proc/kmsg") which simply checks |
|
* for pending data, not the size; return the count of |
|
* records, not the length. |
|
*/ |
|
error = log_next_seq - syslog_seq; |
|
} else { |
|
u64 seq = syslog_seq; |
|
u32 idx = syslog_idx; |
|
|
|
while (seq < log_next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
|
|
error += msg_print_text(msg, true, NULL, 0); |
|
idx = log_next(idx); |
|
seq++; |
|
} |
|
error -= syslog_partial; |
|
} |
|
logbuf_unlock_irq(); |
|
break; |
|
/* Size of the log buffer */ |
|
case SYSLOG_ACTION_SIZE_BUFFER: |
|
error = log_buf_len; |
|
break; |
|
default: |
|
error = -EINVAL; |
|
break; |
|
} |
|
|
|
return error; |
|
} |
|
|
|
SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len) |
|
{ |
|
return do_syslog(type, buf, len, SYSLOG_FROM_READER); |
|
} |
|
|
|
/* |
|
* Special console_lock variants that help to reduce the risk of soft-lockups. |
|
* They allow to pass console_lock to another printk() call using a busy wait. |
|
*/ |
|
|
|
#ifdef CONFIG_LOCKDEP |
|
static struct lockdep_map console_owner_dep_map = { |
|
.name = "console_owner" |
|
}; |
|
#endif |
|
|
|
static DEFINE_RAW_SPINLOCK(console_owner_lock); |
|
static struct task_struct *console_owner; |
|
static bool console_waiter; |
|
|
|
/** |
|
* console_lock_spinning_enable - mark beginning of code where another |
|
* thread might safely busy wait |
|
* |
|
* This basically converts console_lock into a spinlock. This marks |
|
* the section where the console_lock owner can not sleep, because |
|
* there may be a waiter spinning (like a spinlock). Also it must be |
|
* ready to hand over the lock at the end of the section. |
|
*/ |
|
static void console_lock_spinning_enable(void) |
|
{ |
|
raw_spin_lock(&console_owner_lock); |
|
console_owner = current; |
|
raw_spin_unlock(&console_owner_lock); |
|
|
|
/* The waiter may spin on us after setting console_owner */ |
|
spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_); |
|
} |
|
|
|
/** |
|
* console_lock_spinning_disable_and_check - mark end of code where another |
|
* thread was able to busy wait and check if there is a waiter |
|
* |
|
* This is called at the end of the section where spinning is allowed. |
|
* It has two functions. First, it is a signal that it is no longer |
|
* safe to start busy waiting for the lock. Second, it checks if |
|
* there is a busy waiter and passes the lock rights to her. |
|
* |
|
* Important: Callers lose the lock if there was a busy waiter. |
|
* They must not touch items synchronized by console_lock |
|
* in this case. |
|
* |
|
* Return: 1 if the lock rights were passed, 0 otherwise. |
|
*/ |
|
static int console_lock_spinning_disable_and_check(void) |
|
{ |
|
int waiter; |
|
|
|
raw_spin_lock(&console_owner_lock); |
|
waiter = READ_ONCE(console_waiter); |
|
console_owner = NULL; |
|
raw_spin_unlock(&console_owner_lock); |
|
|
|
if (!waiter) { |
|
spin_release(&console_owner_dep_map, 1, _THIS_IP_); |
|
return 0; |
|
} |
|
|
|
/* The waiter is now free to continue */ |
|
WRITE_ONCE(console_waiter, false); |
|
|
|
spin_release(&console_owner_dep_map, 1, _THIS_IP_); |
|
|
|
/* |
|
* Hand off console_lock to waiter. The waiter will perform |
|
* the up(). After this, the waiter is the console_lock owner. |
|
*/ |
|
mutex_release(&console_lock_dep_map, 1, _THIS_IP_); |
|
return 1; |
|
} |
|
|
|
/** |
|
* console_trylock_spinning - try to get console_lock by busy waiting |
|
* |
|
* This allows to busy wait for the console_lock when the current |
|
* owner is running in specially marked sections. It means that |
|
* the current owner is running and cannot reschedule until it |
|
* is ready to lose the lock. |
|
* |
|
* Return: 1 if we got the lock, 0 othrewise |
|
*/ |
|
static int console_trylock_spinning(void) |
|
{ |
|
struct task_struct *owner = NULL; |
|
bool waiter; |
|
bool spin = false; |
|
unsigned long flags; |
|
|
|
if (console_trylock()) |
|
return 1; |
|
|
|
printk_safe_enter_irqsave(flags); |
|
|
|
raw_spin_lock(&console_owner_lock); |
|
owner = READ_ONCE(console_owner); |
|
waiter = READ_ONCE(console_waiter); |
|
if (!waiter && owner && owner != current) { |
|
WRITE_ONCE(console_waiter, true); |
|
spin = true; |
|
} |
|
raw_spin_unlock(&console_owner_lock); |
|
|
|
/* |
|
* If there is an active printk() writing to the |
|
* consoles, instead of having it write our data too, |
|
* see if we can offload that load from the active |
|
* printer, and do some printing ourselves. |
|
* Go into a spin only if there isn't already a waiter |
|
* spinning, and there is an active printer, and |
|
* that active printer isn't us (recursive printk?). |
|
*/ |
|
if (!spin) { |
|
printk_safe_exit_irqrestore(flags); |
|
return 0; |
|
} |
|
|
|
/* We spin waiting for the owner to release us */ |
|
spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_); |
|
/* Owner will clear console_waiter on hand off */ |
|
while (READ_ONCE(console_waiter)) |
|
cpu_relax(); |
|
spin_release(&console_owner_dep_map, 1, _THIS_IP_); |
|
|
|
printk_safe_exit_irqrestore(flags); |
|
/* |
|
* The owner passed the console lock to us. |
|
* Since we did not spin on console lock, annotate |
|
* this as a trylock. Otherwise lockdep will |
|
* complain. |
|
*/ |
|
mutex_acquire(&console_lock_dep_map, 0, 1, _THIS_IP_); |
|
|
|
return 1; |
|
} |
|
|
|
/* |
|
* Call the console drivers, asking them to write out |
|
* log_buf[start] to log_buf[end - 1]. |
|
* The console_lock must be held. |
|
*/ |
|
static void call_console_drivers(const char *ext_text, size_t ext_len, |
|
const char *text, size_t len) |
|
{ |
|
struct console *con; |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
unsigned long interval_con_write = 0; |
|
#endif |
|
|
|
trace_console_rcuidle(text, len); |
|
|
|
if (!console_drivers) |
|
return; |
|
|
|
for_each_console(con) { |
|
/* if uart printk disabled */ |
|
if ((printk_disable_uart == 1) && (con->flags & CON_CONSDEV)) |
|
continue; |
|
if (exclusive_console && con != exclusive_console) |
|
continue; |
|
if (!(con->flags & CON_ENABLED)) |
|
continue; |
|
if (!con->write) |
|
continue; |
|
if (!cpu_online(smp_processor_id()) && |
|
!(con->flags & CON_ANYTIME)) |
|
continue; |
|
if (con->flags & CON_EXTENDED) |
|
con->write(con, ext_text, ext_len); |
|
else { |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
conwrite_stat_struct.con = con; |
|
conwrite_stat_struct.time_before_conwrite |
|
= local_clock(); |
|
con->write(con, text, len); |
|
conwrite_stat_struct.time_after_conwrite |
|
= local_clock(); |
|
interval_con_write = |
|
conwrite_stat_struct.time_after_conwrite - |
|
conwrite_stat_struct.time_before_conwrite; |
|
if (!strcmp(con->name, "ttyS")) { |
|
time_con_write_ttyS += interval_con_write; |
|
len_con_write_ttyS += len; |
|
} else if (!strcmp(con->name, "pstore")) { |
|
time_con_write_pstore += interval_con_write; |
|
len_con_write_pstore += len; |
|
} |
|
#else |
|
con->write(con, text, len); |
|
#endif |
|
} |
|
} |
|
} |
|
|
|
#ifdef CONFIG_MTK_AEE_FEATURE |
|
/* if logbuf lock in aee_wdt flow, zap locks uncondationally */ |
|
void aee_wdt_zap_locks(void) |
|
{ |
|
debug_locks_off(); |
|
/* If a crash is occurring, make sure we can't deadlock */ |
|
raw_spin_lock_init(&logbuf_lock); |
|
/* And make sure that we print immediately */ |
|
sema_init(&console_sem, 1); |
|
} |
|
#endif |
|
|
|
int printk_delay_msec __read_mostly; |
|
|
|
static inline void printk_delay(void) |
|
{ |
|
if (unlikely(printk_delay_msec)) { |
|
int m = printk_delay_msec; |
|
|
|
while (m--) { |
|
mdelay(1); |
|
touch_nmi_watchdog(); |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* Continuation lines are buffered, and not committed to the record buffer |
|
* until the line is complete, or a race forces it. The line fragments |
|
* though, are printed immediately to the consoles to ensure everything has |
|
* reached the console in case of a kernel crash. |
|
*/ |
|
static struct cont { |
|
char buf[LOG_LINE_MAX]; |
|
size_t len; /* length == 0 means unused buffer */ |
|
struct task_struct *owner; /* task of first print*/ |
|
u64 ts_nsec; /* time of first print */ |
|
u8 level; /* log level of first message */ |
|
u8 facility; /* log facility of first message */ |
|
enum log_flags flags; /* prefix, newline flags */ |
|
} cont; |
|
|
|
static void cont_flush(void) |
|
{ |
|
if (cont.len == 0) |
|
return; |
|
|
|
log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec, |
|
NULL, 0, cont.buf, cont.len); |
|
cont.len = 0; |
|
} |
|
|
|
static bool cont_add(int facility, int level, enum log_flags flags, const char *text, size_t len) |
|
{ |
|
/* |
|
* If ext consoles are present, flush and skip in-kernel |
|
* continuation. See nr_ext_console_drivers definition. Also, if |
|
* the line gets too long, split it up in separate records. |
|
*/ |
|
if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) { |
|
cont_flush(); |
|
return false; |
|
} |
|
|
|
if (!cont.len) { |
|
cont.facility = facility; |
|
cont.level = level; |
|
cont.owner = current; |
|
cont.ts_nsec = local_clock(); |
|
cont.flags = flags; |
|
} |
|
|
|
memcpy(cont.buf + cont.len, text, len); |
|
cont.len += len; |
|
|
|
// The original flags come from the first line, |
|
// but later continuations can add a newline. |
|
if (flags & LOG_NEWLINE) { |
|
cont.flags |= LOG_NEWLINE; |
|
cont_flush(); |
|
} |
|
|
|
if (cont.len > (sizeof(cont.buf) * 80) / 100) |
|
cont_flush(); |
|
|
|
return true; |
|
} |
|
|
|
static size_t log_output(int facility, int level, enum log_flags lflags, const char *dict, size_t dictlen, char *text, size_t text_len) |
|
{ |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
u64 log_enter_time = local_clock(); |
|
#endif |
|
/* |
|
* If an earlier line was buffered, and we're a continuation |
|
* write from the same process, try to add it to the buffer. |
|
*/ |
|
if (cont.len) { |
|
if (cont.owner == current && (lflags & LOG_CONT)) { |
|
if (cont_add(facility, level, lflags, text, text_len)) |
|
return text_len; |
|
} |
|
/* Otherwise, make sure it's flushed */ |
|
cont_flush(); |
|
} |
|
|
|
/* Skip empty continuation lines that couldn't be added - they just flush */ |
|
if (!text_len && (lflags & LOG_CONT)) |
|
return 0; |
|
|
|
/* If it doesn't end in a newline, try to buffer the current line */ |
|
if (!(lflags & LOG_NEWLINE)) { |
|
if (cont_add(facility, level, lflags, text, text_len)) |
|
return text_len; |
|
} |
|
|
|
/* Store it in the record log */ |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
return log_store(facility, level, lflags, |
|
log_enter_time, dict, dictlen, text, text_len); |
|
#else |
|
return log_store(facility, level, lflags, 0, dict, dictlen, text, text_len); |
|
#endif |
|
} |
|
|
|
/* Must be called under logbuf_lock. */ |
|
int vprintk_store(int facility, int level, |
|
const char *dict, size_t dictlen, |
|
const char *fmt, va_list args) |
|
{ |
|
static char textbuf[LOG_LINE_MAX]; |
|
char *text = textbuf; |
|
size_t text_len; |
|
enum log_flags lflags = 0; |
|
|
|
/* |
|
* The printf needs to come first; we need the syslog |
|
* prefix which might be passed-in as a parameter. |
|
*/ |
|
text_len = vscnprintf(text, sizeof(textbuf), fmt, args); |
|
|
|
/* mark and strip a trailing newline */ |
|
if (text_len && text[text_len-1] == '\n') { |
|
text_len--; |
|
lflags |= LOG_NEWLINE; |
|
} |
|
|
|
/* strip kernel syslog prefix and extract log level or control flags */ |
|
if (facility == 0) { |
|
int kern_level; |
|
|
|
while ((kern_level = printk_get_level(text)) != 0) { |
|
switch (kern_level) { |
|
case '0' ... '7': |
|
if (level == LOGLEVEL_DEFAULT) |
|
level = kern_level - '0'; |
|
/* fallthrough */ |
|
case 'd': /* KERN_DEFAULT */ |
|
lflags |= LOG_PREFIX; |
|
break; |
|
case 'c': /* KERN_CONT */ |
|
lflags |= LOG_CONT; |
|
} |
|
|
|
text_len -= 2; |
|
text += 2; |
|
} |
|
} |
|
|
|
if (level == LOGLEVEL_DEFAULT) |
|
level = default_message_loglevel; |
|
|
|
if (dict) |
|
lflags |= LOG_PREFIX|LOG_NEWLINE; |
|
|
|
/* MTK_prefix */ |
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
/* if irqs_disabled() is true*/ |
|
if (isIrqsDisabled) |
|
this_cpu_write(printk_state, '-'); |
|
#ifdef CONFIG_MTK_PRINTK_UART_CONSOLE |
|
/* if uart printk enabled */ |
|
else if (printk_disable_uart != 1) |
|
this_cpu_write(printk_state, '.'); |
|
#endif |
|
else |
|
this_cpu_write(printk_state, ' '); |
|
#endif |
|
|
|
return log_output(facility, level, lflags, |
|
dict, dictlen, text, text_len); |
|
} |
|
|
|
asmlinkage int vprintk_emit(int facility, int level, |
|
const char *dict, size_t dictlen, |
|
const char *fmt, va_list args) |
|
{ |
|
int printed_len; |
|
bool in_sched = false; |
|
unsigned long flags; |
|
#ifdef CONFIG_PRINTK_MT_PREFIX |
|
/* save the status of irqs_disabled() */ |
|
isIrqsDisabled = irqs_disabled(); |
|
#endif |
|
if (level == LOGLEVEL_SCHED) { |
|
level = LOGLEVEL_DEFAULT; |
|
in_sched = true; |
|
} |
|
|
|
boot_delay_msec(level); |
|
printk_delay(); |
|
|
|
/* This stops the holder of console_sem just where we want him */ |
|
logbuf_lock_irqsave(flags); |
|
printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args); |
|
logbuf_unlock_irqrestore(flags); |
|
|
|
/* If called from the scheduler, we can not call up(). */ |
|
if (!in_sched && cpu_online(raw_smp_processor_id())) { |
|
/* |
|
* Try to acquire and then immediately release the console |
|
* semaphore. The release will print out buffers and wake up |
|
* /dev/kmsg and syslog() users. |
|
*/ |
|
if (console_trylock_spinning()) |
|
console_unlock(); |
|
} |
|
|
|
return printed_len; |
|
} |
|
EXPORT_SYMBOL(vprintk_emit); |
|
|
|
asmlinkage int vprintk(const char *fmt, va_list args) |
|
{ |
|
return vprintk_func(fmt, args); |
|
} |
|
EXPORT_SYMBOL(vprintk); |
|
|
|
asmlinkage int printk_emit(int facility, int level, |
|
const char *dict, size_t dictlen, |
|
const char *fmt, ...) |
|
{ |
|
va_list args; |
|
int r; |
|
|
|
va_start(args, fmt); |
|
r = vprintk_emit(facility, level, dict, dictlen, fmt, args); |
|
va_end(args); |
|
|
|
return r; |
|
} |
|
EXPORT_SYMBOL(printk_emit); |
|
|
|
int vprintk_default(const char *fmt, va_list args) |
|
{ |
|
int r; |
|
|
|
#ifdef CONFIG_KGDB_KDB |
|
/* Allow to pass printk() to kdb but avoid a recursion. */ |
|
if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0)) { |
|
r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args); |
|
return r; |
|
} |
|
#endif |
|
r = vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args); |
|
|
|
return r; |
|
} |
|
EXPORT_SYMBOL_GPL(vprintk_default); |
|
|
|
/** |
|
* printk - print a kernel message |
|
* @fmt: format string |
|
* |
|
* This is printk(). It can be called from any context. We want it to work. |
|
* |
|
* We try to grab the console_lock. If we succeed, it's easy - we log the |
|
* output and call the console drivers. If we fail to get the semaphore, we |
|
* place the output into the log buffer and return. The current holder of |
|
* the console_sem will notice the new output in console_unlock(); and will |
|
* send it to the consoles before releasing the lock. |
|
* |
|
* One effect of this deferred printing is that code which calls printk() and |
|
* then changes console_loglevel may break. This is because console_loglevel |
|
* is inspected when the actual printing occurs. |
|
* |
|
* See also: |
|
* printf(3) |
|
* |
|
* See the vsnprintf() documentation for format string extensions over C99. |
|
*/ |
|
asmlinkage __visible int printk(const char *fmt, ...) |
|
{ |
|
va_list args; |
|
int r; |
|
|
|
va_start(args, fmt); |
|
r = vprintk_func(fmt, args); |
|
va_end(args); |
|
|
|
return r; |
|
} |
|
EXPORT_SYMBOL(printk); |
|
|
|
#else /* CONFIG_PRINTK */ |
|
|
|
#define LOG_LINE_MAX 0 |
|
#define PREFIX_MAX 0 |
|
|
|
static u64 syslog_seq; |
|
static u32 syslog_idx; |
|
static u64 console_seq; |
|
static u32 console_idx; |
|
static u64 log_first_seq; |
|
static u32 log_first_idx; |
|
static u64 log_next_seq; |
|
static char *log_text(const struct printk_log *msg) { return NULL; } |
|
static char *log_dict(const struct printk_log *msg) { return NULL; } |
|
static struct printk_log *log_from_idx(u32 idx) { return NULL; } |
|
static u32 log_next(u32 idx) { return 0; } |
|
static ssize_t msg_print_ext_header(char *buf, size_t size, |
|
struct printk_log *msg, |
|
u64 seq) { return 0; } |
|
static ssize_t msg_print_ext_body(char *buf, size_t size, |
|
char *dict, size_t dict_len, |
|
char *text, size_t text_len) { return 0; } |
|
static void console_lock_spinning_enable(void) { } |
|
static int console_lock_spinning_disable_and_check(void) { return 0; } |
|
static void call_console_drivers(const char *ext_text, size_t ext_len, |
|
const char *text, size_t len) {} |
|
static size_t msg_print_text(const struct printk_log *msg, |
|
bool syslog, char *buf, size_t size) { return 0; } |
|
static bool suppress_message_printing(int level) { return false; } |
|
|
|
#endif /* CONFIG_PRINTK */ |
|
|
|
#ifdef CONFIG_EARLY_PRINTK |
|
struct console *early_console; |
|
|
|
asmlinkage __visible void early_printk(const char *fmt, ...) |
|
{ |
|
va_list ap; |
|
char buf[512]; |
|
int n; |
|
|
|
if (!early_console) |
|
return; |
|
|
|
va_start(ap, fmt); |
|
n = vscnprintf(buf, sizeof(buf), fmt, ap); |
|
va_end(ap); |
|
|
|
early_console->write(early_console, buf, n); |
|
} |
|
#endif |
|
|
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
static int parse_log_file(void) |
|
{ |
|
char buff[LOG_LINE_MAX + PREFIX_MAX]; |
|
u32 log_index = start_idx; |
|
u64 log_seq = start_seq; |
|
size_t count = 0; |
|
struct printk_log *msg; |
|
enum log_flags prev = 0; |
|
|
|
if (log_much == NULL) |
|
return -ENOMEM; |
|
|
|
log_count = 0; |
|
while (log_seq < log_next_seq) { |
|
msg = log_from_idx(log_index); |
|
count = msg_print_text(msg, true, buff, sizeof(buff)); |
|
prev = msg->flags; |
|
|
|
if (log_count + count > log_buf_len + LOG_MUCH_PLUS_LEN) |
|
break; |
|
memcpy(log_much + log_count, buff, count); |
|
log_count += count; |
|
|
|
log_index = log_next(log_index); |
|
log_seq++; |
|
} |
|
return 0; |
|
} |
|
|
|
static void log_much_do_check_and_delay(struct printk_log *msg) |
|
{ |
|
if (delta_count * DETECT_TIME > detect_count * delta_time) { |
|
if (!parse_log_file()) { |
|
t_base = msg->ts_nsec + DELAY_TIME; |
|
flag_toomuch = true; |
|
} |
|
} |
|
} |
|
|
|
static int log_much_show(struct seq_file *m, void *v) |
|
{ |
|
if (log_much == NULL) { |
|
seq_puts(m, "log buff is null.\n"); |
|
return 0; |
|
} |
|
seq_write(m, log_much, log_count); |
|
return 0; |
|
} |
|
|
|
static int log_much_open(struct inode *inode, struct file *file) |
|
{ |
|
return single_open(file, log_much_show, inode->i_private); |
|
} |
|
|
|
static const struct file_operations log_much_ops = { |
|
.owner = THIS_MODULE, |
|
.open = log_much_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = single_release, |
|
}; |
|
#endif |
|
|
|
static int __add_preferred_console(char *name, int idx, char *options, |
|
char *brl_options) |
|
{ |
|
struct console_cmdline *c; |
|
int i; |
|
|
|
/* |
|
* See if this tty is not yet registered, and |
|
* if we have a slot free. |
|
*/ |
|
for (i = 0, c = console_cmdline; |
|
i < MAX_CMDLINECONSOLES && c->name[0]; |
|
i++, c++) { |
|
if (strcmp(c->name, name) == 0 && c->index == idx) { |
|
if (!brl_options) |
|
preferred_console = i; |
|
return 0; |
|
} |
|
} |
|
if (i == MAX_CMDLINECONSOLES) |
|
return -E2BIG; |
|
if (!brl_options) |
|
preferred_console = i; |
|
strlcpy(c->name, name, sizeof(c->name)); |
|
c->options = options; |
|
braille_set_options(c, brl_options); |
|
|
|
c->index = idx; |
|
return 0; |
|
} |
|
/* |
|
* Set up a console. Called via do_early_param() in init/main.c |
|
* for each "console=" parameter in the boot command line. |
|
*/ |
|
static int __init console_setup(char *str) |
|
{ |
|
char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for "ttyS" */ |
|
char *s, *options, *brl_options = NULL; |
|
int idx; |
|
|
|
if (_braille_console_setup(&str, &brl_options)) |
|
return 1; |
|
|
|
/* |
|
* Decode str into name, index, options. |
|
*/ |
|
if (str[0] >= '0' && str[0] <= '9') { |
|
strcpy(buf, "ttyS"); |
|
strncpy(buf + 4, str, sizeof(buf) - 5); |
|
} else { |
|
strncpy(buf, str, sizeof(buf) - 1); |
|
} |
|
buf[sizeof(buf) - 1] = 0; |
|
options = strchr(str, ','); |
|
if (options) |
|
*(options++) = 0; |
|
#ifdef __sparc__ |
|
if (!strcmp(str, "ttya")) |
|
strcpy(buf, "ttyS0"); |
|
if (!strcmp(str, "ttyb")) |
|
strcpy(buf, "ttyS1"); |
|
#endif |
|
for (s = buf; *s; s++) |
|
if (isdigit(*s) || *s == ',') |
|
break; |
|
idx = simple_strtoul(s, NULL, 10); |
|
*s = 0; |
|
|
|
__add_preferred_console(buf, idx, options, brl_options); |
|
console_set_on_cmdline = 1; |
|
return 1; |
|
} |
|
__setup("console=", console_setup); |
|
|
|
/** |
|
* add_preferred_console - add a device to the list of preferred consoles. |
|
* @name: device name |
|
* @idx: device index |
|
* @options: options for this console |
|
* |
|
* The last preferred console added will be used for kernel messages |
|
* and stdin/out/err for init. Normally this is used by console_setup |
|
* above to handle user-supplied console arguments; however it can also |
|
* be used by arch-specific code either to override the user or more |
|
* commonly to provide a default console (ie from PROM variables) when |
|
* the user has not supplied one. |
|
*/ |
|
int add_preferred_console(char *name, int idx, char *options) |
|
{ |
|
return __add_preferred_console(name, idx, options, NULL); |
|
} |
|
|
|
bool console_suspend_enabled = true; |
|
EXPORT_SYMBOL(console_suspend_enabled); |
|
|
|
static int __init console_suspend_disable(char *str) |
|
{ |
|
console_suspend_enabled = false; |
|
return 1; |
|
} |
|
__setup("no_console_suspend", console_suspend_disable); |
|
module_param_named(console_suspend, console_suspend_enabled, |
|
bool, S_IRUGO | S_IWUSR); |
|
MODULE_PARM_DESC(console_suspend, "suspend console during suspend" |
|
" and hibernate operations"); |
|
|
|
/** |
|
* suspend_console - suspend the console subsystem |
|
* |
|
* This disables printk() while we go into suspend states |
|
*/ |
|
void suspend_console(void) |
|
{ |
|
if (!console_suspend_enabled) |
|
return; |
|
printk("Suspending console(s) (use no_console_suspend to debug)\n"); |
|
console_lock(); |
|
console_suspended = 1; |
|
up_console_sem(); |
|
} |
|
|
|
void resume_console(void) |
|
{ |
|
if (!console_suspend_enabled) |
|
return; |
|
down_console_sem(); |
|
console_suspended = 0; |
|
console_unlock(); |
|
} |
|
|
|
/** |
|
* console_cpu_notify - print deferred console messages after CPU hotplug |
|
* @cpu: unused |
|
* |
|
* If printk() is called from a CPU that is not online yet, the messages |
|
* will be printed on the console only if there are CON_ANYTIME consoles. |
|
* This function is called when a new CPU comes online (or fails to come |
|
* up) or goes offline. |
|
*/ |
|
static int console_cpu_notify(unsigned int cpu) |
|
{ |
|
if (!cpuhp_tasks_frozen) { |
|
/* If trylock fails, someone else is doing the printing */ |
|
if (console_trylock()) |
|
console_unlock(); |
|
} |
|
return 0; |
|
} |
|
|
|
/** |
|
* console_lock - lock the console system for exclusive use. |
|
* |
|
* Acquires a lock which guarantees that the caller has |
|
* exclusive access to the console system and the console_drivers list. |
|
* |
|
* Can sleep, returns nothing. |
|
*/ |
|
void console_lock(void) |
|
{ |
|
might_sleep(); |
|
|
|
down_console_sem(); |
|
if (console_suspended) |
|
return; |
|
console_locked = 1; |
|
console_may_schedule = 1; |
|
} |
|
EXPORT_SYMBOL(console_lock); |
|
|
|
/** |
|
* console_trylock - try to lock the console system for exclusive use. |
|
* |
|
* Try to acquire a lock which guarantees that the caller has exclusive |
|
* access to the console system and the console_drivers list. |
|
* |
|
* returns 1 on success, and 0 on failure to acquire the lock. |
|
*/ |
|
int console_trylock(void) |
|
{ |
|
if (down_trylock_console_sem()) |
|
return 0; |
|
if (console_suspended) { |
|
up_console_sem(); |
|
return 0; |
|
} |
|
console_locked = 1; |
|
/* |
|
* When PREEMPT_COUNT disabled we can't reliably detect if it's |
|
* safe to schedule (e.g. calling printk while holding a spin_lock), |
|
* because preempt_disable()/preempt_enable() are just barriers there |
|
* and preempt_count() is always 0. |
|
* |
|
* RCU read sections have a separate preemption counter when |
|
* PREEMPT_RCU enabled thus we must take extra care and check |
|
* rcu_preempt_depth(), otherwise RCU read sections modify |
|
* preempt_count(). |
|
*/ |
|
console_may_schedule = !oops_in_progress && |
|
preemptible() && |
|
!rcu_preempt_depth(); |
|
return 1; |
|
} |
|
EXPORT_SYMBOL(console_trylock); |
|
|
|
int is_console_locked(void) |
|
{ |
|
return console_locked; |
|
} |
|
|
|
/* |
|
* Check if we have any console that is capable of printing while cpu is |
|
* booting or shutting down. Requires console_sem. |
|
*/ |
|
static int have_callable_console(void) |
|
{ |
|
struct console *con; |
|
|
|
for_each_console(con) |
|
if ((con->flags & CON_ENABLED) && |
|
(con->flags & CON_ANYTIME)) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Can we actually use the console at this time on this cpu? |
|
* |
|
* Console drivers may assume that per-cpu resources have been allocated. So |
|
* unless they're explicitly marked as being able to cope (CON_ANYTIME) don't |
|
* call them until this CPU is officially up. |
|
*/ |
|
static inline int can_use_console(void) |
|
{ |
|
return cpu_online(raw_smp_processor_id()) || have_callable_console(); |
|
} |
|
|
|
/** |
|
* console_unlock - unlock the console system |
|
* |
|
* Releases the console_lock which the caller holds on the console system |
|
* and the console driver list. |
|
* |
|
* While the console_lock was held, console output may have been buffered |
|
* by printk(). If this is the case, console_unlock(); emits |
|
* the output prior to releasing the lock. |
|
* |
|
* If there is output waiting, we wake /dev/kmsg and syslog() users. |
|
* |
|
* console_unlock(); may be called from any context. |
|
*/ |
|
void console_unlock(void) |
|
{ |
|
static char ext_text[CONSOLE_EXT_LOG_MAX]; |
|
static char text[LOG_LINE_MAX + PREFIX_MAX]; |
|
static u64 seen_seq; |
|
unsigned long flags; |
|
bool wake_klogd = false; |
|
bool do_cond_resched, retry; |
|
|
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
/* length can not beyond 63 because of aee API args limitation */ |
|
char aee_str[63]; |
|
int add_len; |
|
u64 period; |
|
unsigned long rem_nsec; |
|
#endif |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
bool block_overtime = false; |
|
u64 con_dura_time = local_clock(); |
|
u64 current_time; |
|
|
|
len_con_write_ttyS = len_con_write_pstore = 0; |
|
time_con_write_ttyS = time_con_write_pstore = 0; |
|
rem_nsec_con_write_ttyS = rem_nsec_con_write_pstore = 0; |
|
#endif |
|
if (console_suspended) { |
|
up_console_sem(); |
|
return; |
|
} |
|
|
|
/* |
|
* Console drivers are called with interrupts disabled, so |
|
* @console_may_schedule should be cleared before; however, we may |
|
* end up dumping a lot of lines, for example, if called from |
|
* console registration path, and should invoke cond_resched() |
|
* between lines if allowable. Not doing so can cause a very long |
|
* scheduling stall on a slow console leading to RCU stall and |
|
* softlockup warnings which exacerbate the issue with more |
|
* messages practically incapacitating the system. |
|
* |
|
* console_trylock() is not able to detect the preemptive |
|
* context reliably. Therefore the value must be stored before |
|
* and cleared after the the "again" goto label. |
|
*/ |
|
do_cond_resched = console_may_schedule; |
|
again: |
|
console_may_schedule = 0; |
|
|
|
/* |
|
* We released the console_sem lock, so we need to recheck if |
|
* cpu is online and (if not) is there at least one CON_ANYTIME |
|
* console. |
|
*/ |
|
if (!can_use_console()) { |
|
console_locked = 0; |
|
up_console_sem(); |
|
return; |
|
} |
|
|
|
for (;;) { |
|
struct printk_log *msg; |
|
size_t ext_len = 0; |
|
size_t len; |
|
|
|
printk_safe_enter_irqsave(flags); |
|
raw_spin_lock(&logbuf_lock); |
|
if (seen_seq != log_next_seq) { |
|
wake_klogd = true; |
|
seen_seq = log_next_seq; |
|
} |
|
|
|
if (console_seq < log_first_seq) { |
|
len = sprintf(text, "** %u printk messages dropped ** ", |
|
(unsigned)(log_first_seq - console_seq)); |
|
|
|
/* messages are gone, move to first one */ |
|
console_seq = log_first_seq; |
|
console_idx = log_first_idx; |
|
} else { |
|
len = 0; |
|
} |
|
skip: |
|
if (console_seq == log_next_seq) |
|
break; |
|
|
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
/* console_unlock block time over 2 seconds */ |
|
current_time = local_clock(); |
|
if ((current_time - con_dura_time) > 2000000000ULL) { |
|
unsigned long tmp_rem_nsec_start = 0, |
|
tmp_rem_nsec_end = 0; |
|
block_overtime = true; |
|
console_status_detected = true; |
|
|
|
rem_nsec_con_write_ttyS = do_div |
|
(time_con_write_ttyS, 1000000000); |
|
rem_nsec_con_write_pstore = do_div |
|
(time_con_write_pstore, 1000000000); |
|
tmp_rem_nsec_start = do_div(con_dura_time, 1000000000); |
|
tmp_rem_nsec_end = do_div(current_time, 1000000000); |
|
memset(conwrite_stat_struct.con_write_statbuf, 0x0, |
|
sizeof(conwrite_stat_struct.con_write_statbuf) |
|
- 1); |
|
snprintf(conwrite_stat_struct.con_write_statbuf, |
|
sizeof(conwrite_stat_struct.con_write_statbuf) |
|
- 1, |
|
"cpu%d [%lu.%06lu]--[%lu.%06lu] 'ttyS' %lubytes %lu.%06lus, 'pstore' %lubytes %lu.%06lus\n", |
|
smp_processor_id(), |
|
(unsigned long)con_dura_time, |
|
tmp_rem_nsec_start/1000, |
|
(unsigned long)current_time, |
|
tmp_rem_nsec_end/1000, |
|
(unsigned long)len_con_write_ttyS, |
|
(unsigned long)time_con_write_ttyS, |
|
rem_nsec_con_write_ttyS/1000, |
|
(unsigned long)len_con_write_pstore, |
|
(unsigned long)time_con_write_pstore, |
|
rem_nsec_con_write_pstore/1000); |
|
break; |
|
} |
|
/* print the uart status next time enter the console_unlock */ |
|
if (console_status_detected) { |
|
len += snprintf(text + len, |
|
strlen(conwrite_stat_struct.con_write_statbuf), |
|
conwrite_stat_struct.con_write_statbuf); |
|
console_status_detected = false; |
|
} |
|
#endif |
|
|
|
msg = log_from_idx(console_idx); |
|
if (suppress_message_printing(msg->level)) { |
|
/* |
|
* Skip record we have buffered and already printed |
|
* directly to the console when we received it, and |
|
* record that has level above the console loglevel. |
|
*/ |
|
console_idx = log_next(console_idx); |
|
console_seq++; |
|
goto skip; |
|
} |
|
|
|
len += msg_print_text(msg, false, text + len, sizeof(text) - len); |
|
if (nr_ext_console_drivers) { |
|
ext_len = msg_print_ext_header(ext_text, |
|
sizeof(ext_text), |
|
msg, console_seq); |
|
ext_len += msg_print_ext_body(ext_text + ext_len, |
|
sizeof(ext_text) - ext_len, |
|
log_dict(msg), msg->dict_len, |
|
log_text(msg), msg->text_len); |
|
} |
|
console_idx = log_next(console_idx); |
|
console_seq++; |
|
raw_spin_unlock(&logbuf_lock); |
|
|
|
/* |
|
* While actively printing out messages, if another printk() |
|
* were to occur on another CPU, it may wait for this one to |
|
* finish. This task can not be preempted if there is a |
|
* waiter waiting to take over. |
|
*/ |
|
console_lock_spinning_enable(); |
|
|
|
stop_critical_timings(); /* don't trace print latency */ |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
if (flag_toomuch == true) { |
|
flag_toomuch = false; |
|
add_len = scnprintf(aee_str, 63, |
|
"Printk too much: >%d L/s, L: %llu, ", |
|
detect_count, delta_count); |
|
if (add_len + 12 <= 63) { |
|
period = delta_time; |
|
rem_nsec = do_div(period, 1000000000); |
|
scnprintf(aee_str + add_len, 63 - add_len, |
|
"S: %llu.%06lu\n", |
|
period, rem_nsec / 1000); |
|
} |
|
aee_kernel_warning_api(__FILE__, __LINE__, |
|
DB_OPT_PRINTK_TOO_MUCH | DB_OPT_DUMMY_DUMP, |
|
aee_str, "Need to shrink kernel log"); |
|
} else |
|
call_console_drivers(ext_text, ext_len, text, len); |
|
#else |
|
call_console_drivers(ext_text, ext_len, text, len); |
|
#endif |
|
start_critical_timings(); |
|
|
|
if (console_lock_spinning_disable_and_check()) { |
|
printk_safe_exit_irqrestore(flags); |
|
goto out; |
|
} |
|
|
|
printk_safe_exit_irqrestore(flags); |
|
|
|
if (do_cond_resched) |
|
cond_resched(); |
|
} |
|
|
|
console_locked = 0; |
|
|
|
/* Release the exclusive_console once it is used */ |
|
if (unlikely(exclusive_console)) |
|
exclusive_console = NULL; |
|
|
|
raw_spin_unlock(&logbuf_lock); |
|
|
|
up_console_sem(); |
|
|
|
/* |
|
* Someone could have filled up the buffer again, so re-check if there's |
|
* something to flush. In case we cannot trylock the console_sem again, |
|
* there's a new owner and the console_unlock() from them will do the |
|
* flush, no worries. |
|
*/ |
|
raw_spin_lock(&logbuf_lock); |
|
#ifdef CONFIG_CONSOLE_LOCK_DURATION_DETECT |
|
retry = !block_overtime && (console_seq != log_next_seq); |
|
#else |
|
retry = console_seq != log_next_seq; |
|
#endif |
|
raw_spin_unlock(&logbuf_lock); |
|
printk_safe_exit_irqrestore(flags); |
|
|
|
if (retry && console_trylock()) |
|
goto again; |
|
|
|
out: |
|
if (wake_klogd) |
|
wake_up_klogd(); |
|
} |
|
EXPORT_SYMBOL(console_unlock); |
|
|
|
/** |
|
* console_conditional_schedule - yield the CPU if required |
|
* |
|
* If the console code is currently allowed to sleep, and |
|
* if this CPU should yield the CPU to another task, do |
|
* so here. |
|
* |
|
* Must be called within console_lock();. |
|
*/ |
|
void __sched console_conditional_schedule(void) |
|
{ |
|
if (console_may_schedule) |
|
cond_resched(); |
|
} |
|
EXPORT_SYMBOL(console_conditional_schedule); |
|
|
|
void console_unblank(void) |
|
{ |
|
struct console *c; |
|
|
|
/* |
|
* console_unblank can no longer be called in interrupt context unless |
|
* oops_in_progress is set to 1.. |
|
*/ |
|
if (oops_in_progress) { |
|
if (down_trylock_console_sem() != 0) |
|
return; |
|
} else |
|
console_lock(); |
|
|
|
console_locked = 1; |
|
console_may_schedule = 0; |
|
for_each_console(c) |
|
if ((c->flags & CON_ENABLED) && c->unblank) |
|
c->unblank(); |
|
console_unlock(); |
|
} |
|
|
|
/** |
|
* console_flush_on_panic - flush console content on panic |
|
* |
|
* Immediately output all pending messages no matter what. |
|
*/ |
|
void console_flush_on_panic(void) |
|
{ |
|
/* |
|
* If someone else is holding the console lock, trylock will fail |
|
* and may_schedule may be set. Ignore and proceed to unlock so |
|
* that messages are flushed out. As this can be called from any |
|
* context and we don't want to get preempted while flushing, |
|
* ensure may_schedule is cleared. |
|
*/ |
|
console_trylock(); |
|
console_may_schedule = 0; |
|
console_unlock(); |
|
} |
|
|
|
/* |
|
* Return the console tty driver structure and its associated index |
|
*/ |
|
struct tty_driver *console_device(int *index) |
|
{ |
|
struct console *c; |
|
struct tty_driver *driver = NULL; |
|
|
|
console_lock(); |
|
for_each_console(c) { |
|
if (!c->device) |
|
continue; |
|
driver = c->device(c, index); |
|
if (driver) |
|
break; |
|
} |
|
console_unlock(); |
|
return driver; |
|
} |
|
|
|
/* |
|
* Prevent further output on the passed console device so that (for example) |
|
* serial drivers can disable console output before suspending a port, and can |
|
* re-enable output afterwards. |
|
*/ |
|
void console_stop(struct console *console) |
|
{ |
|
console_lock(); |
|
console->flags &= ~CON_ENABLED; |
|
console_unlock(); |
|
} |
|
EXPORT_SYMBOL(console_stop); |
|
|
|
void console_start(struct console *console) |
|
{ |
|
console_lock(); |
|
console->flags |= CON_ENABLED; |
|
console_unlock(); |
|
} |
|
EXPORT_SYMBOL(console_start); |
|
|
|
static int __read_mostly keep_bootcon; |
|
|
|
static int __init keep_bootcon_setup(char *str) |
|
{ |
|
keep_bootcon = 1; |
|
pr_info("debug: skip boot console de-registration.\n"); |
|
|
|
return 0; |
|
} |
|
|
|
early_param("keep_bootcon", keep_bootcon_setup); |
|
|
|
/* |
|
* The console driver calls this routine during kernel initialization |
|
* to register the console printing procedure with printk() and to |
|
* print any messages that were printed by the kernel before the |
|
* console driver was initialized. |
|
* |
|
* This can happen pretty early during the boot process (because of |
|
* early_printk) - sometimes before setup_arch() completes - be careful |
|
* of what kernel features are used - they may not be initialised yet. |
|
* |
|
* There are two types of consoles - bootconsoles (early_printk) and |
|
* "real" consoles (everything which is not a bootconsole) which are |
|
* handled differently. |
|
* - Any number of bootconsoles can be registered at any time. |
|
* - As soon as a "real" console is registered, all bootconsoles |
|
* will be unregistered automatically. |
|
* - Once a "real" console is registered, any attempt to register a |
|
* bootconsoles will be rejected |
|
*/ |
|
void register_console(struct console *newcon) |
|
{ |
|
int i; |
|
unsigned long flags; |
|
struct console *bcon = NULL; |
|
struct console_cmdline *c; |
|
static bool has_preferred; |
|
|
|
if (console_drivers) |
|
for_each_console(bcon) |
|
if (WARN(bcon == newcon, |
|
"console '%s%d' already registered\n", |
|
bcon->name, bcon->index)) |
|
return; |
|
|
|
/* |
|
* before we register a new CON_BOOT console, make sure we don't |
|
* already have a valid console |
|
*/ |
|
if (console_drivers && newcon->flags & CON_BOOT) { |
|
/* find the last or real console */ |
|
for_each_console(bcon) { |
|
if (!(bcon->flags & CON_BOOT)) { |
|
pr_info("Too late to register bootconsole %s%d\n", |
|
newcon->name, newcon->index); |
|
return; |
|
} |
|
} |
|
} |
|
|
|
if (console_drivers && console_drivers->flags & CON_BOOT) |
|
bcon = console_drivers; |
|
|
|
if (!has_preferred || bcon || !console_drivers) |
|
has_preferred = preferred_console >= 0; |
|
|
|
/* |
|
* See if we want to use this console driver. If we |
|
* didn't select a console we take the first one |
|
* that registers here. |
|
*/ |
|
if (!has_preferred) { |
|
if (newcon->index < 0) |
|
newcon->index = 0; |
|
if (newcon->setup == NULL || |
|
newcon->setup(newcon, NULL) == 0) { |
|
newcon->flags |= CON_ENABLED; |
|
if (newcon->device) { |
|
newcon->flags |= CON_CONSDEV; |
|
has_preferred = true; |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* See if this console matches one we selected on |
|
* the command line. |
|
*/ |
|
for (i = 0, c = console_cmdline; |
|
i < MAX_CMDLINECONSOLES && c->name[0]; |
|
i++, c++) { |
|
if (!newcon->match || |
|
newcon->match(newcon, c->name, c->index, c->options) != 0) { |
|
/* default matching */ |
|
BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name)); |
|
if (strcmp(c->name, newcon->name) != 0) |
|
continue; |
|
if (newcon->index >= 0 && |
|
newcon->index != c->index) |
|
continue; |
|
if (newcon->index < 0) |
|
newcon->index = c->index; |
|
|
|
if (_braille_register_console(newcon, c)) |
|
return; |
|
|
|
if (newcon->setup && |
|
newcon->setup(newcon, c->options) != 0) |
|
break; |
|
} |
|
|
|
newcon->flags |= CON_ENABLED; |
|
if (i == preferred_console) { |
|
newcon->flags |= CON_CONSDEV; |
|
has_preferred = true; |
|
} |
|
break; |
|
} |
|
|
|
if (!(newcon->flags & CON_ENABLED)) |
|
return; |
|
|
|
/* |
|
* If we have a bootconsole, and are switching to a real console, |
|
* don't print everything out again, since when the boot console, and |
|
* the real console are the same physical device, it's annoying to |
|
* see the beginning boot messages twice |
|
*/ |
|
if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV)) |
|
newcon->flags &= ~CON_PRINTBUFFER; |
|
|
|
/* |
|
* Put this console in the list - keep the |
|
* preferred driver at the head of the list. |
|
*/ |
|
console_lock(); |
|
if ((newcon->flags & CON_CONSDEV) || console_drivers == NULL) { |
|
newcon->next = console_drivers; |
|
console_drivers = newcon; |
|
if (newcon->next) |
|
newcon->next->flags &= ~CON_CONSDEV; |
|
} else { |
|
newcon->next = console_drivers->next; |
|
console_drivers->next = newcon; |
|
} |
|
|
|
if (newcon->flags & CON_EXTENDED) |
|
if (!nr_ext_console_drivers++) |
|
pr_info("printk: continuation disabled due to ext consoles, expect more fragments in /dev/kmsg\n"); |
|
|
|
if (newcon->flags & CON_PRINTBUFFER) { |
|
/* |
|
* console_unlock(); will print out the buffered messages |
|
* for us. |
|
*/ |
|
logbuf_lock_irqsave(flags); |
|
console_seq = syslog_seq; |
|
console_idx = syslog_idx; |
|
logbuf_unlock_irqrestore(flags); |
|
/* |
|
* We're about to replay the log buffer. Only do this to the |
|
* just-registered console to avoid excessive message spam to |
|
* the already-registered consoles. |
|
*/ |
|
exclusive_console = newcon; |
|
} |
|
console_unlock(); |
|
console_sysfs_notify(); |
|
|
|
/* |
|
* By unregistering the bootconsoles after we enable the real console |
|
* we get the "console xxx enabled" message on all the consoles - |
|
* boot consoles, real consoles, etc - this is to ensure that end |
|
* users know there might be something in the kernel's log buffer that |
|
* went to the bootconsole (that they do not see on the real console) |
|
*/ |
|
pr_info("%sconsole [%s%d] enabled\n", |
|
(newcon->flags & CON_BOOT) ? "boot" : "" , |
|
newcon->name, newcon->index); |
|
if (bcon && |
|
((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV) && |
|
!keep_bootcon) { |
|
/* We need to iterate through all boot consoles, to make |
|
* sure we print everything out, before we unregister them. |
|
*/ |
|
for_each_console(bcon) |
|
if (bcon->flags & CON_BOOT) |
|
unregister_console(bcon); |
|
} |
|
} |
|
EXPORT_SYMBOL(register_console); |
|
|
|
int unregister_console(struct console *console) |
|
{ |
|
struct console *a, *b; |
|
int res; |
|
|
|
pr_info("%sconsole [%s%d] disabled\n", |
|
(console->flags & CON_BOOT) ? "boot" : "" , |
|
console->name, console->index); |
|
|
|
res = _braille_unregister_console(console); |
|
if (res) |
|
return res; |
|
|
|
res = 1; |
|
console_lock(); |
|
if (console_drivers == console) { |
|
console_drivers=console->next; |
|
res = 0; |
|
} else if (console_drivers) { |
|
for (a=console_drivers->next, b=console_drivers ; |
|
a; b=a, a=b->next) { |
|
if (a == console) { |
|
b->next = a->next; |
|
res = 0; |
|
break; |
|
} |
|
} |
|
} |
|
|
|
if (!res && (console->flags & CON_EXTENDED)) |
|
nr_ext_console_drivers--; |
|
|
|
/* |
|
* If this isn't the last console and it has CON_CONSDEV set, we |
|
* need to set it on the next preferred console. |
|
*/ |
|
if (console_drivers != NULL && console->flags & CON_CONSDEV) |
|
console_drivers->flags |= CON_CONSDEV; |
|
|
|
console->flags &= ~CON_ENABLED; |
|
console_unlock(); |
|
console_sysfs_notify(); |
|
return res; |
|
} |
|
EXPORT_SYMBOL(unregister_console); |
|
|
|
/* |
|
* Initialize the console device. This is called *early*, so |
|
* we can't necessarily depend on lots of kernel help here. |
|
* Just do some early initializations, and do the complex setup |
|
* later. |
|
*/ |
|
void __init console_init(void) |
|
{ |
|
initcall_t *call; |
|
|
|
/* Setup the default TTY line discipline. */ |
|
n_tty_init(); |
|
|
|
/* |
|
* set up the console device so that later boot sequences can |
|
* inform about problems etc.. |
|
*/ |
|
call = __con_initcall_start; |
|
while (call < __con_initcall_end) { |
|
(*call)(); |
|
call++; |
|
} |
|
} |
|
|
|
/* |
|
* Some boot consoles access data that is in the init section and which will |
|
* be discarded after the initcalls have been run. To make sure that no code |
|
* will access this data, unregister the boot consoles in a late initcall. |
|
* |
|
* If for some reason, such as deferred probe or the driver being a loadable |
|
* module, the real console hasn't registered yet at this point, there will |
|
* be a brief interval in which no messages are logged to the console, which |
|
* makes it difficult to diagnose problems that occur during this time. |
|
* |
|
* To mitigate this problem somewhat, only unregister consoles whose memory |
|
* intersects with the init section. Note that all other boot consoles will |
|
* get unregistred when the real preferred console is registered. |
|
*/ |
|
static int __init printk_late_init(void) |
|
{ |
|
struct console *con; |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
struct proc_dir_entry *entry; |
|
#endif |
|
int ret; |
|
|
|
for_each_console(con) { |
|
if (!(con->flags & CON_BOOT)) |
|
continue; |
|
|
|
/* Check addresses that might be used for enabled consoles. */ |
|
if (init_section_intersects(con, sizeof(*con)) || |
|
init_section_contains(con->write, 0) || |
|
init_section_contains(con->read, 0) || |
|
init_section_contains(con->device, 0) || |
|
init_section_contains(con->unblank, 0) || |
|
init_section_contains(con->data, 0)) { |
|
/* |
|
* Please, consider moving the reported consoles out |
|
* of the init section. |
|
*/ |
|
pr_warn("bootconsole [%s%d] uses init memory and must be disabled even before the real one is ready\n", |
|
con->name, con->index); |
|
unregister_console(con); |
|
} |
|
} |
|
ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL, |
|
console_cpu_notify); |
|
WARN_ON(ret < 0); |
|
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online", |
|
console_cpu_notify, NULL); |
|
WARN_ON(ret < 0); |
|
#if defined(CONFIG_MTK_ENG_BUILD) && defined(CONFIG_LOG_TOO_MUCH_WARNING) |
|
entry = proc_create("log_much", 0444, NULL, &log_much_ops); |
|
if (!entry) { |
|
pr_notice("printk: failed to create proc log much entry\n"); |
|
return 1; |
|
} |
|
log_much = kmalloc(log_buf_len + LOG_MUCH_PLUS_LEN, GFP_KERNEL); |
|
#endif |
|
return 0; |
|
} |
|
late_initcall(printk_late_init); |
|
|
|
#if defined CONFIG_PRINTK |
|
/* |
|
* Delayed printk version, for scheduler-internal messages: |
|
*/ |
|
#define PRINTK_PENDING_WAKEUP 0x01 |
|
#define PRINTK_PENDING_OUTPUT 0x02 |
|
|
|
static DEFINE_PER_CPU(int, printk_pending); |
|
|
|
static void wake_up_klogd_work_func(struct irq_work *irq_work) |
|
{ |
|
int pending = __this_cpu_xchg(printk_pending, 0); |
|
|
|
if (pending & PRINTK_PENDING_OUTPUT) { |
|
/* If trylock fails, someone else is doing the printing */ |
|
if (console_trylock()) |
|
console_unlock(); |
|
} |
|
|
|
if (pending & PRINTK_PENDING_WAKEUP) |
|
wake_up_interruptible(&log_wait); |
|
} |
|
|
|
static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = { |
|
.func = wake_up_klogd_work_func, |
|
.flags = IRQ_WORK_LAZY, |
|
}; |
|
|
|
void wake_up_klogd(void) |
|
{ |
|
preempt_disable(); |
|
if (waitqueue_active(&log_wait)) { |
|
this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP); |
|
irq_work_queue(this_cpu_ptr(&wake_up_klogd_work)); |
|
} |
|
preempt_enable(); |
|
} |
|
|
|
void defer_console_output(void) |
|
{ |
|
preempt_disable(); |
|
__this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT); |
|
irq_work_queue(this_cpu_ptr(&wake_up_klogd_work)); |
|
preempt_enable(); |
|
} |
|
|
|
int vprintk_deferred(const char *fmt, va_list args) |
|
{ |
|
int r; |
|
|
|
r = vprintk_emit(0, LOGLEVEL_SCHED, NULL, 0, fmt, args); |
|
defer_console_output(); |
|
|
|
return r; |
|
} |
|
|
|
int printk_deferred(const char *fmt, ...) |
|
{ |
|
va_list args; |
|
int r; |
|
|
|
va_start(args, fmt); |
|
r = vprintk_deferred(fmt, args); |
|
va_end(args); |
|
|
|
return r; |
|
} |
|
|
|
/* |
|
* printk rate limiting, lifted from the networking subsystem. |
|
* |
|
* This enforces a rate limit: not more than 10 kernel messages |
|
* every 5s to make a denial-of-service attack impossible. |
|
*/ |
|
DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10); |
|
|
|
int __printk_ratelimit(const char *func) |
|
{ |
|
return ___ratelimit(&printk_ratelimit_state, func); |
|
} |
|
EXPORT_SYMBOL(__printk_ratelimit); |
|
|
|
/** |
|
* printk_timed_ratelimit - caller-controlled printk ratelimiting |
|
* @caller_jiffies: pointer to caller's state |
|
* @interval_msecs: minimum interval between prints |
|
* |
|
* printk_timed_ratelimit() returns true if more than @interval_msecs |
|
* milliseconds have elapsed since the last time printk_timed_ratelimit() |
|
* returned true. |
|
*/ |
|
bool printk_timed_ratelimit(unsigned long *caller_jiffies, |
|
unsigned int interval_msecs) |
|
{ |
|
unsigned long elapsed = jiffies - *caller_jiffies; |
|
|
|
if (*caller_jiffies && elapsed <= msecs_to_jiffies(interval_msecs)) |
|
return false; |
|
|
|
*caller_jiffies = jiffies; |
|
return true; |
|
} |
|
EXPORT_SYMBOL(printk_timed_ratelimit); |
|
|
|
static DEFINE_SPINLOCK(dump_list_lock); |
|
static LIST_HEAD(dump_list); |
|
|
|
/** |
|
* kmsg_dump_register - register a kernel log dumper. |
|
* @dumper: pointer to the kmsg_dumper structure |
|
* |
|
* Adds a kernel log dumper to the system. The dump callback in the |
|
* structure will be called when the kernel oopses or panics and must be |
|
* set. Returns zero on success and %-EINVAL or %-EBUSY otherwise. |
|
*/ |
|
int kmsg_dump_register(struct kmsg_dumper *dumper) |
|
{ |
|
unsigned long flags; |
|
int err = -EBUSY; |
|
|
|
/* The dump callback needs to be set */ |
|
if (!dumper->dump) |
|
return -EINVAL; |
|
|
|
spin_lock_irqsave(&dump_list_lock, flags); |
|
/* Don't allow registering multiple times */ |
|
if (!dumper->registered) { |
|
dumper->registered = 1; |
|
list_add_tail_rcu(&dumper->list, &dump_list); |
|
err = 0; |
|
} |
|
spin_unlock_irqrestore(&dump_list_lock, flags); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(kmsg_dump_register); |
|
|
|
/** |
|
* kmsg_dump_unregister - unregister a kmsg dumper. |
|
* @dumper: pointer to the kmsg_dumper structure |
|
* |
|
* Removes a dump device from the system. Returns zero on success and |
|
* %-EINVAL otherwise. |
|
*/ |
|
int kmsg_dump_unregister(struct kmsg_dumper *dumper) |
|
{ |
|
unsigned long flags; |
|
int err = -EINVAL; |
|
|
|
spin_lock_irqsave(&dump_list_lock, flags); |
|
if (dumper->registered) { |
|
dumper->registered = 0; |
|
list_del_rcu(&dumper->list); |
|
err = 0; |
|
} |
|
spin_unlock_irqrestore(&dump_list_lock, flags); |
|
synchronize_rcu(); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(kmsg_dump_unregister); |
|
|
|
static bool always_kmsg_dump; |
|
module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR); |
|
|
|
/** |
|
* kmsg_dump - dump kernel log to kernel message dumpers. |
|
* @reason: the reason (oops, panic etc) for dumping |
|
* |
|
* Call each of the registered dumper's dump() callback, which can |
|
* retrieve the kmsg records with kmsg_dump_get_line() or |
|
* kmsg_dump_get_buffer(). |
|
*/ |
|
void kmsg_dump(enum kmsg_dump_reason reason) |
|
{ |
|
struct kmsg_dumper *dumper; |
|
unsigned long flags; |
|
|
|
if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump) |
|
return; |
|
|
|
rcu_read_lock(); |
|
list_for_each_entry_rcu(dumper, &dump_list, list) { |
|
if (dumper->max_reason && reason > dumper->max_reason) |
|
continue; |
|
|
|
/* initialize iterator with data about the stored records */ |
|
dumper->active = true; |
|
|
|
logbuf_lock_irqsave(flags); |
|
dumper->cur_seq = clear_seq; |
|
dumper->cur_idx = clear_idx; |
|
dumper->next_seq = log_next_seq; |
|
dumper->next_idx = log_next_idx; |
|
logbuf_unlock_irqrestore(flags); |
|
|
|
/* invoke dumper which will iterate over records */ |
|
dumper->dump(dumper, reason); |
|
|
|
/* reset iterator */ |
|
dumper->active = false; |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
/** |
|
* kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version) |
|
* @dumper: registered kmsg dumper |
|
* @syslog: include the "<4>" prefixes |
|
* @line: buffer to copy the line to |
|
* @size: maximum size of the buffer |
|
* @len: length of line placed into buffer |
|
* |
|
* Start at the beginning of the kmsg buffer, with the oldest kmsg |
|
* record, and copy one record into the provided buffer. |
|
* |
|
* Consecutive calls will return the next available record moving |
|
* towards the end of the buffer with the youngest messages. |
|
* |
|
* A return value of FALSE indicates that there are no more records to |
|
* read. |
|
* |
|
* The function is similar to kmsg_dump_get_line(), but grabs no locks. |
|
*/ |
|
bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog, |
|
char *line, size_t size, size_t *len) |
|
{ |
|
struct printk_log *msg; |
|
size_t l = 0; |
|
bool ret = false; |
|
|
|
if (!dumper->active) |
|
goto out; |
|
|
|
if (dumper->cur_seq < log_first_seq) { |
|
/* messages are gone, move to first available one */ |
|
dumper->cur_seq = log_first_seq; |
|
dumper->cur_idx = log_first_idx; |
|
} |
|
|
|
/* last entry */ |
|
if (dumper->cur_seq >= log_next_seq) |
|
goto out; |
|
|
|
msg = log_from_idx(dumper->cur_idx); |
|
l = msg_print_text(msg, syslog, line, size); |
|
|
|
dumper->cur_idx = log_next(dumper->cur_idx); |
|
dumper->cur_seq++; |
|
ret = true; |
|
out: |
|
if (len) |
|
*len = l; |
|
return ret; |
|
} |
|
|
|
/** |
|
* kmsg_dump_get_line - retrieve one kmsg log line |
|
* @dumper: registered kmsg dumper |
|
* @syslog: include the "<4>" prefixes |
|
* @line: buffer to copy the line to |
|
* @size: maximum size of the buffer |
|
* @len: length of line placed into buffer |
|
* |
|
* Start at the beginning of the kmsg buffer, with the oldest kmsg |
|
* record, and copy one record into the provided buffer. |
|
* |
|
* Consecutive calls will return the next available record moving |
|
* towards the end of the buffer with the youngest messages. |
|
* |
|
* A return value of FALSE indicates that there are no more records to |
|
* read. |
|
*/ |
|
bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog, |
|
char *line, size_t size, size_t *len) |
|
{ |
|
unsigned long flags; |
|
bool ret; |
|
|
|
logbuf_lock_irqsave(flags); |
|
ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len); |
|
logbuf_unlock_irqrestore(flags); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(kmsg_dump_get_line); |
|
|
|
/** |
|
* kmsg_dump_get_buffer - copy kmsg log lines |
|
* @dumper: registered kmsg dumper |
|
* @syslog: include the "<4>" prefixes |
|
* @buf: buffer to copy the line to |
|
* @size: maximum size of the buffer |
|
* @len: length of line placed into buffer |
|
* |
|
* Start at the end of the kmsg buffer and fill the provided buffer |
|
* with as many of the the *youngest* kmsg records that fit into it. |
|
* If the buffer is large enough, all available kmsg records will be |
|
* copied with a single call. |
|
* |
|
* Consecutive calls will fill the buffer with the next block of |
|
* available older records, not including the earlier retrieved ones. |
|
* |
|
* A return value of FALSE indicates that there are no more records to |
|
* read. |
|
*/ |
|
bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog, |
|
char *buf, size_t size, size_t *len) |
|
{ |
|
unsigned long flags; |
|
u64 seq; |
|
u32 idx; |
|
u64 next_seq; |
|
u32 next_idx; |
|
size_t l = 0; |
|
bool ret = false; |
|
|
|
if (!dumper->active) |
|
goto out; |
|
|
|
logbuf_lock_irqsave(flags); |
|
if (dumper->cur_seq < log_first_seq) { |
|
/* messages are gone, move to first available one */ |
|
dumper->cur_seq = log_first_seq; |
|
dumper->cur_idx = log_first_idx; |
|
} |
|
|
|
/* last entry */ |
|
if (dumper->cur_seq >= dumper->next_seq) { |
|
logbuf_unlock_irqrestore(flags); |
|
goto out; |
|
} |
|
|
|
/* calculate length of entire buffer */ |
|
seq = dumper->cur_seq; |
|
idx = dumper->cur_idx; |
|
while (seq < dumper->next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
|
|
l += msg_print_text(msg, true, NULL, 0); |
|
idx = log_next(idx); |
|
seq++; |
|
} |
|
|
|
/* move first record forward until length fits into the buffer */ |
|
seq = dumper->cur_seq; |
|
idx = dumper->cur_idx; |
|
while (l > size && seq < dumper->next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
|
|
l -= msg_print_text(msg, true, NULL, 0); |
|
idx = log_next(idx); |
|
seq++; |
|
} |
|
|
|
/* last message in next interation */ |
|
next_seq = seq; |
|
next_idx = idx; |
|
|
|
l = 0; |
|
while (seq < dumper->next_seq) { |
|
struct printk_log *msg = log_from_idx(idx); |
|
|
|
l += msg_print_text(msg, syslog, buf + l, size - l); |
|
idx = log_next(idx); |
|
seq++; |
|
} |
|
|
|
dumper->next_seq = next_seq; |
|
dumper->next_idx = next_idx; |
|
ret = true; |
|
logbuf_unlock_irqrestore(flags); |
|
out: |
|
if (len) |
|
*len = l; |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer); |
|
|
|
/** |
|
* kmsg_dump_rewind_nolock - reset the interator (unlocked version) |
|
* @dumper: registered kmsg dumper |
|
* |
|
* Reset the dumper's iterator so that kmsg_dump_get_line() and |
|
* kmsg_dump_get_buffer() can be called again and used multiple |
|
* times within the same dumper.dump() callback. |
|
* |
|
* The function is similar to kmsg_dump_rewind(), but grabs no locks. |
|
*/ |
|
void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper) |
|
{ |
|
dumper->cur_seq = clear_seq; |
|
dumper->cur_idx = clear_idx; |
|
dumper->next_seq = log_next_seq; |
|
dumper->next_idx = log_next_idx; |
|
} |
|
|
|
/** |
|
* kmsg_dump_rewind - reset the interator |
|
* @dumper: registered kmsg dumper |
|
* |
|
* Reset the dumper's iterator so that kmsg_dump_get_line() and |
|
* kmsg_dump_get_buffer() can be called again and used multiple |
|
* times within the same dumper.dump() callback. |
|
*/ |
|
void kmsg_dump_rewind(struct kmsg_dumper *dumper) |
|
{ |
|
unsigned long flags; |
|
|
|
logbuf_lock_irqsave(flags); |
|
kmsg_dump_rewind_nolock(dumper); |
|
logbuf_unlock_irqrestore(flags); |
|
} |
|
EXPORT_SYMBOL_GPL(kmsg_dump_rewind); |
|
|
|
static char dump_stack_arch_desc_str[128]; |
|
|
|
/** |
|
* dump_stack_set_arch_desc - set arch-specific str to show with task dumps |
|
* @fmt: printf-style format string |
|
* @...: arguments for the format string |
|
* |
|
* The configured string will be printed right after utsname during task |
|
* dumps. Usually used to add arch-specific system identifiers. If an |
|
* arch wants to make use of such an ID string, it should initialize this |
|
* as soon as possible during boot. |
|
*/ |
|
void __init dump_stack_set_arch_desc(const char *fmt, ...) |
|
{ |
|
va_list args; |
|
|
|
va_start(args, fmt); |
|
vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str), |
|
fmt, args); |
|
va_end(args); |
|
} |
|
|
|
/** |
|
* dump_stack_print_info - print generic debug info for dump_stack() |
|
* @log_lvl: log level |
|
* |
|
* Arch-specific dump_stack() implementations can use this function to |
|
* print out the same debug information as the generic dump_stack(). |
|
*/ |
|
void dump_stack_print_info(const char *log_lvl) |
|
{ |
|
printk("%sCPU: %d PID: %d Comm: %.20s %s %s %.*s\n", |
|
log_lvl, raw_smp_processor_id(), current->pid, current->comm, |
|
print_tainted(), init_utsname()->release, |
|
(int)strcspn(init_utsname()->version, " "), |
|
init_utsname()->version); |
|
|
|
if (dump_stack_arch_desc_str[0] != '\0') |
|
printk("%sHardware name: %s\n", |
|
log_lvl, dump_stack_arch_desc_str); |
|
|
|
print_worker_info(log_lvl, current); |
|
} |
|
|
|
/** |
|
* show_regs_print_info - print generic debug info for show_regs() |
|
* @log_lvl: log level |
|
* |
|
* show_regs() implementations can use this function to print out generic |
|
* debug information. |
|
*/ |
|
void show_regs_print_info(const char *log_lvl) |
|
{ |
|
dump_stack_print_info(log_lvl); |
|
|
|
printk("%stask: %p task.stack: %p\n", |
|
log_lvl, current, task_stack_page(current)); |
|
} |
|
|
|
void get_kernel_log_buffer(unsigned long *addr, |
|
unsigned long *size, unsigned long *start) |
|
{ |
|
*addr = (unsigned long)log_buf; |
|
*size = log_buf_len; |
|
*start = (unsigned long)&log_first_idx; |
|
} |
|
#endif
|
|
|