kernel/sysctl: add panic_print into sysctl

So that we can also runtime chose to print out the needed system info
for panic, other than setting the kernel cmdline.

Link: http://lkml.kernel.org/r/1543398842-19295-3-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Feng Tang 2019-01-03 15:28:20 -08:00 committed by Linus Torvalds
parent d999bd9392
commit 81c9d43f94
6 changed files with 28 additions and 1 deletions

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@ -60,6 +60,7 @@ show up in /proc/sys/kernel:
- panic_on_stackoverflow
- panic_on_unrecovered_nmi
- panic_on_warn
- panic_print
- panic_on_rcu_stall
- perf_cpu_time_max_percent
- perf_event_paranoid
@ -654,6 +655,22 @@ a kernel rebuild when attempting to kdump at the location of a WARN().
==============================================================
panic_print:
Bitmask for printing system info when panic happens. User can chose
combination of the following bits:
bit 0: print all tasks info
bit 1: print system memory info
bit 2: print timer info
bit 3: print locks info if CONFIG_LOCKDEP is on
bit 4: print ftrace buffer
So for example to print tasks and memory info on panic, user can:
echo 3 > /proc/sys/kernel/panic_print
==============================================================
panic_on_rcu_stall:
When set to 1, calls panic() after RCU stall detection messages. This

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@ -527,6 +527,7 @@ static inline u32 int_sqrt64(u64 x)
extern void bust_spinlocks(int yes);
extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
extern int panic_timeout;
extern unsigned long panic_print;
extern int panic_on_oops;
extern int panic_on_unrecovered_nmi;
extern int panic_on_io_nmi;

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@ -153,6 +153,7 @@ enum
KERN_NMI_WATCHDOG=75, /* int: enable/disable nmi watchdog */
KERN_PANIC_ON_NMI=76, /* int: whether we will panic on an unrecovered */
KERN_PANIC_ON_WARN=77, /* int: call panic() in WARN() functions */
KERN_PANIC_PRINT=78, /* ulong: bitmask to print system info on panic */
};

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@ -51,7 +51,7 @@ EXPORT_SYMBOL_GPL(panic_timeout);
#define PANIC_PRINT_TIMER_INFO 0x00000004
#define PANIC_PRINT_LOCK_INFO 0x00000008
#define PANIC_PRINT_FTRACE_INFO 0x00000010
static unsigned long panic_print;
unsigned long panic_print;
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);

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@ -807,6 +807,13 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "panic_print",
.data = &panic_print,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
#if defined CONFIG_PRINTK
{
.procname = "printk",

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@ -140,6 +140,7 @@ static const struct bin_table bin_kern_table[] = {
{ CTL_INT, KERN_MAX_LOCK_DEPTH, "max_lock_depth" },
{ CTL_INT, KERN_PANIC_ON_NMI, "panic_on_unrecovered_nmi" },
{ CTL_INT, KERN_PANIC_ON_WARN, "panic_on_warn" },
{ CTL_ULONG, KERN_PANIC_PRINT, "panic_print" },
{}
};