From 69361eef9056b0babb507798c2135ad1572f0ef7 Mon Sep 17 00:00:00 2001 From: Josh Hunt Date: Fri, 8 Aug 2014 14:22:31 -0700 Subject: panic: add TAINT_SOFTLOCKUP This taint flag will be set if the system has ever entered a softlockup state. Similar to TAINT_WARN it is useful to know whether or not the system has been in a softlockup state when debugging. [akpm@linux-foundation.org: apply the taint before calling panic()] Signed-off-by: Josh Hunt Cc: Jason Baron Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/oops-tracing.txt | 2 ++ Documentation/sysctl/kernel.txt | 1 + include/linux/kernel.h | 1 + kernel/panic.c | 1 + kernel/watchdog.c | 1 + 5 files changed, 6 insertions(+) diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt index e3155995ddd8..beefb9f82902 100644 --- a/Documentation/oops-tracing.txt +++ b/Documentation/oops-tracing.txt @@ -268,6 +268,8 @@ characters, each representing a particular tainted value. 14: 'E' if an unsigned module has been loaded in a kernel supporting module signature. + 15: 'L' if a soft lockup has previously occurred on the system. + The primary reason for the 'Tainted: ' string is to tell kernel debuggers if this is a clean kernel or if anything unusual has occurred. Tainting is permanent: even if an offending module is diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index c14374e71775..f79eb9666379 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -826,6 +826,7 @@ can be ORed together: 4096 - An out-of-tree module has been loaded. 8192 - An unsigned module has been loaded in a kernel supporting module signature. +16384 - A soft lockup has previously occurred on the system. ============================================================== diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3dc22abbc68a..31ae66f34235 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -470,6 +470,7 @@ extern enum system_states { #define TAINT_FIRMWARE_WORKAROUND 11 #define TAINT_OOT_MODULE 12 #define TAINT_UNSIGNED_MODULE 13 +#define TAINT_SOFTLOCKUP 14 extern const char hex_asc[]; #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] diff --git a/kernel/panic.c b/kernel/panic.c index 62e16cef9cc2..d09dc5c32c67 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -224,6 +224,7 @@ static const struct tnt tnts[] = { { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' }, { TAINT_OOT_MODULE, 'O', ' ' }, { TAINT_UNSIGNED_MODULE, 'E', ' ' }, + { TAINT_SOFTLOCKUP, 'L', ' ' }, }; /** diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 51b29e9d2ba6..a8d6914030fe 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -368,6 +368,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) smp_mb__after_atomic(); } + add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK); if (softlockup_panic) panic("softlockup: hung tasks"); __this_cpu_write(soft_watchdog_warn, true); -- cgit