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authorPeter Zijlstra <peterz@infradead.org>2023-01-26 16:08:31 +0100
committerIngo Molnar <mingo@kernel.org>2023-01-31 15:01:45 +0100
commit5a5d7e9badd2cb8065db171961bd30bd3595e4b6 (patch)
tree988449d46c78147323f4c97631166a2d3416671f /kernel/panic.c
parentcpuidle: drivers: firmware: psci: Dont instrument suspend code (diff)
downloadlinux-5a5d7e9badd2cb8065db171961bd30bd3595e4b6.tar.xz
linux-5a5d7e9badd2cb8065db171961bd30bd3595e4b6.zip
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
In order to avoid WARN/BUG from generating nested or even recursive warnings, force rcu_is_watching() true during WARN/lockdep_rcu_suspicious(). Notably things like unwinding the stack can trigger rcu_dereference() warnings, which then triggers more unwinding which then triggers more warnings etc.. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230126151323.408156109@infradead.org
Diffstat (limited to 'kernel/panic.c')
-rw-r--r--kernel/panic.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/panic.c b/kernel/panic.c
index 463c9295bc28..487f5b03bf83 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -34,6 +34,7 @@
#include <linux/ratelimit.h>
#include <linux/debugfs.h>
#include <linux/sysfs.h>
+#include <linux/context_tracking.h>
#include <trace/events/error_report.h>
#include <asm/sections.h>
@@ -679,6 +680,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
void warn_slowpath_fmt(const char *file, int line, unsigned taint,
const char *fmt, ...)
{
+ bool rcu = warn_rcu_enter();
struct warn_args args;
pr_warn(CUT_HERE);
@@ -693,11 +695,13 @@ void warn_slowpath_fmt(const char *file, int line, unsigned taint,
va_start(args.args, fmt);
__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
va_end(args.args);
+ warn_rcu_exit(rcu);
}
EXPORT_SYMBOL(warn_slowpath_fmt);
#else
void __warn_printk(const char *fmt, ...)
{
+ bool rcu = warn_rcu_enter();
va_list args;
pr_warn(CUT_HERE);
@@ -705,6 +709,7 @@ void __warn_printk(const char *fmt, ...)
va_start(args, fmt);
vprintk(fmt, args);
va_end(args);
+ warn_rcu_exit(rcu);
}
EXPORT_SYMBOL(__warn_printk);
#endif