diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2023-01-26 16:08:31 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-01-31 15:01:45 +0100 |
| commit | 5a5d7e9badd2cb8065db171961bd30bd3595e4b6 (patch) | |
| tree | 988449d46c78147323f4c97631166a2d3416671f /kernel | |
| parent | 393e2ea30aec634b37004d401863428e120d5e1b (diff) | |
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')
| -rw-r--r-- | kernel/locking/lockdep.c | 3 | ||||
| -rw-r--r-- | kernel/panic.c | 5 |
2 files changed, 8 insertions, 0 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e3375bc40dad..50d4863974e7 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -55,6 +55,7 @@ #include <linux/rcupdate.h> #include <linux/kprobes.h> #include <linux/lockdep.h> +#include <linux/context_tracking.h> #include <asm/sections.h> @@ -6555,6 +6556,7 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) { struct task_struct *curr = current; int dl = READ_ONCE(debug_locks); + bool rcu = warn_rcu_enter(); /* Note: the following can be executed concurrently, so be careful. */ pr_warn("\n"); @@ -6595,5 +6597,6 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) lockdep_print_held_locks(curr); pr_warn("\nstack backtrace:\n"); dump_stack(); + warn_rcu_exit(rcu); } EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious); 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 |