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authorPeter Zijlstra <peterz@infradead.org>2023-01-26 18:08:31 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-10 11:33:47 +0300
commitb78434f6eee0e6d7da3e301cfc33184a98edb08b (patch)
tree00bdefbcb51a7c2086bc70676a1c403e995d0ea4 /lib
parent463ef209628e682b65b86e1b86945f0018cb358a (diff)
downloadlinux-b78434f6eee0e6d7da3e301cfc33184a98edb08b.tar.xz
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
[ Upstream commit 5a5d7e9badd2cb8065db171961bd30bd3595e4b6 ] 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 Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/bug.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/lib/bug.c b/lib/bug.c
index c223a2575b72..e0ff21989990 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -47,6 +47,7 @@
#include <linux/sched.h>
#include <linux/rculist.h>
#include <linux/ftrace.h>
+#include <linux/context_tracking.h>
extern struct bug_entry __start___bug_table[], __stop___bug_table[];
@@ -153,7 +154,7 @@ struct bug_entry *find_bug(unsigned long bugaddr)
return module_find_bug(bugaddr);
}
-enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
+static enum bug_trap_type __report_bug(unsigned long bugaddr, struct pt_regs *regs)
{
struct bug_entry *bug;
const char *file;
@@ -209,6 +210,18 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
return BUG_TRAP_TYPE_BUG;
}
+enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
+{
+ enum bug_trap_type ret;
+ bool rcu = false;
+
+ rcu = warn_rcu_enter();
+ ret = __report_bug(bugaddr, regs);
+ warn_rcu_exit(rcu);
+
+ return ret;
+}
+
static void clear_once_table(struct bug_entry *start, struct bug_entry *end)
{
struct bug_entry *bug;