[PATCH 5.10 16/20] panic: Consolidate open-coded panic_on_warn checks

[Eric Biggers]

From: Kees Cook <keescook@xxxxxxxxxxxx>

commit 79cc1ba7badf9e7a12af99695a557e9ce27ee967 upstream.

Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.

Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: David Gow <davidgow@xxxxxxxxxx>
Cc: tangmeng <tangmeng@xxxxxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxx>
Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Cc: kasan-dev@xxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@xxxxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
 include/linux/kernel.h | 1 +
 kernel/kcsan/report.c  | 4 ++--
 kernel/panic.c         | 9 +++++++--
 kernel/sched/core.c    | 3 +--
 lib/ubsan.c            | 3 +--
 mm/kasan/report.c      | 4 ++--
 6 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 084d97070ed99..394f10fc29aad 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -320,6 +320,7 @@ extern long (*panic_blink)(int state);
 __printf(1, 2)
 void panic(const char *fmt, ...) __noreturn __cold;
 void nmi_panic(struct pt_regs *regs, const char *msg);
+void check_panic_on_warn(const char *origin);
 extern void oops_enter(void);
 extern void oops_exit(void);
 extern bool oops_may_print(void);
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index d3bf87e6007ca..069830f5a5d24 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -630,8 +630,8 @@ void kcsan_report(const volatile void *ptr, size_t size, int access_type,
 		bool reported = value_change != KCSAN_VALUE_CHANGE_FALSE &&
 				print_report(value_change, type, &ai, other_info);
 
-		if (reported && panic_on_warn)
-			panic("panic_on_warn set ...\n");
+		if (reported)
+			check_panic_on_warn("KCSAN");
 
 		release_report(&flags, other_info);
 	}
diff --git a/kernel/panic.c b/kernel/panic.c
index 09f0802212c38..0da47888f72e8 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -192,6 +192,12 @@ static void panic_print_sys_info(void)
 		ftrace_dump(DUMP_ALL);
 }
 
+void check_panic_on_warn(const char *origin)
+{
+	if (panic_on_warn)
+		panic("%s: panic_on_warn set ...\n", origin);
+}
+
 /**
  *	panic - halt the system
  *	@fmt: The text string to print
@@ -630,8 +636,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 	if (regs)
 		show_regs(regs);
 
-	if (panic_on_warn)
-		panic("panic_on_warn set ...\n");
+	check_panic_on_warn("kernel");
 
 	if (!regs)
 		dump_stack();
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a875bc59804eb..1303a2607f1f8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4280,8 +4280,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 		pr_err("Preemption disabled at:");
 		print_ip_sym(KERN_ERR, preempt_disable_ip);
 	}
-	if (panic_on_warn)
-		panic("scheduling while atomic\n");
+	check_panic_on_warn("scheduling while atomic");
 
 	dump_stack();
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
diff --git a/lib/ubsan.c b/lib/ubsan.c
index d81d107f64f41..ee14c46cac897 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -151,8 +151,7 @@ static void ubsan_epilogue(void)
 
 	current->in_ubsan--;
 
-	if (panic_on_warn)
-		panic("panic_on_warn set ...\n");
+	check_panic_on_warn("UBSAN");
 }
 
 static void handle_overflow(struct overflow_data *data, void *lhs,
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 91714acea0d61..2f5e96ac4d008 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -95,8 +95,8 @@ static void end_report(unsigned long *flags)
 	pr_err("==================================================================\n");
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
 	spin_unlock_irqrestore(&report_lock, *flags);
-	if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
-		panic("panic_on_warn set ...\n");
+	if (!test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
+		check_panic_on_warn("KASAN");
 	kasan_enable_current();
 }
 
-- 
2.39.1