[PATCH 4.14 v2 11/15] panic: Consolidate open-coded panic_on_warn checks

Eric Biggers
2023-02-03T00:36:27Z

From: Kees Cook <keescook@chromium.org>

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

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 22b9146655958..a4ac278d02d0a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -293,6 +293,7 @@ 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);
void print_oops_end_marker(void);
diff --git a/kernel/panic.c b/kernel/panic.c
index bd7c3ea3bf1e6..8e3460e985904 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -122,6 +122,12 @@ void nmi_panic(struct pt_regs *regs, const char *msg)
}
EXPORT_SYMBOL(nmi_panic);

+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
@@ -546,8 +552,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
if (args)
vprintk(args->fmt, args->args);

- if (panic_on_warn)
- panic("panic_on_warn set ...\n");
+ check_panic_on_warn("kernel");

print_modules();

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 544a1cb66d90d..5dc66377864a9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3185,8 +3185,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
print_ip_sym(preempt_disable_ip);
pr_cont("\n");
}
- 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/mm/kasan/report.c b/mm/kasan/report.c
index 6bcfb01ba0386..1c96c83f97751 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -172,8 +172,7 @@ static void kasan_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)
- panic("panic_on_warn set ...\n");
+ check_panic_on_warn("KASAN");
kasan_enable_current();
}

--
2.39.1