[PATCH v8 03/22] panic: Add vpanic()

Nam Cao
2025-05-12T10:51:16Z

vpanic() is useful for implementing runtime verification reactors. Add it.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
---
include/linux/panic.h | 3 +++
kernel/panic.c | 18 +++++++++++++-----
2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/include/linux/panic.h b/include/linux/panic.h
index 2494d51707ef..bcca63a02aef 100644
--- a/include/linux/panic.h
+++ b/include/linux/panic.h
@@ -3,6 +3,7 @@
#define _LINUX_PANIC_H

#include <linux/compiler_attributes.h>
+#include <linux/stdarg.h>
#include <linux/types.h>

struct pt_regs;
@@ -10,6 +11,8 @@ struct pt_regs;
extern long (*panic_blink)(int state);
__printf(1, 2)
void panic(const char *fmt, ...) __noreturn __cold;
+__printf(1, 0)
+void vpanic(const char *fmt, va_list args) __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);
diff --git a/kernel/panic.c b/kernel/panic.c
index a3889f38153d..278eae74bf17 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -277,17 +277,17 @@ static void panic_other_cpus_shutdown(bool crash_kexec)
}

/**
- * panic - halt the system
+ * vpanic - halt the system
* @fmt: The text string to print
+ * @args: Arguments for the format string
*
* Display a message, then perform cleanups.
*
* This function never returns.
*/
-void panic(const char *fmt, ...)
+void vpanic(const char *fmt, va_list args)
{
static char buf[1024];
- va_list args;
long i, i_next = 0, len;
int state = 0;
int old_cpu, this_cpu;
@@ -338,9 +338,7 @@ void panic(const char *fmt, ...)

console_verbose();
bust_spinlocks(1);
- va_start(args, fmt);
len = vscnprintf(buf, sizeof(buf), fmt, args);
- va_end(args);

if (len && buf[len - 1] == '\n')
buf[len - 1] = '\0';
@@ -477,7 +475,17 @@ void panic(const char *fmt, ...)
mdelay(PANIC_TIMER_STEP);
}
}
+EXPORT_SYMBOL(vpanic);

+/* Identical to vpanic(), except it takes variadic arguments instead of va_list */
+void panic(const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ vpanic(fmt, args);
+ va_end(args);
+}
EXPORT_SYMBOL(panic);

#define TAINT_FLAG(taint, _c_true, _c_false, _module) \
--
2.39.5