[PATCH 6.18 153/227] panic: only warn about deprecated panic_print on write access

Greg Kroah-Hartman
2026-01-28T15:58:41Z

From: Gal Pressman <gal@nvidia.com>

commit 90f3c123247e9564f2ecf861946ec41ceaf5e198 upstream.

The panic_print_deprecated() warning is being triggered on both read and
write operations to the panic_print parameter.

This causes spurious warnings when users run 'sysctl -a' to list all
sysctl values, since that command reads /proc/sys/kernel/panic_print and
triggers the deprecation notice.

Modify the handlers to only emit the deprecation warning when the
parameter is actually being set:

- sysctl_panic_print_handler(): check 'write' flag before warning.
- panic_print_get(): remove the deprecation call entirely.

This way, users are only warned when they actively try to use the
deprecated parameter, not when passively querying system state.

Link: https://lkml.kernel.org/r/20260106163321.83586-1-gal@nvidia.com
Fixes: ee13240cd78b ("panic: add note that panic_print sysctl interface is deprecated")
Fixes: 2683df6539cb ("panic: add note that 'panic_print' parameter is deprecated")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Cc: Feng Tang <feng.tang@linux.alibaba.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/panic.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -131,7 +131,8 @@ static int proc_taint(const struct ctl_t
static int sysctl_panic_print_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
- panic_print_deprecated();
+ if (write)
+ panic_print_deprecated();
return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}

@@ -1010,7 +1011,6 @@ static int panic_print_set(const char *v

static int panic_print_get(char *val, const struct kernel_param *kp)
{
- panic_print_deprecated();
return param_get_ulong(val, kp);
}