fadump is registered in panic_notifier_list and gets triggered before kmsg_dump_desc() in the panic path. As a result, kmsg_dumpers such as pstore are not executed during fadump crashes.
This is problematic because pstore provides a critical fallback mechanism for crash analysis. When fadump fails to successfully reboot the system or capture a dump, pstore logs may be the only available information from the crashed kernel. Without invoking kmsg_dump_desc() in the fadump path, we lose this valuable diagnostic data. Invoke kmsg_dump_desc() from the fadump panic handler, but only when fadump is actually registered (checked via should_fadump_crash()). This ensures kmsg_dumpers are called without duplicating the call that occurs later in panic() when fadump is not active. The call is placed before crash_fadump() to ensure logs are captured before the system attempts to trigger the firmware-assisted dump. Cc: Hari Bathini <[email protected]> Cc: Madhavan Srinivasan <[email protected]> Cc: Mahesh Salgaonkar <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Ritesh Harjani (IBM) <[email protected]> Reported-by: Shirisha G <[email protected]> Suggested-by: Sourabh Jain <[email protected]> Signed-off-by: Shivang Upadhyay <[email protected]> --- Changelog: v2: address comments from Sourabh, and sashikio-ai added should_fadump_crash() v1: https://lore.kernel.org/all/[email protected]/ --- arch/powerpc/kernel/setup-common.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index b1761909c23f..87afc8003a03 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -68,6 +68,7 @@ #include <asm/kasan.h> #include <asm/mce.h> #include <asm/systemcfg.h> +#include <linux/kmsg_dump.h> #include "setup.h" @@ -744,6 +745,13 @@ static int ppc_panic_fadump_handler(struct notifier_block *this, */ hard_irq_disable(); + /* + * Invoke kmsg_dump (e.g., pstore) before crash_fadump() as fadump + * runs before panic()'s kmsg_dump_desc() call. + */ + if (should_fadump_crash()) + kmsg_dump_desc(KMSG_DUMP_PANIC, (char *)ptr); + /* * If firmware-assisted dump has been registered then trigger * its callback and let the firmware handles everything else. -- 2.53.0
