diff options
| author | Pnina Feder <pnina.feder@mobileye.com> | 2026-01-22 13:24:57 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-02-03 19:21:26 +0300 |
| commit | 2e171ab29f916455a49274a2042bac4a4b35570e (patch) | |
| tree | fd2f068b6c5231beb0b7d49a016bfae9e3b62770 /include/linux | |
| parent | f3951e93d4fe9cc85128dc38915877ff6ef633db (diff) | |
| download | linux-2e171ab29f916455a49274a2042bac4a4b35570e.tar.xz | |
panic: add panic_force_cpu= parameter to redirect panic to a specific CPU
Some platforms require panic handling to execute on a specific CPU for
crash dump to work reliably. This can be due to firmware limitations,
interrupt routing constraints, or platform-specific requirements where
only a single CPU is able to safely enter the crash kernel.
Add the panic_force_cpu= kernel command-line parameter to redirect panic
execution to a designated CPU. When the parameter is provided, the CPU
that initially triggers panic forwards the panic context to the target CPU
via IPI, which then proceeds with the normal panic and kexec flow.
The IPI delivery is implemented as a weak function
(panic_smp_redirect_cpu) so architectures with NMI support can override it
for more reliable delivery.
If the specified CPU is invalid, offline, or a panic is already in
progress on another CPU, the redirection is skipped and panic continues on
the current CPU.
[pnina.feder@mobileye.com: fix unused variable warning]
Link: https://lkml.kernel.org/r/20260126122618.2967950-1-pnina.feder@mobileye.com
Link: https://lkml.kernel.org/r/20260122102457.1154599-1-pnina.feder@mobileye.com
Signed-off-by: Pnina Feder <pnina.feder@mobileye.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/panic.h | 8 | ||||
| -rw-r--r-- | include/linux/smp.h | 1 |
2 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/panic.h b/include/linux/panic.h index a00bc0937698..f1dd417e54b2 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -41,6 +41,14 @@ void abort(void); * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). */ extern atomic_t panic_cpu; + +/* + * panic_redirect_cpu is used when panic is redirected to a specific CPU via + * the panic_force_cpu= boot parameter. It holds the CPU number that originally + * triggered the panic before redirection. A value of PANIC_CPU_INVALID means + * no redirection has occurred. + */ +extern atomic_t panic_redirect_cpu; #define PANIC_CPU_INVALID -1 bool panic_try_start(void); diff --git a/include/linux/smp.h b/include/linux/smp.h index 91d0ecf3b8d3..1ebd88026119 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -62,6 +62,7 @@ int smp_call_function_single_async(int cpu, call_single_data_t *csd); void __noreturn panic_smp_self_stop(void); void __noreturn nmi_panic_self_stop(struct pt_regs *regs); void crash_smp_send_stop(void); +int panic_smp_redirect_cpu(int target_cpu, void *msg); /* * Call a function on all processors |