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| author | Hari Bathini <hbathini@linux.ibm.com> | 2021-12-07 16:07:18 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-12-09 22:41:22 +1100 |
| commit | 219572d2fc4135b5ce65c735d881787d48b10e71 (patch) | |
| tree | 9cb8fe21a962e5d81c5db88cdf37bc484f62b34c /arch/powerpc/kernel/smp.c | |
| parent | 3c42e9542050d49610077e083c7c3f5fd5e26820 (diff) | |
| download | linux-219572d2fc4135b5ce65c735d881787d48b10e71.tar.gz | |
powerpc: handle kdump appropriately with crash_kexec_post_notifiers option
Kdump can be triggered after panic_notifers since commit f06e5153f4ae2
("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump
after panic_notifers") introduced crash_kexec_post_notifiers option.
But using this option would mean smp_send_stop(), that marks all other
CPUs as offline, gets called before kdump is triggered. As a result,
kdump routines fail to save other CPUs' registers. To fix this, kdump
friendly crash_smp_send_stop() function was introduced with kernel
commit 0ee59413c967 ("x86/panic: replace smp_send_stop() with kdump
friendly version in panic path"). Override this kdump friendly weak
function to handle crash_kexec_post_notifiers option appropriately
on powerpc.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
[Fixed signature of crash_stop_this_cpu() - reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211207103719.91117-1-hbathini@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index aee3a7119f9773..7201fdcf02f1c2 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -621,6 +621,36 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) #endif #ifdef CONFIG_NMI_IPI +static void crash_stop_this_cpu(struct pt_regs *regs) +#else +static void crash_stop_this_cpu(void *dummy) +#endif +{ + /* + * Just busy wait here and avoid marking CPU as offline to ensure + * register data is captured appropriately. + */ + while (1) + cpu_relax(); +} + +void crash_smp_send_stop(void) +{ + static bool stopped = false; + + if (stopped) + return; + + stopped = true; + +#ifdef CONFIG_NMI_IPI + smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, crash_stop_this_cpu, 1000000); +#else + smp_call_function(crash_stop_this_cpu, NULL, 0); +#endif /* CONFIG_NMI_IPI */ +} + +#ifdef CONFIG_NMI_IPI static void nmi_stop_this_cpu(struct pt_regs *regs) { /* |