diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/fadump.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index 8f0c7c5d93f2..8ff0dd4e77a7 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -406,12 +406,35 @@ static void register_fw_dump(struct fadump_mem_struct *fdm) void crash_fadump(struct pt_regs *regs, const char *str) { struct fadump_crash_info_header *fdh = NULL; + int old_cpu, this_cpu; if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) return; + /* + * old_cpu == -1 means this is the first CPU which has come here, + * go ahead and trigger fadump. + * + * old_cpu != -1 means some other CPU has already on it's way + * to trigger fadump, just keep looping here. + */ + this_cpu = smp_processor_id(); + old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); + + if (old_cpu != -1) { + /* + * We can't loop here indefinitely. Wait as long as fadump + * is in force. If we race with fadump un-registration this + * loop will break and then we go down to normal panic path + * and reboot. If fadump is in force the first crashing + * cpu will definitely trigger fadump. + */ + while (fw_dump.dump_registered) + cpu_relax(); + return; + } + fdh = __va(fw_dump.fadumphdr_addr); - crashing_cpu = smp_processor_id(); fdh->crashing_cpu = crashing_cpu; crash_save_vmcoreinfo(); |