• Vivek Goyal's avatar
    [PATCH] Kexec: Kexec on panic fix with nmi watchdog enabled · a3ea8ac8
    Vivek Goyal authored
    o Problem: Kexec on panic hangs if first kernel is booted with nmi_watchdog
      command line parameter. This problem occurs because kexec crash shutdown
      code replaces the NMI callback handler. This handler saves the cpu register
      states and halts the cpu. If system is booted with nmi_watchdog parameter,
      then crashing cpu also runs this nmi handler and halts itself.
    
    o This patch fixes the problem by keeping a track of crashing cpu and not
      executing the new nmi handler on crashing cpu.
    
    o There is a dependence on smp_processor_id() function which might return
      insane value for cpu, if cpu field of thread_info is corrupted.
    Signed-off-by: default avatarVivek Goyal <vgoyal@in.ibm.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    a3ea8ac8
crash.c 5.45 KB