• Christophe Leroy's avatar
    powerpc/32: Clear on-stack exception marker upon exception return · 40b97853
    Christophe Leroy authored
    commit 9580b71b upstream.
    
    Clear the on-stack STACK_FRAME_REGS_MARKER on exception exit in order
    to avoid confusing stacktrace like the one below.
    
      Call Trace:
      [c0e9dca0] [c01c42a0] print_address_description+0x64/0x2bc (unreliable)
      [c0e9dcd0] [c01c4684] kasan_report+0xfc/0x180
      [c0e9dd10] [c0895130] memchr+0x24/0x74
      [c0e9dd30] [c00a9e38] msg_print_text+0x124/0x574
      [c0e9dde0] [c00ab710] console_unlock+0x114/0x4f8
      [c0e9de40] [c00adc60] vprintk_emit+0x188/0x1c4
      --- interrupt: c0e9df00 at 0x400f330
          LR = init_stack+0x1f00/0x2000
      [c0e9de80] [c00ae3c4] printk+0xa8/0xcc (unreliable)
      [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
      [c0e9df50] [c0c15434] start_kernel+0x310/0x488
      [c0e9dff0] [00003484] 0x3484
    
    With this patch the trace becomes:
    
      Call Trace:
      [c0e9dca0] [c01c42c0] print_address_description+0x64/0x2bc (unreliable)
      [c0e9dcd0] [c01c46a4] kasan_report+0xfc/0x180
      [c0e9dd10] [c0895150] memchr+0x24/0x74
      [c0e9dd30] [c00a9e58] msg_print_text+0x124/0x574
      [c0e9dde0] [c00ab730] console_unlock+0x114/0x4f8
      [c0e9de40] [c00adc80] vprintk_emit+0x188/0x1c4
      [c0e9de80] [c00ae3e4] printk+0xa8/0xcc
      [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
      [c0e9df50] [c0c15434] start_kernel+0x310/0x488
      [c0e9dff0] [00003484] 0x3484
    
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    40b97853
entry_32.S 34.1 KB