• Tejun Heo's avatar
    dump_stack: unify debug information printed by show_regs() · a43cb95d
    Tejun Heo authored
    
    
    show_regs() is inherently arch-dependent but it does make sense to print
    generic debug information and some archs already do albeit in slightly
    different forms.  This patch introduces a generic function to print debug
    information from show_regs() so that different archs print out the same
    information and it's much easier to modify what's printed.
    
    show_regs_print_info() prints out the same debug info as dump_stack()
    does plus task and thread_info pointers.
    
    * Archs which didn't print debug info now do.
    
      alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
      metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
      um, xtensa
    
    * Already prints debug info.  Replaced with show_regs_print_info().
      The printed information is superset of what used to be there.
    
      arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
    
    * s390 is special in that it used to print arch-specific information
      along with generic debug info.  Heiko and Martin think that the
      arch-specific extra isn't worth keeping s390 specfic implementation.
      Converted to use the generic version.
    
    Note that now all archs print the debug info before actual register
    dumps.
    
    An example BUG() dump follows.
    
     kernel BUG at /work/os/work/kernel/workqueue.c:4841!
     invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
     Modules linked in:
     CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
     Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
     task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
     RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
     RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
     RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
     RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
     RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
     R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
     R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
     FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
     CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
     CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
     DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
     DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
     Stack:
      ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
      0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
      ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
     Call Trace:
      [<ffffffff81000312>] do_one_initcall+0x122/0x170
      [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
      [<ffffffff81c47760>] ? rest_init+0x140/0x140
      [<ffffffff81c4776e>] kernel_init+0xe/0xf0
      [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
      [<ffffffff81c47760>] ? rest_init+0x140/0x140
      ...
    
    v2: Typo fix in x86-32.
    
    v3: CPU number dropped from show_regs_print_info() as
        dump_stack_print_info() has been updated to print it.  s390
        specific implementation dropped as requested by s390 maintainers.
    
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
    Acked-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
    Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
    Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
    Cc: Bjorn Helgaas <bhelgaas@google.com>
    Cc: Fengguang Wu <fengguang.wu@intel.com>
    Cc: Mike Frysinger <vapier@gentoo.org>
    Cc: Vineet Gupta <vgupta@synopsys.com>
    Cc: Sam Ravnborg <sam@ravnborg.org>
    Acked-by: Chris Metcalf <cmetcalf@tilera.com>		[tile bits]
    Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    a43cb95d