linux-sg2042/arch/x86/mm/kmemcheck
Soeren Sandmann Pedersen 9c0729dc80 x86: Eliminate bp argument from the stack tracing routines
The various stack tracing routines take a 'bp' argument in which the
caller is supposed to provide the base pointer to use, or 0 if doesn't
have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not
defined, this means all callers in principle should either always pass
0, or be conditional on CONFIG_FRAME_POINTER.

However, there are only really three use cases for stack tracing:

(a) Trace the current task, including IRQ stack if any
(b) Trace the current task, but skip IRQ stack
(c) Trace some other task

In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just
be 0.  If it _is_ defined, then

- in case (a) bp should be gotten directly from the CPU's register, so
  the caller should pass NULL for regs,

- in case (b) the caller should should pass the IRQ registers to
  dump_trace(),

- in case (c) bp should be gotten from the top of the task's stack, so
  the caller should pass NULL for regs.

Hence, the bp argument is not necessary because the combination of
task and regs is sufficient to determine an appropriate value for bp.

This patch introduces a new inline function stack_frame(task, regs)
that computes the desired bp. This function is then called from the
two versions of dump_stack().

Signed-off-by: Soren Sandmann <ssp@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>,
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>,
LKML-Reference: <m3oc9rop28.fsf@dhcp-100-3-82.bos.redhat.com>>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-11-18 14:37:34 +01:00
..
Makefile kmemcheck: add opcode self-testing at boot 2009-06-15 15:49:22 +02:00
error.c x86: Eliminate bp argument from the stack tracing routines 2010-11-18 14:37:34 +01:00
error.h kmemcheck: add the kmemcheck core 2009-06-13 15:37:30 +02:00
kmemcheck.c x86: Barf when vmalloc and kmemcheck faults happen in NMI 2010-10-14 20:43:36 +02:00
opcode.c x86, kmemcheck: Remove double test 2010-08-30 09:19:28 +02:00
opcode.h kmemcheck: add the kmemcheck core 2009-06-13 15:37:30 +02:00
pte.c kmemcheck: add the kmemcheck core 2009-06-13 15:37:30 +02:00
pte.h kmemcheck: add the kmemcheck core 2009-06-13 15:37:30 +02:00
selftest.c kmemcheck: add opcode self-testing at boot 2009-06-15 15:49:22 +02:00
selftest.h kmemcheck: add opcode self-testing at boot 2009-06-15 15:49:22 +02:00
shadow.c kmemcheck: Test the full object in kmemcheck_is_obj_initialized() 2010-02-17 21:39:08 +02:00
shadow.h kmemcheck: Test the full object in kmemcheck_is_obj_initialized() 2010-02-17 21:39:08 +02:00