[PATCH 2/2] process: change from __backtrace to dump_stack_regs in show_regs
From: Nicolas Pitre <hidden>
Date: 2011-08-24 18:57:48
On Wed, 24 Aug 2011, Laura Abbott wrote:
Currently, show_regs calls __backtrace which does nothing if CONIFG_FRAME_POINTER is not set. Switch to
s/CONIFG/CONFIG/
quoted hunk ↗ jump to hunk
dump_stack_regs to show the backtrace from a given set of registers. Signed-off-by: Laura Abbott <redacted> --- arch/arm/kernel/process.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 1a347f4..6f11213 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c@@ -319,7 +319,7 @@ void show_regs(struct pt_regs * regs) printk("\n"); printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); __show_regs(regs); - __backtrace(); + dump_stack_regs(regs);
This is not equivalent. A call to __backtrace() will display a call trace leading to this show_regs(). Given that you defined dump_stack_regs(regs) as dump_backtrace(regs, NULL), the trace will instead contain calls leading up to the point where those regs were saved. A better way to achieve what you want would be: - remove the __backtrace entry point from lib/backtrace.S - define __backtrace() in kernel/traps.c as a call to dump_backtrace(NULL, NULL) which will have the same effect as the assembly code for __backtrace(). - realize that dump_stack() is already doing exactly that, therefore... - use dump_stack() in show_regs() which is the only caller of __backtrace and get rid of __backtrace entirely. Obviously the above can be collapsed in one patch. Nicolas