[PATCH, resend] x86: avoid double stack traces withshow_regs()

From: Jan Beulich
Date: Wed May 09 2012 - 04:55:38 EST


What was called show_registers() so far already showed a stack trace
for kernel faults, and kernel_stack_pointer() isn't even valid to be
used for faults from user mode, hence it was pointless for show_regs()
to call show_trace() after show_registers(). Simply rename
show_registers() to show_regs() and eliminate the old definition.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

---
arch/x86/include/asm/kdebug.h | 1 -
arch/x86/kernel/dumpstack.c | 2 +-
arch/x86/kernel/dumpstack_32.c | 2 +-
arch/x86/kernel/dumpstack_64.c | 2 +-
arch/x86/kernel/kprobes.c | 4 ++--
arch/x86/kernel/nmi.c | 2 +-
arch/x86/kernel/process.c | 6 ------
7 files changed, 6 insertions(+), 13 deletions(-)

--- 3.4-rc6/arch/x86/include/asm/kdebug.h
+++ 3.4-rc6-x86-no-show_registers/arch/x86/include/asm/kdebug.h
@@ -24,7 +24,6 @@ enum die_val {
extern void printk_address(unsigned long address, int reliable);
extern void die(const char *, struct pt_regs *,long);
extern int __must_check __die(const char *, struct pt_regs *, long);
-extern void show_registers(struct pt_regs *regs);
extern void show_trace(struct task_struct *t, struct pt_regs *regs,
unsigned long *sp, unsigned long bp);
extern void __show_regs(struct pt_regs *regs, int all);
--- 3.4-rc6/arch/x86/kernel/dumpstack.c
+++ 3.4-rc6-x86-no-show_registers/arch/x86/kernel/dumpstack.c
@@ -271,7 +271,7 @@ int __kprobes __die(const char *str, str
current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
return 1;

- show_registers(regs);
+ show_regs(regs);
#ifdef CONFIG_X86_32
if (user_mode_vm(regs)) {
sp = regs->sp;
--- 3.4-rc6/arch/x86/kernel/dumpstack_32.c
+++ 3.4-rc6-x86-no-show_registers/arch/x86/kernel/dumpstack_32.c
@@ -82,7 +82,7 @@ show_stack_log_lvl(struct task_struct *t
}


-void show_registers(struct pt_regs *regs)
+void show_regs(struct pt_regs *regs)
{
int i;

--- 3.4-rc6/arch/x86/kernel/dumpstack_64.c
+++ 3.4-rc6-x86-no-show_registers/arch/x86/kernel/dumpstack_64.c
@@ -245,7 +245,7 @@ show_stack_log_lvl(struct task_struct *t
show_trace_log_lvl(task, regs, sp, bp, log_lvl);
}

-void show_registers(struct pt_regs *regs)
+void show_regs(struct pt_regs *regs)
{
int i;
unsigned long sp;
--- 3.4-rc6/arch/x86/kernel/kprobes.c
+++ 3.4-rc6-x86-no-show_registers/arch/x86/kernel/kprobes.c
@@ -1037,9 +1037,9 @@ int __kprobes longjmp_break_handler(stru
"current sp %p does not match saved sp %p\n",
stack_addr(regs), kcb->jprobe_saved_sp);
printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
- show_registers(saved_regs);
+ show_regs(saved_regs);
printk(KERN_ERR "Current registers\n");
- show_registers(regs);
+ show_regs(regs);
BUG();
}
*regs = kcb->jprobe_saved_regs;
--- 3.4-rc6/arch/x86/kernel/nmi.c
+++ 3.4-rc6-x86-no-show_registers/arch/x86/kernel/nmi.c
@@ -244,7 +244,7 @@ io_check_error(unsigned char reason, str
pr_emerg(
"NMI: IOCK error (debug interrupt?) for reason %02x on CPU %d.\n",
reason, smp_processor_id());
- show_registers(regs);
+ show_regs(regs);

if (panic_on_io_nmi)
panic("NMI IOCK error: Not continuing");
--- 3.4-rc6/arch/x86/kernel/process.c
+++ 3.4-rc6-x86-no-show_registers/arch/x86/kernel/process.c
@@ -105,12 +105,6 @@ void exit_thread(void)
}
}

-void show_regs(struct pt_regs *regs)
-{
- show_registers(regs);
- show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs), 0);
-}
-
void show_regs_common(void)
{
const char *vendor, *product, *board;



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/