[tip:x86/debug] x86: Avoid double stack traces with show_regs()

[tip-bot for Jan Beulich <JBeulich@suse.com>]

Commit-ID:  57da8b960b9a25646a8ddb5a9c1d0b5978e69bec
Gitweb:     http://git.kernel.org/tip/57da8b960b9a25646a8ddb5a9c1d0b5978e69bec
Author:     Jan Beulich <JBeulich@suse.com>
AuthorDate: Wed, 9 May 2012 08:47:37 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 9 May 2012 11:44:42 +0200

x86: Avoid double stack traces with show_regs()

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@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/4FAA3D3902000078000826E1@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 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(-)

diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
index d73f157..2c37aad 100644
--- a/arch/x86/include/asm/kdebug.h
+++ b/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);
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 1b81839..40989da 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -271,7 +271,7 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 			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;
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 88ec912..e0b1d78 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -82,7 +82,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 }
 
 
-void show_registers(struct pt_regs *regs)
+void show_regs(struct pt_regs *regs)
 {
 	int i;
 
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 17107bd..791b761 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -245,7 +245,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 	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;
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index e213fc8..e2f751e 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -1037,9 +1037,9 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
 			       "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;
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 47acaf3..03c1345 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -244,7 +244,7 @@ io_check_error(unsigned char reason, struct pt_regs *regs)
 	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");
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 1d92a5a..856d5bc 100644
--- a/arch/x86/kernel/process.c
+++ b/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;