[PATCH] i386: reliable stack trace support (i386)
These are the i386-specific pieces to enable reliable stack traces. This is
going to be even more useful once CFI annotations get added to he assembly
code, namely to entry.S.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index dcc1447..2865846 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -28,6 +28,7 @@
#include <linux/utsname.h>
#include <linux/kprobes.h>
#include <linux/kexec.h>
+#include <linux/unwind.h>
#ifdef CONFIG_EISA
#include <linux/ioport.h>
@@ -47,7 +48,7 @@
#include <asm/desc.h>
#include <asm/i387.h>
#include <asm/nmi.h>
-
+#include <asm/unwind.h>
#include <asm/smp.h>
#include <asm/arch_hooks.h>
#include <asm/kdebug.h>
@@ -170,14 +171,43 @@
return ebp;
}
-static void show_trace_log_lvl(struct task_struct *task,
+static asmlinkage void show_trace_unwind(struct unwind_frame_info *info, void *log_lvl)
+{
+ int printed = 0; /* nr of entries already printed on current line */
+
+ while (unwind(info) == 0 && UNW_PC(info)) {
+ printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed);
+ if (arch_unw_user_mode(info))
+ break;
+ }
+ if (printed)
+ printk("\n");
+}
+
+static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, char *log_lvl)
{
unsigned long ebp;
+ struct unwind_frame_info info;
if (!task)
task = current;
+ if (regs) {
+ if (unwind_init_frame_info(&info, task, regs) == 0) {
+ show_trace_unwind(&info, log_lvl);
+ return;
+ }
+ } else if (task == current) {
+ if (unwind_init_running(&info, show_trace_unwind, log_lvl) == 0)
+ return;
+ } else {
+ if (unwind_init_blocked(&info, task) == 0) {
+ show_trace_unwind(&info, log_lvl);
+ return;
+ }
+ }
+
if (task == current) {
/* Grab ebp right from our regs */
asm ("movl %%ebp, %0" : "=r" (ebp) : );
@@ -198,13 +228,13 @@
}
}
-void show_trace(struct task_struct *task, unsigned long * stack)
+void show_trace(struct task_struct *task, struct pt_regs *regs, unsigned long * stack)
{
- show_trace_log_lvl(task, stack, "");
+ show_trace_log_lvl(task, regs, stack, "");
}
-static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
- char *log_lvl)
+static void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *esp, char *log_lvl)
{
unsigned long *stack;
int i;
@@ -225,13 +255,13 @@
printk("%08lx ", *stack++);
}
printk("\n%sCall Trace:\n", log_lvl);
- show_trace_log_lvl(task, esp, log_lvl);
+ show_trace_log_lvl(task, regs, esp, log_lvl);
}
void show_stack(struct task_struct *task, unsigned long *esp)
{
printk(" ");
- show_stack_log_lvl(task, esp, "");
+ show_stack_log_lvl(task, NULL, esp, "");
}
/*
@@ -241,7 +271,7 @@
{
unsigned long stack;
- show_trace(current, &stack);
+ show_trace(current, NULL, &stack);
}
EXPORT_SYMBOL(dump_stack);
@@ -285,7 +315,7 @@
u8 __user *eip;
printk("\n" KERN_EMERG "Stack: ");
- show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG);
+ show_stack_log_lvl(NULL, regs, (unsigned long *)esp, KERN_EMERG);
printk(KERN_EMERG "Code: ");