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authorRichard Weinberger <richard@nod.at>2013-09-23 17:38:01 +0200
committerRichard Weinberger <richard@nod.at>2013-11-17 11:27:25 +0100
commit9d1ee8ce92e16c6aa0a3fd91ee8ed9e403b3a2eb (patch)
treefa38685d0c62cbc97d9016750bb18c7feac54799 /arch/um
parent5e01dc7b26d9f24f39abace5da98ccbd6a5ceb52 (diff)
downloadlinux-linaro-stable-9d1ee8ce92e16c6aa0a3fd91ee8ed9e403b3a2eb.tar.gz
um: Rewrite show_stack()
Currently on UML stack traces are not very reliable and both x86 and x86_64 have their on implementations. This patch unifies both and adds support to outline unreliable functions calls. Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/kernel/sysrq.c85
-rw-r--r--arch/um/kernel/um_arch.c1
2 files changed, 53 insertions, 33 deletions
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index 0dc4d1c6f98a..33cc72e26c6e 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -1,6 +1,10 @@
/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
+ * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
*/
#include <linux/kallsyms.h>
@@ -9,58 +13,75 @@
#include <linux/sched.h>
#include <asm/sysrq.h>
-/* Catch non-i386 SUBARCH's. */
-#if !defined(CONFIG_UML_X86) || defined(CONFIG_64BIT)
-void show_trace(struct task_struct *task, unsigned long * stack)
+struct stack_frame {
+ struct stack_frame *next_frame;
+ unsigned long return_address;
+};
+
+static void print_stack_trace(unsigned long *sp, unsigned long bp)
{
+ int reliable;
unsigned long addr;
+ struct stack_frame *frame = (struct stack_frame *)bp;
- if (!stack) {
- stack = (unsigned long*) &stack;
- WARN_ON(1);
- }
-
- printk(KERN_INFO "Call Trace: \n");
- while (((long) stack & (THREAD_SIZE-1)) != 0) {
- addr = *stack;
+ printk(KERN_INFO "Call Trace:\n");
+ while (((long) sp & (THREAD_SIZE-1)) != 0) {
+ addr = *sp;
if (__kernel_text_address(addr)) {
- printk(KERN_INFO "%08lx: [<%08lx>]",
- (unsigned long) stack, addr);
- print_symbol(KERN_CONT " %s", addr);
+ reliable = 0;
+ if ((unsigned long) sp == bp + sizeof(long)) {
+ frame = frame ? frame->next_frame : NULL;
+ bp = (unsigned long)frame;
+ reliable = 1;
+ }
+
+ printk(KERN_INFO " [<%08lx>]", addr);
+ printk(KERN_CONT " %s", reliable ? "" : "? ");
+ print_symbol(KERN_CONT "%s", addr);
printk(KERN_CONT "\n");
}
- stack++;
+ sp++;
}
printk(KERN_INFO "\n");
}
-#endif
/*Stolen from arch/i386/kernel/traps.c */
static const int kstack_depth_to_print = 24;
-/* This recently started being used in arch-independent code too, as in
- * kernel/sched/core.c.*/
-void show_stack(struct task_struct *task, unsigned long *esp)
+static unsigned long get_frame_pointer(struct task_struct *task)
+{
+ if (!task || task == current)
+ return current_bp();
+ else
+ return KSTK_EBP(task);
+}
+
+void show_stack(struct task_struct *task, unsigned long *stack)
{
- unsigned long *stack;
+ unsigned long *sp = stack, bp = 0;
int i;
- if (esp == NULL) {
- if (task != current && task != NULL) {
- esp = (unsigned long *) KSTK_ESP(task);
- } else {
- esp = (unsigned long *) &esp;
- }
+#ifdef CONFIG_FRAME_POINTER
+ bp = get_frame_pointer(task);
+#endif
+
+ if (!stack) {
+ if (!task || task == current)
+ sp = current_sp();
+ else
+ sp = (unsigned long *)KSTK_ESP(task);
}
- stack = esp;
+ printk(KERN_INFO "Stack:\n");
+ stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
if (kstack_end(stack))
break;
- if (i && ((i % 8) == 0))
- printk(KERN_INFO " ");
- printk(KERN_CONT "%08lx ", *stack++);
+ if (i && ((i % STACKSLOTS_PER_LINE) == 0))
+ printk(KERN_CONT "\n");
+ printk(KERN_CONT " %08lx", *stack++);
}
+ printk(KERN_CONT "\n");
- show_trace(task, esp);
+ print_stack_trace(sp, bp);
}
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 87df5e3acc26..b9dd13e6f206 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -234,7 +234,6 @@ static int panic_exit(struct notifier_block *self, unsigned long unused1,
void *unused2)
{
bust_spinlocks(1);
- show_regs(&(current->thread.regs));
bust_spinlocks(0);
uml_exitcode = 1;
os_dump_core();