2004-10-01 10:38:28

by Kirill Korotaev

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Subject: [PATCH] Fix of stack dump in {SOFT|HARD}IRQs

---

--- ./arch/i386/kernel/traps.c.dumpstack 2004-10-01 14:21:40.000000000 +0400
+++ ./arch/i386/kernel/traps.c 2004-10-01 14:30:10.109733400 +0400
@@ -95,11 +95,16 @@ static int kstack_depth_to_print = 24;

static int valid_stack_ptr(struct task_struct *task, void *p)
{
- if (p <= (void *)task->thread_info)
- return 0;
- if (kstack_end(p))
- return 0;
- return 1;
+ extern int is_irq_stack_ptr(struct task_struct *, void *);
+
+ if (is_irq_stack_ptr(task, p))
+ return 1;
+ if (p >= (void *)task->thread_info &&
+ p < (void *)task->thread_info + THREAD_SIZE &&
+ !kstack_end(p))
+ return 1;
+
+ return 0;
}

#ifdef CONFIG_FRAME_POINTER
--- ./arch/i386/kernel/irq.c.dumpstack 2004-09-20 14:14:58.000000000 +0400
+++ ./arch/i386/kernel/irq.c 2004-10-01 14:28:15.806110192 +0400
@@ -1126,6 +1126,21 @@ void init_irq_proc (void)
static char softirq_stack[NR_CPUS * THREAD_SIZE] __attribute__((__aligned__(THREAD_SIZE)));
static char hardirq_stack[NR_CPUS * THREAD_SIZE] __attribute__((__aligned__(THREAD_SIZE)));

+int is_irq_stack_ptr(struct task_struct *task, void *p)
+{
+ unsigned long off;
+
+ off = task->thread_info->cpu * THREAD_SIZE;
+ if (p >= (void *)hardirq_stack + off &&
+ p < (void *)hardirq_stack + off + THREAD_SIZE)
+ return 1;
+ if (p >= (void *)softirq_stack + off &&
+ p < (void *)softirq_stack + off + THREAD_SIZE)
+ return 1;
+
+ return 0;
+}
+
/*
* allocate per-cpu stacks for hardirq and for softirq processing
*/

---

Attachments:

diff-dumpstack (1.44 kB)

2004-10-01 22:09:54

by Andrew Morton

[permalink] [raw]

Subject: Re: [PATCH] Fix of stack dump in {SOFT|HARD}IRQs

---

Kirill Korotaev <[email protected]> wrote:
>
> This patch fixes incorrect check for stack ptr in
> show_trace()->valid_stack_ptr(). When called from hardirq/softirq
> show_trace() prints "Stack pointer is garbage, not printing trace"
> message instead of call traces.

Thanks for fixing that up.

In future, please ensure that patches are in `patch -p1' form, as described
in http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt.

And please don't declare external functions in .c files - it defeats
compiler typechecking. I'll use the below fixup for that.

--- 25/arch/i386/kernel/irq.c~fix-of-stack-dump-in-soft-hardirqs-cleanup Fri Oct 1 15:05:24 2004
+++ 25-akpm/arch/i386/kernel/irq.c Fri Oct 1 15:05:45 2004
@@ -10,12 +10,14 @@
* io_apic.c.)
*/

-#include <asm/uaccess.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>

+#include <asm/uaccess.h>
+#include <asm/hardirq.h>
+
#ifdef CONFIG_4KSTACKS
/*
* per-CPU IRQ handling contexts (thread information and stack)
diff -puN arch/i386/kernel/traps.c~fix-of-stack-dump-in-soft-hardirqs-cleanup arch/i386/kernel/traps.c
--- 25/arch/i386/kernel/traps.c~fix-of-stack-dump-in-soft-hardirqs-cleanup Fri Oct 1 15:05:24 2004
+++ 25-akpm/arch/i386/kernel/traps.c Fri Oct 1 15:06:01 2004
@@ -50,6 +50,7 @@
#include <asm/smp.h>
#include <asm/arch_hooks.h>
#include <asm/kdebug.h>
+#include <asm/hardirq.h>

#include <linux/irq.h>
#include <linux/module.h>
@@ -107,8 +108,6 @@ int register_die_notifier(struct notifie

static int valid_stack_ptr(struct task_struct *task, void *p)
{
- extern int is_irq_stack_ptr(struct task_struct *, void *);
-
if (is_irq_stack_ptr(task, p))
return 1;
if (p >= (void *)task->thread_info &&
diff -puN include/asm-i386/hardirq.h~fix-of-stack-dump-in-soft-hardirqs-cleanup include/asm-i386/hardirq.h
--- 25/include/asm-i386/hardirq.h~fix-of-stack-dump-in-soft-hardirqs-cleanup Fri Oct 1 15:05:24 2004
+++ 25-akpm/include/asm-i386/hardirq.h Fri Oct 1 15:06:29 2004
@@ -36,4 +36,7 @@ static inline void ack_bad_irq(unsigned
#endif
}

+struct task_struct;
+int is_irq_stack_ptr(struct task_struct *task, void *p);
+
#endif /* __ASM_HARDIRQ_H */
_