From: Anton Blanchard <anton@samba.org>
The might_sleep infrastructure doesnt like our get_users in the backtrace
code, we often end up with might_sleep warnings inside might_sleep warnings.
Instead just be careful about pointers before dereferencing them.
Also remove the hack where we only printed the bottom 32bits of the WCHAN
value.
---
arch/ppc64/kernel/process.c | 63 ++++++++++++++++++++++++++------------------
1 files changed, 38 insertions(+), 25 deletions(-)
diff -puN arch/ppc64/kernel/process.c~ppc64-remove-get-user arch/ppc64/kernel/process.c
--- 25/arch/ppc64/kernel/process.c~ppc64-remove-get-user 2004-02-21 20:58:27.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/process.c 2004-02-21 20:58:27.000000000 -0800
@@ -202,13 +202,11 @@ void show_regs(struct pt_regs * regs)
#endif /* CONFIG_SMP */
for (i = 0; i < 32; i++) {
- long r;
if ((i % 4) == 0) {
printk("\n" KERN_INFO "GPR%02d: ", i);
}
- if (__get_user(r, &(regs->gpr[i])))
- return;
- printk("%016lX ", r);
+
+ printk("%016lX ", regs->gpr[i]);
}
printk("\n");
/*
@@ -473,6 +471,20 @@ out:
return error;
}
+static int kstack_depth_to_print = 64;
+
+static inline int validate_sp(unsigned long sp, struct task_struct *p)
+{
+ unsigned long stack_page = (unsigned long)p->thread_info;
+
+ if (sp < stack_page + sizeof(struct thread_struct))
+ return 0;
+ if (sp >= stack_page + THREAD_SIZE)
+ return 0;
+
+ return 1;
+}
+
/*
* These bracket the sleeping functions..
*/
@@ -484,24 +496,23 @@ extern void scheduling_functions_end_her
unsigned long get_wchan(struct task_struct *p)
{
unsigned long ip, sp;
- unsigned long stack_page = (unsigned long)p->thread_info;
int count = 0;
+
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
+
sp = p->thread.ksp;
+ if (!validate_sp(sp, p))
+ return 0;
+
do {
sp = *(unsigned long *)sp;
- if (sp < (stack_page + sizeof(struct thread_struct)) ||
- sp >= (stack_page + THREAD_SIZE))
+ if (!validate_sp(sp, p))
return 0;
if (count > 0) {
ip = *(unsigned long *)(sp + 16);
- /*
- * XXX we mask the upper 32 bits until procps
- * gets fixed.
- */
if (ip < first_sched || ip >= last_sched)
- return (ip & 0xFFFFFFFF);
+ return ip;
}
} while (count++ < 16);
return 0;
@@ -510,28 +521,30 @@ unsigned long get_wchan(struct task_stru
void show_stack(struct task_struct *p, unsigned long *_sp)
{
unsigned long ip;
- unsigned long stack_page = (unsigned long)p->thread_info;
int count = 0;
unsigned long sp = (unsigned long)_sp;
- if (!p)
+ if (sp == 0) {
+ if (p) {
+ sp = p->thread.ksp;
+ } else {
+ sp = (unsigned long)_get_SP();
+ p = current;
+ }
+ }
+
+ if (!validate_sp(sp, p))
return;
- if (sp == 0)
- sp = p->thread.ksp;
printk("Call Trace:\n");
do {
- if (__get_user(sp, (unsigned long *)sp))
- break;
- if (sp < stack_page + sizeof(struct thread_struct))
- break;
- if (sp >= stack_page + THREAD_SIZE)
- break;
- if (__get_user(ip, (unsigned long *)(sp + 16)))
- break;
+ sp = *(unsigned long *)sp;
+ if (!validate_sp(sp, p))
+ return;
+ ip = *(unsigned long *)(sp + 16);
printk("[%016lx] ", ip);
print_symbol("%s\n", ip);
- } while (count++ < 32);
+ } while (count++ < kstack_depth_to_print);
}
void dump_stack(void)
_