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authorRobin Getz <rgetz@blackfin.uclinux.org>2008-04-25 03:36:31 +0800
committerBryan Wu <cooloney@kernel.org>2008-04-25 03:36:31 +0800
commit7f1c906808a36630990d83d872935c079b76595b (patch)
tree7e29d44cb56fabea3080654480be06c5969b93cc /arch
parent4d555630704d3f6c0257dde3e622f9295f221c8b (diff)
[Blackfin] arch: try to remove condition that causes double fault, by checking current before it gets dereferenced
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/blackfin/kernel/traps.c34
1 files changed, 24 insertions, 10 deletions
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index de249d6fdd9..d0f67542207 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -137,17 +137,30 @@ static void decode_address(char *buf, unsigned long address)
/* FLAT does not have its text aligned to the start of
* the map while FDPIC ELF does ...
*/
- if (current->mm &&
- (address > current->mm->start_code) &&
- (address < current->mm->end_code))
- offset = address - current->mm->start_code;
- else
- offset = (address - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
-
- sprintf(buf, "<0x%p> [ %s + 0x%lx ]",
- (void *)address, name, offset);
+
+ /* before we can check flat/fdpic, we need to
+ * make sure current is valid
+ */
+ if ((unsigned long)current >= FIXED_CODE_START &&
+ !((unsigned long)current & 0x3)) {
+ if (current->mm &&
+ (address > current->mm->start_code) &&
+ (address < current->mm->end_code))
+ offset = address - current->mm->start_code;
+ else
+ offset = (address - vma->vm_start) +
+ (vma->vm_pgoff << PAGE_SHIFT);
+
+ sprintf(buf, "<0x%p> [ %s + 0x%lx ]",
+ (void *)address, name, offset);
+ } else
+ sprintf(buf, "<0x%p> [ %s vma:0x%lx-0x%lx]",
+ (void *)address, name,
+ vma->vm_start, vma->vm_end);
+
if (!in_atomic)
mmput(mm);
+
goto done;
}
@@ -658,7 +671,8 @@ void dump_bfin_process(struct pt_regs *fp)
/* Because we are crashing, and pointers could be bad, we check things
* pretty closely before we use them
*/
- if (!((unsigned long)current & 0x3) && current->pid) {
+ if ((unsigned long)current >= FIXED_CODE_START &&
+ !((unsigned long)current & 0x3) && current->pid) {
printk(KERN_NOTICE "CURRENT PROCESS:\n");
if (current->comm >= (char *)FIXED_CODE_START)
printk(KERN_NOTICE "COMM=%s PID=%d\n",