diff options
| author | Robin Getz <rgetz@blackfin.uclinux.org> | 2008-03-26 09:15:58 +0800 |
|---|---|---|
| committer | Bryan Wu <cooloney@kernel.org> | 2008-03-26 09:15:58 +0800 |
| commit | 9a62ca40fd793742f92565104c6b44319af8c282 (patch) | |
| tree | 6f35dc65b76e9d789da6dc6ca72624adbc389f41 | |
| parent | 81d9c7f27dd679df6d03df53eba4fd12caafdb47 (diff) | |
[Blackfin] arch: fix bug - when we crash, current is not valid
Sometimes when we crash, current is not valid, (has been written
over), so the existing code causes a invalid read during exception
context - which is a unrecoverable double fault. This fixes this.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
| -rw-r--r-- | arch/blackfin/kernel/traps.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c index e8e8f735c23..7557d0dce21 100644 --- a/arch/blackfin/kernel/traps.c +++ b/arch/blackfin/kernel/traps.c @@ -655,21 +655,30 @@ void dump_bfin_process(struct pt_regs *fp) else if (context & 0x8000) printk(KERN_NOTICE "Kernel process context\n"); - if (current->pid && current->mm) { + /* 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) { printk(KERN_NOTICE "CURRENT PROCESS:\n"); - printk(KERN_NOTICE "COMM=%s PID=%d\n", - current->comm, current->pid); - - printk(KERN_NOTICE "TEXT = 0x%p-0x%p DATA = 0x%p-0x%p\n" - KERN_NOTICE "BSS = 0x%p-0x%p USER-STACK = 0x%p\n" - KERN_NOTICE "\n", - (void *)current->mm->start_code, - (void *)current->mm->end_code, - (void *)current->mm->start_data, - (void *)current->mm->end_data, - (void *)current->mm->end_data, - (void *)current->mm->brk, - (void *)current->mm->start_stack); + if (current->comm >= (char *)FIXED_CODE_START) + printk(KERN_NOTICE "COMM=%s PID=%d\n", + current->comm, current->pid); + else + printk(KERN_NOTICE "COMM= invalid\n"); + + if (!((unsigned long)current->mm & 0x3) && (unsigned long)current->mm >= FIXED_CODE_START) + printk(KERN_NOTICE "TEXT = 0x%p-0x%p DATA = 0x%p-0x%p\n" + KERN_NOTICE " BSS = 0x%p-0x%p USER-STACK = 0x%p\n" + KERN_NOTICE "\n", + (void *)current->mm->start_code, + (void *)current->mm->end_code, + (void *)current->mm->start_data, + (void *)current->mm->end_data, + (void *)current->mm->end_data, + (void *)current->mm->brk, + (void *)current->mm->start_stack); + else + printk(KERN_NOTICE "invalid mm\n"); } else printk(KERN_NOTICE "\n" KERN_NOTICE "No Valid process in current context\n"); |