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| author | Andy Lutomirski <luto@kernel.org> | 2016-07-14 22:22:53 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-15 10:26:27 +0200 |
| commit | 98f30b1207932b6553ea605c99393d8afca12324 (patch) | |
| tree | 5149ed332c37aaf207a3417a9e0a49d840590c6e /arch/x86 | |
| parent | x86/dumpstack: Try harder to get a call trace on stack overflow (diff) | |
| download | linux-98f30b1207932b6553ea605c99393d8afca12324.tar.xz linux-98f30b1207932b6553ea605c99393d8afca12324.zip | |
x86/dumpstack/64: Handle faults when printing the "Stack: " part of an OOPS
If we overflow the stack into a guard page, we'll recursively fault
when trying to dump the contents of the guard page. Use
probe_kernel_address() so we can recover if this happens.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e626d47a55d7b04dcb1b4d33faa95e8505b217c8.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index d558a8a49016..2552a1eadfed 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -272,6 +272,8 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, stack = sp; for (i = 0; i < kstack_depth_to_print; i++) { + unsigned long word; + if (stack >= irq_stack && stack <= irq_stack_end) { if (stack == irq_stack_end) { stack = (unsigned long *) (irq_stack_end[-1]); @@ -281,12 +283,18 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, if (kstack_end(stack)) break; } + + if (probe_kernel_address(stack, word)) + break; + if ((i % STACKSLOTS_PER_LINE) == 0) { if (i != 0) pr_cont("\n"); - printk("%s %016lx", log_lvl, *stack++); + printk("%s %016lx", log_lvl, word); } else - pr_cont(" %016lx", *stack++); + pr_cont(" %016lx", word); + + stack++; touch_nmi_watchdog(); } preempt_enable(); |