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x86/dumpstack: Handle stack overflow on all stacks

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We currently special-case stack overflow on the task stack.  We're
going to start putting special stacks in the fixmap with a custom
layout, so they'll have guard pages, too.  Teach the unwinder to be
able to unwind an overflow of any of the stacks.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.802057305@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2017-12-04 15:07:18 +01:00 committed by Ingo Molnar
parent 7fb983b4dd
commit 6e60e58342
1 changed files with 14 additions and 10 deletions
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16
arch/x86/kernel/dumpstack.c
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@ -112,24 +112,28 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
* - task stack * - task stack
* - interrupt stack * - interrupt stack
* - HW exception stacks (double fault, nmi, debug, mce) * - HW exception stacks (double fault, nmi, debug, mce)
* - SYSENTER stack
* *
* x86-32 can have up to three stacks: * x86-32 can have up to four stacks:
* - task stack * - task stack
* - softirq stack * - softirq stack
* - hardirq stack * - hardirq stack
* - SYSENTER stack
*/ */
for (regs = NULL; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { for (regs = NULL; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
const char *stack_name; const char *stack_name;
if (get_stack_info(stack, task, &stack_info, &visit_mask)) {
/* /*
* If we overflowed the task stack into a guard page, jump back * We weren't on a valid stack. It's possible that
* to the bottom of the usable stack. * we overflowed a valid stack into a guard page.
* See if the next page up is valid so that we can
* generate some kind of backtrace if this happens.
*/ */
if (task_stack_page(task) - (void *)stack < PAGE_SIZE) stack = (unsigned long *)PAGE_ALIGN((unsigned long)stack);
stack = task_stack_page(task);
if (get_stack_info(stack, task, &stack_info, &visit_mask)) if (get_stack_info(stack, task, &stack_info, &visit_mask))
break; break;
}
stack_name = stack_type_name(stack_info.type); stack_name = stack_type_name(stack_info.type);
if (stack_name) if (stack_name)