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x86/dumpstack: Fix occasionally missing registers

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If two consecutive stack frames have pt_regs, the oops dump code fails
to print the second frame's registers.  Fix that.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
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: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Fixes: 3b3fa11bc7 ("x86/dumpstack: Print any pt_regs found on the stack")
Link: http://lkml.kernel.org/r/269c5c00c7d45c699f3dcea42a3a594c6cf7a9a3.1499786555.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Josh Poimboeuf 2017-07-11 10:33:40 -05:00 committed by Ingo Molnar
parent 2995590964
commit b0529beceb
1 changed files with 7 additions and 5 deletions
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12
arch/x86/kernel/dumpstack.c
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@ -94,6 +94,9 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
if (stack_name)
printk("%s <%s>\n", log_lvl, stack_name);
if (regs && on_stack(&stack_info, regs, sizeof(*regs)))
__show_regs(regs, 0);
/*
* Scan the stack, printing any text addresses we find. At the
* same time, follow proper stack frames with the unwinder.
@ -118,10 +121,8 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
* Don't print regs->ip again if it was already printed
* by __show_regs() below.
*/
if (regs && stack == &regs->ip) {
unwind_next_frame(&state);
continue;
}
if (regs && stack == &regs->ip)
goto next;
if (stack == ret_addr_p)
reliable = 1;
@ -144,6 +145,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
if (!reliable)
continue;
next:
/*
* Get the next frame from the unwinder. No need to
* check for an error: if anything goes wrong, the rest
@ -153,7 +155,7 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
/* if the frame has entry regs, print them */
regs = unwind_get_entry_regs(&state);
if (regs)
if (regs && on_stack(&stack_info, regs, sizeof(*regs)))
__show_regs(regs, 0);
}