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Commit b0529bec authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Ingo Molnar
Browse files

x86/dumpstack: Fix occasionally missing registers 



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: default avatarJosh 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: 3b3fa11b ("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: default avatarIngo Molnar <mingo@kernel.org>
parent 29955909

arch/x86/kernel/dumpstack.c

+7 −5
Original line number Diff line number Diff line
@@ -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);

		}