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Commit 9f15c826 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Kyle McMartin
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[PARISC] Fix show_stack() when we can't kmalloc 



show_stack() was calling kzalloc() to allocate a struct pt_regs.
This meant that *really* early stack dumps would cause a null pointer
dereference.  x86_64 allocates its pt_regs on the stack, so do the same.

Kyle actually committed this exact patch to CVS on
Wed Jul 26 14:32:39 2006 UTC, and never moved it across to git.
Bad Kyle.

Signed-off-by: default avatarMatthew Wilcox <matthew@wil.cx>
Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent e6fc0449

arch/parisc/kernel/traps.c

+10 −9
Original line number Diff line number Diff line
@@ -187,18 +187,19 @@ void show_stack(struct task_struct *task, unsigned long *s) 


	if (!task) {

		unsigned long sp;

		struct pt_regs *r;



HERE:

		asm volatile ("copy %%r30, %0" : "=r"(sp));

		r = kzalloc(sizeof(struct pt_regs), GFP_KERNEL);

		if (!r)

			return;

		r->iaoq[0] = (unsigned long)&&HERE;

		r->gr[2] = (unsigned long)__builtin_return_address(0);

		r->gr[30] = sp;

		unwind_frame_init(&info, current, r);

		kfree(r);

		{

			struct pt_regs r;



			memset(&r, 0, sizeof(struct pt_regs));

			r.iaoq[0] = (unsigned long)&&HERE;

			r.gr[2] = (unsigned long)__builtin_return_address(0);

			r.gr[30] = sp;



			unwind_frame_init(&info, current, &r);

		}

	} else {

		unwind_frame_init_from_blocked_task(&info, task);

	}