Commit d42d8d10 authored Dec 19, 2016 by Matt Redfearn Committed by Ralf Baechle Jan 03, 2017

MIPS: Stack unwinding while on IRQ stack

Within unwind stack, check if the stack pointer being unwound is within
the CPU's irq_stack and if so use that page rather than the task's stack
page.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Acked-by: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14741/

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent fe8bd18f

arch/mips/kernel/process.c

+14 −1

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@
		#include <asm/dsemul.h>
		#include <asm/dsp.h>
		#include <asm/fpu.h>
		#include <asm/irq.h>
		#include <asm/msa.h>
		#include <asm/pgtable.h>
		#include <asm/mipsregs.h>
		@@ -511,7 +512,19 @@ EXPORT_SYMBOL(unwind_stack_by_address);
		unsigned long unwind_stack(struct task_struct task, unsigned long sp,
		unsigned long pc, unsigned long *ra)
		{
		unsigned long stack_page = (unsigned long)task_stack_page(task);
		unsigned long stack_page = 0;
		int cpu;

		for_each_possible_cpu(cpu) {
		if (on_irq_stack(cpu, *sp)) {
		stack_page = (unsigned long)irq_stack[cpu];
		break;
		}
		}

		if (!stack_page)
		stack_page = (unsigned long)task_stack_page(task);

		return unwind_stack_by_address(stack_page, sp, pc, ra);
		}
		#endif

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