4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Redfearn <matt.redfearn@xxxxxxxxxx> commit d42d8d106b0275b027c1e8992c42aecf933436ea upstream. 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@xxxxxxxxxx> Acked-by: Jason A. Donenfeld <jason@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Adam Buchbinder <adam.buchbinder@xxxxxxxxx> Cc: Maciej W. Rozycki <macro@xxxxxxxxxx> Cc: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx> Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx> Cc: James Hogan <james.hogan@xxxxxxxxxx> Cc: Paul Burton <paul.burton@xxxxxxxxxx> Cc: Jiri Slaby <jslaby@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/14741/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/kernel/process.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -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> @@ -556,7 +557,19 @@ 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
