From c547c77ee4d0408907847f64c403df1bf2f9c7a0 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 28 Nov 2006 20:12:59 +0100 Subject: [PATCH] [PATCH] x86-64: Use stricter in process stack check for unwinder Previously it would check for alignment only, which could break if the stack pointer was unaligned. Now explicitely check if the stack pointer is in the stack page of the current process. Ported from i386. Signed-off-by: Andi Kleen --- arch/x86_64/kernel/traps.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index a153d0a01b72..0d65b22f229c 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -242,12 +242,19 @@ static int dump_trace_unwind(struct unwind_frame_info *info, void *context) * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack */ +static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) +{ + void *t = (void *)tinfo; + return p > t && p < t + THREAD_SIZE - 3; +} + void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack, struct stacktrace_ops *ops, void *data) { const unsigned cpu = smp_processor_id(); unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr; unsigned used = 0; + struct thread_info *tinfo; if (!tsk) tsk = current; @@ -370,7 +377,8 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s /* * This handles the process stack: */ - HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0); + tinfo = current_thread_info(); + HANDLE_STACK (valid_stack_ptr(tinfo, stack)); #undef HANDLE_STACK } EXPORT_SYMBOL(dump_trace);