Re: [PATCH 1/2] sched: Add helper for task stack page overrun checking
From: Oleg Nesterov <oleg@redhat.com>
Date: 2014-09-04 15:05:41
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On 09/04, Aaron Tomlin wrote:
+#define task_stack_end_corrupted(task) \ + (*(end_of_stack(task)) != STACK_END_MAGIC)
and it is always used along with "tsk != init_task". But why we exclude swapper/0? Can't we add end_of_stack(current) = STACK_END_MAGIC; somewhere at the start of start_kernel() ? If not, perhaps this new helper should check "task != &init_task" itself so that we can simplify its users? Oleg.
quoted hunk ↗ jump to hunk
static inline int object_is_on_stack(void *obj) {diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 8a4e5cb..06c7390 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c@@ -13,7 +13,6 @@ #include <linux/sysctl.h> #include <linux/init.h> #include <linux/fs.h> -#include <linux/magic.h> #include <asm/setup.h>@@ -171,8 +170,8 @@ check_stack(unsigned long ip, unsigned long *stack) i++; } - if ((current != &init_task && - *(end_of_stack(current)) != STACK_END_MAGIC)) { + if (current != &init_task && + task_stack_end_corrupted(current)) { print_max_stack(); BUG(); }-- 1.9.3