Messages in this thread | | | Date | Thu, 4 Sep 2014 17:02:34 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/2] sched: Add helper for task stack page overrun checking |
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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.
> > 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 >
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