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ia64: Fix thread stack allocation permission set (BZ #21672)

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This patch fixes ia64 failures on thread exit by madvise the required
area taking in consideration its disjoing stacks
(NEED_SEPARATE_REGISTER_STACK).  Also the snippet that setup the
madvise call to advertise kernel the area won't be used anymore in
near future is reallocated in allocatestack.c (for consistency to
put all stack management function in one place).

Checked on x86_64-linux-gnu and i686-linux-gnu for sanity (since
it is not expected code changes for architecture that do not
define NEED_SEPARATE_REGISTER_STACK) and also got a report that
it fixes ia64-linux-gnu failures from Sergei Trofimovich
<slyfox@gentoo.org>.

	[BZ #21672]
	* nptl/allocatestack.c [_STACK_GROWS_DOWN] (setup_stack_prot):
	Set to use !NEED_SEPARATE_REGISTER_STACK as well.
	(advise_stack_range): New function.
	* nptl/pthread_create.c (START_THREAD_DEFN): Move logic to mark
	stack non required to advise_stack_range at allocatestack.c
This commit is contained in:
Adhemerval Zanella
2017-08-28 11:24:35 -03:00
parent 16f138a49a
commit 01b87c656f
3 changed files with 39 additions and 26 deletions
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27
nptl/pthread_create.c
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@ -551,31 +551,8 @@ START_THREAD_DEFN
}
#endif
/* Mark the memory of the stack as usable to the kernel. We free
everything except for the space used for the TCB itself. */
size_t pagesize_m1 = __getpagesize () - 1;
#ifdef _STACK_GROWS_DOWN
char *sp = CURRENT_STACK_FRAME;
size_t freesize = (sp - (char *) pd->stackblock) & ~pagesize_m1;
assert (freesize < pd->stackblock_size);
if (freesize > PTHREAD_STACK_MIN)
__madvise (pd->stackblock, freesize - PTHREAD_STACK_MIN, MADV_DONTNEED);
#else
/* Page aligned start of memory to free (higher than or equal
to current sp plus the minimum stack size). */
void *freeblock = (void*)((size_t)(CURRENT_STACK_FRAME
+ PTHREAD_STACK_MIN
+ pagesize_m1)
& ~pagesize_m1);
char *free_end = (char *) (((uintptr_t) pd - pd->guardsize) & ~pagesize_m1);
/* Is there any space to free? */
if (free_end > (char *)freeblock)
{
size_t freesize = (size_t)(free_end - (char *)freeblock);
assert (freesize < pd->stackblock_size);
__madvise (freeblock, freesize, MADV_DONTNEED);
}
#endif
advise_stack_range (pd->stackblock, pd->stackblock_size, (uintptr_t) pd,
pd->guardsize);
/* If the thread is detached free the TCB. */
if (IS_DETACHED (pd))