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nptl: support thread stacks that grow up

Gentoo has been carrying this for all arches since 2.17.

URL: http://bugs.gentoo.org/301642
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Carlos O'Donell Mike Frysinger
Carlos O'Donell authored and Mike Frysinger committed Aug 9, 2015
1 parent 11fca96 commit d615a47355699d29df01b28a120cef29c8a38091
Showing with 55 additions and 12 deletions.
  1. +11 −0 ChangeLog
  2. +13 −7 nptl/allocatestack.c
  3. +16 −3 nptl/pthread_create.c
  4. +15 −2 nptl/pthread_getattr_np.c
@@ -1,3 +1,14 @@
2016-02-19 Carlos O'Donell <carlos@systemhalted.org>

* nptl/allocatestack.c (allocate_stack): Declare new stackaddr,
assign attr->stackaddr to it, and adjust it down when
_STACK_GROWS_UP. Change all attr->stackaddr to stackaddr.
[_STACK_GROWS_UP]: Delete assert.
* nptl/pthread_create.c (START_THREAD_DEFN) [!_STACK_GROWS_DOWN]:
Implement stack grows up logic.
* nptl/pthread_getattr_np.c (pthread_getattr_np): Implement
stack grows up logic.

2016-02-19 Adhemerval Zanella <adhemerval.zanella@linaro.org>

* NEWS: Update with 2.24 template.
@@ -372,6 +372,13 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
if (__glibc_unlikely (attr->flags & ATTR_FLAG_STACKADDR))
{
uintptr_t adj;
char *stackaddr = (char *) attr->stackaddr;

/* Assume the same layout as the _STACK_GROWS_DOWN case, with struct
pthread at the top of the stack block. Later we adjust the guard
location and stack address to match the _STACK_GROWS_UP case. */
if (_STACK_GROWS_UP)
stackaddr += attr->stacksize;

/* If the user also specified the size of the stack make sure it
is large enough. */
@@ -381,11 +388,11 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,

/* Adjust stack size for alignment of the TLS block. */
#if TLS_TCB_AT_TP
adj = ((uintptr_t) attr->stackaddr - TLS_TCB_SIZE)
adj = ((uintptr_t) stackaddr - TLS_TCB_SIZE)
& __static_tls_align_m1;
assert (size > adj + TLS_TCB_SIZE);
#elif TLS_DTV_AT_TP
adj = ((uintptr_t) attr->stackaddr - __static_tls_size)
adj = ((uintptr_t) stackaddr - __static_tls_size)
& __static_tls_align_m1;
assert (size > adj);
#endif
@@ -395,10 +402,10 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
the stack. It is the user's responsibility to do this if it
is wanted. */
#if TLS_TCB_AT_TP
pd = (struct pthread *) ((uintptr_t) attr->stackaddr
pd = (struct pthread *) ((uintptr_t) stackaddr
- TLS_TCB_SIZE - adj);
#elif TLS_DTV_AT_TP
pd = (struct pthread *) (((uintptr_t) attr->stackaddr
pd = (struct pthread *) (((uintptr_t) stackaddr
- __static_tls_size - adj)
- TLS_PRE_TCB_SIZE);
#endif
@@ -410,7 +417,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
pd->specific[0] = pd->specific_1stblock;

/* Remember the stack-related values. */
pd->stackblock = (char *) attr->stackaddr - size;
pd->stackblock = (char *) stackaddr - size;
pd->stackblock_size = size;

/* This is a user-provided stack. It will not be queued in the
@@ -634,7 +641,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
char *guard = mem + (((size - guardsize) / 2) & ~pagesize_m1);
#elif _STACK_GROWS_DOWN
char *guard = mem;
# elif _STACK_GROWS_UP
#elif _STACK_GROWS_UP
char *guard = (char *) (((uintptr_t) pd - guardsize) & ~pagesize_m1);
#endif
if (mprotect (guard, guardsize, PROT_NONE) != 0)
@@ -734,7 +741,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
# endif
#else
*stack = pd->stackblock;
assert (*stack > 0);
#endif

return 0;
@@ -427,12 +427,25 @@ START_THREAD_DEFN
#ifdef _STACK_GROWS_DOWN
char *sp = CURRENT_STACK_FRAME;
size_t freesize = (sp - (char *) pd->stackblock) & ~pagesize_m1;
#else
# error "to do"
#endif
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

/* If the thread is detached free the TCB. */
if (IS_DETACHED (pd))
@@ -58,7 +58,11 @@ pthread_getattr_np (pthread_t thread_id, pthread_attr_t *attr)
if (__glibc_likely (thread->stackblock != NULL))
{
iattr->stacksize = thread->stackblock_size;
#if _STACK_GROWS_DOWN
iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize;
#else
iattr->stackaddr = (char *) thread->stackblock;
#endif
}
else
{
@@ -103,7 +107,9 @@ pthread_getattr_np (pthread_t thread_id, pthread_attr_t *attr)

char *line = NULL;
size_t linelen = 0;
#if _STACK_GROWS_DOWN
uintptr_t last_to = 0;
#endif

while (! feof_unlocked (fp))
{
@@ -127,17 +133,24 @@ pthread_getattr_np (pthread_t thread_id, pthread_attr_t *attr)
stack extension request. */
iattr->stacksize = (iattr->stacksize
& -(intptr_t) GLRO(dl_pagesize));

#if _STACK_GROWS_DOWN
/* The limit might be too high. */
if ((size_t) iattr->stacksize
> (size_t) iattr->stackaddr - last_to)
iattr->stacksize = (size_t) iattr->stackaddr - last_to;

#else
/* The limit might be too high. */
if ((size_t) iattr->stacksize
> to - (size_t) iattr->stackaddr)
iattr->stacksize = to - (size_t) iattr->stackaddr;
#endif
/* We succeed and no need to look further. */
ret = 0;
break;
}
#if _STACK_GROWS_DOWN
last_to = to;
#endif
}

free (line);

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