diff options
| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2017-12-06 13:05:50 +0000 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2018-01-08 19:02:11 +0000 |
| commit | 630f4cc3aa019ede55976ea561f1a7af2f068639 (patch) | |
| tree | 67f9cc70df8a9b90122106ec5be5ac7495f00dda /nptl/pthread_getattr_np.c | |
| parent | c70e4e9c9efff9df4c847dd7cfd81bae674219ab (diff) | |
[BZ #22637] Fix stack guard size accounting
Previously if user requested S stack and G guard when creating a
thread, the total mapping was S and the actual available stack was
S - G - static_tls, which is not what the user requested.
This patch fixes the guard size accounting by pretending the user
requested S+G stack. This way all later logic works out except
when reporting the user requested stack size (pthread_getattr_np)
or when computing the minimal stack size (__pthread_get_minstack).
Normally this will increase thread stack allocations by one page.
TLS accounting is not affected, that will require a separate fix.
[BZ #22637]
* nptl/descr.h (stackblock, stackblock_size): Update comments.
* nptl/allocatestack.c (allocate_stack): Add guardsize to stacksize.
* nptl/nptl-init.c (__pthread_get_minstack): Remove guardsize from
stacksize.
* nptl/pthread_getattr_np.c (pthread_getattr_np): Likewise.
Diffstat (limited to 'nptl/pthread_getattr_np.c')
| -rw-r--r-- | nptl/pthread_getattr_np.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/nptl/pthread_getattr_np.c b/nptl/pthread_getattr_np.c index 961d711fd2..ae12592294 100644 --- a/nptl/pthread_getattr_np.c +++ b/nptl/pthread_getattr_np.c @@ -57,9 +57,12 @@ pthread_getattr_np (pthread_t thread_id, pthread_attr_t *attr) /* The sizes are subject to alignment. */ if (__glibc_likely (thread->stackblock != NULL)) { - iattr->stacksize = thread->stackblock_size; + /* The stack size reported to the user should not include the + guard size. */ + iattr->stacksize = thread->stackblock_size - thread->guardsize; #if _STACK_GROWS_DOWN - iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize; + iattr->stackaddr = (char *) thread->stackblock + + thread->stackblock_size; #else iattr->stackaddr = (char *) thread->stackblock; #endif |