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| 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/allocatestack.c | |
| parent | c70e4e9c9efff9df4c847dd7cfd81bae674219ab (diff) | |
| download | glibc-630f4cc3aa019ede55976ea561f1a7af2f068639.tar.gz glibc-630f4cc3aa019ede55976ea561f1a7af2f068639.tar.xz glibc-630f4cc3aa019ede55976ea561f1a7af2f068639.zip | |
[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/allocatestack.c')
| -rw-r--r-- | nptl/allocatestack.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 05b8ed331b..b374f4794d 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -532,6 +532,10 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, /* Make sure the size of the stack is enough for the guard and eventually the thread descriptor. */ guardsize = (attr->guardsize + pagesize_m1) & ~pagesize_m1; + if (guardsize < attr->guardsize || size + guardsize < guardsize) + /* Arithmetic overflow. */ + return EINVAL; + size += guardsize; if (__builtin_expect (size < ((guardsize + __static_tls_size + MINIMAL_REST_STACK + pagesize_m1) & ~pagesize_m1), |