diff options
Diffstat (limited to 'nptl/allocatestack.c')
| -rw-r--r-- | nptl/allocatestack.c | 53 |
1 files changed, 46 insertions, 7 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 6ada1fe138..dc501650b8 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -351,11 +351,12 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, } else { - /* Allocate some anonymous memory. If possible use the - cache. */ + /* Allocate some anonymous memory. If possible use the cache. */ size_t guardsize; size_t reqsize; void *mem; + const int prot = (PROT_READ | PROT_WRITE + | ((GL(dl_stack_flags) & PF_X) ? PROT_EXEC : 0)); #if COLORING_INCREMENT != 0 /* Add one more page for stack coloring. Don't do it for stacks @@ -392,7 +393,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, size += pagesize_m1 + 1; #endif - mem = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC, + mem = mmap (NULL, size, prot, MAP_PRIVATE | MAP_ANONYMOUS | ARCH_MAP_FLAGS, -1, 0); if (__builtin_expect (mem == MAP_FAILED, 0)) @@ -546,17 +547,16 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, char *oldguard = mem + (((size - pd->guardsize) / 2) & ~pagesize_m1); if (oldguard < guard - && mprotect (oldguard, guard - oldguard, - PROT_READ | PROT_WRITE | PROT_EXEC) != 0) + && mprotect (oldguard, guard - oldguard, prot) != 0) goto mprot_error; if (mprotect (guard + guardsize, oldguard + pd->guardsize - guard - guardsize, - PROT_READ | PROT_WRITE | PROT_EXEC) != 0) + prot) != 0) goto mprot_error; #else if (mprotect ((char *) mem + guardsize, pd->guardsize - guardsize, - PROT_READ | PROT_WRITE | PROT_EXEC) != 0) + prot) != 0) goto mprot_error; #endif @@ -616,6 +616,45 @@ __deallocate_stack (struct pthread *pd) } +int +internal_function +__make_stacks_executable (void) +{ +#ifdef NEED_SEPARATE_REGISTER_STACK + const size_t pagemask = ~(__getpagesize () - 1); +#endif + + lll_lock (stack_cache_lock); + + int err = 0; + list_t *runp; + list_for_each (runp, &stack_used) + { + struct pthread *const pd = list_entry (runp, struct pthread, list); +#ifdef NEED_SEPARATE_REGISTER_STACK + void *stack = (pd->stackblock + + (((((pd->stackblock_size - pd->guardsize) / 2) + & pagemask) + pd->guardsize) & pagemask)); + size_t len = pd->stackblock + pd->stackblock_size - stack; +#else + void *stack = pd->stackblock + pd->guardsize; + size_t len = pd->stackblock_size - pd->guardsize; +#endif + if (mprotect (stack, len, PROT_READ | PROT_WRITE | PROT_EXEC) != 0) + { + err = errno; + break; + } + } + + lll_unlock (stack_cache_lock); + + _dl_make_stack_executable (); + + return err; +} + + /* In case of a fork() call the memory allocation in the child will be the same but only one thread is running. All stacks except that of the one running thread are not used anymore. We have to recycle |