diff options
Diffstat (limited to 'linuxthreads/manager.c')
| -rw-r--r-- | linuxthreads/manager.c | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/linuxthreads/manager.c b/linuxthreads/manager.c index 37f4267..8442629 100644 --- a/linuxthreads/manager.c +++ b/linuxthreads/manager.c @@ -418,7 +418,7 @@ static int pthread_allocate_stack(const pthread_attr_t *attr, new_thread_bottom = (char *) map_addr + guardsize; new_thread = ((pthread_descr) (new_thread_bottom + stacksize)) - 1; -# else +# else /* !FLOATING_STACKS */ if (attr != NULL) { guardsize = page_roundup (attr->__guardsize, granularity); @@ -696,23 +696,24 @@ static void pthread_free(pthread_descr th) { size_t guardsize = th->p_guardsize; /* Free the stack and thread descriptor area */ -#ifdef NEED_SEPARATE_REGISTER_STACK char *guardaddr = th->p_guardaddr; - /* We unmap exactly what we mapped, in case there was something - else in the same region. Guardaddr is always set, eve if - guardsize is 0. This allows us to compute everything else. */ + /* Guardaddr is always set, even if guardsize is 0. This allows + us to compute everything else. */ size_t stacksize = (char *)(th+1) - guardaddr - guardsize; - /* Unmap the register stack, which is below guardaddr. */ - munmap((caddr_t)(guardaddr-stacksize), - 2 * stacksize + th->p_guardsize); +#ifdef NEED_SEPARATE_REGISTER_STACK + /* Take account of the register stack, which is below guardaddr. */ + guardaddr -= stacksize; + stacksize *= 2; +#endif +#if FLOATING_STACKS + /* Can unmap safely. */ + munmap(guardaddr, stacksize + guardsize); #else - char *guardaddr = th->p_guardaddr; - /* We unmap exactly what we mapped, in case there was something - else in the same region. Guardaddr is always set, eve if - guardsize is 0. This allows us to compute everything else. */ - size_t stacksize = (char *)(th+1) - guardaddr - guardsize; - - munmap (guardaddr, stacksize + guardsize); + /* Only remap to PROT_NONE, so that the region is reserved in + case we map the stack again later. Avoid collision with + other mmap()s, in particular by malloc(). */ + mmap(guardaddr, stacksize + guardsize, PROT_NONE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); #endif } } |