File stack-guard-size-accounting.patch of Package glibc.15121
2018-01-08 Szabolcs Nagy <szabolcs.nagy@arm.com>
[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.
Index: glibc-2.26/nptl/allocatestack.c
===================================================================
--- glibc-2.26.orig/nptl/allocatestack.c
+++ glibc-2.26/nptl/allocatestack.c
@@ -506,6 +506,10 @@ allocate_stack (const struct pthread_att
/* 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),
Index: glibc-2.26/nptl/descr.h
===================================================================
--- glibc-2.26.orig/nptl/descr.h
+++ glibc-2.26/nptl/descr.h
@@ -380,9 +380,9 @@ struct pthread
/* Machine-specific unwind info. */
struct _Unwind_Exception exc;
- /* If nonzero pointer to area allocated for the stack and its
- size. */
+ /* If nonzero, pointer to the area allocated for the stack and guard. */
void *stackblock;
+ /* Size of the stackblock area including the guard. */
size_t stackblock_size;
/* Size of the included guard area. */
size_t guardsize;
Index: glibc-2.26/nptl/nptl-init.c
===================================================================
--- glibc-2.26.orig/nptl/nptl-init.c
+++ glibc-2.26/nptl/nptl-init.c
@@ -473,8 +473,5 @@ strong_alias (__pthread_initialize_minim
size_t
__pthread_get_minstack (const pthread_attr_t *attr)
{
- struct pthread_attr *iattr = (struct pthread_attr *) attr;
-
- return (GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN
- + iattr->guardsize);
+ return GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN;
}
Index: glibc-2.26/nptl/pthread_getattr_np.c
===================================================================
--- glibc-2.26.orig/nptl/pthread_getattr_np.c
+++ glibc-2.26/nptl/pthread_getattr_np.c
@@ -57,9 +57,12 @@ pthread_getattr_np (pthread_t thread_id,
/* 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