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authorH.J. Lu <hjl.tools@gmail.com>2017-12-19 02:43:50 -0800
committerH.J. Lu <hjl.tools@gmail.com>2017-12-19 02:44:04 -0800
commitf81ddabffd76ac9dd600b02adbf3e1dac4bb10ec (patch)
tree7f9cac093b8e4d135be6ba830cd2bfe9a004131f /sysdeps/nptl
parent1a49fc59e42513247eaeac3feac6b099157eea7c (diff)
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Linux/x86: Update cancel_jmp_buf to match __jmp_buf_tag [BZ #22563]
On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer to support shadow stack in Intel Control-flow Enforcemen Technology. Since the cancel_jmp_buf array is passed to setjmp and longjmp by casting it to pointer to struct __jmp_buf_tag, it should be as large as struct __jmp_buf_tag. Otherwise when shadow stack is enabled, setjmp and longjmp will write and read beyond cancel_jmp_buf when saving and restoring shadow stack pointer. This patch adds bits/types/__cancel_jmp_buf_tag.h to define struct __cancel_jmp_buf_tag so that Linux/x86 can add saved_mask to cancel_jmp_buf. Tested natively on i386, x86_64 and x32. Tested hppa-linux-gnu with build-many-glibcs.py. [BZ #22563] * bits/types/__cancel_jmp_buf_tag.h: New file. * sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h * sysdeps/unix/sysv/linux/x86/pthreaddef.h: Likewise. * sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h: Likewise. * nptl/Makefile (headers): Add bits/types/__cancel_jmp_buf_tag.h. * nptl/descr.h [NEED_SAVED_MASK_IN_CANCEL_JMP_BUF] (pthread_unwind_buf): Add saved_mask to cancel_jmp_buf. * sysdeps/nptl/pthread.h: Include <bits/types/__cancel_jmp_buf_tag.h>. (__pthread_unwind_buf_t): Use struct __cancel_jmp_buf_tag with __cancel_jmp_buf. * sysdeps/unix/sysv/linux/hppa/pthread.h: Likewise.
Diffstat (limited to 'sysdeps/nptl')
-rw-r--r--sysdeps/nptl/pthread.h7
1 files changed, 2 insertions, 5 deletions
diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h
index 2b2b386..787ac6e 100644
--- a/sysdeps/nptl/pthread.h
+++ b/sysdeps/nptl/pthread.h
@@ -27,6 +27,7 @@
#include <bits/setjmp.h>
#include <bits/wordsize.h>
#include <bits/types/struct_timespec.h>
+#include <bits/types/__cancel_jmp_buf_tag.h>
/* Detach state. */
@@ -523,11 +524,7 @@ extern void pthread_testcancel (void);
typedef struct
{
- struct
- {
- __jmp_buf __cancel_jmp_buf;
- int __mask_was_saved;
- } __cancel_jmp_buf[1];
+ struct __cancel_jmp_buf_tag __cancel_jmp_buf[1];
void *__pad[4];
} __pthread_unwind_buf_t __attribute__ ((__aligned__));