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| author | H.J. Lu <hjl.tools@gmail.com> | 2018-07-24 07:55:35 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2018-07-24 07:55:47 -0700 |
| commit | e27f41ba2b6101be1a511905bff5502ffd23828b (patch) | |
| tree | f7bd74631da12cc22e2dc5f6556a9ea2b45de5f0 /string | |
| parent | 21526a507df8f1b2e37492193a754534d8938c0b (diff) | |
| download | glibc-e27f41ba2b6101be1a511905bff5502ffd23828b.zip glibc-e27f41ba2b6101be1a511905bff5502ffd23828b.tar.gz glibc-e27f41ba2b6101be1a511905bff5502ffd23828b.tar.bz2 | |
Add <bits/indirect-return.h>
Add <bits/indirect-return.h> and include it in <ucontext.h>.
__INDIRECT_RETURN defined in <bits/indirect-return.h> indicates if
swapcontext requires special compiler treatment. The default
__INDIRECT_RETURN is empty.
On x86, when shadow stack is enabled, __INDIRECT_RETURN is defined
with indirect_return attribute, which has been added to GCC 9, to
indicate that swapcontext returns via indirect branch. Otherwise
__INDIRECT_RETURN is defined with returns_twice attribute.
When shadow stack is enabled, remove always_inline attribute from
prepare_test_buffer in string/tst-xbzero-opt.c to avoid:
tst-xbzero-opt.c: In function ‘prepare_test_buffer’:
tst-xbzero-opt.c:105:1: error: function ‘prepare_test_buffer’ can never be inlined because it uses setjmp
prepare_test_buffer (unsigned char *buf)
when indirect_return attribute isn't available.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* bits/indirect-return.h: New file.
* misc/sys/cdefs.h (__glibc_has_attribute): New.
* sysdeps/x86/bits/indirect-return.h: Likewise.
* stdlib/Makefile (headers): Add bits/indirect-return.h.
* stdlib/ucontext.h: Include <bits/indirect-return.h>.
(swapcontext): Add __INDIRECT_RETURN.
* string/tst-xbzero-opt.c (ALWAYS_INLINE): New.
(prepare_test_buffer): Use it.
Diffstat (limited to 'string')
| -rw-r--r-- | string/tst-xbzero-opt.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/string/tst-xbzero-opt.c b/string/tst-xbzero-opt.c index cf7041f..aab4a7f 100644 --- a/string/tst-xbzero-opt.c +++ b/string/tst-xbzero-opt.c @@ -100,7 +100,15 @@ static ucontext_t uc_main, uc_co; /* Always check the test buffer immediately after filling it; this makes externally visible side effects depend on the buffer existing and having been filled in. */ -static inline __attribute__ ((always_inline)) void +#if defined __CET__ && !__glibc_has_attribute (__indirect_return__) +/* Note: swapcontext returns via indirect branch when SHSTK is enabled. + Without indirect_return attribute, swapcontext is marked with + returns_twice attribute, which prevents always_inline to work. */ +# define ALWAYS_INLINE +#else +# define ALWAYS_INLINE __attribute__ ((always_inline)) +#endif +static inline ALWAYS_INLINE void prepare_test_buffer (unsigned char *buf) { for (unsigned int i = 0; i < PATTERN_REPS; i++) |