glibc/setjmp
H.J. Lu d6cc1829aa x86: Use pad in pthread_unwind_buf to preserve shadow stack register
The pad array in struct pthread_unwind_buf is used by setjmp to save
shadow stack register.  We assert that size of struct pthread_unwind_buf
is no less than offset of shadow stack pointer + shadow stack pointer
size.

Since functions, like LIBC_START_MAIN, START_THREAD_DEFN as well as
these with thread cancellation, call setjmp, but never return after
__libc_unwind_longjmp, __libc_unwind_longjmp, which is defined as
__libc_longjmp on x86, doesn't need to restore shadow stack register.
__libc_longjmp, which is a private interface for thread cancellation
implementation in libpthread, is changed to call __longjmp_cancel,
instead of __longjmp.  __longjmp_cancel is a new internal function
in libc, which is similar to __longjmp, but doesn't restore shadow
stack register.

The compatibility longjmp and siglongjmp in libpthread.so are changed
to call __libc_siglongjmp, instead of __libc_longjmp, so that they will
restore shadow stack register.

Tested with build-many-glibcs.py.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

	* nptl/pthread_create.c (START_THREAD_DEFN): Clear previous
	handlers after setjmp.
	* setjmp/longjmp.c (__libc_longjmp): Don't define alias if
	defined.
	* sysdeps/unix/sysv/linux/x86/setjmpP.h: Include
	<libc-pointer-arith.h>.
	(_JUMP_BUF_SIGSET_BITS_PER_WORD): New.
	(_JUMP_BUF_SIGSET_NSIG): Changed to 96.
	(_JUMP_BUF_SIGSET_NWORDS): Changed to use ALIGN_UP and
	_JUMP_BUF_SIGSET_BITS_PER_WORD.
	* sysdeps/x86/Makefile (sysdep_routines): Add __longjmp_cancel.
	* sysdeps/x86/__longjmp_cancel.S: New file.
	* sysdeps/x86/longjmp.c: Likewise.
	* sysdeps/x86/nptl/pt-longjmp.c: Likewise.
2018-05-02 06:17:41 -07:00
..
bits Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
__longjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bsd-_setjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bsd-setjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bug269-setjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
jmp-unwind.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
jmpbug.c Fix warning in setjmp/jmpbug.c. 2014-11-26 00:45:19 +00:00
longjmp.c x86: Use pad in pthread_unwind_buf to preserve shadow stack register 2018-05-02 06:17:41 -07:00
Makefile Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
setjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
setjmp.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
sigjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-setjmp-fp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-setjmp-static.c ARM: Use movw/movt more when available 2014-10-22 14:20:35 -07:00
tst-setjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-sigsetjmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
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