Commit 87db14ff authored by Michael Jeanson's avatar Michael Jeanson Committed by rminmin
Browse files

selftests/rseq: check if libc rseq support is registered 

mainline inclusion
from mainline-v6.0-rc1
commit d1a997ba
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I69PT8

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d1a997ba4c1bf65497d956aea90de42a6398f73a



--------------------------------

commit d1a997ba upstream.

When checking for libc rseq support in the library constructor, don't
only depend on the symbols presence, check that the registration was
completed.

This targets a scenario where the libc has rseq support but it is not
wired for the current architecture in 'bits/rseq.h', we want to fallback
to our internal registration mechanism.

Signed-off-by: default avatarMichael Jeanson <mjeanson@efficios.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20220614154830.1367382-4-mjeanson@efficios.com


Signed-off-by: default avatarrminmin <renmm6@chinaunicom.cn>
parent 2da4a932

tools/testing/selftests/rseq/rseq.c

+2 −1
Original line number Diff line number Diff line
@@ -111,7 +111,8 @@ void rseq_init(void) 
	libc_rseq_offset_p = dlsym(RTLD_NEXT, "__rseq_offset");

	libc_rseq_size_p = dlsym(RTLD_NEXT, "__rseq_size");

	libc_rseq_flags_p = dlsym(RTLD_NEXT, "__rseq_flags");

	if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p) {

	if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p &&

			*libc_rseq_size_p != 0) {

		/* rseq registration owned by glibc */

		rseq_offset = *libc_rseq_offset_p;

		rseq_size = *libc_rseq_size_p;