On 1/14/25 07:51, Mathieu Desnoyers wrote:
When porting librseq commit:
commit c7b45750fa85 ("Adapt to glibc __rseq_size feature detection")
from librseq to the kernel selftests, the following line was missed
at the end of rseq_init():
rseq_size = get_rseq_kernel_feature_size();
which effectively leaves rseq_size initialized to -1U when glibc does not
have rseq support. glibc supports rseq from version 2.35 onwards.
In a following librseq commit
commit c67d198627c2 ("Only set 'rseq_size' on first thread registration")
to mimic the libc behavior, a new approach is taken: don't set the
feature size in 'rseq_size' until at least one thread has successfully
registered. This allows using 'rseq_size' in fast-paths to test for both
registration status and available features. The caveat is that on libc
either all threads are registered or none are, while with bare librseq
it is the responsability of the user to register all threads using rseq.
This combines the changes from the following librseq commits:
commit c7b45750fa85 ("Adapt to glibc __rseq_size feature detection")
commit c67d198627c2 ("Only set 'rseq_size' on first thread registration")
Fixes: 73a4f5a704a2 ("selftests/rseq: Fix mm_cid test failure")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Hi Mathieu,
Can you double check these commits and make sure these are right
ones in the mainline rc7?
I am seeing "Unknown commit id" warnings on all of these - my
repo is at 6.13 rc7
Also would you like to add Reported-by for Raghavendra Rao Ananta?
thanks,
-- Shuah
