When copying the EXTRA context our calculation of the amount of data we need to copy is incorrect, we only calculate the amount of data needed within uc_mcontext.__reserved, not taking account of the fixed portion of the context. Add in the offset of the reserved data so that we copy everything we should.

This will only cause test failures in cases where the last context in the EXTRA context is smaller than the missing data since we don't currently validate any of the register data and all the buffers we copy into are statically allocated so default to zero meaning that if we walk beyond the end of what we copied we'll encounter what looks like a context with magic and length both 0 which is a valid terminator record.

Signed-off-by: Mark Brown broonie@kernel.org --- tools/testing/selftests/arm64/signal/test_signals_utils.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.c b/tools/testing/selftests/arm64/signal/test_signals_utils.c index 308e229e58ab..746a4f70f082 100644 --- a/tools/testing/selftests/arm64/signal/test_signals_utils.c +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.c @@ -192,8 +192,10 @@ static bool handle_signal_copyctx(struct tdescr *td, * in the copy, this was previously validated in * ASSERT_GOOD_CONTEXT(). */ - to_copy = offset + sizeof(struct extra_context) + 16 + - extra->size; + to_copy = __builtin_offsetof(ucontext_t, + uc_mcontext.__reserved); + to_copy += offset + sizeof(struct extra_context) + 16; + to_copy += extra->size; copied_extra = (struct extra_context *)&(td->live_uc->uc_mcontext.__reserved[offset]); } else { copied_extra = NULL;

--- base-commit: b7bfaa761d760e72a969d116517eaa12e404c262 change-id: 20230201-arm64-kselftest-full-extra-164baae78412

Best regards,