kselftest/arm64: fp-ptrace: Fix checks for inactive SVE and SSVE regsets

The checks on the header size reported for the inactive regset of the
NT_ARM_SVE/NT_ARM_SSVE pair compare it against sizeof(sve), but sve is
a struct user_sve_header *, so this is 8 rather than the intended 16.
The kernel carried the identical typo when filling in the header, so
kernel and test agreed on the wrong value and the test passed.

Compare against sizeof(*sve), stop after the header checks for an
inactive regset since it has no payload to compare, and prefill the
buffer with a sentinel to verify that reading an inactive regset
leaves everything after the header untouched. This also covers the
getter's return value, which determines how many bytes ptrace copies
back to userspace.

Fixes: 864f3ddcd715 ("kselftest/arm64: fp-ptrace: Adjust to new inactive mode behaviour")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>

0 files changed, 0 insertions, 0 deletions