Commit
6d502b6ba1b2 ("arm64: signal: nofpsimd: Handle fp/simd context for
signal frames") introduced saving the fp/simd context for signal handling
only when support is available. But setup_sigframe_layout() always
reserves memory for fp/simd context. The additional memory is not touched
because preserve_fpsimd_context() is not called and thus the magic is
invalid.
This may lead to an error when parse_user_sigframe() checks the fp/simd
area and does not find a valid magic number.
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Reviwed-by: Mark Brown <broonie@kernel.org>
Fixes:
6d502b6ba1b267b3 ("arm64: signal: nofpsimd: Handle fp/simd context for signal frames")
Cc: <stable@vger.kernel.org> # 5.6.x
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220225104008.820289-1-david.engraf@sysgo.com
Signed-off-by: Will Deacon <will@kernel.org>
{
int err;
- err = sigframe_alloc(user, &user->fpsimd_offset,
- sizeof(struct fpsimd_context));
- if (err)
- return err;
+ if (system_supports_fpsimd()) {
+ err = sigframe_alloc(user, &user->fpsimd_offset,
+ sizeof(struct fpsimd_context));
+ if (err)
+ return err;
+ }
/* fault information, if valid */
if (add_all || current->thread.fault_code) {