| Message ID | 20250404174435.3288106-10-mark.rutland@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: Preparatory FPSIMD/SVE/SME fixes | expand |
On Fri, Apr 04, 2025 at 06:44:30PM +0100, Mark Rutland wrote: > An exec() is expected to reset all FPSIMD/SVE/SME state, and barring > special handling of the vector lengths, the state is expected to reset > to zero. This reset is handled in fpsimd_flush_thread(), which the core > exec() code calls via flush_thread(). Reviewed-by: Mark Brown <broonie@kernel.org>
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 4a0b0bb3a3fad..0b6fda5b7bad5 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1638,6 +1638,9 @@ void fpsimd_flush_thread(void) current->thread.svcr = 0; } + if (system_supports_fpmr()) + current->thread.uw.fpmr = 0; + current->thread.fp_type = FP_STATE_FPSIMD; put_cpu_fpsimd_context();
An exec() is expected to reset all FPSIMD/SVE/SME state, and barring special handling of the vector lengths, the state is expected to reset to zero. This reset is handled in fpsimd_flush_thread(), which the core exec() code calls via flush_thread(). When support was added for FPMR, no logic was added to fpsimd_flush_thread() to reset the FPMR value, and thus it is erroneously inherited across an exec(). Add the missing reset of FPMR. Fixes: 203f2b95a882dc46 ("arm64/fpsimd: Support FEAT_FPMR") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> --- arch/arm64/kernel/fpsimd.c | 3 +++ 1 file changed, 3 insertions(+)