diff options
| -rw-r--r-- | arch/arm64/kernel/signal.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 38e6fa204..6a06a4e35 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -433,6 +433,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user) unsigned int vl, vq; struct user_fpsimd_state fpsimd; u16 user_vl, flags; + bool fpsimd_only; bool sm; if (user->sve_size < sizeof(*user->sve)) @@ -443,19 +444,33 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user) if (err) return err; + fpsimd_only = (user->sve_size == sizeof(*user->sve)); sm = flags & SVE_SIG_FLAG_SM; + if (sm) { if (!system_supports_sme()) return -EINVAL; + /* + * Streaming SVE state is always preserved with an SVE payload. + * Only accept streaming state which has an SVE payload. + */ + if (fpsimd_only) + return -EINVAL; + vl = task_get_sme_vl(current); } else { /* - * A SME only system use SVE for streaming mode so can - * have a SVE formatted context with a zero VL and no - * payload data. + * Non-streaming SVE state may be preserved without an SVE + * payload, in which case all state is saved in the FPSIMD + * context. + * + * On SME-only systems, non-streaming (FPSIMD-only) state is + * always preserved without an SVE payload, and with VL==0. On + * such systems, only accept non-streaming state without an SVE + * payload. */ - if (!system_supports_sve() && !system_supports_sme()) + if (!system_supports_sve() && !fpsimd_only) return -EINVAL; vl = task_get_sve_vl(current); @@ -464,16 +479,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user) if (user_vl != vl) return -EINVAL; - /* - * Non-streaming SVE state may be preserved without an SVE payload, in - * which case the SVE context only has a header with VL==0, and all - * state can be restored from the FPSIMD context. - * - * Streaming SVE state is always preserved with an SVE payload. For - * consistency and robustness, reject restoring streaming SVE state - * without an SVE payload. - */ - if (!sm && user->sve_size == sizeof(*user->sve)) + if (fpsimd_only) return restore_fpsimd_context(user); vq = sve_vq_from_vl(vl); |