arm64/signal: Clean up SVE/SME feature checking inconsistency

Currently when restoring signal state we check to see if SVE is supported
in restore_sigframe() but check to see if SVE is supported inside
restore_sve_fpsimd_context(). This makes no real difference since SVE is
always supported in systems with SME but looks a bit untidy and makes
things slightly harder to follow, move the SVE check next to the SME one
in restore_sve_fpsimd_context().

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220624172108.555000-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index b0980fbb6bc7f2df7b64e056d9d0e04e2546b67a..3e6d0352d7d36469d85853af6059a9523a5fa8e4 100644 (file)
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -280,6 +280,9 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user)
 
                vl = task_get_sme_vl(current);
        } else {
+               if (!system_supports_sve())
+                       return -EINVAL;
+
                vl = task_get_sve_vl(current);
        }
 
@@ -342,9 +345,14 @@ fpsimd_only:
 
 #else /* ! CONFIG_ARM64_SVE */
 
-/* Turn any non-optimised out attempts to use these into a link error: */
+static int restore_sve_fpsimd_context(struct user_ctxs *user)
+{
+       WARN_ON_ONCE(1);
+       return -EINVAL;
+}
+
+/* Turn any non-optimised out attempts to use this into a link error: */
 extern int preserve_sve_context(void __user *ctx);
-extern int restore_sve_fpsimd_context(struct user_ctxs *user);
 
 #endif /* ! CONFIG_ARM64_SVE */
 
@@ -649,14 +657,10 @@ static int restore_sigframe(struct pt_regs *regs,
                if (!user.fpsimd)
                        return -EINVAL;
 
-               if (user.sve) {
-                       if (!system_supports_sve())
-                               return -EINVAL;
-
+               if (user.sve)
                        err = restore_sve_fpsimd_context(&user);
-               } else {
+               else
                        err = restore_fpsimd_context(user.fpsimd);
-               }
        }
 
        if (err == 0 && system_supports_sme() && user.za)