diff mbox series

[v2,3/8] powerpc/signal64: Move non-inline functions out of setup_sigcontext()

Message ID 20201105051701.25053-4-cmr@codefail.de
State Superseded
Headers show
Series Improve signal performance on PPC64 with KUAP | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (cf7cd542d1b538f6e9e83490bc090dd773f4266d)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (1344a232016dbb0492be81f8517c4bf8fc1c6610)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (4ef8451b332662d004df269d4cdeb7d9f31419b5)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (3cea11cd5e3b00d91caf0b4730194039b45c5891)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (58b9041431fcf9f3f87c8def87ca82dd54cf80dd)

Commit Message

Christopher M. Riedl Nov. 5, 2020, 5:16 a.m. UTC
There are non-inline functions which get called in setup_sigcontext() to
save register state to the thread struct. Move these functions into a
separate prepare_setup_sigcontext() function so that
setup_sigcontext() can be refactored later into an "unsafe" version
which assumes an open uaccess window. Non-inline functions should be
avoided when uaccess is open.

Signed-off-by: Christopher M. Riedl <cmr@codefail.de>
---
 arch/powerpc/kernel/signal_64.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 7df088b9ad0f..ece1f982dd05 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -79,6 +79,24 @@  static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
 }
 #endif
 
+static void prepare_setup_sigcontext(struct task_struct *tsk, int ctx_has_vsx_region)
+{
+#ifdef CONFIG_ALTIVEC
+	/* save altivec registers */
+	if (tsk->thread.used_vr)
+		flush_altivec_to_thread(tsk);
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		tsk->thread.vrsave = mfspr(SPRN_VRSAVE);
+#endif /* CONFIG_ALTIVEC */
+
+	flush_fp_to_thread(tsk);
+
+#ifdef CONFIG_VSX
+	if (tsk->thread.used_vsr && ctx_has_vsx_region)
+		flush_vsx_to_thread(tsk);
+#endif /* CONFIG_VSX */
+}
+
 /*
  * Set up the sigcontext for the signal frame.
  */
@@ -97,7 +115,6 @@  static long setup_sigcontext(struct sigcontext __user *sc,
 	 */
 #ifdef CONFIG_ALTIVEC
 	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
-	unsigned long vrsave;
 #endif
 	struct pt_regs *regs = tsk->thread.regs;
 	unsigned long msr = regs->msr;
@@ -112,7 +129,6 @@  static long setup_sigcontext(struct sigcontext __user *sc,
 
 	/* save altivec registers */
 	if (tsk->thread.used_vr) {
-		flush_altivec_to_thread(tsk);
 		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
 		err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
 				      33 * sizeof(vector128));
@@ -124,17 +140,10 @@  static long setup_sigcontext(struct sigcontext __user *sc,
 	/* We always copy to/from vrsave, it's 0 if we don't have or don't
 	 * use altivec.
 	 */
-	vrsave = 0;
-	if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
-		vrsave = mfspr(SPRN_VRSAVE);
-		tsk->thread.vrsave = vrsave;
-	}
-
-	err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
+	err |= __put_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
 #else /* CONFIG_ALTIVEC */
 	err |= __put_user(0, &sc->v_regs);
 #endif /* CONFIG_ALTIVEC */
-	flush_fp_to_thread(tsk);
 	/* copy fpr regs and fpscr */
 	err |= copy_fpr_to_user(&sc->fp_regs, tsk);
 
@@ -150,7 +159,6 @@  static long setup_sigcontext(struct sigcontext __user *sc,
 	 * VMX data.
 	 */
 	if (tsk->thread.used_vsr && ctx_has_vsx_region) {
-		flush_vsx_to_thread(tsk);
 		v_regs += ELF_NVRREG;
 		err |= copy_vsx_to_user(v_regs, tsk);
 		/* set MSR_VSX in the MSR value in the frame to
@@ -655,6 +663,7 @@  SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
 		ctx_has_vsx_region = 1;
 
 	if (old_ctx != NULL) {
+		prepare_setup_sigcontext(current, ctx_has_vsx_region);
 		if (!access_ok(old_ctx, ctx_size)
 		    || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
 					ctx_has_vsx_region)
@@ -842,6 +851,7 @@  int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 #endif
 	{
 		err |= __put_user(0, &frame->uc.uc_link);
+		prepare_setup_sigcontext(tsk, 1);
 		err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
 					NULL, (unsigned long)ksig->ka.sa.sa_handler,
 					1);