[PATCH v1 8/8] powerpc/signal: Use unsafe_copy_siginfo_to_user()

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Use unsafe_copy_siginfo_to_user() in order to do the copy
within the user access block.

On an mpc 8321 (book3s/32) the improvment is about 5% on a process
sending a signal to itself.

Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
---
 arch/powerpc/kernel/signal_32.c | 18 +++++++++---------
 arch/powerpc/kernel/signal_64.c |  5 +----
 2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 6b1fbd95b07d..99a3efa874eb 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -716,12 +716,6 @@ static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *s
 }
 #endif
 
-#ifdef CONFIG_PPC64
-
-#define copy_siginfo_to_user	copy_siginfo_to_user32
-
-#endif /* CONFIG_PPC64 */
-
 /*
  * Set up a signal frame for a "real-time" signal handler
  * (one which gets siginfo).
@@ -735,6 +729,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	struct pt_regs *regs = tsk->thread.regs;
 	/* Save the thread's msr before get_tm_stackpointer() changes it */
 	unsigned long msr = regs->msr;
+	compat_siginfo_t uinfo;
 
 	/* Set up Signal Frame */
 	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
@@ -744,6 +739,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	else
 		prepare_save_user_regs(1);
 
+	if (IS_ENABLED(CONFIG_COMPAT))
+		copy_siginfo_to_external32(&uinfo, &ksig->info);
+
 	scoped_user_rw_access_size(newsp, __SIGNAL_FRAMESIZE + 16 + sizeof(*frame), badframe) {
 		struct mcontext __user *mctx;
 		struct mcontext __user *tm_mctx = NULL;
@@ -785,14 +783,16 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 			asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0]));
 		}
 		unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, badframe);
+		if (IS_ENABLED(CONFIG_COMPAT))
+			unsafe_copy_to_user(&frame->info, &uinfo, sizeof(frame->info), badframe);
+		else
+			unsafe_copy_siginfo_to_user((void __user *)&frame->info, &ksig->info,
+						    badframe);
 
 		/* create a stack frame for the caller of the handler */
 		unsafe_put_user(regs->gpr[1], newsp, badframe);
 	}
 
-	if (copy_siginfo_to_user(&frame->info, &ksig->info))
-		goto badframe;
-
 	regs->link = tramp;
 
 #ifdef CONFIG_PPC_FPU_REGS
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 67de29cf581a..fa18ac43eb2a 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -893,14 +893,11 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 		}
 
 		unsafe_copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set), badframe);
+		unsafe_copy_siginfo_to_user(&frame->info, &ksig->info, badframe);
 		/* Allocate a dummy caller frame for the signal handler. */
 		unsafe_put_user(regs->gpr[1], newsp, badframe);
 	}
 
-	/* Save the siginfo outside of the unsafe block. */
-	if (copy_siginfo_to_user(&frame->info, &ksig->info))
-		goto badframe;
-
 	/* Make sure signal handler doesn't get spurious FP exceptions */
 	tsk->thread.fp_state.fpscr = 0;
 
-- 
2.54.0