[RFC PATCH v1 09/19] powerpc/signal: Call get_tm_stackpointer() from get_sigframe()

From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	ldv@altlinux.org, viro@zeniv.linux.org.uk
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [RFC PATCH v1 09/19] powerpc/signal: Call get_tm_stackpointer() from get_sigframe()
Date: Wed, 12 Aug 2020 12:06:00 +0000 (UTC)	[thread overview]
Message-ID: <80617809ab5d23c6ac4863cc1964cca4bfe49f4f.1597233555.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1597233555.git.christophe.leroy@csgroup.eu>

Instead of calling get_tm_stackpointer() from the caller, call it
directly from get_sigframe(). This avoids a double call and
allows get_tm_stackpointer() to become static and be inlined
into get_sigframe() by GCC.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/signal.c    | 9 ++++++---
 arch/powerpc/kernel/signal.h    | 6 ++----
 arch/powerpc/kernel/signal_32.c | 4 ++--
 arch/powerpc/kernel/signal_64.c | 2 +-
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a295d482adec..5edded5c5d20 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -144,10 +144,13 @@ int show_unhandled_signals = 1;
 /*
  * Allocate space for the signal frame
  */
-void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
-			   size_t frame_size, int is_32)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk);
+
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32)
 {
         unsigned long oldsp, newsp;
+	unsigned long sp = get_tm_stackpointer(tsk);
 
         /* Default to using normal stack */
 	if (is_32)
@@ -304,7 +307,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 	user_enter();
 }
 
-unsigned long get_tm_stackpointer(struct task_struct *tsk)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 {
 	/* When in an active transaction that takes a signal, we need to be
 	 * careful with the stack.  It's possible that the stack has moved back
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 6c2a33ab042c..fb98731348c3 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -10,8 +10,8 @@
 #ifndef _POWERPC_ARCH_SIGNAL_H
 #define _POWERPC_ARCH_SIGNAL_H
 
-extern void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
-				  size_t frame_size, int is_32);
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32);
 
 extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 			   struct task_struct *tsk);
@@ -19,8 +19,6 @@ extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 			      struct task_struct *tsk);
 
-extern unsigned long get_tm_stackpointer(struct task_struct *tsk);
-
 #ifdef CONFIG_VSX
 extern unsigned long copy_vsx_to_user(void __user *to,
 				      struct task_struct *task);
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 5a838188a181..3356f6aba4ae 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -768,7 +768,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 
 	/* Set up Signal Frame */
 	/* Put a Real Time Context onto stack */
-	rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
+	rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
 	addr = rt_sf;
 	if (!access_ok(rt_sf, sizeof(*rt_sf)))
 		goto badframe;
@@ -1230,7 +1230,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	BUG_ON(tsk != current);
 
 	/* Set up Signal Frame */
-	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	sc = (struct sigcontext __user *) &frame->sctx;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index ec259a0efe24..92d152c1155c 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -824,7 +824,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 
 	BUG_ON(tsk != current);
 
-	frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 
-- 
2.25.0

