[PATCH 1/5] x86: signal: add __user annotation

[PATCH 1/5] x86: signal: add __user annotation

[Hiroshi Shimamoto]

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: cleanup

Add missing __user annotation to the parameter of get_sigframe().
Also change cast type to void __user * of *fpstate.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/kernel/signal.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 4d34410..d6883b7 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -215,7 +215,7 @@ static const struct {
  */
 static inline void __user *
 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
-	     void **fpstate)
+	     void __user **fpstate)
 {
 	unsigned long sp;
 
@@ -243,7 +243,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 
 	if (used_math()) {
 		sp = sp - sig_xstate_size;
-		*fpstate = (struct _fpstate *) sp;
+		*fpstate = (void __user *) sp;
 		if (save_i387_xstate(*fpstate) < 0)
 			return (void __user *)-1L;
 	}
-- 
1.6.1.2

[PATCH 2/5] x86: signal: intrroduce get_sigframe() and replace get_sigstack()

[Hiroshi Shimamoto]

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: cleanup

Introduce get_sigframe() like 32-bit to replace get_sigstack().
Move the i387 stuff into get_sigframe().

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/kernel/signal.c |   32 +++++++++++++++++++-------------
 1 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index d6883b7..5ed4533 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -392,10 +392,13 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  * Determine which stack to use..
  */
 static void __user *
-get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
+	     void __user **fpstate)
 {
-	/* Default to using normal stack - redzone*/
-	sp -= 128;
+	unsigned long sp;
+
+	/* Default to using normal stack - redzone */
+	sp = regs->sp - 128;
 
 	/* This is the X/Open sanctioned signal stack switching.  */
 	if (ka->sa.sa_flags & SA_ONSTACK) {
@@ -403,7 +406,18 @@ get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
 			sp = current->sas_ss_sp + current->sas_ss_size;
 	}
 
-	return (void __user *)round_down(sp - size, 64);
+	if (used_math()) {
+		sp -= sig_xstate_size;
+		*fpstate = (void __user *)round_down(sp, 64);
+		if (save_i387_xstate(*fpstate) < 0)
+			return (void __user *) -1L;
+
+		sp -= frame_size;
+		return (void __user *)round_down(sp, 16) - 8;
+	}
+
+	sp -= frame_size;
+	return (void __user *)round_down(sp, 64) - 8;
 }
 
 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
@@ -414,15 +428,7 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	int err = 0;
 	struct task_struct *me = current;
 
-	if (used_math()) {
-		fp = get_stack(ka, regs->sp, sig_xstate_size);
-		frame = (void __user *)round_down(
-			(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
-
-		if (save_i387_xstate(fp) < 0)
-			return -EFAULT;
-	} else
-		frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;
+	frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
 
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;
-- 
1.6.1.2

[PATCH 3/5] x86: signal: use 16 bytes boundary for rt_sigframe

[Hiroshi Shimamoto]

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: cleanup

Supporting xsave/xrestore introduces 64 bytes boundary for save_i387_xstate().
16 bytes boundary is OK for rt_sigframe.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/kernel/signal.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 5ed4533..951aa60 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -409,15 +409,13 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 	if (used_math()) {
 		sp -= sig_xstate_size;
 		*fpstate = (void __user *)round_down(sp, 64);
+
 		if (save_i387_xstate(*fpstate) < 0)
 			return (void __user *) -1L;
-
-		sp -= frame_size;
-		return (void __user *)round_down(sp, 16) - 8;
 	}
 
 	sp -= frame_size;
-	return (void __user *)round_down(sp, 64) - 8;
+	return (void __user *)round_down(sp, 16) - 8;
 }
 
 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
-- 
1.6.1.2

[PATCH 4/5] x86: signal: unify get_sigframe()

[Hiroshi Shimamoto]

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: cleanup

Unify get_sigframe().

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/kernel/signal.c |   97 +++++++++++++++++++--------------------------
 1 files changed, 41 insertions(+), 56 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 951aa60..83212e3 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -187,28 +187,6 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 /*
  * Set up a signal frame.
  */
-#ifdef CONFIG_X86_32
-static const struct {
-	u16 poplmovl;
-	u32 val;
-	u16 int80;
-} __attribute__((packed)) retcode = {
-	0xb858,		/* popl %eax; movl $..., %eax */
-	__NR_sigreturn,
-	0x80cd,		/* int $0x80 */
-};
-
-static const struct {
-	u8  movl;
-	u32 val;
-	u16 int80;
-	u8  pad;
-} __attribute__((packed)) rt_retcode = {
-	0xb8,		/* movl $..., %eax */
-	__NR_rt_sigreturn,
-	0x80cd,		/* int $0x80 */
-	0
-};
 
 /*
  * Determine which stack to use..
@@ -217,10 +195,13 @@ static inline void __user *
 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 	     void __user **fpstate)
 {
-	unsigned long sp;
-
 	/* Default to using normal stack */
-	sp = regs->sp;
+	unsigned long sp = regs->sp;
+
+#ifdef CONFIG_X86_64
+	/* redzone */
+	sp -= 128;
+#endif /* CONFIG_X86_64 */
 
 	/*
 	 * If we are on the alternate signal stack and would overflow it, don't.
@@ -234,30 +215,64 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 		if (sas_ss_flags(sp) == 0)
 			sp = current->sas_ss_sp + current->sas_ss_size;
 	} else {
+#ifdef CONFIG_X86_32
 		/* This is the legacy signal stack switching. */
 		if ((regs->ss & 0xffff) != __USER_DS &&
 			!(ka->sa.sa_flags & SA_RESTORER) &&
 				ka->sa.sa_restorer)
 			sp = (unsigned long) ka->sa.sa_restorer;
+#endif /* CONFIG_X86_32 */
 	}
 
 	if (used_math()) {
-		sp = sp - sig_xstate_size;
+		sp -= sig_xstate_size;
+#ifdef CONFIG_X86_32
 		*fpstate = (void __user *) sp;
+#else /* !CONFIG_X86_32 */
+		*fpstate = (void __user *)round_down(sp, 64);
+#endif /* CONFIG_X86_32 */
+
 		if (save_i387_xstate(*fpstate) < 0)
 			return (void __user *)-1L;
 	}
 
 	sp -= frame_size;
+#ifdef CONFIG_X86_32
 	/*
 	 * Align the stack pointer according to the i386 ABI,
 	 * i.e. so that on function entry ((sp + 4) & 15) == 0.
 	 */
 	sp = ((sp + 4) & -16ul) - 4;
+#else /* !CONFIG_X86_32 */
+	sp = round_down(sp, 16) - 8;
+#endif
 
 	return (void __user *) sp;
 }
 
+#ifdef CONFIG_X86_32
+static const struct {
+	u16 poplmovl;
+	u32 val;
+	u16 int80;
+} __attribute__((packed)) retcode = {
+	0xb858,		/* popl %eax; movl $..., %eax */
+	__NR_sigreturn,
+	0x80cd,		/* int $0x80 */
+};
+
+static const struct {
+	u8  movl;
+	u32 val;
+	u16 int80;
+	u8  pad;
+} __attribute__((packed)) rt_retcode = {
+	0xb8,		/* movl $..., %eax */
+	__NR_rt_sigreturn,
+	0x80cd,		/* int $0x80 */
+	0
+};
+
 static int
 __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 	      struct pt_regs *regs)
@@ -388,36 +403,6 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	return 0;
 }
 #else /* !CONFIG_X86_32 */
-/*
- * Determine which stack to use..
- */
-static void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
-	     void __user **fpstate)
-{
-	unsigned long sp;
-
-	/* Default to using normal stack - redzone */
-	sp = regs->sp - 128;
-
-	/* This is the X/Open sanctioned signal stack switching.  */
-	if (ka->sa.sa_flags & SA_ONSTACK) {
-		if (sas_ss_flags(sp) == 0)
-			sp = current->sas_ss_sp + current->sas_ss_size;
-	}
-
-	if (used_math()) {
-		sp -= sig_xstate_size;
-		*fpstate = (void __user *)round_down(sp, 64);
-
-		if (save_i387_xstate(*fpstate) < 0)
-			return (void __user *) -1L;
-	}
-
-	sp -= frame_size;
-	return (void __user *)round_down(sp, 16) - 8;
-}
-
 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 			    sigset_t *set, struct pt_regs *regs)
 {
-- 
1.6.1.2

[PATCH 5/5] x86: signal: introduce helper align_sigframe()

[Hiroshi Shimamoto]

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: cleanup

Introduce helper align_sigframe() to align stack pointer for signal frame.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/kernel/signal.c |   27 +++++++++++++++------------
 1 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 83212e3..ceeb466 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -191,6 +191,20 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 /*
  * Determine which stack to use..
  */
+static unsigned long align_sigframe(unsigned long sp)
+{
+#ifdef CONFIG_X86_32
+	/*
+	 * Align the stack pointer according to the i386 ABI,
+	 * i.e. so that on function entry ((sp + 4) & 15) == 0.
+	 */
+	sp = ((sp + 4) & -16ul) - 4;
+#else /* !CONFIG_X86_32 */
+	sp = round_down(sp, 16) - 8;
+#endif
+	return sp;
+}
+
 static inline void __user *
 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 	     void __user **fpstate)
@@ -236,18 +250,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 			return (void __user *)-1L;
 	}
 
-	sp -= frame_size;
-#ifdef CONFIG_X86_32
-	/*
-	 * Align the stack pointer according to the i386 ABI,
-	 * i.e. so that on function entry ((sp + 4) & 15) == 0.
-	 */
-	sp = ((sp + 4) & -16ul) - 4;
-#else /* !CONFIG_X86_32 */
-	sp = round_down(sp, 16) - 8;
-#endif
-
-	return (void __user *) sp;
+	return (void __user *)align_sigframe(sp - frame_size);
 }
 
 #ifdef CONFIG_X86_32
-- 
1.6.1.2