From 98e3d45edad207b4358948d6e2cac4e482c3bb5d Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Fri, 23 Jan 2009 15:50:10 -0800
Subject: x86: signal: use {get|put}_user_try and catch

Impact: use new framework

Use {get|put}_user_try, catch, and _ex in arch/x86/kernel/signal.c.

Note: this patch contains "WARNING: line over 80 characters", because when
introducing new block I insert an indent to avoid mistakes by edit.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/kernel/signal.c | 291 +++++++++++++++++++++++++----------------------
 1 file changed, 154 insertions(+), 137 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 89bb7668041..cf34eb37fbe 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -51,24 +51,24 @@
 #endif
 
 #define COPY(x)			{		\
-	err |= __get_user(regs->x, &sc->x);	\
+	get_user_ex(regs->x, &sc->x);		\
 }
 
 #define COPY_SEG(seg)		{			\
 		unsigned short tmp;			\
-		err |= __get_user(tmp, &sc->seg);	\
+		get_user_ex(tmp, &sc->seg);		\
 		regs->seg = tmp;			\
 }
 
 #define COPY_SEG_CPL3(seg)	{			\
 		unsigned short tmp;			\
-		err |= __get_user(tmp, &sc->seg);	\
+		get_user_ex(tmp, &sc->seg);		\
 		regs->seg = tmp | 3;			\
 }
 
 #define GET_SEG(seg)		{			\
 		unsigned short tmp;			\
-		err |= __get_user(tmp, &sc->seg);	\
+		get_user_ex(tmp, &sc->seg);		\
 		loadsegment(seg, tmp);			\
 }
 
@@ -83,45 +83,49 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 	/* Always make any pending restarted system calls return -EINTR */
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
+	get_user_try {
+
 #ifdef CONFIG_X86_32
-	GET_SEG(gs);
-	COPY_SEG(fs);
-	COPY_SEG(es);
-	COPY_SEG(ds);
+		GET_SEG(gs);
+		COPY_SEG(fs);
+		COPY_SEG(es);
+		COPY_SEG(ds);
 #endif /* CONFIG_X86_32 */
 
-	COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
-	COPY(dx); COPY(cx); COPY(ip);
+		COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+		COPY(dx); COPY(cx); COPY(ip);
 
 #ifdef CONFIG_X86_64
-	COPY(r8);
-	COPY(r9);
-	COPY(r10);
-	COPY(r11);
-	COPY(r12);
-	COPY(r13);
-	COPY(r14);
-	COPY(r15);
+		COPY(r8);
+		COPY(r9);
+		COPY(r10);
+		COPY(r11);
+		COPY(r12);
+		COPY(r13);
+		COPY(r14);
+		COPY(r15);
 #endif /* CONFIG_X86_64 */
 
 #ifdef CONFIG_X86_32
-	COPY_SEG_CPL3(cs);
-	COPY_SEG_CPL3(ss);
+		COPY_SEG_CPL3(cs);
+		COPY_SEG_CPL3(ss);
 #else /* !CONFIG_X86_32 */
-	/* Kernel saves and restores only the CS segment register on signals,
-	 * which is the bare minimum needed to allow mixed 32/64-bit code.
-	 * App's signal handler can save/restore other segments if needed. */
-	COPY_SEG_CPL3(cs);
+		/* Kernel saves and restores only the CS segment register on signals,
+		 * which is the bare minimum needed to allow mixed 32/64-bit code.
+		 * App's signal handler can save/restore other segments if needed. */
+		COPY_SEG_CPL3(cs);
 #endif /* CONFIG_X86_32 */
 
-	err |= __get_user(tmpflags, &sc->flags);
-	regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
-	regs->orig_ax = -1;		/* disable syscall checks */
+		get_user_ex(tmpflags, &sc->flags);
+		regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+		regs->orig_ax = -1;		/* disable syscall checks */
+
+		get_user_ex(buf, &sc->fpstate);
+		err |= restore_i387_xstate(buf);
 
-	err |= __get_user(buf, &sc->fpstate);
-	err |= restore_i387_xstate(buf);
+		get_user_ex(*pax, &sc->ax);
+	} get_user_catch(err);
 
-	err |= __get_user(*pax, &sc->ax);
 	return err;
 }
 
@@ -131,57 +135,60 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 {
 	int err = 0;
 
+	put_user_try {
+
 #ifdef CONFIG_X86_32
-	{
-		unsigned int tmp;
+		{
+			unsigned int tmp;
 
-		savesegment(gs, tmp);
-		err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
-	}
-	err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
-	err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
-	err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
+			savesegment(gs, tmp);
+			put_user_ex(tmp, (unsigned int __user *)&sc->gs);
+		}
+		put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
+		put_user_ex(regs->es, (unsigned int __user *)&sc->es);
+		put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
 #endif /* CONFIG_X86_32 */
 
-	err |= __put_user(regs->di, &sc->di);
-	err |= __put_user(regs->si, &sc->si);
-	err |= __put_user(regs->bp, &sc->bp);
-	err |= __put_user(regs->sp, &sc->sp);
-	err |= __put_user(regs->bx, &sc->bx);
-	err |= __put_user(regs->dx, &sc->dx);
-	err |= __put_user(regs->cx, &sc->cx);
-	err |= __put_user(regs->ax, &sc->ax);
+		put_user_ex(regs->di, &sc->di);
+		put_user_ex(regs->si, &sc->si);
+		put_user_ex(regs->bp, &sc->bp);
+		put_user_ex(regs->sp, &sc->sp);
+		put_user_ex(regs->bx, &sc->bx);
+		put_user_ex(regs->dx, &sc->dx);
+		put_user_ex(regs->cx, &sc->cx);
+		put_user_ex(regs->ax, &sc->ax);
 #ifdef CONFIG_X86_64
-	err |= __put_user(regs->r8, &sc->r8);
-	err |= __put_user(regs->r9, &sc->r9);
-	err |= __put_user(regs->r10, &sc->r10);
-	err |= __put_user(regs->r11, &sc->r11);
-	err |= __put_user(regs->r12, &sc->r12);
-	err |= __put_user(regs->r13, &sc->r13);
-	err |= __put_user(regs->r14, &sc->r14);
-	err |= __put_user(regs->r15, &sc->r15);
+		put_user_ex(regs->r8, &sc->r8);
+		put_user_ex(regs->r9, &sc->r9);
+		put_user_ex(regs->r10, &sc->r10);
+		put_user_ex(regs->r11, &sc->r11);
+		put_user_ex(regs->r12, &sc->r12);
+		put_user_ex(regs->r13, &sc->r13);
+		put_user_ex(regs->r14, &sc->r14);
+		put_user_ex(regs->r15, &sc->r15);
 #endif /* CONFIG_X86_64 */
 
-	err |= __put_user(current->thread.trap_no, &sc->trapno);
-	err |= __put_user(current->thread.error_code, &sc->err);
-	err |= __put_user(regs->ip, &sc->ip);
+		put_user_ex(current->thread.trap_no, &sc->trapno);
+		put_user_ex(current->thread.error_code, &sc->err);
+		put_user_ex(regs->ip, &sc->ip);
 #ifdef CONFIG_X86_32
-	err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
-	err |= __put_user(regs->flags, &sc->flags);
-	err |= __put_user(regs->sp, &sc->sp_at_signal);
-	err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
+		put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
+		put_user_ex(regs->flags, &sc->flags);
+		put_user_ex(regs->sp, &sc->sp_at_signal);
+		put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
 #else /* !CONFIG_X86_32 */
-	err |= __put_user(regs->flags, &sc->flags);
-	err |= __put_user(regs->cs, &sc->cs);
-	err |= __put_user(0, &sc->gs);
-	err |= __put_user(0, &sc->fs);
+		put_user_ex(regs->flags, &sc->flags);
+		put_user_ex(regs->cs, &sc->cs);
+		put_user_ex(0, &sc->gs);
+		put_user_ex(0, &sc->fs);
 #endif /* CONFIG_X86_32 */
 
-	err |= __put_user(fpstate, &sc->fpstate);
+		put_user_ex(fpstate, &sc->fpstate);
 
-	/* non-iBCS2 extensions.. */
-	err |= __put_user(mask, &sc->oldmask);
-	err |= __put_user(current->thread.cr2, &sc->cr2);
+		/* non-iBCS2 extensions.. */
+		put_user_ex(mask, &sc->oldmask);
+		put_user_ex(current->thread.cr2, &sc->cr2);
+	} put_user_catch(err);
 
 	return err;
 }
@@ -336,43 +343,41 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;
 
-	err |= __put_user(sig, &frame->sig);
-	err |= __put_user(&frame->info, &frame->pinfo);
-	err |= __put_user(&frame->uc, &frame->puc);
-	err |= copy_siginfo_to_user(&frame->info, info);
-	if (err)
-		return -EFAULT;
-
-	/* Create the ucontext.  */
-	if (cpu_has_xsave)
-		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
-	else
-		err |= __put_user(0, &frame->uc.uc_flags);
-	err |= __put_user(0, &frame->uc.uc_link);
-	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->sp),
-			  &frame->uc.uc_stack.ss_flags);
-	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
-	err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
-				regs, set->sig[0]);
-	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-	if (err)
-		return -EFAULT;
+	put_user_try {
+		put_user_ex(sig, &frame->sig);
+		put_user_ex(&frame->info, &frame->pinfo);
+		put_user_ex(&frame->uc, &frame->puc);
+		err |= copy_siginfo_to_user(&frame->info, info);
 
-	/* Set up to return from userspace.  */
-	restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
-	if (ka->sa.sa_flags & SA_RESTORER)
-		restorer = ka->sa.sa_restorer;
-	err |= __put_user(restorer, &frame->pretcode);
+		/* Create the ucontext.  */
+		if (cpu_has_xsave)
+			put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
+		else
+			put_user_ex(0, &frame->uc.uc_flags);
+		put_user_ex(0, &frame->uc.uc_link);
+		put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+		put_user_ex(sas_ss_flags(regs->sp),
+			    &frame->uc.uc_stack.ss_flags);
+		put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+		err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
+					regs, set->sig[0]);
+		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+		/* Set up to return from userspace.  */
+		restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
+		if (ka->sa.sa_flags & SA_RESTORER)
+			restorer = ka->sa.sa_restorer;
+		put_user_ex(restorer, &frame->pretcode);
 
-	/*
-	 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
-	 *
-	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
-	 * reasons and because gdb uses it as a signature to notice
-	 * signal handler stack frames.
-	 */
-	err |= __put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
+		/*
+		 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
+		 *
+		 * WE DO NOT USE IT ANY MORE! It's only left here for historical
+		 * reasons and because gdb uses it as a signature to notice
+		 * signal handler stack frames.
+		 */
+		put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
+	} put_user_catch(err);
 
 	if (err)
 		return -EFAULT;
@@ -436,28 +441,30 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 			return -EFAULT;
 	}
 
-	/* Create the ucontext.  */
-	if (cpu_has_xsave)
-		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
-	else
-		err |= __put_user(0, &frame->uc.uc_flags);
-	err |= __put_user(0, &frame->uc.uc_link);
-	err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->sp),
-			  &frame->uc.uc_stack.ss_flags);
-	err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
-	err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
-	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-
-	/* Set up to return from userspace.  If provided, use a stub
-	   already in userspace.  */
-	/* x86-64 should always use SA_RESTORER. */
-	if (ka->sa.sa_flags & SA_RESTORER) {
-		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
-	} else {
-		/* could use a vstub here */
-		return -EFAULT;
-	}
+	put_user_try {
+		/* Create the ucontext.  */
+		if (cpu_has_xsave)
+			put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
+		else
+			put_user_ex(0, &frame->uc.uc_flags);
+		put_user_ex(0, &frame->uc.uc_link);
+		put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+		put_user_ex(sas_ss_flags(regs->sp),
+			    &frame->uc.uc_stack.ss_flags);
+		put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+		err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
+		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+		/* Set up to return from userspace.  If provided, use a stub
+		   already in userspace.  */
+		/* x86-64 should always use SA_RESTORER. */
+		if (ka->sa.sa_flags & SA_RESTORER) {
+			put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
+		} else {
+			/* could use a vstub here */
+			err |= -EFAULT;
+		}
+	} put_user_catch(err);
 
 	if (err)
 		return -EFAULT;
@@ -509,31 +516,41 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 	      struct old_sigaction __user *oact)
 {
 	struct k_sigaction new_ka, old_ka;
-	int ret;
+	int ret = 0;
 
 	if (act) {
 		old_sigset_t mask;
 
-		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
-		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
 			return -EFAULT;
 
-		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
-		__get_user(mask, &act->sa_mask);
+		get_user_try {
+			get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
+			get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
+			get_user_ex(mask, &act->sa_mask);
+			get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
+		} get_user_catch(ret);
+
+		if (ret)
+			return -EFAULT;
 		siginitset(&new_ka.sa.sa_mask, mask);
 	}
 
 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 
 	if (!ret && oact) {
-		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
-		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
 			return -EFAULT;
 
-		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+		put_user_try {
+			put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
+			put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
+			put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+			put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
+		} put_user_catch(ret);
+
+		if (ret)
+			return -EFAULT;
 	}
 
 	return ret;
-- 
cgit v1.2.3-70-g09d2


From d9a89a26e02ef9ed03f74a755a8b4d8f3a066622 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Mon, 9 Feb 2009 22:17:40 +0900
Subject: x86: add %gs accessors for x86_32

Impact: cleanup

On x86_32, %gs is handled lazily.  It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places.  Currently, it's done by
calling savesegment() and loadsegment() explicitly.  Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.

While at it, clean up register access macros in signal.c.

This cleans up code a bit and will help future changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/a.out-core.h  |  2 +-
 arch/x86/include/asm/elf.h         |  2 +-
 arch/x86/include/asm/mmu_context.h |  2 +-
 arch/x86/include/asm/system.h      |  9 +++++++++
 arch/x86/kernel/process_32.c       |  6 +++---
 arch/x86/kernel/ptrace.c           | 14 ++++++-------
 arch/x86/kernel/signal.c           | 41 +++++++++++++++-----------------------
 arch/x86/kernel/vm86_32.c          |  4 ++--
 arch/x86/math-emu/get_address.c    |  6 ++----
 9 files changed, 41 insertions(+), 45 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/include/asm/a.out-core.h b/arch/x86/include/asm/a.out-core.h
index 3c601f8224b..bb70e397aa8 100644
--- a/arch/x86/include/asm/a.out-core.h
+++ b/arch/x86/include/asm/a.out-core.h
@@ -55,7 +55,7 @@ static inline void aout_dump_thread(struct pt_regs *regs, struct user *dump)
 	dump->regs.ds = (u16)regs->ds;
 	dump->regs.es = (u16)regs->es;
 	dump->regs.fs = (u16)regs->fs;
-	savesegment(gs, dump->regs.gs);
+	dump->regs.gs = get_user_gs(regs);
 	dump->regs.orig_ax = regs->orig_ax;
 	dump->regs.ip = regs->ip;
 	dump->regs.cs = (u16)regs->cs;
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index f51a3ddde01..39b0aac1675 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -124,7 +124,7 @@ do {						\
 	pr_reg[7] = regs->ds & 0xffff;		\
 	pr_reg[8] = regs->es & 0xffff;		\
 	pr_reg[9] = regs->fs & 0xffff;		\
-	savesegment(gs, pr_reg[10]);		\
+	pr_reg[10] = get_user_gs(regs);		\
 	pr_reg[11] = regs->orig_ax;		\
 	pr_reg[12] = regs->ip;			\
 	pr_reg[13] = regs->cs & 0xffff;		\
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 52948df9cd1..4955165682c 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -79,7 +79,7 @@ do {						\
 #ifdef CONFIG_X86_32
 #define deactivate_mm(tsk, mm)			\
 do {						\
-	loadsegment(gs, 0);			\
+	set_user_gs(task_pt_regs(tsk), 0);	\
 } while (0)
 #else
 #define deactivate_mm(tsk, mm)			\
diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index 2fcc70bc85f..70c74b8db87 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -182,6 +182,15 @@ extern void native_load_gs_index(unsigned);
 #define savesegment(seg, value)				\
 	asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
 
+/*
+ * x86_32 user gs accessors.
+ */
+#ifdef CONFIG_X86_32
+#define get_user_gs(regs)	(u16)({unsigned long v; savesegment(gs, v); v;})
+#define set_user_gs(regs, v)	loadsegment(gs, (unsigned long)(v))
+#define task_user_gs(tsk)	((tsk)->thread.gs)
+#endif
+
 static inline unsigned long get_limit(unsigned long segment)
 {
 	unsigned long __limit;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 1a1ae8edc40..d58a340e1be 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -131,7 +131,7 @@ void __show_regs(struct pt_regs *regs, int all)
 	if (user_mode_vm(regs)) {
 		sp = regs->sp;
 		ss = regs->ss & 0xffff;
-		savesegment(gs, gs);
+		gs = get_user_gs(regs);
 	} else {
 		sp = (unsigned long) (&regs->sp);
 		savesegment(ss, ss);
@@ -304,7 +304,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 
 	p->thread.ip = (unsigned long) ret_from_fork;
 
-	savesegment(gs, p->thread.gs);
+	task_user_gs(p) = get_user_gs(regs);
 
 	tsk = current;
 	if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
@@ -342,7 +342,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 void
 start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
 {
-	__asm__("movl %0, %%gs" : : "r"(0));
+	set_user_gs(regs, 0);
 	regs->fs		= 0;
 	set_fs(USER_DS);
 	regs->ds		= __USER_DS;
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 0a5df5f82fb..508b6b57d0c 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -90,9 +90,10 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
 	if (offset != offsetof(struct user_regs_struct, gs))
 		retval = *pt_regs_access(task_pt_regs(task), offset);
 	else {
-		retval = task->thread.gs;
 		if (task == current)
-			savesegment(gs, retval);
+			retval = get_user_gs(task_pt_regs(task));
+		else
+			retval = task_user_gs(task);
 	}
 	return retval;
 }
@@ -126,13 +127,10 @@ static int set_segment_reg(struct task_struct *task,
 		break;
 
 	case offsetof(struct user_regs_struct, gs):
-		task->thread.gs = value;
 		if (task == current)
-			/*
-			 * The user-mode %gs is not affected by
-			 * kernel entry, so we must update the CPU.
-			 */
-			loadsegment(gs, value);
+			set_user_gs(task_pt_regs(task), value);
+		else
+			task_user_gs(task) = value;
 	}
 
 	return 0;
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 7fc78b01981..8562387c75a 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -50,27 +50,23 @@
 # define FIX_EFLAGS	__FIX_EFLAGS
 #endif
 
-#define COPY(x)			{		\
-	get_user_ex(regs->x, &sc->x);		\
-}
+#define COPY(x)			do {			\
+	get_user_ex(regs->x, &sc->x);			\
+} while (0)
 
-#define COPY_SEG(seg)		{			\
-		unsigned short tmp;			\
-		get_user_ex(tmp, &sc->seg);		\
-		regs->seg = tmp;			\
-}
+#define GET_SEG(seg)		({			\
+	unsigned short tmp;				\
+	get_user_ex(tmp, &sc->seg);			\
+	tmp;						\
+})
 
-#define COPY_SEG_CPL3(seg)	{			\
-		unsigned short tmp;			\
-		get_user_ex(tmp, &sc->seg);		\
-		regs->seg = tmp | 3;			\
-}
+#define COPY_SEG(seg)		do {			\
+	regs->seg = GET_SEG(seg);			\
+} while (0)
 
-#define GET_SEG(seg)		{			\
-		unsigned short tmp;			\
-		get_user_ex(tmp, &sc->seg);		\
-		loadsegment(seg, tmp);			\
-}
+#define COPY_SEG_CPL3(seg)	do {			\
+	regs->seg = GET_SEG(seg) | 3;			\
+} while (0)
 
 static int
 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
@@ -86,7 +82,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 	get_user_try {
 
 #ifdef CONFIG_X86_32
-		GET_SEG(gs);
+		set_user_gs(regs, GET_SEG(gs));
 		COPY_SEG(fs);
 		COPY_SEG(es);
 		COPY_SEG(ds);
@@ -138,12 +134,7 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 	put_user_try {
 
 #ifdef CONFIG_X86_32
-		{
-			unsigned int tmp;
-
-			savesegment(gs, tmp);
-			put_user_ex(tmp, (unsigned int __user *)&sc->gs);
-		}
+		put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
 		put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
 		put_user_ex(regs->es, (unsigned int __user *)&sc->es);
 		put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 4eeb5cf9720..55ea30d2a3d 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -158,7 +158,7 @@ struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs)
 	ret = KVM86->regs32;
 
 	ret->fs = current->thread.saved_fs;
-	loadsegment(gs, current->thread.saved_gs);
+	set_user_gs(ret, current->thread.saved_gs);
 
 	return ret;
 }
@@ -323,7 +323,7 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
 	info->regs32->ax = 0;
 	tsk->thread.saved_sp0 = tsk->thread.sp0;
 	tsk->thread.saved_fs = info->regs32->fs;
-	savesegment(gs, tsk->thread.saved_gs);
+	tsk->thread.saved_gs = get_user_gs(info->regs32);
 
 	tss = &per_cpu(init_tss, get_cpu());
 	tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0;
diff --git a/arch/x86/math-emu/get_address.c b/arch/x86/math-emu/get_address.c
index 420b3b6e391..6ef5e99380f 100644
--- a/arch/x86/math-emu/get_address.c
+++ b/arch/x86/math-emu/get_address.c
@@ -150,11 +150,9 @@ static long pm_address(u_char FPU_modrm, u_char segment,
 #endif /* PARANOID */
 
 	switch (segment) {
-		/* gs isn't used by the kernel, so it still has its
-		   user-space value. */
 	case PREFIX_GS_ - 1:
-		/* N.B. - movl %seg, mem is a 2 byte write regardless of prefix */
-		savesegment(gs, addr->selector);
+		/* user gs handling can be lazy, use special accessors */
+		addr->selector = get_user_gs(FPU_info->regs);
 		break;
 	default:
 		addr->selector = PM_REG_(segment);
-- 
cgit v1.2.3-70-g09d2


From 253f29a4ae9cc6cdc7b94f96517f27a93885a6ce Mon Sep 17 00:00:00 2001
From: Brian Gerst <brgerst@gmail.com>
Date: Tue, 10 Feb 2009 09:51:46 -0500
Subject: x86: pass in pt_regs pointer for syscalls that need it

Some syscalls need to access the pt_regs structure, either to copy
user register state or to modifiy it.  This patch adds stubs to load
the address of the pt_regs struct into the %eax register, and changes
the syscalls to regparm(1) to receive the pt_regs pointer as the
first argument.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/linkage.h     |  7 +++++++
 arch/x86/include/asm/syscalls.h    | 25 +++++++++++++++----------
 arch/x86/kernel/entry_32.S         | 20 ++++++++++++++++++++
 arch/x86/kernel/ioport.c           |  4 +---
 arch/x86/kernel/process_32.c       | 35 ++++++++++++++---------------------
 arch/x86/kernel/signal.c           | 35 +++++++----------------------------
 arch/x86/kernel/syscall_table_32.S | 20 ++++++++++----------
 arch/x86/kernel/vm86_32.c          | 15 +++++++--------
 8 files changed, 81 insertions(+), 80 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index 5d98d0b68ff..2fd5926fb97 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -17,6 +17,13 @@
  */
 #define asmregparm __attribute__((regparm(3)))
 
+/*
+ * For syscalls that need a pointer to the pt_regs struct (ie. fork).
+ * The regs pointer is passed in %eax as the first argument.  The
+ * remaining function arguments remain on the stack.
+ */
+#define ptregscall __attribute__((regparm(1)))
+
 /*
  * Make sure the compiler doesn't do anything stupid with the
  * arguments on the stack - they are owned by the *caller*, not
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index c0b0bda754e..617295255a1 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -29,21 +29,26 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *);
 /* X86_32 only */
 #ifdef CONFIG_X86_32
 /* kernel/process_32.c */
-asmlinkage int sys_fork(struct pt_regs);
-asmlinkage int sys_clone(struct pt_regs);
-asmlinkage int sys_vfork(struct pt_regs);
-asmlinkage int sys_execve(struct pt_regs);
+ptregscall int sys_fork(struct pt_regs *);
+ptregscall int sys_clone(struct pt_regs *, unsigned long,
+			 unsigned long, int __user *,
+			 unsigned long, int __user *);
+ptregscall int sys_vfork(struct pt_regs *);
+ptregscall int sys_execve(struct pt_regs *, char __user *,
+			  char __user * __user *,
+			  char __user * __user *);
 
 /* kernel/signal_32.c */
 asmlinkage int sys_sigsuspend(int, int, old_sigset_t);
 asmlinkage int sys_sigaction(int, const struct old_sigaction __user *,
 			     struct old_sigaction __user *);
-asmlinkage int sys_sigaltstack(unsigned long);
-asmlinkage unsigned long sys_sigreturn(unsigned long);
-asmlinkage int sys_rt_sigreturn(unsigned long);
+ptregscall int sys_sigaltstack(struct pt_regs *, const stack_t __user *,
+			       stack_t __user *);
+ptregscall unsigned long sys_sigreturn(struct pt_regs *);
+ptregscall int sys_rt_sigreturn(struct pt_regs *);
 
 /* kernel/ioport.c */
-asmlinkage long sys_iopl(unsigned long);
+ptregscall long sys_iopl(struct pt_regs *, unsigned int);
 
 /* kernel/sys_i386_32.c */
 asmlinkage long sys_mmap2(unsigned long, unsigned long, unsigned long,
@@ -59,8 +64,8 @@ struct oldold_utsname;
 asmlinkage int sys_olduname(struct oldold_utsname __user *);
 
 /* kernel/vm86_32.c */
-asmlinkage int sys_vm86old(struct pt_regs);
-asmlinkage int sys_vm86(struct pt_regs);
+ptregscall int sys_vm86old(struct pt_regs *, struct vm86_struct __user *);
+ptregscall int sys_vm86(struct pt_regs *, unsigned long, unsigned long);
 
 #else /* CONFIG_X86_32 */
 
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 5f5bd22adcd..3de7b5710dc 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -697,6 +697,26 @@ syscall_badsys:
 END(syscall_badsys)
 	CFI_ENDPROC
 
+/*
+ * System calls that need a pt_regs pointer.
+ */
+#define PTREGSCALL(name) \
+	ALIGN; \
+ptregs_##name: \
+	leal 4(%esp),%eax; \
+	jmp sys_##name;
+
+PTREGSCALL(iopl)
+PTREGSCALL(fork)
+PTREGSCALL(clone)
+PTREGSCALL(vfork)
+PTREGSCALL(execve)
+PTREGSCALL(sigaltstack)
+PTREGSCALL(sigreturn)
+PTREGSCALL(rt_sigreturn)
+PTREGSCALL(vm86)
+PTREGSCALL(vm86old)
+
 .macro FIXUP_ESPFIX_STACK
 	/* since we are on a wrong stack, we cant make it a C code :( */
 	PER_CPU(gdt_page, %ebx)
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index b12208f4dfe..7ec14864631 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -131,10 +131,8 @@ static int do_iopl(unsigned int level, struct pt_regs *regs)
 }
 
 #ifdef CONFIG_X86_32
-asmlinkage long sys_iopl(unsigned long regsp)
+ptregscall long sys_iopl(struct pt_regs *regs, unsigned int level)
 {
-	struct pt_regs *regs = (struct pt_regs *)&regsp;
-	unsigned int level = regs->bx;
 	struct thread_struct *t = &current->thread;
 	int rc;
 
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b50604bb1e4..5a9dcfb01f7 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -603,24 +603,18 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	return prev_p;
 }
 
-asmlinkage int sys_fork(struct pt_regs regs)
+ptregscall int sys_fork(struct pt_regs *regs)
 {
-	return do_fork(SIGCHLD, regs.sp, &regs, 0, NULL, NULL);
+	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
 }
 
-asmlinkage int sys_clone(struct pt_regs regs)
+ptregscall int sys_clone(struct pt_regs *regs, unsigned long clone_flags,
+			 unsigned long newsp, int __user *parent_tidptr,
+			 unsigned long unused, int __user *child_tidptr)
 {
-	unsigned long clone_flags;
-	unsigned long newsp;
-	int __user *parent_tidptr, *child_tidptr;
-
-	clone_flags = regs.bx;
-	newsp = regs.cx;
-	parent_tidptr = (int __user *)regs.dx;
-	child_tidptr = (int __user *)regs.di;
 	if (!newsp)
-		newsp = regs.sp;
-	return do_fork(clone_flags, newsp, &regs, 0, parent_tidptr, child_tidptr);
+		newsp = regs->sp;
+	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
 }
 
 /*
@@ -633,27 +627,26 @@ asmlinkage int sys_clone(struct pt_regs regs)
  * do not have enough call-clobbered registers to hold all
  * the information you need.
  */
-asmlinkage int sys_vfork(struct pt_regs regs)
+ptregscall int sys_vfork(struct pt_regs *regs)
 {
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.sp, &regs, 0, NULL, NULL);
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, NULL, NULL);
 }
 
 /*
  * sys_execve() executes a new program.
  */
-asmlinkage int sys_execve(struct pt_regs regs)
+ptregscall int sys_execve(struct pt_regs *regs, char __user *u_filename,
+			  char __user * __user *argv,
+			  char __user * __user *envp)
 {
 	int error;
 	char *filename;
 
-	filename = getname((char __user *) regs.bx);
+	filename = getname(u_filename);
 	error = PTR_ERR(filename);
 	if (IS_ERR(filename))
 		goto out;
-	error = do_execve(filename,
-			(char __user * __user *) regs.cx,
-			(char __user * __user *) regs.dx,
-			&regs);
+	error = do_execve(filename, argv, envp, regs);
 	if (error == 0) {
 		/* Make sure we don't return using sysenter.. */
 		set_thread_flag(TIF_IRET);
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 8562387c75a..d7a158367e3 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -549,39 +549,28 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 #endif /* CONFIG_X86_32 */
 
 #ifdef CONFIG_X86_32
-asmlinkage int sys_sigaltstack(unsigned long bx)
-{
-	/*
-	 * This is needed to make gcc realize it doesn't own the
-	 * "struct pt_regs"
-	 */
-	struct pt_regs *regs = (struct pt_regs *)&bx;
-	const stack_t __user *uss = (const stack_t __user *)bx;
-	stack_t __user *uoss = (stack_t __user *)regs->cx;
-
-	return do_sigaltstack(uss, uoss, regs->sp);
-}
+ptregscall int
+sys_sigaltstack(struct pt_regs *regs, const stack_t __user *uss,
+		stack_t __user *uoss)
 #else /* !CONFIG_X86_32 */
 asmlinkage long
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 		struct pt_regs *regs)
+#endif /* CONFIG_X86_32 */
 {
 	return do_sigaltstack(uss, uoss, regs->sp);
 }
-#endif /* CONFIG_X86_32 */
 
 /*
  * Do a signal return; undo the signal stack.
  */
 #ifdef CONFIG_X86_32
-asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
+ptregscall unsigned long sys_sigreturn(struct pt_regs *regs)
 {
 	struct sigframe __user *frame;
-	struct pt_regs *regs;
 	unsigned long ax;
 	sigset_t set;
 
-	regs = (struct pt_regs *) &__unused;
 	frame = (struct sigframe __user *)(regs->sp - 8);
 
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -640,23 +629,13 @@ badframe:
 }
 
 #ifdef CONFIG_X86_32
-/*
- * Note: do not pass in pt_regs directly as with tail-call optimization
- * GCC will incorrectly stomp on the caller's frame and corrupt user-space
- * register state:
- */
-asmlinkage int sys_rt_sigreturn(unsigned long __unused)
-{
-	struct pt_regs *regs = (struct pt_regs *)&__unused;
-
-	return do_rt_sigreturn(regs);
-}
+ptregscall int sys_rt_sigreturn(struct pt_regs *regs)
 #else /* !CONFIG_X86_32 */
 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+#endif /* CONFIG_X86_32 */
 {
 	return do_rt_sigreturn(regs);
 }
-#endif /* CONFIG_X86_32 */
 
 /*
  * OK, we're invoking a handler:
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index e2e86a08f31..3bdb64829b8 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -1,7 +1,7 @@
 ENTRY(sys_call_table)
 	.long sys_restart_syscall	/* 0 - old "setup()" system call, used for restarting */
 	.long sys_exit
-	.long sys_fork
+	.long ptregs_fork
 	.long sys_read
 	.long sys_write
 	.long sys_open		/* 5 */
@@ -10,7 +10,7 @@ ENTRY(sys_call_table)
 	.long sys_creat
 	.long sys_link
 	.long sys_unlink	/* 10 */
-	.long sys_execve
+	.long ptregs_execve
 	.long sys_chdir
 	.long sys_time
 	.long sys_mknod
@@ -109,17 +109,17 @@ ENTRY(sys_call_table)
 	.long sys_newlstat
 	.long sys_newfstat
 	.long sys_uname
-	.long sys_iopl		/* 110 */
+	.long ptregs_iopl	/* 110 */
 	.long sys_vhangup
 	.long sys_ni_syscall	/* old "idle" system call */
-	.long sys_vm86old
+	.long ptregs_vm86old
 	.long sys_wait4
 	.long sys_swapoff	/* 115 */
 	.long sys_sysinfo
 	.long sys_ipc
 	.long sys_fsync
-	.long sys_sigreturn
-	.long sys_clone		/* 120 */
+	.long ptregs_sigreturn
+	.long ptregs_clone	/* 120 */
 	.long sys_setdomainname
 	.long sys_newuname
 	.long sys_modify_ldt
@@ -165,14 +165,14 @@ ENTRY(sys_call_table)
 	.long sys_mremap
 	.long sys_setresuid16
 	.long sys_getresuid16	/* 165 */
-	.long sys_vm86
+	.long ptregs_vm86
 	.long sys_ni_syscall	/* Old sys_query_module */
 	.long sys_poll
 	.long sys_nfsservctl
 	.long sys_setresgid16	/* 170 */
 	.long sys_getresgid16
 	.long sys_prctl
-	.long sys_rt_sigreturn
+	.long ptregs_rt_sigreturn
 	.long sys_rt_sigaction
 	.long sys_rt_sigprocmask	/* 175 */
 	.long sys_rt_sigpending
@@ -185,11 +185,11 @@ ENTRY(sys_call_table)
 	.long sys_getcwd
 	.long sys_capget
 	.long sys_capset	/* 185 */
-	.long sys_sigaltstack
+	.long ptregs_sigaltstack
 	.long sys_sendfile
 	.long sys_ni_syscall	/* reserved for streams1 */
 	.long sys_ni_syscall	/* reserved for streams2 */
-	.long sys_vfork		/* 190 */
+	.long ptregs_vfork	/* 190 */
 	.long sys_getrlimit
 	.long sys_mmap2
 	.long sys_truncate64
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 55ea30d2a3d..8fa6ba7c923 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -197,9 +197,8 @@ out:
 static int do_vm86_irq_handling(int subfunction, int irqnumber);
 static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk);
 
-asmlinkage int sys_vm86old(struct pt_regs regs)
+ptregscall int sys_vm86old(struct pt_regs *regs, struct vm86_struct __user *v86)
 {
-	struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs.bx;
 	struct kernel_vm86_struct info; /* declare this _on top_,
 					 * this avoids wasting of stack space.
 					 * This remains on the stack until we
@@ -218,7 +217,7 @@ asmlinkage int sys_vm86old(struct pt_regs regs)
 	if (tmp)
 		goto out;
 	memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus);
-	info.regs32 = &regs;
+	info.regs32 = regs;
 	tsk->thread.vm86_info = v86;
 	do_sys_vm86(&info, tsk);
 	ret = 0;	/* we never return here */
@@ -227,7 +226,7 @@ out:
 }
 
 
-asmlinkage int sys_vm86(struct pt_regs regs)
+ptregscall int sys_vm86(struct pt_regs *regs, unsigned long cmd, unsigned long arg)
 {
 	struct kernel_vm86_struct info; /* declare this _on top_,
 					 * this avoids wasting of stack space.
@@ -239,12 +238,12 @@ asmlinkage int sys_vm86(struct pt_regs regs)
 	struct vm86plus_struct __user *v86;
 
 	tsk = current;
-	switch (regs.bx) {
+	switch (cmd) {
 	case VM86_REQUEST_IRQ:
 	case VM86_FREE_IRQ:
 	case VM86_GET_IRQ_BITS:
 	case VM86_GET_AND_RESET_IRQ:
-		ret = do_vm86_irq_handling(regs.bx, (int)regs.cx);
+		ret = do_vm86_irq_handling(cmd, (int)arg);
 		goto out;
 	case VM86_PLUS_INSTALL_CHECK:
 		/*
@@ -261,14 +260,14 @@ asmlinkage int sys_vm86(struct pt_regs regs)
 	ret = -EPERM;
 	if (tsk->thread.saved_sp0)
 		goto out;
-	v86 = (struct vm86plus_struct __user *)regs.cx;
+	v86 = (struct vm86plus_struct __user *)arg;
 	tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
 				       offsetof(struct kernel_vm86_struct, regs32) -
 				       sizeof(info.regs));
 	ret = -EFAULT;
 	if (tmp)
 		goto out;
-	info.regs32 = &regs;
+	info.regs32 = regs;
 	info.vm86plus.is_vm86pus = 1;
 	tsk->thread.vm86_info = (struct vm86_struct __user *)v86;
 	do_sys_vm86(&info, tsk);
-- 
cgit v1.2.3-70-g09d2


From b12bdaf11f935d7be030207e3c77faeaeab8ded3 Mon Sep 17 00:00:00 2001
From: Brian Gerst <brgerst@gmail.com>
Date: Wed, 11 Feb 2009 16:43:58 -0500
Subject: x86: use regparm(3) for passed-in pt_regs pointer

Some syscalls need to access the pt_regs structure, either to copy
user register state or to modifiy it.  This patch adds stubs to load
the address of the pt_regs struct into the %eax register, and changes
the syscalls to take the pointer as an argument instead of relying on
the assumption that the pt_regs structure overlaps the function
arguments.

Drop the use of regparm(1) due to concern about gcc bugs, and to move
in the direction of the eventual removal of regparm(0) for asmlinkage.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/include/asm/linkage.h  |  7 -------
 arch/x86/include/asm/syscalls.h | 25 ++++++++++---------------
 arch/x86/kernel/ioport.c        |  3 ++-
 arch/x86/kernel/process_32.c    | 27 +++++++++++++++++----------
 arch/x86/kernel/signal.c        | 21 ++++++++++++++-------
 arch/x86/kernel/vm86_32.c       | 11 ++++++-----
 6 files changed, 49 insertions(+), 45 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index 2fd5926fb97..5d98d0b68ff 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -17,13 +17,6 @@
  */
 #define asmregparm __attribute__((regparm(3)))
 
-/*
- * For syscalls that need a pointer to the pt_regs struct (ie. fork).
- * The regs pointer is passed in %eax as the first argument.  The
- * remaining function arguments remain on the stack.
- */
-#define ptregscall __attribute__((regparm(1)))
-
 /*
  * Make sure the compiler doesn't do anything stupid with the
  * arguments on the stack - they are owned by the *caller*, not
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index 617295255a1..77bb31a88ba 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -29,26 +29,21 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *);
 /* X86_32 only */
 #ifdef CONFIG_X86_32
 /* kernel/process_32.c */
-ptregscall int sys_fork(struct pt_regs *);
-ptregscall int sys_clone(struct pt_regs *, unsigned long,
-			 unsigned long, int __user *,
-			 unsigned long, int __user *);
-ptregscall int sys_vfork(struct pt_regs *);
-ptregscall int sys_execve(struct pt_regs *, char __user *,
-			  char __user * __user *,
-			  char __user * __user *);
+int sys_fork(struct pt_regs *);
+int sys_clone(struct pt_regs *);
+int sys_vfork(struct pt_regs *);
+int sys_execve(struct pt_regs *);
 
 /* kernel/signal_32.c */
 asmlinkage int sys_sigsuspend(int, int, old_sigset_t);
 asmlinkage int sys_sigaction(int, const struct old_sigaction __user *,
 			     struct old_sigaction __user *);
-ptregscall int sys_sigaltstack(struct pt_regs *, const stack_t __user *,
-			       stack_t __user *);
-ptregscall unsigned long sys_sigreturn(struct pt_regs *);
-ptregscall int sys_rt_sigreturn(struct pt_regs *);
+int sys_sigaltstack(struct pt_regs *);
+unsigned long sys_sigreturn(struct pt_regs *);
+int sys_rt_sigreturn(struct pt_regs *);
 
 /* kernel/ioport.c */
-ptregscall long sys_iopl(struct pt_regs *, unsigned int);
+long sys_iopl(struct pt_regs *);
 
 /* kernel/sys_i386_32.c */
 asmlinkage long sys_mmap2(unsigned long, unsigned long, unsigned long,
@@ -64,8 +59,8 @@ struct oldold_utsname;
 asmlinkage int sys_olduname(struct oldold_utsname __user *);
 
 /* kernel/vm86_32.c */
-ptregscall int sys_vm86old(struct pt_regs *, struct vm86_struct __user *);
-ptregscall int sys_vm86(struct pt_regs *, unsigned long, unsigned long);
+int sys_vm86old(struct pt_regs *);
+int sys_vm86(struct pt_regs *);
 
 #else /* CONFIG_X86_32 */
 
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 7ec14864631..e41980a373a 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -131,8 +131,9 @@ static int do_iopl(unsigned int level, struct pt_regs *regs)
 }
 
 #ifdef CONFIG_X86_32
-ptregscall long sys_iopl(struct pt_regs *regs, unsigned int level)
+long sys_iopl(struct pt_regs *regs)
 {
+	unsigned int level = regs->bx;
 	struct thread_struct *t = &current->thread;
 	int rc;
 
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 5a9dcfb01f7..fec79ad85dc 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -603,15 +603,21 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	return prev_p;
 }
 
-ptregscall int sys_fork(struct pt_regs *regs)
+int sys_fork(struct pt_regs *regs)
 {
 	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
 }
 
-ptregscall int sys_clone(struct pt_regs *regs, unsigned long clone_flags,
-			 unsigned long newsp, int __user *parent_tidptr,
-			 unsigned long unused, int __user *child_tidptr)
+int sys_clone(struct pt_regs *regs)
 {
+	unsigned long clone_flags;
+	unsigned long newsp;
+	int __user *parent_tidptr, *child_tidptr;
+
+	clone_flags = regs->bx;
+	newsp = regs->cx;
+	parent_tidptr = (int __user *)regs->dx;
+	child_tidptr = (int __user *)regs->di;
 	if (!newsp)
 		newsp = regs->sp;
 	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
@@ -627,7 +633,7 @@ ptregscall int sys_clone(struct pt_regs *regs, unsigned long clone_flags,
  * do not have enough call-clobbered registers to hold all
  * the information you need.
  */
-ptregscall int sys_vfork(struct pt_regs *regs)
+int sys_vfork(struct pt_regs *regs)
 {
 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, NULL, NULL);
 }
@@ -635,18 +641,19 @@ ptregscall int sys_vfork(struct pt_regs *regs)
 /*
  * sys_execve() executes a new program.
  */
-ptregscall int sys_execve(struct pt_regs *regs, char __user *u_filename,
-			  char __user * __user *argv,
-			  char __user * __user *envp)
+int sys_execve(struct pt_regs *regs)
 {
 	int error;
 	char *filename;
 
-	filename = getname(u_filename);
+	filename = getname((char __user *) regs->bx);
 	error = PTR_ERR(filename);
 	if (IS_ERR(filename))
 		goto out;
-	error = do_execve(filename, argv, envp, regs);
+	error = do_execve(filename,
+			(char __user * __user *) regs->cx,
+			(char __user * __user *) regs->dx,
+			regs);
 	if (error == 0) {
 		/* Make sure we don't return using sysenter.. */
 		set_thread_flag(TIF_IRET);
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index d7a158367e3..ccfb27412f0 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -549,23 +549,27 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 #endif /* CONFIG_X86_32 */
 
 #ifdef CONFIG_X86_32
-ptregscall int
-sys_sigaltstack(struct pt_regs *regs, const stack_t __user *uss,
-		stack_t __user *uoss)
+int sys_sigaltstack(struct pt_regs *regs)
+{
+	const stack_t __user *uss = (const stack_t __user *)regs->bx;
+	stack_t __user *uoss = (stack_t __user *)regs->cx;
+
+	return do_sigaltstack(uss, uoss, regs->sp);
+}
 #else /* !CONFIG_X86_32 */
 asmlinkage long
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 		struct pt_regs *regs)
-#endif /* CONFIG_X86_32 */
 {
 	return do_sigaltstack(uss, uoss, regs->sp);
 }
+#endif /* CONFIG_X86_32 */
 
 /*
  * Do a signal return; undo the signal stack.
  */
 #ifdef CONFIG_X86_32
-ptregscall unsigned long sys_sigreturn(struct pt_regs *regs)
+unsigned long sys_sigreturn(struct pt_regs *regs)
 {
 	struct sigframe __user *frame;
 	unsigned long ax;
@@ -629,13 +633,16 @@ badframe:
 }
 
 #ifdef CONFIG_X86_32
-ptregscall int sys_rt_sigreturn(struct pt_regs *regs)
+int sys_rt_sigreturn(struct pt_regs *regs)
+{
+	return do_rt_sigreturn(regs);
+}
 #else /* !CONFIG_X86_32 */
 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
-#endif /* CONFIG_X86_32 */
 {
 	return do_rt_sigreturn(regs);
 }
+#endif /* CONFIG_X86_32 */
 
 /*
  * OK, we're invoking a handler:
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 8fa6ba7c923..d7ac84e7fc1 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -197,8 +197,9 @@ out:
 static int do_vm86_irq_handling(int subfunction, int irqnumber);
 static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk);
 
-ptregscall int sys_vm86old(struct pt_regs *regs, struct vm86_struct __user *v86)
+int sys_vm86old(struct pt_regs *regs)
 {
+	struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs->bx;
 	struct kernel_vm86_struct info; /* declare this _on top_,
 					 * this avoids wasting of stack space.
 					 * This remains on the stack until we
@@ -226,7 +227,7 @@ out:
 }
 
 
-ptregscall int sys_vm86(struct pt_regs *regs, unsigned long cmd, unsigned long arg)
+int sys_vm86(struct pt_regs *regs)
 {
 	struct kernel_vm86_struct info; /* declare this _on top_,
 					 * this avoids wasting of stack space.
@@ -238,12 +239,12 @@ ptregscall int sys_vm86(struct pt_regs *regs, unsigned long cmd, unsigned long a
 	struct vm86plus_struct __user *v86;
 
 	tsk = current;
-	switch (cmd) {
+	switch (regs->bx) {
 	case VM86_REQUEST_IRQ:
 	case VM86_FREE_IRQ:
 	case VM86_GET_IRQ_BITS:
 	case VM86_GET_AND_RESET_IRQ:
-		ret = do_vm86_irq_handling(cmd, (int)arg);
+		ret = do_vm86_irq_handling(regs->bx, (int)regs->cx);
 		goto out;
 	case VM86_PLUS_INSTALL_CHECK:
 		/*
@@ -260,7 +261,7 @@ ptregscall int sys_vm86(struct pt_regs *regs, unsigned long cmd, unsigned long a
 	ret = -EPERM;
 	if (tsk->thread.saved_sp0)
 		goto out;
-	v86 = (struct vm86plus_struct __user *)arg;
+	v86 = (struct vm86plus_struct __user *)regs->cx;
 	tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
 				       offsetof(struct kernel_vm86_struct, regs32) -
 				       sizeof(info.regs));
-- 
cgit v1.2.3-70-g09d2


From 744525092727827a9cf0044074db3e22dcf354fd Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@linux.intel.com>
Date: Wed, 11 Feb 2009 16:31:40 -0800
Subject: x86: merge sys_rt_sigreturn between 32 and 64 bits

Impact: cleanup

With the recent changes in the 32-bit code to make system calls which
use struct pt_regs take a pointer, sys_rt_sigreturn() have become
identical between 32 and 64 bits, and both are empty wrappers around
do_rt_sigreturn().  Remove both wrappers and rename both to
sys_rt_sigreturn().

Cc: Brian Gerst <brgerst@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/include/asm/syscalls.h |  2 +-
 arch/x86/kernel/signal.c        | 14 +-------------
 2 files changed, 2 insertions(+), 14 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index 77bb31a88ba..68b1be10cfa 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -40,7 +40,7 @@ asmlinkage int sys_sigaction(int, const struct old_sigaction __user *,
 			     struct old_sigaction __user *);
 int sys_sigaltstack(struct pt_regs *);
 unsigned long sys_sigreturn(struct pt_regs *);
-int sys_rt_sigreturn(struct pt_regs *);
+long sys_rt_sigreturn(struct pt_regs *);
 
 /* kernel/ioport.c */
 long sys_iopl(struct pt_regs *);
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index ccfb27412f0..7cdcd16885e 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -601,7 +601,7 @@ badframe:
 }
 #endif /* CONFIG_X86_32 */
 
-static long do_rt_sigreturn(struct pt_regs *regs)
+long sys_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
 	unsigned long ax;
@@ -632,18 +632,6 @@ badframe:
 	return 0;
 }
 
-#ifdef CONFIG_X86_32
-int sys_rt_sigreturn(struct pt_regs *regs)
-{
-	return do_rt_sigreturn(regs);
-}
-#else /* !CONFIG_X86_32 */
-asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
-{
-	return do_rt_sigreturn(regs);
-}
-#endif /* CONFIG_X86_32 */
-
 /*
  * OK, we're invoking a handler:
  */
-- 
cgit v1.2.3-70-g09d2


From 144b0712dd9dd9ebd4e80c4e5388c9f6afc2b497 Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Fri, 27 Feb 2009 10:27:04 -0800
Subject: x86: signal: add __user annotation

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>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/signal.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 7cdcd16885e..e89eaf417e5 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;
 	}
-- 
cgit v1.2.3-70-g09d2


From 97286a2b64725aac2d584ddd1f94871f9991d5a1 Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Fri, 27 Feb 2009 10:28:48 -0800
Subject: x86: signal: intrroduce get_sigframe() and replace get_sigstack()

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>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/signal.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index e89eaf417e5..82d37c77b0f 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;
-- 
cgit v1.2.3-70-g09d2


From 36a4526583ad61fe7cb7432f53bce52ea198813a Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Fri, 27 Feb 2009 10:29:09 -0800
Subject: x86: signal: use 16 bytes boundary for rt_sigframe

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>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/signal.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 82d37c77b0f..89ef90df985 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,
-- 
cgit v1.2.3-70-g09d2


From 75779f05264b9968d7ae7ecb4ca5127b08785692 Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Fri, 27 Feb 2009 10:29:57 -0800
Subject: x86: signal: unify get_sigframe()

Impact: cleanup

Unify get_sigframe().

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

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 89ef90df985..53425c681f2 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)
 {
-- 
cgit v1.2.3-70-g09d2


From 1fae0279ce4811fa123001515d1ed3d68c1d557f Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Fri, 27 Feb 2009 10:30:32 -0800
Subject: x86: signal: introduce helper align_sigframe()

Impact: cleanup

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

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

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 53425c681f2..dde3f2ae237 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
-- 
cgit v1.2.3-70-g09d2


From 2505170211f7630361a852e25b60f4df4c878daa Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Mon, 2 Mar 2009 17:20:01 -0800
Subject: x86, signals: fix xine & firefox bustage

Impact: fix bad frame in rt_sigreturn on 64-bit

After commit 97286a2b64725aac2d584ddd1f94871f9991d5a1 some applications
fail to return from signal handler:

[  145.150133] firefox[3250] bad frame in rt_sigreturn frame:00007f902b44eb28 ip:352e80b307 sp:7f902b44ef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000]
[  665.519017] firefox[5420] bad frame in rt_sigreturn frame:00007faa8deaeb28 ip:352e80b307 sp:7faa8deaef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000]

The root cause is forgetting to keep 64 byte aligned value of
fpstate for next stack pointer calculation.

Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
LKML-Reference: <49AC85C1.7060600@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/signal.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

(limited to 'arch/x86/kernel/signal.c')

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index dde3f2ae237..d2cc6428c58 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -240,11 +240,10 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
 
 	if (used_math()) {
 		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 */
+#ifdef CONFIG_X86_64
+		sp = round_down(sp, 64);
+#endif /* CONFIG_X86_64 */
+		*fpstate = (void __user *)sp;
 
 		if (save_i387_xstate(*fpstate) < 0)
 			return (void __user *)-1L;
-- 
cgit v1.2.3-70-g09d2