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

@@ -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;