[RFC -tip 4/4] x86: ia32_signal: use __{get|put}_user exception handling framework

[Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>]

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

Impact: cleanup

Use __{get|put}_user exception handling framework.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/ia32/ia32_signal.c |  194 ++++++++++++++++++++++++-------------------
 1 files changed, 109 insertions(+), 85 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index b195f85..a3b6918 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -47,7 +47,9 @@ void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
 
 int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
 {
-	int err;
+	int err = 0;
+
+	__put_user_ex_try(&err, -EFAULT);
 
 	if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
 		return -EFAULT;
@@ -57,69 +59,74 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
 	   It should never copy any pad contained in the structure
 	   to avoid security leaks, but must copy the generic
 	   3 ints plus the relevant union member.  */
-	err = __put_user(from->si_signo, &to->si_signo);
-	err |= __put_user(from->si_errno, &to->si_errno);
-	err |= __put_user((short)from->si_code, &to->si_code);
+	__put_user_ex(from->si_signo, &to->si_signo);
+	__put_user_ex(from->si_errno, &to->si_errno);
+	__put_user_ex((short)from->si_code, &to->si_code);
 
 	if (from->si_code < 0) {
-		err |= __put_user(from->si_pid, &to->si_pid);
-		err |= __put_user(from->si_uid, &to->si_uid);
-		err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
+		__put_user_ex(from->si_pid, &to->si_pid);
+		__put_user_ex(from->si_uid, &to->si_uid);
+		__put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
 	} else {
 		/*
 		 * First 32bits of unions are always present:
 		 * si_pid === si_band === si_tid === si_addr(LS half)
 		 */
-		err |= __put_user(from->_sifields._pad[0],
+		__put_user_ex(from->_sifields._pad[0],
 				  &to->_sifields._pad[0]);
 		switch (from->si_code >> 16) {
 		case __SI_FAULT >> 16:
 			break;
 		case __SI_CHLD >> 16:
-			err |= __put_user(from->si_utime, &to->si_utime);
-			err |= __put_user(from->si_stime, &to->si_stime);
-			err |= __put_user(from->si_status, &to->si_status);
+			__put_user_ex(from->si_utime, &to->si_utime);
+			__put_user_ex(from->si_stime, &to->si_stime);
+			__put_user_ex(from->si_status, &to->si_status);
 			/* FALL THROUGH */
 		default:
 		case __SI_KILL >> 16:
-			err |= __put_user(from->si_uid, &to->si_uid);
+			__put_user_ex(from->si_uid, &to->si_uid);
 			break;
 		case __SI_POLL >> 16:
-			err |= __put_user(from->si_fd, &to->si_fd);
+			__put_user_ex(from->si_fd, &to->si_fd);
 			break;
 		case __SI_TIMER >> 16:
-			err |= __put_user(from->si_overrun, &to->si_overrun);
-			err |= __put_user(ptr_to_compat(from->si_ptr),
+			__put_user_ex(from->si_overrun, &to->si_overrun);
+			__put_user_ex(ptr_to_compat(from->si_ptr),
 					  &to->si_ptr);
 			break;
 			 /* This is not generated by the kernel as of now.  */
 		case __SI_RT >> 16:
 		case __SI_MESGQ >> 16:
-			err |= __put_user(from->si_uid, &to->si_uid);
-			err |= __put_user(from->si_int, &to->si_int);
+			__put_user_ex(from->si_uid, &to->si_uid);
+			__put_user_ex(from->si_int, &to->si_int);
 			break;
 		}
 	}
+
+	__put_user_ex_catch();
 	return err;
 }
 
 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 {
-	int err;
+	int err = 0;
 	u32 ptr32;
 
+	__get_user_ex_try(&err, -EFAULT);
+
 	if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
 		return -EFAULT;
 
-	err = __get_user(to->si_signo, &from->si_signo);
-	err |= __get_user(to->si_errno, &from->si_errno);
-	err |= __get_user(to->si_code, &from->si_code);
+	__get_user_ex(to->si_signo, &from->si_signo);
+	__get_user_ex(to->si_errno, &from->si_errno);
+	__get_user_ex(to->si_code, &from->si_code);
 
-	err |= __get_user(to->si_pid, &from->si_pid);
-	err |= __get_user(to->si_uid, &from->si_uid);
-	err |= __get_user(ptr32, &from->si_ptr);
+	__get_user_ex(to->si_pid, &from->si_pid);
+	__get_user_ex(to->si_uid, &from->si_uid);
+	__get_user_ex(ptr32, &from->si_ptr);
 	to->si_ptr = compat_ptr(ptr32);
 
+	__get_user_ex_catch();
 	return err;
 }
 
@@ -143,18 +150,21 @@ asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
 				  struct pt_regs *regs)
 {
 	stack_t uss, uoss;
-	int ret;
+	int ret = 0;
 	mm_segment_t seg;
 
+	__put_user_ex_try(&ret, -EFAULT);
+	__get_user_ex_try(&ret, -EFAULT);
+
 	if (uss_ptr) {
 		u32 ptr;
 
 		memset(&uss, 0, sizeof(stack_t));
-		if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)) ||
-			    __get_user(ptr, &uss_ptr->ss_sp) ||
-			    __get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
-			    __get_user(uss.ss_size, &uss_ptr->ss_size))
+		if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
 			return -EFAULT;
+		__get_user_ex(ptr, &uss_ptr->ss_sp);
+		__get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
+		__get_user_ex(uss.ss_size, &uss_ptr->ss_size);
 		uss.ss_sp = compat_ptr(ptr);
 	}
 	seg = get_fs();
@@ -162,12 +172,16 @@ asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
 	ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp);
 	set_fs(seg);
 	if (ret >= 0 && uoss_ptr)  {
-		if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)) ||
-		    __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
-		    __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
-		    __put_user(uoss.ss_size, &uoss_ptr->ss_size))
+		if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
 			ret = -EFAULT;
+		__put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
+		__put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
+		__put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
 	}
+
+	__get_user_ex_catch();
+	__put_user_ex_catch();
+
 	return ret;
 }
 
@@ -175,18 +189,18 @@ asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
  * Do a signal return; undo the signal stack.
  */
 #define COPY(x)			{		\
-	err |= __get_user(regs->x, &sc->x);	\
+	__get_user_ex(regs->x, &sc->x);	\
 }
 
 #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 RELOAD_SEG(seg)		{		\
 	unsigned int cur, pre;			\
-	err |= __get_user(pre, &sc->seg);	\
+	__get_user_ex(pre, &sc->seg);	\
 	savesegment(seg, cur);			\
 	pre |= 3;				\
 	if (pre != cur)				\
@@ -204,6 +218,8 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	/* Always make any pending restarted system calls return -EINTR */
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
+	__get_user_ex_try(&err, -EFAULT);
+
 #if DEBUG_SIG
 	printk(KERN_DEBUG "SIG restore_sigcontext: "
 	       "sc=%p err(%x) eip(%x) cs(%x) flg(%x)\n",
@@ -216,7 +232,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	 * the handler, but does not clobber them at least in the
 	 * normal case.
 	 */
-	err |= __get_user(gs, &sc->gs);
+	__get_user_ex(gs, &sc->gs);
 	gs |= 3;
 	savesegment(gs, oldgs);
 	if (gs != oldgs)
@@ -233,16 +249,18 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	COPY_SEG_CPL3(cs);
 	COPY_SEG_CPL3(ss);
 
-	err |= __get_user(tmpflags, &sc->flags);
+	__get_user_ex(tmpflags, &sc->flags);
 	regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
 	/* disable syscall checks */
 	regs->orig_ax = -1;
 
-	err |= __get_user(tmp, &sc->fpstate);
+	__get_user_ex(tmp, &sc->fpstate);
 	buf = compat_ptr(tmp);
 	err |= restore_i387_xstate_ia32(buf);
 
-	err |= __get_user(*pax, &sc->ax);
+	__get_user_ex(*pax, &sc->ax);
+
+	__get_user_ex_catch();
 	return err;
 }
 
@@ -320,36 +338,40 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
 {
 	int tmp, err = 0;
 
+	__put_user_ex_try(&err, -EFAULT);
+
 	savesegment(gs, tmp);
-	err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
+	__put_user_ex(tmp, (unsigned int __user *)&sc->gs);
 	savesegment(fs, tmp);
-	err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
+	__put_user_ex(tmp, (unsigned int __user *)&sc->fs);
 	savesegment(ds, tmp);
-	err |= __put_user(tmp, (unsigned int __user *)&sc->ds);
+	__put_user_ex(tmp, (unsigned int __user *)&sc->ds);
 	savesegment(es, tmp);
-	err |= __put_user(tmp, (unsigned int __user *)&sc->es);
-
-	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);
-	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);
-	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);
-
-	err |= __put_user(ptr_to_compat(fpstate), &sc->fpstate);
+	__put_user_ex(tmp, (unsigned int __user *)&sc->es);
+
+	__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);
+	__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);
+	__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);
+
+	__put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);
 
 	/* non-iBCS2 extensions.. */
-	err |= __put_user(mask, &sc->oldmask);
-	err |= __put_user(current->thread.cr2, &sc->cr2);
+	__put_user_ex(mask, &sc->oldmask);
+	__put_user_ex(current->thread.cr2, &sc->cr2);
+
+	__put_user_ex_catch();
 
 	return err;
 }
@@ -411,13 +433,14 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
 		0x80cd,		/* int $0x80 */
 	};
 
+	__put_user_ex_try(&err, -EFAULT);
+
 	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;
 
-	if (__put_user(sig, &frame->sig))
-		return -EFAULT;
+	__put_user_ex(sig, &frame->sig);
 
 	if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
 		return -EFAULT;
@@ -438,15 +461,13 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
 		else
 			restorer = &frame->retcode;
 	}
-	err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
+	__put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
 
 	/*
 	 * These are actually not used anymore, but left because some
 	 * gdb versions depend on them as a marker.
 	 */
-	err |= __put_user(*((u64 *)&code), (u64 *)frame->retcode);
-	if (err)
-		return -EFAULT;
+	__put_user_ex(*((u64 *)&code), (u64 *)frame->retcode);
 
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long) frame;
@@ -468,7 +489,9 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
 	       current->comm, current->pid, frame, regs->ip, frame->pretcode);
 #endif
 
-	return 0;
+	__put_user_ex_catch();
+
+	return err;
 }
 
 int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
@@ -492,28 +515,30 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 		0,
 	};
 
+	__put_user_ex_try(&err, -EFAULT);
+
 	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;
 
-	err |= __put_user(sig, &frame->sig);
-	err |= __put_user(ptr_to_compat(&frame->info), &frame->pinfo);
-	err |= __put_user(ptr_to_compat(&frame->uc), &frame->puc);
+	__put_user_ex(sig, &frame->sig);
+	__put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
+	__put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
 	err |= copy_siginfo_to_user32(&frame->info, info);
 	if (err)
 		return -EFAULT;
 
 	/* Create the ucontext.  */
 	if (cpu_has_xsave)
-		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+		__put_user_ex(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),
+		__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);
-	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	__put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 	err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
 				     regs, set->sig[0]);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
@@ -525,15 +550,13 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	else
 		restorer = VDSO32_SYMBOL(current->mm->context.vdso,
 					 rt_sigreturn);
-	err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
+	__put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
 
 	/*
 	 * Not actually used anymore, but left because some gdb
 	 * versions need it.
 	 */
-	err |= __put_user(*((u64 *)&code), (u64 *)frame->retcode);
-	if (err)
-		return -EFAULT;
+	__put_user_ex(*((u64 *)&code), (u64 *)frame->retcode);
 
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long) frame;
@@ -555,5 +578,6 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	       current->comm, current->pid, frame, regs->ip, frame->pretcode);
 #endif
 
-	return 0;
+	__put_user_ex_catch();
+	return err;
 }
-- 
1.6.0.4