From 01f7ae056916b4e75ccaa48b9daacb9806caf4aa Mon Sep 17 00:00:00 2001 From: Chen Gang Date: Sun, 2 Nov 2014 10:13:11 +0800 Subject: [PATCH] arch: tile: kernel: signal.c: Use __copy_from/to_user() instead of __get/put_user() setup/restore_sigcontext() want to copy all related registers between user and kernel. So use block copy instead of each registers copy. Then can let code simple and clearer (which can avoid compiler's warning): The related warning (with allmodconfig under tile): CC arch/tile/kernel/signal.o In file included from include/linux/poll.h:11:0, from include/linux/ring_buffer.h:7, from include/linux/ftrace_event.h:5, from include/trace/syscall.h:6, from include/linux/syscalls.h:81, from arch/tile/kernel/signal.c:30: arch/tile/kernel/signal.c: In function 'setup_sigcontext': arch/tile/kernel/signal.c:116:31: warning: iteration 53u invokes undefined behavior [-Waggressive-loop-optimizations] err |= __put_user(regs->regs[i], &sc->gregs[i]); ^ ./arch/tile/include/asm/uaccess.h:236:26: note: in definition of macro '__put_user_asm' : "r" (ptr), "r" (x), "i" (-EFAULT)) ^ ./arch/tile/include/asm/uaccess.h:297:10: note: in expansion of macro '__put_user_8' case 8: __put_user_8(x, ptr, __ret); break; \ ^ arch/tile/kernel/signal.c:116:10: note: in expansion of macro '__put_user' err |= __put_user(regs->regs[i], &sc->gregs[i]); ^ arch/tile/kernel/signal.c:115:2: note: containing loop for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i) ^ Signed-off-by: Chen Gang Signed-off-by: Chris Metcalf --- arch/tile/kernel/signal.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c index 7c2fecc52177..491669065ffb 100644 --- a/arch/tile/kernel/signal.c +++ b/arch/tile/kernel/signal.c @@ -45,8 +45,7 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { - int err = 0; - int i; + int err; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; @@ -57,9 +56,7 @@ int restore_sigcontext(struct pt_regs *regs, */ BUILD_BUG_ON(sizeof(struct sigcontext) != sizeof(struct pt_regs)); BUILD_BUG_ON(sizeof(struct sigcontext) % 8 != 0); - - for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i) - err |= __get_user(regs->regs[i], &sc->gregs[i]); + err = __copy_from_user(regs, sc, sizeof(*regs)); /* Ensure that the PL is always set to USER_PL. */ regs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(regs->ex1)); @@ -110,12 +107,7 @@ badframe: int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) { - int i, err = 0; - - for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i) - err |= __put_user(regs->regs[i], &sc->gregs[i]); - - return err; + return __copy_to_user(sc, regs, sizeof(*regs)); } /* -- 2.30.2