From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shi Weihua Date: Thu, 22 Nov 2007 03:15:55 +0000 Subject: [PATCH RFC][try 2] IA64 signal : remove redundant code in setup_sigcontext() Message-Id: <4744F46B.6050004@cn.fujitsu.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org Cc: tony.luck@intel.com, linux-ia64@vger.kernel.org This patch removes some redundant code in the function setup_sigcontext(). The registers ar.ccv,b7,r14,ar.csd,ar.ssd,r2-r3 and r16-r31 are not restored in restore_sigcontext() when (flags & IA64_SC_FLAG_IN_SYSCALL) is true. So we don't need to zero those variables in setup_sigcontext(). Signed-off-by: Shi Weihua --- diff -urp linux-2.6.24-rc3-git1.orig/arch/ia64/kernel/signal.c linux-2.6.24-rc3-git1/arch/ia64/kernel/signal.c --- linux-2.6.24-rc3-git1.orig/arch/ia64/kernel/signal.c 2007-11-17 13:16:36.000000000 +0800 +++ linux-2.6.24-rc3-git1/arch/ia64/kernel/signal.c 2007-11-22 11:02:27.000000000 +0800 @@ -280,15 +280,7 @@ setup_sigcontext (struct sigcontext __us err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */ err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip); - if (flags & IA64_SC_FLAG_IN_SYSCALL) { - /* Clear scratch registers if the signal interrupted a system call. */ - err |= __put_user(0, &sc->sc_ar_ccv); /* ar.ccv */ - err |= __put_user(0, &sc->sc_br[7]); /* b7 */ - err |= __put_user(0, &sc->sc_gr[14]); /* r14 */ - err |= __clear_user(&sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */ - err |= __clear_user(&sc->sc_gr[2], 2*8); /* r2-r3 */ - err |= __clear_user(&sc->sc_gr[16], 16*8); /* r16-r31 */ - } else { + if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */ err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */