Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751778AbaJZOMY (ORCPT ); Sun, 26 Oct 2014 10:12:24 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:64733 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751461AbaJZOMX (ORCPT ); Sun, 26 Oct 2014 10:12:23 -0400 From: linyongting@gmail.com To: linux@arm.linux.org.uk, stefano.stabellini@eu.citrix.com, haojian.zhuang@gmail.com, christoffer.dall@linaro.org, nsekhar@ti.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: linyongting@huawei.com, linyongting@gmail.com Subject: [PATCH] ARM: Add unwinding support for memset function Date: Sun, 26 Oct 2014 22:11:25 +0800 Message-Id: <1414332685-22774-1-git-send-email-linyongting@gmail.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lin Yongting The memset function never had unwinding annotations added. Currently, when accessing NULL pointer by memset occurs the backtrace shown will stop at memset or some completely unrelated function. Add unwinding annotations in hopes of getting a more useful backtrace when accessing NULL pointer by memset, kprobe or interrupt. Signed-off-by: Lin Yongting --- arch/arm/lib/memset.S | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S index 671455c..a4ee97b 100644 --- a/arch/arm/lib/memset.S +++ b/arch/arm/lib/memset.S @@ -11,11 +11,13 @@ */ #include #include +#include .text .align 5 ENTRY(memset) +UNWIND( .fnstart ) ands r3, r0, #3 @ 1 unaligned? mov ip, r0 @ preserve r0 as return value bne 6f @ 1 @@ -34,6 +36,9 @@ ENTRY(memset) * We need 2 extra registers for this loop - use r8 and the LR */ stmfd sp!, {r8, lr} +UNWIND( .fnend ) +UNWIND( .fnstart ) +UNWIND( .save {r8, lr} ) mov r8, r1 mov lr, r1 @@ -53,6 +58,7 @@ ENTRY(memset) tst r2, #16 stmneia ip!, {r1, r3, r8, lr} ldmfd sp!, {r8, lr} +UNWIND( .fnend ) #else @@ -62,6 +68,9 @@ ENTRY(memset) */ stmfd sp!, {r4-r8, lr} +UNWIND( .fnend ) +UNWIND( .fnstart ) +UNWIND( .save {r4-r8, lr} ) mov r4, r1 mov r5, r1 mov r6, r1 @@ -94,9 +103,11 @@ ENTRY(memset) tst r2, #16 stmneia ip!, {r4-r7} ldmfd sp!, {r4-r8, lr} +UNWIND( .fnend ) #endif +UNWIND( .fnstart ) 4: tst r2, #8 stmneia ip!, {r1, r3} tst r2, #4 @@ -120,4 +131,5 @@ ENTRY(memset) strb r1, [ip], #1 @ 1 add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3)) b 1b +UNWIND( .fnend ) ENDPROC(memset) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/