From patchwork Tue Nov 19 10:56:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Venkataramanan Kumar X-Patchwork-Id: 21610 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-pd0-f198.google.com (mail-pd0-f198.google.com [209.85.192.198]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id 0059923FB4 for ; Tue, 19 Nov 2013 10:56:55 +0000 (UTC) Received: by mail-pd0-f198.google.com with SMTP id g10sf6803168pdj.9 for ; Tue, 19 Nov 2013 02:56:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:delivered-to:mime-version:date:message-id :subject:from:to:x-original-sender:x-original-authentication-results :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-unsubscribe:content-type; bh=Rw4fok+q162WOjSGxN3Qb5zktkmU7mSdz8DNJJqu1es=; b=HAMkokpubwLraSFrrC0OGM922jUpyERCRmR66SH4r8A9sVnaKDAc2MsA3XVApnMZ9Z uFwO1ro5obN+w3UP/G+FgyPHbXdNDwjuIx2/Z2snPq06keMhXEoWS6vBb9roMidfD87X OVo+BJodUVFkqpTe7qUYRdwLQvSkiehPLYMoobpy5j19+zFtmItgJLWU+HNeN52WfXus EutGRxF9ev7TSplrX4NoT07aUMEb7nEz9QFfTwOudPj/f/Hf82q+6FeJaP6KChIof4kA X8bT+ZW6gIy/BN1ooehZxHc8qAx1Wcq/HRfrlpqv37Anxs11J5qDFHx/5Qszpp/xtke7 0uqg== X-Gm-Message-State: ALoCoQnfSJI7Sl2FUtteCVLzVRSC127I1WI8joCSm3TxEg36iFlaHvmrJXQpbyc9ECae+Leib9xo X-Received: by 10.66.231.132 with SMTP id tg4mr9617031pac.31.1384858614859; Tue, 19 Nov 2013 02:56:54 -0800 (PST) X-BeenThere: patchwork-forward@linaro.org Received: by 10.49.37.225 with SMTP id b1ls1560515qek.8.gmail; Tue, 19 Nov 2013 02:56:54 -0800 (PST) X-Received: by 10.220.184.70 with SMTP id cj6mr659675vcb.23.1384858614692; Tue, 19 Nov 2013 02:56:54 -0800 (PST) Received: from mail-vb0-f48.google.com (mail-vb0-f48.google.com [209.85.212.48]) by mx.google.com with ESMTPS id td8si7993315vdc.40.2013.11.19.02.56.54 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 19 Nov 2013 02:56:54 -0800 (PST) Received-SPF: neutral (google.com: 209.85.212.48 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.212.48; Received: by mail-vb0-f48.google.com with SMTP id x16so1334973vbf.35 for ; Tue, 19 Nov 2013 02:56:54 -0800 (PST) X-Received: by 10.220.16.73 with SMTP id n9mr436054vca.24.1384858614598; Tue, 19 Nov 2013 02:56:54 -0800 (PST) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patch@linaro.org Received: by 10.220.174.196 with SMTP id u4csp268837vcz; Tue, 19 Nov 2013 02:56:53 -0800 (PST) X-Received: by 10.49.62.167 with SMTP id z7mr41497909qer.67.1384858613573; Tue, 19 Nov 2013 02:56:53 -0800 (PST) Received: from mail-qe0-f54.google.com (mail-qe0-f54.google.com [209.85.128.54]) by mx.google.com with ESMTPS id j1si897977qer.1.2013.11.19.02.56.53 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 19 Nov 2013 02:56:53 -0800 (PST) Received-SPF: neutral (google.com: 209.85.128.54 is neither permitted nor denied by best guess record for domain of venkataramanan.kumar@linaro.org) client-ip=209.85.128.54; Received: by mail-qe0-f54.google.com with SMTP id 1so4894525qec.41 for ; Tue, 19 Nov 2013 02:56:53 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.224.165.12 with SMTP id g12mr41170257qay.89.1384858613114; Tue, 19 Nov 2013 02:56:53 -0800 (PST) Received: by 10.140.25.72 with HTTP; Tue, 19 Nov 2013 02:56:52 -0800 (PST) Date: Tue, 19 Nov 2013 16:26:52 +0530 Message-ID: Subject: [RFC] [PATCH, AARCH64] Machine descriptions to support stack smashing protection From: Venkataramanan Kumar To: Marcus Shawcroft , Richard Earnshaw , "gcc-patches@gcc.gnu.org" , Patch Tracking , Marcus Shawcroft X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: venkataramanan.kumar@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.212.48 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , Hi Maintainers, This is RFC patch that adds machine descriptions to support stack smashing protection in AArch64. I have written a very simple patch that prints "stack set" and "stack test" as template of instructions. I had 2 assumptions. 1) For "stack_protect_set" and "stack_protect_test", I used "memory_operand" as predicate. GCC pushes the memory operand in a register much earlier during expand phase before these patterns are invoked. So assuming that I will get a memory operand "__stack_chk_gaurd" in a register when we are not using TLS based stack guard. 2) For the TLS case, assuming stack guard value will be stored at "-8" offset from "tp" GCC generates below code for stack set. mrs x0, tpidr_el0 ldr x1, [x0,-8] str x1, [x29,24] mov x1,0 I submitted Glibc patches some time before https://sourceware.org/ml/libc-ports/2013-08/msg00044.html. There are few regressions, the pthread_cancel tests in glibc fails I am currently debugging :(. GCC with the patch generates below code for stack test ldr x1, [x29,24] ldr x0, [x0,-8] eor x0, x1, x0 cbnz x0, .L4 ................................. ...................................... .L4: bl __stack_chk_f I generate "eor" since it has 2 purpose one for checking equality, and two for clearing the canary loaded register. Request your feedback to shape this into a better patch. regards, Venkat. Index: gcc/testsuite/gcc.dg/pr46440.c =================================================================== --- gcc/testsuite/gcc.dg/pr46440.c (revision 204932) +++ gcc/testsuite/gcc.dg/pr46440.c (working copy) @@ -1,7 +1,6 @@ /* PR rtl-optimization/46440 */ /* { dg-do compile } */ /* { dg-options "-O -fstack-protector -fno-tree-dominator-opts -fno-tree-fre" } */ -/* { dg-require-effective-target fstack_protector } */ int i; Index: gcc/testsuite/gcc.dg/ssp-1.c =================================================================== --- gcc/testsuite/gcc.dg/ssp-1.c (revision 204932) +++ gcc/testsuite/gcc.dg/ssp-1.c (working copy) @@ -1,6 +1,4 @@ -/* { dg-do run { target native } } */ /* { dg-options "-fstack-protector" } */ -/* { dg-require-effective-target fstack_protector } */ #include Index: gcc/testsuite/gcc.dg/pr47766.c =================================================================== --- gcc/testsuite/gcc.dg/pr47766.c (revision 204932) +++ gcc/testsuite/gcc.dg/pr47766.c (working copy) @@ -1,6 +1,5 @@ /* { dg-do compile } */ /* { dg-options "-O2 -fstack-protector" } */ -/* { dg-require-effective-target fstack_protector } */ int parse_opt (int key) Index: gcc/testsuite/gcc.dg/ssp-2.c =================================================================== --- gcc/testsuite/gcc.dg/ssp-2.c (revision 204932) +++ gcc/testsuite/gcc.dg/ssp-2.c (working copy) @@ -1,7 +1,5 @@ -/* { dg-do run { target native } } */ /* { dg-options "-fstack-protector" } */ /* { dg-options "-fstack-protector -Wl,-multiply_defined,suppress" { target *-*-darwin* } } */ -/* { dg-require-effective-target fstack_protector } */ #include Index: gcc/testsuite/gcc.dg/fstack-protector-strong.c =================================================================== --- gcc/testsuite/gcc.dg/fstack-protector-strong.c (revision 204932) +++ gcc/testsuite/gcc.dg/fstack-protector-strong.c (working copy) @@ -1,6 +1,6 @@ /* Test that stack protection is done on chosen functions. */ -/* { dg-do compile { target i?86-*-* x86_64-*-* rs6000-*-* s390x-*-* } } */ +/* { dg-do compile { target i?86-*-* x86_64-*-* rs6000-*-* s390x-*-* aarch64-*-*} } */ /* { dg-options "-O2 -fstack-protector-strong" } */ #include Index: gcc/testsuite/g++.dg/fstack-protector-strong.C =================================================================== --- gcc/testsuite/g++.dg/fstack-protector-strong.C (revision 204932) +++ gcc/testsuite/g++.dg/fstack-protector-strong.C (working copy) @@ -1,6 +1,6 @@ /* Test that stack protection is done on chosen functions. */ -/* { dg-do compile { target i?86-*-* x86_64-*-* } } */ +/* { dg-do compile { target i?86-*-* x86_64-*-* aarch64-*-* } } */ /* { dg-options "-O2 -fstack-protector-strong" } */ class A Index: gcc/config/aarch64/aarch64-linux.h =================================================================== --- gcc/config/aarch64/aarch64-linux.h (revision 204932) +++ gcc/config/aarch64/aarch64-linux.h (working copy) @@ -43,4 +43,9 @@ } \ while (0) +#ifdef TARGET_LIBC_PROVIDES_SSP +/* Aarch64 glibc provides __stack_chk_guard in [tp - 0x8]. */ +#define TARGET_THREAD_SSP_OFFSET (-1 * GET_MODE_SIZE (ptr_mode)) +#endif + #endif /* GCC_AARCH64_LINUX_H */ Index: gcc/config/aarch64/aarch64.md =================================================================== --- gcc/config/aarch64/aarch64.md (revision 204932) +++ gcc/config/aarch64/aarch64.md (working copy) @@ -99,6 +99,10 @@ UNSPEC_TLSDESC UNSPEC_USHL_2S UNSPEC_VSTRUCTDUMMY + UNSPEC_SP_SET + UNSPEC_SP_TEST + UNSPEC_SP_TLS_SET + UNSPEC_SP_TLS_TEST ]) (define_c_enum "unspecv" [ @@ -320,6 +324,7 @@ (include "../arm/cortex-a53.md") (include "../arm/cortex-a15.md") + ;; ------------------------------------------------------------------- ;; Jumps and other miscellaneous insns ;; ------------------------------------------------------------------- @@ -4181,6 +4186,82 @@ DONE; }) +;; Named patterns for stack smashing protection + +(define_expand "stack_protect_set" + [(match_operand 0 "memory_operand") + (match_operand 1 "memory_operand")] + "" +{ + enum machine_mode mode = GET_MODE (operands[0]); + +#ifdef TARGET_THREAD_SSP_OFFSET + rtx tlsreg = gen_reg_rtx (Pmode); + emit_insn (gen_aarch64_load_tp_hard (tlsreg)); + rtx addr = gen_rtx_PLUS (Pmode, tlsreg, GEN_INT (TARGET_THREAD_SSP_OFFSET)); + operands[1] = gen_rtx_MEM (Pmode, addr); +#endif + + emit_insn ((mode == DImode + ? gen_stack_protect_set_di + : gen_stack_protect_set_si) (operands[0], operands[1])); + DONE; +}) + +(define_insn "stack_protect_set_" + [(set (match_operand:PTR 0 "memory_operand" "=m") + (unspec:PTR [(match_operand:PTR 1 "memory_operand" "m")] + UNSPEC_SP_SET)) + (set (match_scratch:PTR 2 "=&r") (const_int 0))] + "" + "ldr\\t%x2, %1\;str\\t%x2, %0\;mov\t%x2,0" + [(set_attr "length" "12")]) + + +(define_expand "stack_protect_test" + [(match_operand 0 "memory_operand") + (match_operand 1 "memory_operand") + (match_operand 2)] + "" +{ + +#ifdef TARGET_THREAD_SSP_OFFSET + rtx tlsreg = gen_reg_rtx (Pmode); + emit_insn (gen_aarch64_load_tp_hard (tlsreg)); + rtx addr = gen_rtx_PLUS (Pmode, tlsreg, GEN_INT (TARGET_THREAD_SSP_OFFSET)); + operands[1] = gen_rtx_MEM (Pmode, addr); +#endif + + rtx result = gen_reg_rtx (Pmode); + + enum machine_mode mode = GET_MODE (operands[0]); + + emit_insn ((mode == DImode + ? gen_stack_protect_test_di + : gen_stack_protect_test_si) (result, + operands[0], + operands[1])); + + if (mode == DImode) + emit_jump_insn (gen_cbranchdi4 (gen_rtx_EQ (VOIDmode, result, const0_rtx), + result, const0_rtx, operands[2])); + else + emit_jump_insn (gen_cbranchsi4 (gen_rtx_EQ (VOIDmode, result, const0_rtx), + result, const0_rtx, operands[2])); + DONE; +}) + +(define_insn "stack_protect_test_" + [(set (match_operand:PTR 0 "register_operand") + (unspec:PTR [(match_operand:PTR 1 "memory_operand" "m") + (match_operand:PTR 2 "memory_operand" "m")] + UNSPEC_SP_TEST)) + (clobber (match_scratch:PTR 3 "=&r"))] + "" + "ldr\t%x3, %x1\;ldr\t%x0, %x2\;eor\t%x0, %x3, %x0" + [(set_attr "length" "12")]) + + ;; AdvSIMD Stuff (include "aarch64-simd.md")