From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.efficios.com ([167.114.142.138]:53946 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726304AbeIYXsR (ORCPT ); Tue, 25 Sep 2018 19:48:17 -0400 Date: Tue, 25 Sep 2018 13:39:36 -0400 (EDT) From: Mathieu Desnoyers To: Thomas Gleixner , Shuah Khan , linux-kselftest Cc: linux-kernel , linux-api , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson , Paul Turner , Andrew Morton , Russell King , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Chris Lameter , Ben Maurer , rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon , Michael Kerrisk , Joel Fernandes , stable Message-ID: <1367962117.10271.1537897176578.JavaMail.zimbra@efficios.com> In-Reply-To: <20180918135328.32034-1-mathieu.desnoyers@efficios.com> References: <20180918135328.32034-1-mathieu.desnoyers@efficios.com> Subject: Re: [PATCH] rseq/selftests: fix parametrized test with -fpie MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote: > On x86-64, the parametrized selftest code for rseq crashes with a > segmentation fault when compiled with -fpie. This happens when the > param_test binary is loaded at an address beyond 32-bit on x86-64. > > The issue is caused by use of a 32-bit register to hold the address > of the loop counter variable. > > Fix this by using a 64-bit register to calculate the address of the > loop counter variables as an offset from rip. Should this fix go through tip or the selftests tree ? Thanks, Mathieu > > Signed-off-by: Mathieu Desnoyers > Cc: # v4.18 > Cc: Thomas Gleixner > Cc: Joel Fernandes > Cc: Peter Zijlstra > Cc: Catalin Marinas > Cc: Dave Watson > Cc: Will Deacon > Cc: Shuah Khan > Cc: Andi Kleen > Cc: linux-kselftest@vger.kernel.org > Cc: "H . Peter Anvin" > Cc: Chris Lameter > Cc: Russell King > Cc: Michael Kerrisk > Cc: "Paul E . McKenney" > Cc: Paul Turner > Cc: Boqun Feng > Cc: Josh Triplett > Cc: Steven Rostedt > Cc: Ben Maurer > Cc: Andy Lutomirski > Cc: Andrew Morton > Cc: Linus Torvalds > --- > tools/testing/selftests/rseq/param_test.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/tools/testing/selftests/rseq/param_test.c > b/tools/testing/selftests/rseq/param_test.c > index 615252331813..4bc071525bf7 100644 > --- a/tools/testing/selftests/rseq/param_test.c > +++ b/tools/testing/selftests/rseq/param_test.c > @@ -56,15 +56,13 @@ unsigned int yield_mod_cnt, nr_abort; > printf(fmt, ## __VA_ARGS__); \ > } while (0) > > -#if defined(__x86_64__) || defined(__i386__) > +#ifdef __i386__ > > #define INJECT_ASM_REG "eax" > > #define RSEQ_INJECT_CLOBBER \ > , INJECT_ASM_REG > > -#ifdef __i386__ > - > #define RSEQ_INJECT_ASM(n) \ > "mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \ > "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \ > @@ -76,9 +74,16 @@ unsigned int yield_mod_cnt, nr_abort; > > #elif defined(__x86_64__) > > +#define INJECT_ASM_REG_P "rax" > +#define INJECT_ASM_REG "eax" > + > +#define RSEQ_INJECT_CLOBBER \ > + , INJECT_ASM_REG_P \ > + , INJECT_ASM_REG > + > #define RSEQ_INJECT_ASM(n) \ > - "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG "\n\t" \ > - "mov (%%" INJECT_ASM_REG "), %%" INJECT_ASM_REG "\n\t" \ > + "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \ > + "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \ > "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \ > "jz 333f\n\t" \ > "222:\n\t" \ > @@ -86,10 +91,6 @@ unsigned int yield_mod_cnt, nr_abort; > "jnz 222b\n\t" \ > "333:\n\t" > > -#else > -#error "Unsupported architecture" > -#endif > - > #elif defined(__ARMEL__) > > #define RSEQ_INJECT_INPUT \ > -- > 2.11.0 -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com