From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933932AbeBMJFS (ORCPT ); Tue, 13 Feb 2018 04:05:18 -0500 Received: from terminus.zytor.com ([198.137.202.136]:58321 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933901AbeBMJEy (ORCPT ); Tue, 13 Feb 2018 04:04:54 -0500 Date: Tue, 13 Feb 2018 01:04:31 -0800 From: tip-bot for Dominik Brodowski Message-ID: Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, mingo@kernel.org, hpa@zytor.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, linux@dominikbrodowski.net Reply-To: linux-kernel@vger.kernel.org, mingo@kernel.org, torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com, linux@dominikbrodowski.net, luto@kernel.org, peterz@infradead.org In-Reply-To: <20180211111013.16888-3-linux@dominikbrodowski.net> References: <20180211111013.16888-3-linux@dominikbrodowski.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/pti] selftests/x86: Fix vDSO selftest segfault for vsyscall=none Git-Commit-ID: 198ee8e17502da2634f7366395db1d77630e0219 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 198ee8e17502da2634f7366395db1d77630e0219 Gitweb: https://git.kernel.org/tip/198ee8e17502da2634f7366395db1d77630e0219 Author: Dominik Brodowski AuthorDate: Sun, 11 Feb 2018 12:10:10 +0100 Committer: Ingo Molnar CommitDate: Tue, 13 Feb 2018 09:04:55 +0100 selftests/x86: Fix vDSO selftest segfault for vsyscall=none The vDSO selftest tries to execute a vsyscall unconditionally, even if it is not present on the test system (e.g. if booted with vsyscall=none or with CONFIG_LEGACY_VSYSCALL_NONE=y set. Fix this by copying (and tweaking) the vsyscall check from test_vsyscall.c Signed-off-by: Dominik Brodowski Cc: Andrew Lutomirski Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kselftest@vger.kernel.org Cc: shuah@kernel.org Link: http://lkml.kernel.org/r/20180211111013.16888-3-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar --- tools/testing/selftests/x86/test_vdso.c | 50 ++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/x86/test_vdso.c b/tools/testing/selftests/x86/test_vdso.c index 29973cd..558c820 100644 --- a/tools/testing/selftests/x86/test_vdso.c +++ b/tools/testing/selftests/x86/test_vdso.c @@ -28,18 +28,52 @@ int nerrs = 0; +typedef long (*getcpu_t)(unsigned *, unsigned *, void *); + +getcpu_t vgetcpu; +getcpu_t vdso_getcpu; + +static void *vsyscall_getcpu(void) +{ #ifdef __x86_64__ -# define VSYS(x) (x) + FILE *maps; + char line[128]; + bool found = false; + + maps = fopen("/proc/self/maps", "r"); + if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */ + return NULL; + + while (fgets(line, sizeof(line), maps)) { + char r, x; + void *start, *end; + char name[128]; + if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s", + &start, &end, &r, &x, name) != 5) + continue; + + if (strcmp(name, "[vsyscall]")) + continue; + + /* assume entries are OK, as we test vDSO here not vsyscall */ + found = true; + break; + } + + fclose(maps); + + if (!found) { + printf("Warning: failed to find vsyscall getcpu\n"); + return NULL; + } + return (void *) (0xffffffffff600800); #else -# define VSYS(x) 0 + return NULL; #endif +} -typedef long (*getcpu_t)(unsigned *, unsigned *, void *); - -const getcpu_t vgetcpu = (getcpu_t)VSYS(0xffffffffff600800); -getcpu_t vdso_getcpu; -void fill_function_pointers() +static void fill_function_pointers() { void *vdso = dlopen("linux-vdso.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); @@ -54,6 +88,8 @@ void fill_function_pointers() vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu"); if (!vdso_getcpu) printf("Warning: failed to find getcpu in vDSO\n"); + + vgetcpu = (getcpu_t) vsyscall_getcpu(); } static long sys_getcpu(unsigned * cpu, unsigned * node,