From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x227GsakUu+/LeThevya6/3KX3KDXkh4p5XmCKMvMmPXHE7bwjcySmPfAvkmJKJLHDomfj/vk ARC-Seal: i=1; a=rsa-sha256; t=1518347517; cv=none; d=google.com; s=arc-20160816; b=unSfKnlyhlEcyv4A2ITWguT13XswZ6ciPWfNo4zf5Q/MJDu3ELk1rzBPb8+XWNmIxG JEG36Pg6prnxuSwsdh86SC7yQduA5OQpXV7hx+03EsAJDeXcxZU42zqnDqQfDmgae8RK psyyAIp8QlfCx+ZJX5APGmaDTRm8GAd0VgcPA8sTMNqgss+BO2LzOiE/g+QQofn1WC6Y Fdcztw/LjFz3nIy2diZd17Hmz0n+ZzItcPkdGrgr9/y3A9cUEJFV8s1Er/SS2sDLnJyE R0ovVxw2udPP9s/59yQiz/YVb3l9iRdK/tqcz0FbEGqayc1hn94NbXoRs9ArSek3URs/ pQUw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=G+3CH0LksQsaMUKigOP/LrR9NS6VKGoG/boQrIdUOAk=; b=cVAcYUapqXRWUJo0jK1mEz+8VGNkyiB7hLX2SuvBKP9NAs5HS6bdx15uSDIs4e80uq Zsurk2ienvIc8u2H11CtvzU/YbFm0oWkoY4mCZ1S67Lo+gj5S7rQnhRxdot5dP6fZyI9 TUb08ZpodTG6Gcf/fLn9+oDD3KuqVRX3vJJ0ySjz/A4rYRI9C2jAD1m5Wy2twRkTHUeZ Vk8/TG+6Ksv46V3UPLjXxlPTlRegPAyu7/XhY0FXy7+XirxthqtBLoa21qhYts+thDNE juzhFwROSoRlBUHK8lzOS8P4nFhiq2JbcIHDt2/ZEiqDFQ1c5SDL9eBVelF9GP9VcbTp y1sA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kselftest-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kselftest-owner@vger.kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kselftest-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kselftest-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987AbeBKLLT (ORCPT ); Sun, 11 Feb 2018 06:11:19 -0500 Received: from isilmar-4.linta.de ([136.243.71.142]:40670 "EHLO isilmar-4.linta.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbeBKLLF (ORCPT ); Sun, 11 Feb 2018 06:11:05 -0500 From: Dominik Brodowski To: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, x86@kernel.org, shuah@kernel.org Cc: Andrew Lutomirski Subject: [PATCH 2/5] selftests/x86: fix vDSO selftest segfault for vsyscall=none Date: Sun, 11 Feb 2018 12:10:10 +0100 Message-Id: <20180211111013.16888-3-linux@dominikbrodowski.net> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180211111013.16888-1-linux@dominikbrodowski.net> References: <20180211111013.16888-1-linux@dominikbrodowski.net> Sender: linux-kselftest-owner@vger.kernel.org X-Mailing-List: linux-kselftest@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1592102766376680865?= X-GMAIL-MSGID: =?utf-8?q?1592102766376680865?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 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 CC: Andrew Lutomirski Signed-off-by: Dominik Brodowski --- 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 29973cde06d3..558c8207e7b9 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, -- 2.16.1