From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x225PS7qxF3R3aNR/yC2dtotqe8HtPBRfZ1gXxACKUged+LuaDyJ5dYuSlE1eMjjD7dH2va5p ARC-Seal: i=1; a=rsa-sha256; t=1519218171; cv=none; d=google.com; s=arc-20160816; b=MB1JG24LuMO/0zYGeTq6UU8SpUaxf0Sf+ml6xmKuV2gs71unAFWT5uKn54cgqiOmeb hEV22yF1Xqarl6jUGpKSbjeMECm60ugf5OVmSqmEP8zngjorApym2v7yF2FEvi/x4VO3 yJUO9Wi9BTuXqw9kNeM8Dv0VmOjFx1Yne7wNK6JnuxbSvEO4m4+bd2WnJr91Vnx1xndX h4gnFrXfxaGgUjMYEfJy6hD6zqFnL6vxJsxTSL92aNN7BGrtF43aYCatvRpZGvigtOlD 77wzTLclIHy2c+YxvvF1ste5ROm4Z/Es/qFlbRgqXfXsJayaPD+A5YFvyHB/mEFItIaU l1fw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=nw2J/dvkqxaRGOkIcVsHR7KaXeEKKKcoBOZad+20zjs=; b=hV+5pWx/r3gI4AU0k6BHRBmazA+JSQMlOlKDC4dasmrmprgWYdwnQkrADgP0X8HkNn nYehNDVmjCvRmHKXUgQAIulGCq063GrFIYfwkWf6NT4qD/a0twp+1AQe8LputSj96vrS Lrz6BouP9kB7uxZPGBSPpkQul5hPUwqw60vgs23hnvH8+xbgY2OqiyuQdFGxD9zYaTmo R5AMf34AKBdB1G+WDe/YfYViO1umfysMgOUygdflGHhahF5YOnjliehgGS9Nc40ppKjz G6mpRXZVm/FMDx4tzHgl5wweM1TmzrOXh6J7IOhfIzE3670IqntAMlws3MigQUUNa+s+ 6h1g== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ingo Molnar , Dominik Brodowski , Andrew Lutomirski , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: [PATCH 4.14 068/167] selftests/x86: Clean up and document sscanf() usage Date: Wed, 21 Feb 2018 13:47:59 +0100 Message-Id: <20180221124528.233369851@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180221124524.639039577@linuxfoundation.org> References: <20180221124524.639039577@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593015713811581521?= X-GMAIL-MSGID: =?utf-8?q?1593015713811581521?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dominik Brodowski commit d8e92de8ef952bed88c56c7a44c02d8dcae0984e upstream. Replace a couple of magically connected buffer length literal constants with a common definition that makes their relationship obvious. Also document why our sscanf() usage is safe. No intended functional changes. Suggested-by: Ingo Molnar Signed-off-by: Dominik Brodowski Cc: Andrew Lutomirski Cc: Andy 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/20180211205924.GA23210@light.dominikbrodowski.net Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/x86/test_vdso.c | 11 ++++++++--- tools/testing/selftests/x86/test_vsyscall.c | 11 ++++++++--- 2 files changed, 16 insertions(+), 6 deletions(-) --- a/tools/testing/selftests/x86/test_vdso.c +++ b/tools/testing/selftests/x86/test_vdso.c @@ -26,6 +26,9 @@ # endif #endif +/* max length of lines in /proc/self/maps - anything longer is skipped here */ +#define MAPS_LINE_LEN 128 + int nerrs = 0; typedef long (*getcpu_t)(unsigned *, unsigned *, void *); @@ -37,17 +40,19 @@ static void *vsyscall_getcpu(void) { #ifdef __x86_64__ FILE *maps; - char line[128]; + char line[MAPS_LINE_LEN]; 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)) { + while (fgets(line, MAPS_LINE_LEN, maps)) { char r, x; void *start, *end; - char name[128]; + char name[MAPS_LINE_LEN]; + + /* sscanf() is safe here as strlen(name) >= strlen(line) */ if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s", &start, &end, &r, &x, name) != 5) continue; --- a/tools/testing/selftests/x86/test_vsyscall.c +++ b/tools/testing/selftests/x86/test_vsyscall.c @@ -33,6 +33,9 @@ # endif #endif +/* max length of lines in /proc/self/maps - anything longer is skipped here */ +#define MAPS_LINE_LEN 128 + static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), int flags) { @@ -98,7 +101,7 @@ static int init_vsys(void) #ifdef __x86_64__ int nerrs = 0; FILE *maps; - char line[128]; + char line[MAPS_LINE_LEN]; bool found = false; maps = fopen("/proc/self/maps", "r"); @@ -108,10 +111,12 @@ static int init_vsys(void) return 0; } - while (fgets(line, sizeof(line), maps)) { + while (fgets(line, MAPS_LINE_LEN, maps)) { char r, x; void *start, *end; - char name[128]; + char name[MAPS_LINE_LEN]; + + /* sscanf() is safe here as strlen(name) >= strlen(line) */ if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s", &start, &end, &r, &x, name) != 5) continue;