From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00200C433FE for ; Tue, 26 Apr 2022 19:02:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7D2086B0075; Tue, 26 Apr 2022 15:02:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 781D56B0078; Tue, 26 Apr 2022 15:02:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 649DD6B007B; Tue, 26 Apr 2022 15:02:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 569556B0075 for ; Tue, 26 Apr 2022 15:02:31 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 22EE927522 for ; Tue, 26 Apr 2022 19:02:31 +0000 (UTC) X-FDA: 79399951302.30.2E3B8DA Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf11.hostedemail.com (Postfix) with ESMTP id C6AD84004C for ; Tue, 26 Apr 2022 19:02:27 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B1638619D7; Tue, 26 Apr 2022 19:02:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65473C385B2; Tue, 26 Apr 2022 19:02:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650999749; bh=uU32vsAIlQhNOwiz7baeDmqduhS8jWk8Pq/Li7uhVgw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FOxfkei9PuHjOX+C1ynXKtSebr2Qg3tU7of6QoT90N4YsnuQXR/O+G9hWIJbaeJQd iwkFIdM0hTcEgJB2Tusw5R+jVLHqdccdp8aoIORXe4Ys65KUwRYdX56n+s3PqaDrgD pOCxiG5x19ExTKle/xl3V4uTLEEh3ZnohgR5eQ06N2a6Iw67bhDtRR47iNX7vGrB6k 5AYOLBVEB98/+hoG1lKxiTiuSLUJ5cWy0BM5AvuW9VT+TVhyY7hE1VK4Ga5gUc8tzN ktHFpYmsVyiI44M+igBimpCSOF6GpBVBJUGpy9c7cdQKekOYPC3kRUzu17fRoqb0LV PGwzz2EBNgXqA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sidhartha Kumar , Shuah Khan , Andrew Morton , Linus Torvalds , Sasha Levin , shuah@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 14/15] selftest/vm: verify mmap addr in mremap_test Date: Tue, 26 Apr 2022 15:02:13 -0400 Message-Id: <20220426190216.2351413-14-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220426190216.2351413-1-sashal@kernel.org> References: <20220426190216.2351413-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=FOxfkei9; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf11.hostedemail.com: domain of sashal@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sashal@kernel.org X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: C6AD84004C X-Rspam-User: X-Stat-Signature: j3fqhqis578hkkc6ugzz1bps9zwmtw9x X-HE-Tag: 1650999747-606099 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Sidhartha Kumar [ Upstream commit 9c85a9bae267f6b5e5e374d0d023bbbe9db096d3 ] Avoid calling mmap with requested addresses that are less than the system's mmap_min_addr. When run as root, mmap returns EACCES when trying to map addresses < mmap_min_addr. This is not one of the error codes for the condition to retry the mmap in the test. Rather than arbitrarily retrying on EACCES, don't attempt an mmap until addr > vm.mmap_min_addr. Add a munmap call after an alignment check as the mappings are retained after the retry and can reach the vm.max_map_count sysctl. Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar Reviewed-by: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- tools/testing/selftests/vm/mremap_test.c | 41 +++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/vm/mremap_test.c b/tools/testing/selftests/vm/mremap_test.c index 0624d1bd71b5..2b3b4f15185f 100644 --- a/tools/testing/selftests/vm/mremap_test.c +++ b/tools/testing/selftests/vm/mremap_test.c @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -64,6 +65,35 @@ enum { .expect_failure = should_fail \ } +/* Returns mmap_min_addr sysctl tunable from procfs */ +static unsigned long long get_mmap_min_addr(void) +{ + FILE *fp; + int n_matched; + static unsigned long long addr; + + if (addr) + return addr; + + fp = fopen("/proc/sys/vm/mmap_min_addr", "r"); + if (fp == NULL) { + ksft_print_msg("Failed to open /proc/sys/vm/mmap_min_addr: %s\n", + strerror(errno)); + exit(KSFT_SKIP); + } + + n_matched = fscanf(fp, "%llu", &addr); + if (n_matched != 1) { + ksft_print_msg("Failed to read /proc/sys/vm/mmap_min_addr: %s\n", + strerror(errno)); + fclose(fp); + exit(KSFT_SKIP); + } + + fclose(fp); + return addr; +} + /* * Returns the start address of the mapping on success, else returns * NULL on failure. @@ -72,8 +102,15 @@ static void *get_source_mapping(struct config c) { unsigned long long addr = 0ULL; void *src_addr = NULL; + unsigned long long mmap_min_addr; + + mmap_min_addr = get_mmap_min_addr(); + retry: addr += c.src_alignment; + if (addr < mmap_min_addr) + goto retry; + src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE, MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED, -1, 0); @@ -91,8 +128,10 @@ static void *get_source_mapping(struct config c) * alignment in the tests. */ if (((unsigned long long) src_addr & (c.src_alignment - 1)) || - !((unsigned long long) src_addr & c.src_alignment)) + !((unsigned long long) src_addr & c.src_alignment)) { + munmap(src_addr, c.region_size); goto retry; + } if (!src_addr) goto error; -- 2.35.1