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 36FAFC4332F for ; Tue, 26 Apr 2022 19:02:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 365886B0073; Tue, 26 Apr 2022 15:02:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 315226B0074; Tue, 26 Apr 2022 15:02:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1DC766B0075; Tue, 26 Apr 2022 15:02:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 0D98E6B0073 for ; Tue, 26 Apr 2022 15:02:16 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id AF43920775 for ; Tue, 26 Apr 2022 19:02:15 +0000 (UTC) X-FDA: 79399950630.15.FABA803 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf04.hostedemail.com (Postfix) with ESMTP id 7F98640063 for ; Tue, 26 Apr 2022 19:02:10 +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 65FA6619C8; Tue, 26 Apr 2022 19:02:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C037C385AD; Tue, 26 Apr 2022 19:02:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650999733; bh=YZK3UpV4c8YazR2b40tUH2JL2rStNLtVLCBp2JIEX9I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=psI4ufPmRjvssMHDR8sQGb+qstnhcfHREQPlnR9TZRoo5yMlzaPhx6HCHxW3MgwDB OcDKC8Z9SVqZ4BLqPchYRRNScGxikP7dm7bml9YY+iiAvkVEx5r33FRNftJ+KGWXW9 ELbZJkcrtsQf8fB7fKdLYIqnsVuIg82ioyQFW93JgOTT4ZWtAo1s1MPAe7+2QIdeYM Ady4qUxfT1JtVYJGLcHQLDLa4f/8R2l9hSYHQFjWm7VOQamgiRMd0RFXkkxq0dY16r jyeZPD94yTMhjtBUZSj/cNf41mXXl4bMXwFRGyc3hJzZ2AP5vqdSjm16OoUJ9vOlXQ w7hJo8iBiCXMQ== 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 5.17 21/22] selftest/vm: verify mmap addr in mremap_test Date: Tue, 26 Apr 2022 15:01:44 -0400 Message-Id: <20220426190145.2351135-21-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220426190145.2351135-1-sashal@kernel.org> References: <20220426190145.2351135-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 7F98640063 X-Stat-Signature: zfddnsafscjkdru3fjumrsxbye6jzubp Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=psI4ufPm; spf=pass (imf04.hostedemail.com: domain of sashal@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-HE-Tag: 1650999730-488408 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 7c0b0617b9f8..9a518fee6306 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 @@ -63,6 +64,35 @@ 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. @@ -71,8 +101,15 @@ 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); @@ -90,8 +127,10 @@ 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