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 4090DC83F27 for ; Wed, 16 Jul 2025 03:06:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 689866B009A; Tue, 15 Jul 2025 23:06:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 63A596B009B; Tue, 15 Jul 2025 23:06:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5294C6B009C; Tue, 15 Jul 2025 23:06:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 3F5636B009A for ; Tue, 15 Jul 2025 23:06:08 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id C119216025E for ; Wed, 16 Jul 2025 03:06:07 +0000 (UTC) X-FDA: 83668638774.25.0053124 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) by imf30.hostedemail.com (Postfix) with ESMTP id E5E6380005 for ; Wed, 16 Jul 2025 03:06:05 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=F1qCsBjl; spf=pass (imf30.hostedemail.com: domain of 3HBd3aAYKCHEhjgTcQVddVaT.RdbaXcjm-bbZkPRZ.dgV@flex--surenb.bounces.google.com designates 209.85.210.201 as permitted sender) smtp.mailfrom=3HBd3aAYKCHEhjgTcQVddVaT.RdbaXcjm-bbZkPRZ.dgV@flex--surenb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1752635166; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=OwmJhXkBZ0rkJP8ZDJsJXdxfIUoApnDNh42agcrLiOc=; b=3Ux0oK7ANiKEI45JafMdYEz9Rcln+ek73y1yCeHxlDIplH0VDMZ5EjTHxa2clF+lo6Eo01 5xKW+hS9iEvm59S9WMvpFeI67OASrjy/5TStx3KAkNkljZArMW6CZpLe7NJCHyS5fXB7cj OrBQEzla0OjzcJHwbaNe3PS1CjytLCs= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1752635166; a=rsa-sha256; cv=none; b=dwtXbcMWKLKltKIGd5vb4U6PCzsAHiGJCQWVnRSpdDYr3zrFZDTz1wFe9jPTMiQBSZCtof bwKTjIrdZhuhYYOmSGZZRlJWxMbxAp3z0ES/xKRZwJfgs+KT9TAuYe8lU0jTHiGHnZQxah vbYLLbpS/vE1Ma6Mk1J5wPaeApK0DmQ= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=F1qCsBjl; spf=pass (imf30.hostedemail.com: domain of 3HBd3aAYKCHEhjgTcQVddVaT.RdbaXcjm-bbZkPRZ.dgV@flex--surenb.bounces.google.com designates 209.85.210.201 as permitted sender) smtp.mailfrom=3HBd3aAYKCHEhjgTcQVddVaT.RdbaXcjm-bbZkPRZ.dgV@flex--surenb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-74b185fba41so5512259b3a.1 for ; Tue, 15 Jul 2025 20:06:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1752635165; x=1753239965; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=OwmJhXkBZ0rkJP8ZDJsJXdxfIUoApnDNh42agcrLiOc=; b=F1qCsBjlrjSX8Rwtt6uenelokwfy7AidFDIsB/8+GDfxtHvvqizGt2pDS276xK7etV 8gdTWn1kEmNWABq06ZA5kHPDjeDeIiLE6Hfh3AgK3YY62Kr56KbVaha2TPThLp5iA8yb HcJsKvuiuTJViN6zbz5Yogcqnig2WVhF45nP2cTGIjx5qgK+pgX3a8YDXZc7w/2tAaym T2+fa/D12HIkMFiZCSJy8RA5YZwcKHjvX+EFV5lDlQwyi4hRJME7Hs8+AmViLmaTLQNd cduLE4GwBie4xxEGGpgwq8RlsvtNhNU7JVmhjTr/t4rtvKhYfK5W9dFhTfD9Idf8c1qz X2KQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752635165; x=1753239965; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=OwmJhXkBZ0rkJP8ZDJsJXdxfIUoApnDNh42agcrLiOc=; b=lZSCK0TmiTlpSj+8yHv91c7S9m8u+dNZ8H1FuMPj69S15ZcNk0flhjJh2WohscKTwj 3mLbhaOpbRtdllBhCqBihM7qnEePW5LEUdR+rS7v4/3ULdx0nX1zXI7T22B/vSq1XRHX nn8YTfB8E+AgoJEFhWh1xLHBdYSu3BiQMNdPQ87OJNwp75JGT8hbgjxUXgyCMeRkDi0g 5kVaQMOmwqBLTPALi5/xkJb7NvLbfP8Nmt8MT0ZzbsK8SqxOA9qhisnOxmAV3gWvWtUf wLm+OCC1l2fbdTS86n7/uyKuUz87xP0AlHq7chw0M0NQG8+wn9DHzMGllJTLlp1xMtUd LTZQ== X-Forwarded-Encrypted: i=1; AJvYcCUCC7l7dAdcBnFic4A5zjYhllsPYrxB+ipmhLHR8juwQQN0OvY5b1WndL1HItU++Rq+aKHvcKpAcA==@kvack.org X-Gm-Message-State: AOJu0YyWFN7cvPew/9FTaLDY0dQ3qQqX/deCzUmuxzCYbQ+X9jMN/mEf B6wA8Pu7N4l98C5/JpVG9ipePeLurvL2TEvC/Cf3SNcGvt1cb6vAq/XjHS2DrjR42g6gYFhZgn8 rMf++4w== X-Google-Smtp-Source: AGHT+IGzJv3h9zkM0+zyuvpyi7dydp51mDl7cBy864qKJxNT3Tnay4b8zYqfF0oK2BvdPup3ers/Chkr8aM= X-Received: from pgkg9.prod.google.com ([2002:a63:fa49:0:b0:b2f:9d37:5753]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:160f:b0:21f:751a:dd41 with SMTP id adf61e73a8af0-237d896b159mr2950162637.40.1752635164680; Tue, 15 Jul 2025 20:06:04 -0700 (PDT) Date: Tue, 15 Jul 2025 20:05:51 -0700 In-Reply-To: <20250716030557.1547501-1-surenb@google.com> Mime-Version: 1.0 References: <20250716030557.1547501-1-surenb@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250716030557.1547501-3-surenb@google.com> Subject: [PATCH v7 2/7] selftests/proc: extend /proc/pid/maps tearing test to include vma resizing From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, david@redhat.com, vbabka@suse.cz, peterx@redhat.com, jannh@google.com, hannes@cmpxchg.org, mhocko@kernel.org, paulmck@kernel.org, shuah@kernel.org, adobriyan@gmail.com, brauner@kernel.org, josef@toxicpanda.com, yebin10@huawei.com, linux@weissschuh.net, willy@infradead.org, osalvador@suse.de, andrii@kernel.org, ryan.roberts@arm.com, christophe.leroy@csgroup.eu, tjmercier@google.com, kaleshsingh@google.com, aha310510@gmail.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: E5E6380005 X-Stat-Signature: jnxupw48dxtdfzb674cj5q3cp8bye3rc X-Rspam-User: X-HE-Tag: 1752635165-318952 X-HE-Meta: U2FsdGVkX1/KjJE0Lr0mMK9d57k4kEuCrsr/5LD8QkMLoh5SVUHJeXxXHW6PqCjIyQL1KG7yaxnQk94lLXkycV87b1n+ysgdVzcYy91XMyMgxIQXL5pMbG1YS2h+cxe/RKwvZI0SzbLdtsVoE2xvJ7zgmnx3TbCCmhlXmHOX7UIwaqMnN9ZH6ZVtUPXFA3voQYVL2Xp1y4ejRlGQKBAwjW7z+70fhuUQcorAQVyQT2WAIe8/uFcr7UaQGJMuN6y+EDPcIytdkBv3p6+mHCTOSF4iIKL5bN42vwC1Ff23NSuNfjsxt7z1a8xRPcyNmwR3w02UOBy+w6RMgOaOXFGScgTw5defni9czCPin2TuaoxHdRkCLhAmysNyihnRpmRzXx2Eb9yyw1dT+kxp1bScYt45RcygdxYqNwZ7xszr61nOU+Cngl/Y5VvfpytK28z7QTN6KxPPLNUYDg0SSbk2adda13+iJxT9LAd7YTnwm3zOon/a23dmlrE7B+S6cuvHl13PynDTWN4AYSv2F7r04xP8R2rqXT/vXF1ejgsT5gxLgTTqFeH1Yl2Qzg8KfD0T8cy8KsR6IKYhlCGPwfT8QluJtIO21maBvNB6IXZiCTY6z/zJcVsYYrEPdRw+E2M3tmIwCWcpyVPP6yZR2pdDHNcOuti2z8VnwtCStiUsmwjBdqz0fwgaOuM03NJJtH3mkuXNX1KXqTyOnISNZaZNlz0mFTAs06jaKhi403MwC5Ceq8F3XI83kKjC9qQYCm8XI1Wug2OGkRlDFIgYLpT6hp20CvqUgxMgB66E1Uu1rzR01fWygcj9weEqg7on0MAaMkc0g4RGTKc613gozqWzhxr09kHLZbY2EcnGoZhuofMFofSEkXA7j8UFxKW38TWE5aW0NYq97R0IsJHqgnE7YdMked4vMRz+ocLNss5FiKxu4k69mKPv03uasWJ938ld51es3Lz3G8aOOBImVZG 8G4CIOWF 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 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: List-Subscribe: List-Unsubscribe: Test that /proc/pid/maps does not report unexpected holes in the address space when a vma at the edge of the page is being concurrently remapped. This remapping results in the vma shrinking and expanding from under the reader. We should always see either shrunk or expanded (original) version of the vma. Signed-off-by: Suren Baghdasaryan --- tools/testing/selftests/proc/proc-maps-race.c | 83 +++++++++++++++++++ 1 file changed, 83 insertions(+) diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c index 523afd83d34f..10365b4e68e1 100644 --- a/tools/testing/selftests/proc/proc-maps-race.c +++ b/tools/testing/selftests/proc/proc-maps-race.c @@ -336,6 +336,86 @@ static void test_maps_tearing_from_split(int maps_fd, signal_state(mod_info, TEST_DONE); } +static inline void shrink_vma(const struct vma_modifier_info *mod_info) +{ + assert(mremap(mod_info->addr, page_size * 3, page_size, 0) != MAP_FAILED); +} + +static inline void expand_vma(const struct vma_modifier_info *mod_info) +{ + assert(mremap(mod_info->addr, page_size, page_size * 3, 0) != MAP_FAILED); +} + +static inline void check_shrink_result(struct line_content *mod_last_line, + struct line_content *mod_first_line, + struct line_content *restored_last_line, + struct line_content *restored_first_line) +{ + /* Make sure only the last vma of the first page is changing */ + assert(strcmp(mod_last_line->text, restored_last_line->text) != 0); + assert(strcmp(mod_first_line->text, restored_first_line->text) == 0); +} + +static void test_maps_tearing_from_resize(int maps_fd, + struct vma_modifier_info *mod_info, + struct page_content *page1, + struct page_content *page2, + struct line_content *last_line, + struct line_content *first_line) +{ + struct line_content shrunk_last_line; + struct line_content shrunk_first_line; + struct line_content restored_last_line; + struct line_content restored_first_line; + + wait_for_state(mod_info, SETUP_READY); + + /* re-read the file to avoid using stale data from previous test */ + read_boundary_lines(maps_fd, page1, page2, last_line, first_line); + + mod_info->vma_modify = shrink_vma; + mod_info->vma_restore = expand_vma; + mod_info->vma_mod_check = check_shrink_result; + + capture_mod_pattern(maps_fd, mod_info, page1, page2, last_line, first_line, + &shrunk_last_line, &shrunk_first_line, + &restored_last_line, &restored_first_line); + + /* Now start concurrent modifications for test_duration_sec */ + signal_state(mod_info, TEST_READY); + + struct line_content new_last_line; + struct line_content new_first_line; + struct timespec start_ts, end_ts; + + clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts); + do { + read_boundary_lines(maps_fd, page1, page2, &new_last_line, &new_first_line); + + /* Check if we read vmas after shrinking it */ + if (!strcmp(new_last_line.text, shrunk_last_line.text)) { + /* + * The vmas should be consistent with shrunk results, + * however if the vma was concurrently restored, it + * can be reported twice (first as shrunk one, then + * as restored one) because we found it as the next vma + * again. In that case new first line will be the same + * as the last restored line. + */ + assert(!strcmp(new_first_line.text, shrunk_first_line.text) || + !strcmp(new_first_line.text, restored_last_line.text)); + } else { + /* The vmas should be consistent with the original/resored state */ + assert(!strcmp(new_last_line.text, restored_last_line.text) && + !strcmp(new_first_line.text, restored_first_line.text)); + } + clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts); + } while (end_ts.tv_sec - start_ts.tv_sec < test_duration_sec); + + /* Signal the modifyer thread to stop and wait until it exits */ + signal_state(mod_info, TEST_DONE); +} + int usage(void) { fprintf(stderr, "Userland /proc/pid/{s}maps race test cases\n"); @@ -444,6 +524,9 @@ int main(int argc, char **argv) test_maps_tearing_from_split(maps_fd, mod_info, &page1, &page2, &last_line, &first_line); + test_maps_tearing_from_resize(maps_fd, mod_info, &page1, &page2, + &last_line, &first_line); + stop_vma_modifier(mod_info); free(page2.data); -- 2.50.0.727.gbf7dc18ff4-goog