From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f201.google.com (mail-dy1-f201.google.com [74.125.82.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A9A3345CA3 for ; Fri, 24 Apr 2026 07:03:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777014182; cv=none; b=ZAv+48X+AfMQTam1SGqlzSIEeCPipIP5E0j2nbnheGDhmya++YiKn2/ognOMbISXP3glowb6WI+FcRg53B6ZhdWyaM8XAeqBIWUapV7ldwzMrICiyxEazaqi+fLJU+vH3OIYXgCvFS3yMuOOc4mMjZTYOtReQzWuuAQvj3Oa80Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777014182; c=relaxed/simple; bh=WAZtIz9DRaTLMD/Vn5XCDvQ2W8Sy7wUfm/O5/IsoqAQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GfDVO84jRYqKu/9nJzab+QDl3v2y+uAZ9BO8MffqDC8CFnGJOrpOSGfekRrYuUllom9ILpd2PP64KiB7VdzevLq8bBxk08hdSNm2TJHSy4UPU6MhPxs0thjGyVopGGZ/AVzyejSmGu9V9uDBrktycJjtnB8GLUAljrJM2mQhg4s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--surenb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ZAoamA3a; arc=none smtp.client-ip=74.125.82.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--surenb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZAoamA3a" Received: by mail-dy1-f201.google.com with SMTP id 5a478bee46e88-2c0f6593ef5so9251008eec.1 for ; Fri, 24 Apr 2026 00:03:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777014180; x=1777618980; darn=vger.kernel.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=QROYaYs151R/blxNlpky7uyYcAQOpuOKLNbRD4r5/hI=; b=ZAoamA3a5zm17ZcEaQoT86bE2BZ/pAD1NwnFJJM+vOIItd+644Hatwc1O0x2vv87ZJ a9GCDgURVb4bQ3wloUoGgcGM3ZaCm3JLeF9PBAFkbYBaZxqF6MXebF4sV5HQwP7mvY20 vstqhWEmlLxP7Ct4FI/rPZhLkSOTRomQnyohmCA0s+/oxiKhYFVHSpc3ryGmBdvWiYCl +WjgEvnezpWgGFd8vij8gWivdFovvLNDOJHKVxSKDqob6PZXmPbG91G5XU7pwDn5JGLE 5tTWe1qCpwpvA5RbGYW5zHaNHe8SLAa/+tHZUqFMwS8/IhqsrFFN2a8rnZSQmcpSskm1 1x2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777014180; x=1777618980; 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=QROYaYs151R/blxNlpky7uyYcAQOpuOKLNbRD4r5/hI=; b=dyokSeMp2iEyli9gGzhD3E4FEz4Zw4Fc2PiXTXrj8P/laupWMWyBy7bFtHf78h0y34 O5WOT3vodOubgCWsbgUmelNPPz3omawyiORlY8Zx+/Fo5LSeZRwR79dOnBwDsFkXzWCp B0TGbt3jVVPVL7btbPCoaNm8FBBAv6EdXu6AGs4+9oQ95goJHKh9e8d4AtjEbW1Hqqc3 vKjXTmXoJouRRPZl+tNWVH7V/iX7vSIe6/JfNZZvANVHYtuzonBzc0oLadAofM/yv5bU ax+QIxG+PcTVfPTKFgYbK5oyipArGonHU4RR70UDmbI1vtAhy7x4cS5nCxRgDhGAx6h8 +Mhg== X-Forwarded-Encrypted: i=1; AFNElJ8mCnM/a8ik2dM9oUIiFVWlAF4T2jeCFtR64iFryIzBqfIYp4WRAsZ6qBy8hStjDJXj4SpwcmtaQ7/P/2I=@vger.kernel.org X-Gm-Message-State: AOJu0YwS9O5h154/NeA2ySbUBbCuOjT1RQLosTNriLXRuL/DBtK6PjES fEQULkaVPMWFisylEIN40TQSA8H94MQENF2rZf5VFKIfDoKkXq+vjPUyPrDaO4HNUc3p7W/7ONR BXFDe3A== X-Received: from dybqf21.prod.google.com ([2002:a05:7301:6495:b0:2d8:b1cf:5d12]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7300:3252:b0:2dd:2ad3:f799 with SMTP id 5a478bee46e88-2e46ca438admr16552962eec.9.1777014179625; Fri, 24 Apr 2026 00:02:59 -0700 (PDT) Date: Fri, 24 Apr 2026 00:02:33 -0700 In-Reply-To: <20260424070234.190145-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260424070234.190145-1-surenb@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260424070234.190145-3-surenb@google.com> Subject: [PATCH 2/3] selftests/proc: ensure the test is performed at the right page boundary From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, david@redhat.com, willy@infradead.org, jannh@google.com, paulmck@kernel.org, pfalcato@suse.de, shuah@kernel.org, hsukrut3@gmail.com, richard.weiyang@gmail.com, reddybalavignesh9979@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" When running tearing tests we need to ensure the pages we use include VMAs that were mapped by the child process for this test. Currently we always use the first two pages, checking VMAs at their boundaries and this works, however once we add tests for /proc/pid/smaps, the first two pages might not contain the VMAs that child modifies. Locate the page that contains the first VMA mapped by the child and use that and the next page for the test. Signed-off-by: Suren Baghdasaryan --- tools/testing/selftests/proc/proc-maps-race.c | 78 ++++++++++++++++--- 1 file changed, 68 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c index a734553718da..c5031b0593b7 100644 --- a/tools/testing/selftests/proc/proc-maps-race.c +++ b/tools/testing/selftests/proc/proc-maps-race.c @@ -39,6 +39,13 @@ #include #include +#define min(a, b) \ + ({ \ + typeof(a) _a = (a); \ + typeof(b) _b = (b); \ + _a < _b ? _a : _b; \ + }) + /* /proc/pid/maps parsing routines */ struct page_content { char *data; @@ -77,6 +84,7 @@ FIXTURE(proc_maps_race) struct line_content first_line; unsigned long duration_sec; int shared_mem_size; + int skip_pages; int page_size; int vma_count; bool verbose; @@ -105,27 +113,68 @@ struct vma_modifier_info { void *child_mapped_addr[]; }; - -static bool read_two_pages(FIXTURE_DATA(proc_maps_race) *self) +static bool read_page(FIXTURE_DATA(proc_maps_race) *self, + struct page_content *page) { ssize_t bytes_read; - if (lseek(self->maps_fd, 0, SEEK_SET) < 0) + bytes_read = read(self->maps_fd, page->data, self->page_size); + if (bytes_read <= 0) return false; - bytes_read = read(self->maps_fd, self->page1.data, self->page_size); - if (bytes_read <= 0) + /* Make sure data always ends with a newline character. */ + if (page->data[bytes_read - 1] != '\n') return false; - self->page1.size = bytes_read; + page->size = bytes_read; - bytes_read = read(self->maps_fd, self->page2.data, self->page_size); - if (bytes_read <= 0) + return true; +} + +static int locate_containing_page(FIXTURE_DATA(proc_maps_race) *self, + unsigned long addr, unsigned long size) +{ + unsigned long start, end; + int page = 0; + + if (lseek(self->maps_fd, 0, SEEK_SET) < 0) + return -1; + + while (true) { + char *curr_pos; + char *end_pos; + + if (!read_page(self, &self->page1)) + return -1; + + curr_pos = self->page1.data; + end_pos = self->page1.data + self->page1.size; + while (curr_pos < end_pos) { + if (sscanf(curr_pos, "%lx-%lx", &start, &end) == 2 && + start == addr && end == addr + size) + return page; + + curr_pos = strchr(curr_pos, '\n'); + if (!curr_pos) + break; + curr_pos++; + } + page++; + } + + return 0; +} + +static bool read_two_pages(FIXTURE_DATA(proc_maps_race) *self) +{ + if (lseek(self->maps_fd, 0, SEEK_SET) < 0) return false; - self->page2.size = bytes_read; + for (int i = 0; i < self->skip_pages; i++) + if (!read_page(self, &self->page1)) + return false; - return true; + return read_page(self, &self->page1) && read_page(self, &self->page2); } static void copy_first_line(struct page_content *page, char *first_line) @@ -418,6 +467,8 @@ FIXTURE_SETUP(proc_maps_race) struct vma_modifier_info *mod_info; pthread_mutexattr_t mutex_attr; pthread_condattr_t cond_attr; + unsigned long first_map_addr; + unsigned long last_map_addr; unsigned long duration_sec; char fname[32]; @@ -502,6 +553,13 @@ FIXTURE_SETUP(proc_maps_race) self->page2.data = malloc(self->page_size); ASSERT_NE(self->page2.data, NULL); + first_map_addr = (unsigned long)mod_info->child_mapped_addr[0]; + last_map_addr = (unsigned long)mod_info->child_mapped_addr[mod_info->vma_count - 1]; + + self->skip_pages = locate_containing_page(self, + min(first_map_addr, last_map_addr), + self->page_size * 3); + ASSERT_NE(self->skip_pages, -1); ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line)); /* -- 2.54.0.545.g6539524ca2-goog