From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A671617B418; Mon, 12 Jan 2026 09:34:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768210476; cv=none; b=iye5HLWLIWmLqv7v6TUDcNdVI31VBok9JiLHAtbwM5VTRFZ/a5+bOVDCfHz9Yx94zjZtzGZquSrwwHR6u1cK5blQq4DpvPIuTDEP7PuylhLX9wFNWXCxeX6ThZnwfOp88C4RNWYqQqdVnKrXdgoh79HFwMeUaXD8sa6l+CHKcaI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768210476; c=relaxed/simple; bh=TSgLmQf4rntLNZovQ8eRSanEh9kU1TC+CS6f9QbfmKI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=E/JaVYPRz2EPDsZkeV7PTu92CDOaP90jxkOK0ouI/2+DKqf4NOOLugG+L/iB8RoKUN/U7rDGU0O/SnVHm3agIGgdl4OOmsBpb594rwyYCGpCGyF8MvpEeGT1FR3aHGPnbMmD+N1/JKZtaRfJA09q3qDD1e2LGjvY785r66F5Fzk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 56DE1339; Mon, 12 Jan 2026 01:34:27 -0800 (PST) Received: from [10.57.95.123] (unknown [10.57.95.123]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A5C9E3F694; Mon, 12 Jan 2026 01:34:32 -0800 (PST) Message-ID: <315a7239-f5ce-474e-bd0d-f1deca3a7b26@arm.com> Date: Mon, 12 Jan 2026 09:34:31 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 8/8] selftests/mm: report SKIP in pfnmap if a check fails Content-Language: en-GB To: Kevin Brodsky , linux-mm@kvack.org, linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Mark Brown , Shuah Khan References: <20260107164842.3289559-1-kevin.brodsky@arm.com> <20260107164842.3289559-9-kevin.brodsky@arm.com> From: Ryan Roberts In-Reply-To: <20260107164842.3289559-9-kevin.brodsky@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 07/01/2026 16:48, Kevin Brodsky wrote: > pfnmap currently checks the target file in FIXTURE_SETUP(pfnmap), > meaning once for every test, and skips the test if any check fails. > > The target file is the same for every test so this is a little > overkill. More importantly, this approach means that the whole suite > will report PASS even if all the tests are skipped because kernel > configuration (e.g. CONFIG_STRICT_DEVMEM=y) prevented /dev/mem from > being mapped, for instance. > > Let's ensure that KSFT_SKIP is returned as exit code if any check > fails by performing the checks in pfnmap_init(), run once. That > function also takes care of finding the offset of the pages to be > mapped and saves it in a global. The file is still mapped/unmapped > for every test, as some of them modify the mapping. > > Signed-off-by: Kevin Brodsky > --- > tools/testing/selftests/mm/pfnmap.c | 81 ++++++++++++++++++++--------- > 1 file changed, 55 insertions(+), 26 deletions(-) > > diff --git a/tools/testing/selftests/mm/pfnmap.c b/tools/testing/selftests/mm/pfnmap.c > index 35b0e3ed54cd..e41d5464130b 100644 > --- a/tools/testing/selftests/mm/pfnmap.c > +++ b/tools/testing/selftests/mm/pfnmap.c > @@ -25,8 +25,11 @@ > #include "kselftest_harness.h" > #include "vm_util.h" > > +#define DEV_MEM_NPAGES 2 > + > static sigjmp_buf sigjmp_buf_env; > static char *file = "/dev/mem"; > +static off_t file_offset; > > static void signal_handler(int sig) > { > @@ -88,7 +91,7 @@ static int find_ram_target(off_t *offset, > break; > > /* We need two pages. */ > - if (end > start + 2 * pagesize) { > + if (end > start + DEV_MEM_NPAGES * pagesize) { > fclose(file); > *offset = start; > return 0; > @@ -97,9 +100,49 @@ static int find_ram_target(off_t *offset, > return -ENOENT; > } > > +static void pfnmap_init(void) > +{ > + size_t pagesize = getpagesize(); > + size_t size = DEV_MEM_NPAGES * pagesize; > + int fd; > + void *addr; > + > + if (strncmp(file, "/dev/mem", strlen("/dev/mem")) == 0) { > + int err = find_ram_target(&file_offset, pagesize); > + > + if (err) > + ksft_exit_skip("Cannot find ram target in '/proc/iomem': %s\n", > + strerror(-err)); > + } else { > + file_offset = 0; > + } > + > + /* > + * Make sure we can open and map the file, and perform some basic > + * checks; skip the whole suite if anything goes wrong. > + * A fresh mapping is then created for every test case by > + * FIXTURE_SETUP(pfnmap). > + */ > + fd = open(file, O_RDONLY); > + if (fd < 0) > + ksft_exit_skip("Cannot open '%s': %s\n", file, strerror(errno)); > + > + addr = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, file_offset); > + if (addr == MAP_FAILED) > + ksft_exit_skip("Cannot mmap '%s': %s\n", file, strerror(errno)); > + > + if (!check_vmflag_pfnmap(addr)) > + ksft_exit_skip("Invalid file: '%s'. Not pfnmap'ed\n", file); > + > + if (test_read_access(addr, size)) > + ksft_exit_skip("Cannot read-access mmap'ed '%s'\n", file); > + > + munmap(addr, size); > + close(fd); > +} > + > FIXTURE(pfnmap) > { > - off_t offset; > size_t pagesize; > int dev_mem_fd; > char *addr1; > @@ -112,31 +155,13 @@ FIXTURE_SETUP(pfnmap) > { > self->pagesize = getpagesize(); > > - if (strncmp(file, "/dev/mem", strlen("/dev/mem")) == 0) { > - /* We'll require two physical pages throughout our tests ... */ > - if (find_ram_target(&self->offset, self->pagesize)) > - SKIP(return, > - "Cannot find ram target in '/proc/iomem'\n"); > - } else { > - self->offset = 0; > - } > - > self->dev_mem_fd = open(file, O_RDONLY); > - if (self->dev_mem_fd < 0) > - SKIP(return, "Cannot open '%s'\n", file); > + ASSERT_GE(self->dev_mem_fd, 0); > > - self->size1 = self->pagesize * 2; > + self->size1 = DEV_MEM_NPAGES * self->pagesize; > self->addr1 = mmap(NULL, self->size1, PROT_READ, MAP_SHARED, > - self->dev_mem_fd, self->offset); > - if (self->addr1 == MAP_FAILED) > - SKIP(return, "Cannot mmap '%s'\n", file); > - > - if (!check_vmflag_pfnmap(self->addr1)) > - SKIP(return, "Invalid file: '%s'. Not pfnmap'ed\n", file); I wonder if we still want this check per-fd, but upgraded to a fail? Either way: Reviewed-by: Ryan Roberts > - > - /* ... and want to be able to read from them. */ > - if (test_read_access(self->addr1, self->size1)) > - SKIP(return, "Cannot read-access mmap'ed '%s'\n", file); > + self->dev_mem_fd, file_offset); > + ASSERT_NE(self->addr1, MAP_FAILED); > > self->size2 = 0; > self->addr2 = MAP_FAILED; > @@ -189,7 +214,7 @@ TEST_F(pfnmap, munmap_split) > */ > self->size2 = self->pagesize; > self->addr2 = mmap(NULL, self->pagesize, PROT_READ, MAP_SHARED, > - self->dev_mem_fd, self->offset); > + self->dev_mem_fd, file_offset); > ASSERT_NE(self->addr2, MAP_FAILED); > } > > @@ -258,8 +283,12 @@ int main(int argc, char **argv) > if (strcmp(argv[i], "--") == 0) { > if (i + 1 < argc && strlen(argv[i + 1]) > 0) > file = argv[i + 1]; > - return test_harness_run(i, argv); > + argc = i; > + break; > } > } > + > + pfnmap_init(); > + > return test_harness_run(argc, argv); > }