From nobody Tue Feb 10 00:59:03 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 016DD3994A3; Thu, 22 Jan 2026 17:02:52 +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=1769101382; cv=none; b=bu/Poh5a7y44+pyiPH70kZfvv9S2iCSRM7lv6ixENcFkts5mLAbTczppeSMKtJTR5Nya7Xu9qUZcxj0q+YbxIH4oFPWUc2DF9LrmwH0ufRyU0kNY1ZlC7GW1+doDz1OHzaywPbMygTzj+7izok7yyMh+785wMaIAWOmG2zAbkp4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769101382; c=relaxed/simple; bh=LqG8Hnz6Q5OxBgnzVjR/OTNRf+pKJfp6ootXAexNYYs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sbh9MFngFuz+mzwP9obrKv0eBsPoWMiuujSwaQYQXXa+MawQMeKQiHPIqDJ0oAYTnQZUtPTah6h+QqDxxHvz17eICdVM5iwofxapvbwJjHPcgWq8l6rxjLP2JwAz9C42Iysh+pINVMXlLPWrLgqjohw9TX8vsDS7iLpN2heCjko= 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 429D81684; Thu, 22 Jan 2026 09:02:43 -0800 (PST) Received: from e123572-lin.arm.com (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7CCD93F632; Thu, 22 Jan 2026 09:02:48 -0800 (PST) From: Kevin Brodsky To: linux-mm@kvack.org, linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , Andrew Morton , David Hildenbrand , Dev Jain , Lorenzo Stoakes , Mark Brown , Ryan Roberts , Shuah Khan Subject: [PATCH v3 9/9] selftests/mm: report SKIP in pfnmap if a check fails Date: Thu, 22 Jan 2026 17:02:24 +0000 Message-ID: <20260122170224.4056513-10-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20260122170224.4056513-1-kevin.brodsky@arm.com> References: <20260122170224.4056513-1-kevin.brodsky@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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=3Dy) 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 now opened only once and the fd saved in a global, but it is still mapped/unmapped for every test, as some of them modify the mapping. Signed-off-by: Kevin Brodsky Acked-by: David Hildenbrand (Red Hat) --- tools/testing/selftests/mm/pfnmap.c | 84 ++++++++++++++++++----------- 1 file changed, 53 insertions(+), 31 deletions(-) diff --git a/tools/testing/selftests/mm/pfnmap.c b/tools/testing/selftests/= mm/pfnmap.c index 45b5f1cf6019..4f550822385a 100644 --- a/tools/testing/selftests/mm/pfnmap.c +++ b/tools/testing/selftests/mm/pfnmap.c @@ -25,8 +25,12 @@ #include "kselftest_harness.h" #include "vm_util.h" =20 +#define DEV_MEM_NPAGES 2 + static sigjmp_buf sigjmp_buf_env; static char *file =3D "/dev/mem"; +static off_t file_offset; +static int fd; =20 static void signal_handler(int sig) { @@ -88,7 +92,7 @@ static int find_ram_target(off_t *offset, break; =20 /* We need two pages. */ - if (end > start + 2 * pagesize) { + if (end > start + DEV_MEM_NPAGES * pagesize) { fclose(file); *offset =3D start; return 0; @@ -97,11 +101,48 @@ static int find_ram_target(off_t *offset, return -ENOENT; } =20 +static void pfnmap_init(void) +{ + size_t pagesize =3D getpagesize(); + size_t size =3D DEV_MEM_NPAGES * pagesize; + void *addr; + + if (strncmp(file, "/dev/mem", strlen("/dev/mem")) =3D=3D 0) { + int err =3D 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 =3D 0; + } + + fd =3D open(file, O_RDONLY); + if (fd < 0) + ksft_exit_skip("Cannot open '%s': %s\n", file, strerror(errno)); + + /* + * Make sure we can 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). + */ + addr =3D mmap(NULL, size, PROT_READ, MAP_SHARED, fd, file_offset); + if (addr =3D=3D 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, pagesize)) + ksft_exit_skip("Cannot read-access mmap'ed '%s'\n", file); + + munmap(addr, size); +} + FIXTURE(pfnmap) { - off_t offset; size_t pagesize; - int dev_mem_fd; char *addr1; size_t size1; char *addr2; @@ -112,31 +153,10 @@ FIXTURE_SETUP(pfnmap) { self->pagesize =3D getpagesize(); =20 - if (strncmp(file, "/dev/mem", strlen("/dev/mem")) =3D=3D 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 =3D 0; - } - - self->dev_mem_fd =3D open(file, O_RDONLY); - if (self->dev_mem_fd < 0) - SKIP(return, "Cannot open '%s'\n", file); - - self->size1 =3D self->pagesize * 2; + self->size1 =3D DEV_MEM_NPAGES * self->pagesize; self->addr1 =3D mmap(NULL, self->size1, PROT_READ, MAP_SHARED, - self->dev_mem_fd, self->offset); - if (self->addr1 =3D=3D 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); - - /* ... and want to be able to read from them. */ - if (test_read_access(self->addr1, self->size1, self->pagesize)) - SKIP(return, "Cannot read-access mmap'ed '%s'\n", file); + fd, file_offset); + ASSERT_NE(self->addr1, MAP_FAILED); =20 self->size2 =3D 0; self->addr2 =3D MAP_FAILED; @@ -148,8 +168,6 @@ FIXTURE_TEARDOWN(pfnmap) munmap(self->addr2, self->size2); if (self->addr1 !=3D MAP_FAILED) munmap(self->addr1, self->size1); - if (self->dev_mem_fd >=3D 0) - close(self->dev_mem_fd); } =20 TEST_F(pfnmap, madvise_disallowed) @@ -189,7 +207,7 @@ TEST_F(pfnmap, munmap_split) */ self->size2 =3D self->pagesize; self->addr2 =3D mmap(NULL, self->pagesize, PROT_READ, MAP_SHARED, - self->dev_mem_fd, self->offset); + fd, file_offset); ASSERT_NE(self->addr2, MAP_FAILED); } =20 @@ -259,8 +277,12 @@ int main(int argc, char **argv) if (strcmp(argv[i], "--") =3D=3D 0) { if (i + 1 < argc && strlen(argv[i + 1]) > 0) file =3D argv[i + 1]; - return test_harness_run(i, argv); + argc =3D i; + break; } } + + pfnmap_init(); + return test_harness_run(argc, argv); } --=20 2.51.2