On 1/7/26 17:48, 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 <[email protected]>
---
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);
Why not keep the fd open then and supply that to all tests without the
need for them to open/close?
Then, also the file cannot change etc.
--
Cheers
David
