On Fri, Oct 27, 2023 at 3:30 PM Manu Bretelle <chantr4@xxxxxxxxx> wrote: > > Currently this tests tries to umount /sys/kernel/debug (TDIR) but the > system it is running on may have mounts below. > > For example, danobi/vmtest [0] VMs have > mount -t tracefs tracefs /sys/kernel/debug/tracing > as part of their init. > > This change instead creates a "random" directory under /tmp and uses this > as TDIR. > If the directory already exists, ignore the error and keep moving on. > > Test: > > Originally: > > $ vmtest -k $KERNEL_REPO/arch/x86_64/boot/bzImage "./test_progs -vv -a test_bpffs" > => bzImage > ===> Booting > ===> Setting up VM > ===> Running command > [ 2.138818] bpf_testmod: loading out-of-tree module taints kernel. > [ 2.140913] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel > bpf_testmod.ko is already unloaded. > Loading bpf_testmod.ko... > Successfully loaded bpf_testmod.ko. > test_test_bpffs:PASS:clone 0 nsec > fn:PASS:unshare 0 nsec > fn:PASS:mount / 0 nsec > fn:FAIL:umount /sys/kernel/debug unexpected error: -1 (errno 16) > bpf_testmod.ko is already unloaded. > Loading bpf_testmod.ko... > Successfully loaded bpf_testmod.ko. > test_test_bpffs:PASS:clone 0 nsec > test_test_bpffs:PASS:waitpid 0 nsec > test_test_bpffs:FAIL:bpffs test failed 255#282 test_bpffs:FAIL > Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED > Successfully unloaded bpf_testmod.ko. > Command failed with exit code: 1 > > After this change: > > $ vmtest -k $KERNEL_REPO/arch/x86_64/boot/bzImage "./test_progs -vv -a test_bpffs" > => bzImage > ===> Booting > ===> Setting up VM > ===> Running command > [ 2.119236] bpf_testmod: loading out-of-tree module taints kernel. > [ 2.121768] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel > bpf_testmod.ko is already unloaded. > Loading bpf_testmod.ko... > Successfully loaded bpf_testmod.ko. > test_test_bpffs:PASS:clone 0 nsec > fn:PASS:unshare 0 nsec > fn:PASS:mount / 0 nsec > fn:PASS:mount tmpfs 0 nsec > fn:PASS:mkdir /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1 0 nsec > fn:PASS:mkdir /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs2 0 nsec > fn:PASS:mount bpffs /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1 0 nsec > fn:PASS:mount bpffs /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs2 0 nsec > fn:PASS:reading /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/maps.debug 0 nsec > fn:PASS:reading /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs2/progs.debug 0 nsec > fn:PASS:creating /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/a 0 nsec > fn:PASS:creating /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/a/1 0 nsec > fn:PASS:creating /tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/b 0 nsec > fn:PASS:create_map(ARRAY) 0 nsec > fn:PASS:pin map 0 nsec > fn:PASS:stat(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/a) 0 nsec > fn:PASS:renameat2(/fs1/a, /fs1/b, RENAME_EXCHANGE) 0 nsec > fn:PASS:stat(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/b) 0 nsec > fn:PASS:b should have a's inode 0 nsec > fn:PASS:access(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/b/1) 0 nsec > fn:PASS:stat(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/map) 0 nsec > fn:PASS:renameat2(/fs1/c, /fs1/b, RENAME_EXCHANGE) 0 nsec > fn:PASS:stat(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/b) 0 nsec > fn:PASS:b should have c's inode 0 nsec > fn:PASS:access(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/c/1) 0 nsec > fn:PASS:renameat2(RENAME_NOREPLACE) 0 nsec > fn:PASS:access(/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed/fs1/b) 0 nsec > bpf_testmod.ko is already unloaded. > Loading bpf_testmod.ko... > Successfully loaded bpf_testmod.ko. > test_test_bpffs:PASS:clone 0 nsec > test_test_bpffs:PASS:waitpid 0 nsec > test_test_bpffs:PASS:bpffs test 0 nsec > #282 test_bpffs:OK > Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED > Successfully unloaded bpf_testmod.ko. > > [0] https://github.com/danobi/vmtest > > This is a follow-up of https://lore.kernel.org/bpf/20231024201852.1512720-1-chantr4@xxxxxxxxx/T/ > > Signed-off-by: Manu Bretelle <chantr4@xxxxxxxxx> > --- > tools/testing/selftests/bpf/prog_tests/test_bpffs.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c > index 214d9f4a94a5..80a1afb9589d 100644 > --- a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c > +++ b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c > @@ -8,7 +8,8 @@ > #include <sys/types.h> > #include <test_progs.h> > > -#define TDIR "/sys/kernel/debug" > +// TDIR must be in a location we can create a directory in. > +#define TDIR "/tmp/vvnlhrgunvkrfegnlrvnggcudfgdtrhbfelkebeurfed" and "/tmp/test_bpffs_testdir" isn't unique enough? ;) > > static int read_iter(char *file) > { > @@ -43,8 +44,10 @@ static int fn(void) > if (!ASSERT_OK(err, "mount /")) > goto out; > > - err = umount(TDIR); > - if (!ASSERT_OK(err, "umount " TDIR)) > + err = mkdir(TDIR, 0777); > + // If the directory already exists we can carry on. It may be left over > + // from a previous run. we don't use C++-style comments in kernel and selftests code, please change to /* */ same above for TDIR comment > + if ((err && errno != EEXIST) && !ASSERT_OK(err, "mkdir " TDIR)) > goto out; > > err = mount("none", TDIR, "tmpfs", 0, NULL); > @@ -138,6 +141,7 @@ static int fn(void) > rmdir(TDIR "/fs1"); > rmdir(TDIR "/fs2"); > umount(TDIR); > + rmdir(TDIR); > exit(err); > } > > -- > 2.40.1 >
