[PATCH v3 00/14] selftests/nolibc: allow run with minimal kernel config

[PATCH v3 00/14] selftests/nolibc: allow run with minimal kernel config

[Zhangjin Wu]

Willy, Thomas

This is v3 to allow run with minimal kernel config, see v2 [1].

Applied further suggestions from Thomas, It is based on our previous v5
sysret helper series [2] and Thomas' chmod_net removal patchset [3].

Now, a test report on arm/vexpress-a9 without procfs, shmem, tmpfs, net
and memfd_create looks like:

    LOG: testing report for arm/vexpress-a9:

    14 chmod_self                                                   [SKIPPED]
    16 chown_self                                                   [SKIPPED]
    40 link_cross                                                   [SKIPPED]
    0 -fstackprotector not supported                                [SKIPPED]

    139 test(s) passed, 4 skipped, 0 failed.
    See all results in /labs/linux-lab/logging/nolibc/arm-vexpress-a9-nolibc-test.log

    LOG: testing summary:

         arch/board | result
        ------------|------------
    arm/vexpress-a9 | 139 test(s) passed, 4 skipped, 0 failed. See all results in /labs/linux-lab/logging/nolibc/arm-vexpress-a9-nolibc-test.log

Changes from v2 --> v3:

* Added Reviewed-by from Thomas for the whole series, Many Thanks

* selftests/nolibc: stat_fault: silence NULL argument warning with glibc
  selftests/nolibc: gettid: restore for glibc and musl
  selftests/nolibc: add _LARGEFILE64_SOURCE for musl
  selftests/nolibc: fix up int_fast16/32_t test cases for musl
  selftests/nolibc: fix up kernel parameters support
  selftests/nolibc: stat_timestamps: remove procfs dependency
  selftests/nolibc: link_cross: use /proc/self/cmdline
  tools/nolibc: add rmdir() support
  selftests/nolibc: add a new rmdir() test case
  selftests/nolibc: fix up failures when CONFIG_PROC_FS=n
  selftests/nolibc: vfprintf: remove MEMFD_CREATE dependency

    No code changes except some commit message cleanups.

* selftests/nolibc: prepare /tmp for tmpfs or ramfs

    As suggested by Thomas, simply calling mkdir() and mount() to
    prepare /tmp can save a stat() call.

* selftests/nolibc: chroot_exe: remove procfs dependency

    As suggested by Thomas, remove the 'weird' get_tmpfile() and use
    the '/init' for !procfs as we did for stat_timestamps.

    For the worst-case scene, when '/init' is not there, add ENOENT to
    the error check list.

    Now, it is a oneline code change.

* selftests/nolibc: add chmod_tmpdir test

    Without get_tmpfile(), let's direct mkdir() a temp directory for
    chmod_tmpdir test, it function as a substitute for the removed
    chmod_net.

    Now, it is a oneline code change.

Best regards,
Zhangjin
---
[1]: https://lore.kernel.org/lkml/cover.1688078604.git.falcon@tinylab.org/

Zhangjin Wu (14):
  selftests/nolibc: stat_fault: silence NULL argument warning with glibc
  selftests/nolibc: gettid: restore for glibc and musl
  selftests/nolibc: add _LARGEFILE64_SOURCE for musl
  selftests/nolibc: fix up int_fast16/32_t test cases for musl
  selftests/nolibc: fix up kernel parameters support
  selftests/nolibc: stat_timestamps: remove procfs dependency
  selftests/nolibc: chroot_exe: remove procfs dependency
  selftests/nolibc: link_cross: use /proc/self/cmdline
  tools/nolibc: add rmdir() support
  selftests/nolibc: add a new rmdir() test case
  selftests/nolibc: fix up failures when CONFIG_PROC_FS=n
  selftests/nolibc: prepare /tmp for tmpfs or ramfs
  selftests/nolibc: add chmod_tmpdir test
  selftests/nolibc: vfprintf: remove MEMFD_CREATE dependency

 tools/include/nolibc/sys.h                   | 22 ++++++
 tools/testing/selftests/nolibc/nolibc-test.c | 83 +++++++++++++++-----
 2 files changed, 87 insertions(+), 18 deletions(-)

-- 
2.25.1

[PATCH v3 01/14] selftests/nolibc: stat_fault: silence NULL argument warning with glibc

[Zhangjin Wu]

Use another invalid address (void *)1 instead of NULL to silence this
compile warning with glibc:

    $ make libc-test
      CC      libc-test
    nolibc-test.c: In function ‘run_syscall’:
    nolibc-test.c:622:49: warning: null argument where non-null required (argument 1) [-Wnonnull]
      622 |   CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break;
          |                                                 ^~~~
    nolibc-test.c:304:79: note: in definition of macro ‘EXPECT_SYSER2’
      304 |  do { if (!cond) pad_spc(llen, 64, "[SKIPPED]\n"); else ret += expect_syserr2(expr, expret, experr1, experr2, llen); } while (0)
          |                                                                               ^~~~
    nolibc-test.c:622:33: note: in expansion of macro ‘EXPECT_SYSER’
      622 |   CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break;

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index f85f55921410..ffef0ff921bf 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -733,7 +733,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(select_stdout);     EXPECT_SYSNE(1, ({ fd_set fds; FD_ZERO(&fds); FD_SET(1, &fds); select(2, NULL, &fds, NULL, NULL); }), -1); break;
 		CASE_TEST(select_fault);      EXPECT_SYSER(1, select(1, (void *)1, NULL, NULL, 0), -1, EFAULT); break;
 		CASE_TEST(stat_blah);         EXPECT_SYSER(1, stat("/proc/self/blah", &stat_buf), -1, ENOENT); break;
-		CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break;
+		CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat((void *)1, &stat_buf), -1, EFAULT); break;
 		CASE_TEST(stat_timestamps);   EXPECT_SYSZR(1, test_stat_timestamps()); break;
 		CASE_TEST(symlink_root);      EXPECT_SYSER(1, symlink("/", "/"), -1, EEXIST); break;
 		CASE_TEST(unlink_root);       EXPECT_SYSER(1, unlink("/"), -1, EISDIR); break;
-- 
2.25.1

[PATCH v3 02/14] selftests/nolibc: gettid: restore for glibc and musl

[Zhangjin Wu]

As the gettid manpage [1] shows, glibc 2.30 has gettid support, so,
let's enable the test for glibc >= 2.30.

gettid works on musl too.

[1]: https://man7.org/linux/man-pages/man2/gettid.2.html

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index ffef0ff921bf..be7614c897b4 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -659,6 +659,7 @@ int run_syscall(int min, int max)
 	int tmp;
 	int ret = 0;
 	void *p1, *p2;
+	int has_gettid = 1;
 
 	/* <proc> indicates whether or not /proc is mounted */
 	proc = stat("/proc", &stat_buf) == 0;
@@ -666,6 +667,11 @@ int run_syscall(int min, int max)
 	/* this will be used to skip certain tests that can't be run unprivileged */
 	euid0 = geteuid() == 0;
 
+	/* from 2.30, glibc provides gettid() */
+#if defined(__GLIBC_MINOR__) && defined(__GLIBC__)
+	has_gettid = __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 30);
+#endif
+
 	for (test = min; test >= 0 && test <= max; test++) {
 		int llen = 0; /* line length */
 
@@ -675,9 +681,7 @@ int run_syscall(int min, int max)
 		switch (test + __LINE__ + 1) {
 		CASE_TEST(getpid);            EXPECT_SYSNE(1, getpid(), -1); break;
 		CASE_TEST(getppid);           EXPECT_SYSNE(1, getppid(), -1); break;
-#ifdef NOLIBC
-		CASE_TEST(gettid);            EXPECT_SYSNE(1, gettid(), -1); break;
-#endif
+		CASE_TEST(gettid);            EXPECT_SYSNE(has_gettid, gettid(), -1); break;
 		CASE_TEST(getpgid_self);      EXPECT_SYSNE(1, getpgid(0), -1); break;
 		CASE_TEST(getpgid_bad);       EXPECT_SYSER(1, getpgid(-1), -1, ESRCH); break;
 		CASE_TEST(kill_0);            EXPECT_SYSZR(1, kill(getpid(), 0)); break;
-- 
2.25.1

[PATCH v3 03/14] selftests/nolibc: add _LARGEFILE64_SOURCE for musl

[Zhangjin Wu]

_GNU_SOURCE Implies _LARGEFILE64_SOURCE in glibc, but in musl, the
default configuration doesn't enable _LARGEFILE64_SOURCE.

From include/dirent.h of musl, getdents64 is provided as getdents when
_LARGEFILE64_SOURCE is defined.

    #if defined(_LARGEFILE64_SOURCE)
    ...
    #define getdents64 getdents
    #endif

Let's define _LARGEFILE64_SOURCE to fix up this compile error:

    tools/testing/selftests/nolibc/nolibc-test.c: In function ‘test_getdents64’:
    tools/testing/selftests/nolibc/nolibc-test.c:453:8: warning: implicit declaration of function ‘getdents64’; did you mean ‘getdents’? [-Wimplicit-function-declaration]
      453 |  ret = getdents64(fd, (void *)buffer, sizeof(buffer));
          |        ^~~~~~~~~~
          |        getdents
    /usr/bin/ld: /tmp/ccKILm5u.o: in function `test_getdents64':
    nolibc-test.c:(.text+0xe3e): undefined reference to `getdents64'
    collect2: error: ld returned 1 exit status

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index be7614c897b4..d9644244fc95 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 
 #define _GNU_SOURCE
+#define _LARGEFILE64_SOURCE
 
 /* libc-specific include files
  * The program may be built in 3 ways:
-- 
2.25.1

Re: [PATCH v3 03/14] selftests/nolibc: add _LARGEFILE64_SOURCE for musl

[Arnd Bergmann]

On Fri, Jun 30, 2023, at 16:44, Zhangjin Wu wrote:
> _GNU_SOURCE Implies _LARGEFILE64_SOURCE in glibc, but in musl, the
> default configuration doesn't enable _LARGEFILE64_SOURCE.
>
> From include/dirent.h of musl, getdents64 is provided as getdents when
> _LARGEFILE64_SOURCE is defined.
>
>     #if defined(_LARGEFILE64_SOURCE)
>     ...
>     #define getdents64 getdents
>     #endif
>
> Let's define _LARGEFILE64_SOURCE to fix up this compile error:

I think a better solution would be to use the normal getdents() instead
of glibc getdents64(), but then define _FILE_OFFSET_BITS=64 to tell
glibc to use the modern version of all filesystem syscalls.

     Arnd

Re: [PATCH v3 03/14] selftests/nolibc: add _LARGEFILE64_SOURCE for musl

[Zhangjin Wu]

Hi, Arnd

> On Fri, Jun 30, 2023, at 16:44, Zhangjin Wu wrote:
> > _GNU_SOURCE Implies _LARGEFILE64_SOURCE in glibc, but in musl, the
> > default configuration doesn't enable _LARGEFILE64_SOURCE.
> >
> > From include/dirent.h of musl, getdents64 is provided as getdents when
> > _LARGEFILE64_SOURCE is defined.
> >
> >     #if defined(_LARGEFILE64_SOURCE)
> >     ...
> >     #define getdents64 getdents
> >     #endif
> >
> > Let's define _LARGEFILE64_SOURCE to fix up this compile error:
> 
> I think a better solution would be to use the normal getdents() instead
> of glibc getdents64(), but then define _FILE_OFFSET_BITS=64 to tell
> glibc to use the modern version of all filesystem syscalls.
> 

Just checked the getdents manpage[1] and the nolibc code, both of glibc and
nolibc don't provide the getdents() library routine but both of them provide
the getdents64(), only musl provide getdents() by default.

And as the manpage shows, it is not easy to call getdents() with glibc, we
need manually call syscall() and define the 'dirent' struct ourselves:

    glibc does not provide a wrapper for getdents(); call getdents()
    using syscall(2).  In that case you will need to define the
    linux_dirent or linux_dirent64 structure yourself.

And for nolibc, a getdents64() with linux_dirent64 struct (with int64_t offset)
is provided, there is either no getdents() currently.

This patch aims to let nolibc-test at least compile for musl and therefore we
can easily check the new tests for musl, glibc and nolibc together.

For the 64bit offset related stuff, we'd better delay it in another patchset
(part of full rv32 support), which will convert the off_t to 64bit by default.

Thanks,
Zhangjin

[1]: https://man7.org/linux/man-pages/man2/getdents.2.html

>      Arnd

Re: [PATCH v3 03/14] selftests/nolibc: add _LARGEFILE64_SOURCE for musl

[Arnd Bergmann]

On Fri, Jun 30, 2023, at 20:01, Zhangjin Wu wrote:
> Hi, Arnd
>
>> On Fri, Jun 30, 2023, at 16:44, Zhangjin Wu wrote:
>> > _GNU_SOURCE Implies _LARGEFILE64_SOURCE in glibc, but in musl, the
>> > default configuration doesn't enable _LARGEFILE64_SOURCE.
>> >
>> > From include/dirent.h of musl, getdents64 is provided as getdents when
>> > _LARGEFILE64_SOURCE is defined.
>> >
>> >     #if defined(_LARGEFILE64_SOURCE)
>> >     ...
>> >     #define getdents64 getdents
>> >     #endif
>> >
>> > Let's define _LARGEFILE64_SOURCE to fix up this compile error:
>> 
>> I think a better solution would be to use the normal getdents() instead
>> of glibc getdents64(), but then define _FILE_OFFSET_BITS=64 to tell
>> glibc to use the modern version of all filesystem syscalls.
>> 
>
> Just checked the getdents manpage[1] and the nolibc code, both of glibc and
> nolibc don't provide the getdents() library routine but both of them provide
> the getdents64(), only musl provide getdents() by default.
>
> And as the manpage shows, it is not easy to call getdents() with glibc, we
> need manually call syscall() and define the 'dirent' struct ourselves:
>
>     glibc does not provide a wrapper for getdents(); call getdents()
>     using syscall(2).  In that case you will need to define the
>     linux_dirent or linux_dirent64 structure yourself.
>
> And for nolibc, a getdents64() with linux_dirent64 struct (with int64_t offset)
> is provided, there is either no getdents() currently.
>
> This patch aims to let nolibc-test at least compile for musl and therefore we
> can easily check the new tests for musl, glibc and nolibc together.

Ok, I see. Your current approach should be fine then.

> For the 64bit offset related stuff, we'd better delay it in another patchset
> (part of full rv32 support), which will convert the off_t to 64bit by default.

Right, makes sense.


    ARnd

[PATCH v3 04/14] selftests/nolibc: fix up int_fast16/32_t test cases for musl

[Zhangjin Wu]

musl limits the fast signed int in 32bit, but glibc and nolibc don't, to
let such test cases work on musl, let's provide the type based
SINT_MAX_OF_TYPE(type) and SINT_MIN_OF_TYPE(type).

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/bc635c4f-67fe-4e86-bfdf-bcb4879b928d@t-8ch.de/
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index d9644244fc95..290b43c7dc72 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -41,6 +41,10 @@
 #endif
 #endif
 
+/* for the type of int_fast16_t and int_fast32_t, musl differs from glibc and nolibc */
+#define SINT_MAX_OF_TYPE(type) (((type)1 << (sizeof(type) * 8 - 2)) - (type)1 + ((type)1 << (sizeof(type) * 8 - 2)))
+#define SINT_MIN_OF_TYPE(type) (-SINT_MAX_OF_TYPE(type) - 1)
+
 /* will be used by nolibc by getenv() */
 char **environ;
 
@@ -818,11 +822,11 @@ int run_stdlib(int min, int max)
 		CASE_TEST(limit_int_fast8_max);     EXPECT_EQ(1, INT_FAST8_MAX,    (int_fast8_t)     0x7f); break;
 		CASE_TEST(limit_int_fast8_min);     EXPECT_EQ(1, INT_FAST8_MIN,    (int_fast8_t)     0x80); break;
 		CASE_TEST(limit_uint_fast8_max);    EXPECT_EQ(1, UINT_FAST8_MAX,   (uint_fast8_t)    0xff); break;
-		CASE_TEST(limit_int_fast16_min);    EXPECT_EQ(1, INT_FAST16_MIN,   (int_fast16_t)    INTPTR_MIN); break;
-		CASE_TEST(limit_int_fast16_max);    EXPECT_EQ(1, INT_FAST16_MAX,   (int_fast16_t)    INTPTR_MAX); break;
+		CASE_TEST(limit_int_fast16_min);    EXPECT_EQ(1, INT_FAST16_MIN,   (int_fast16_t)    SINT_MIN_OF_TYPE(int_fast16_t)); break;
+		CASE_TEST(limit_int_fast16_max);    EXPECT_EQ(1, INT_FAST16_MAX,   (int_fast16_t)    SINT_MAX_OF_TYPE(int_fast16_t)); break;
 		CASE_TEST(limit_uint_fast16_max);   EXPECT_EQ(1, UINT_FAST16_MAX,  (uint_fast16_t)   UINTPTR_MAX); break;
-		CASE_TEST(limit_int_fast32_min);    EXPECT_EQ(1, INT_FAST32_MIN,   (int_fast32_t)    INTPTR_MIN); break;
-		CASE_TEST(limit_int_fast32_max);    EXPECT_EQ(1, INT_FAST32_MAX,   (int_fast32_t)    INTPTR_MAX); break;
+		CASE_TEST(limit_int_fast32_min);    EXPECT_EQ(1, INT_FAST32_MIN,   (int_fast32_t)    SINT_MIN_OF_TYPE(int_fast32_t)); break;
+		CASE_TEST(limit_int_fast32_max);    EXPECT_EQ(1, INT_FAST32_MAX,   (int_fast32_t)    SINT_MAX_OF_TYPE(int_fast32_t)); break;
 		CASE_TEST(limit_uint_fast32_max);   EXPECT_EQ(1, UINT_FAST32_MAX,  (uint_fast32_t)   UINTPTR_MAX); break;
 		CASE_TEST(limit_int_fast64_min);    EXPECT_EQ(1, INT_FAST64_MIN,   (int_fast64_t)    INT64_MIN); break;
 		CASE_TEST(limit_int_fast64_max);    EXPECT_EQ(1, INT_FAST64_MAX,   (int_fast64_t)    INT64_MAX); break;
-- 
2.25.1

[PATCH v3 05/14] selftests/nolibc: fix up kernel parameters support

[Zhangjin Wu]

kernel parameters allow pass two types of strings, one type is like
'noapic', another type is like 'panic=5', the first type is passed as
arguments of the init program, the second type is passed as environment
variables of the init program.

when users pass kernel parameters like this:

    noapic NOLIBC_TEST=syscall

our nolibc-test program will use the test setting from argv[1] and
ignore the one from NOLIBC_TEST environment variable, and at last, it
will print the following line and ignore the whole test setting.

    Ignoring unknown test name 'noapic'

reversing the parsing order does solve the above issue:

    test = getenv("NOLIBC_TEST");
    if (test)
        test = argv[1];

but it still doesn't work with such kernel parameters (without
NOLIBC_TEST environment variable):

    noapic FOO=bar

To support all of the potential kernel parameters, let's verify the test
setting from both of argv[1] and NOLIBC_TEST environment variable.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 33 ++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 290b43c7dc72..94801961740a 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1062,6 +1062,35 @@ static const struct test test_names[] = {
 	{ 0 }
 };
 
+int is_setting_valid(char *test)
+{
+	int idx, len, test_len, valid = 0;
+	char delimiter;
+
+	if (!test)
+		return valid;
+
+	test_len = strlen(test);
+
+	for (idx = 0; test_names[idx].name; idx++) {
+		len = strlen(test_names[idx].name);
+		if (test_len < len)
+			continue;
+
+		if (strncmp(test, test_names[idx].name, len) != 0)
+			continue;
+
+		delimiter = test[len];
+		if (delimiter != ':' && delimiter != ',' && delimiter != '\0')
+			continue;
+
+		valid = 1;
+		break;
+	}
+
+	return valid;
+}
+
 int main(int argc, char **argv, char **envp)
 {
 	int min = 0;
@@ -1087,10 +1116,10 @@ int main(int argc, char **argv, char **envp)
 	 *    syscall:5-15[:.*],stdlib:8-10
 	 */
 	test = argv[1];
-	if (!test)
+	if (!is_setting_valid(test))
 		test = getenv("NOLIBC_TEST");
 
-	if (test) {
+	if (is_setting_valid(test)) {
 		char *comma, *colon, *dash, *value;
 
 		do {
-- 
2.25.1

[PATCH v3 06/14] selftests/nolibc: stat_timestamps: remove procfs dependency

[Zhangjin Wu]

'/proc/self/' is a good path which doesn't have stale time info but it
is only available for CONFIG_PROC_FS=y.

When CONFIG_PROC_FS=n, use '/init' for initramfs and '/' for the others.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 94801961740a..3e2e808e06c2 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -582,7 +582,7 @@ static int test_stat_timestamps(void)
 	if (sizeof(st.st_atim.tv_sec) != sizeof(st.st_atime))
 		return 1;
 
-	if (stat("/proc/self/", &st))
+	if (stat("/proc/self/", &st) && stat("/init", &st) && stat("/", &st))
 		return 1;
 
 	if (st.st_atim.tv_sec != st.st_atime || st.st_atim.tv_nsec > 1000000000)
-- 
2.25.1

[PATCH v3 07/14] selftests/nolibc: chroot_exe: remove procfs dependency

[Zhangjin Wu]

Use '/init' instead of '/proc/self/exe' for CONFIG_PROC_FS=n.

If '/init' is not there, add ENOENT into the errno check list.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 3e2e808e06c2..a7a4310dec3e 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -702,7 +702,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(chown_self);        EXPECT_SYSER(proc, chown("/proc/self", 0, 0), -1, EPERM); break;
 		CASE_TEST(chroot_root);       EXPECT_SYSZR(euid0, chroot("/")); break;
 		CASE_TEST(chroot_blah);       EXPECT_SYSER(1, chroot("/proc/self/blah"), -1, ENOENT); break;
-		CASE_TEST(chroot_exe);        EXPECT_SYSER(proc, chroot("/proc/self/exe"), -1, ENOTDIR); break;
+		CASE_TEST(chroot_exe);        EXPECT_SYSER2(1, chroot(proc ? "/proc/self/exe" : "/init"), -1, ENOTDIR, ENOENT); break;
 		CASE_TEST(close_m1);          EXPECT_SYSER(1, close(-1), -1, EBADF); break;
 		CASE_TEST(close_dup);         EXPECT_SYSZR(1, close(dup(0))); break;
 		CASE_TEST(dup_0);             tmp = dup(0);  EXPECT_SYSNE(1, tmp, -1); close(tmp); break;
-- 
2.25.1

[PATCH v3 08/14] selftests/nolibc: link_cross: use /proc/self/cmdline

[Zhangjin Wu]

For CONFIG_NET=n, there would be no /proc/self/net, so, use
/proc/self/cmdline instead.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index a7a4310dec3e..8269f900db76 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -723,7 +723,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(link_root1);        EXPECT_SYSER(1, link("/", "/"), -1, EEXIST); break;
 		CASE_TEST(link_blah);         EXPECT_SYSER(1, link("/proc/self/blah", "/blah"), -1, ENOENT); break;
 		CASE_TEST(link_dir);          EXPECT_SYSER(euid0, link("/", "/blah"), -1, EPERM); break;
-		CASE_TEST(link_cross);        EXPECT_SYSER(proc, link("/proc/self/net", "/blah"), -1, EXDEV); break;
+		CASE_TEST(link_cross);        EXPECT_SYSER(proc, link("/proc/self/cmdline", "/blah"), -1, EXDEV); break;
 		CASE_TEST(lseek_m1);          EXPECT_SYSER(1, lseek(-1, 0, SEEK_SET), -1, EBADF); break;
 		CASE_TEST(lseek_0);           EXPECT_SYSER(1, lseek(0, 0, SEEK_SET), -1, ESPIPE); break;
 		CASE_TEST(mkdir_root);        EXPECT_SYSER(1, mkdir("/", 0755), -1, EEXIST); break;
-- 
2.25.1

[PATCH v3 09/14] tools/nolibc: add rmdir() support

[Zhangjin Wu]

a reverse operation of mkdir() is meaningful, add rmdir() here.

required by nolibc-test to remove /proc while CONFIG_PROC_FS is not
enabled.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/include/nolibc/sys.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index b6c33c40c037..7b052958e2ae 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -610,6 +610,28 @@ int mkdir(const char *path, mode_t mode)
 	return __sysret(sys_mkdir(path, mode));
 }
 
+/*
+ * int rmdir(const char *path);
+ */
+
+static __attribute__((unused))
+int sys_rmdir(const char *path)
+{
+#ifdef __NR_rmdir
+	return my_syscall1(__NR_rmdir, path);
+#elif defined(__NR_unlinkat)
+	return my_syscall3(__NR_unlinkat, AT_FDCWD, path, AT_REMOVEDIR);
+#else
+	return -ENOSYS;
+#endif
+}
+
+static __attribute__((unused))
+int rmdir(const char *path)
+{
+	return __sysret(sys_rmdir(path));
+}
+
 
 /*
  * int mknod(const char *path, mode_t mode, dev_t dev);
-- 
2.25.1

[PATCH v3 10/14] selftests/nolibc: add a new rmdir() test case

[Zhangjin Wu]

A new rmdir_blah test case is added to remove a non-existing /blah,
which expects failure with ENOENT errno.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 8269f900db76..34a47c512b97 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -737,6 +737,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(poll_fault);        EXPECT_SYSER(1, poll((void *)1, 1, 0), -1, EFAULT); break;
 		CASE_TEST(prctl);             EXPECT_SYSER(1, prctl(PR_SET_NAME, (unsigned long)NULL, 0, 0, 0), -1, EFAULT); break;
 		CASE_TEST(read_badf);         EXPECT_SYSER(1, read(-1, &tmp, 1), -1, EBADF); break;
+		CASE_TEST(rmdir_blah);        EXPECT_SYSER(1, rmdir("/blah"), -1, ENOENT); break;
 		CASE_TEST(sched_yield);       EXPECT_SYSZR(1, sched_yield()); break;
 		CASE_TEST(select_null);       EXPECT_SYSZR(1, ({ struct timeval tv = { 0 }; select(0, NULL, NULL, NULL, &tv); })); break;
 		CASE_TEST(select_stdout);     EXPECT_SYSNE(1, ({ fd_set fds; FD_ZERO(&fds); FD_SET(1, &fds); select(2, NULL, &fds, NULL, NULL); }), -1); break;
-- 
2.25.1

[PATCH v3 11/14] selftests/nolibc: fix up failures when CONFIG_PROC_FS=n

[Zhangjin Wu]

For CONFIG_PROC_FS=n, the /proc is not mountable, but the /proc
directory has been created in the prepare() stage whenever /proc is
there or not.

so, the checking of /proc in the run_syscall() stage will be always true
and at last it will fail all of the procfs dependent test cases, which
deviates from the 'cond' check design of the EXPECT_xx macros, without
procfs, these test cases should be skipped instead of failed.

To solve this issue, one method is checking /proc/self instead of /proc,
another method is removing the /proc directory completely for
CONFIG_PROC_FS=n, we apply the second method to avoid misleading the
users.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 34a47c512b97..b7ea95dad0fb 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1046,8 +1046,11 @@ int prepare(void)
 
 	/* try to mount /proc if not mounted. Silently fail otherwise */
 	if (stat("/proc/.", &stat_buf) == 0 || mkdir("/proc", 0755) == 0) {
-		if (stat("/proc/self", &stat_buf) != 0)
-			mount("/proc", "/proc", "proc", 0, 0);
+		if (stat("/proc/self", &stat_buf) != 0) {
+			/* If not mountable, remove /proc completely to avoid misuse */
+			if (mount("none", "/proc", "proc", 0, 0) != 0)
+				rmdir("/proc");
+		}
 	}
 
 	return 0;
-- 
2.25.1

[PATCH v3 12/14] selftests/nolibc: prepare /tmp for tmpfs or ramfs

[Zhangjin Wu]

create a /tmp directory and mount tmpfs there, if tmpfs is not
mountable, use ramfs as tmpfs.

tmpfs will be used instead of procfs for some tests.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index b7ea95dad0fb..906b70ddec79 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1053,6 +1053,10 @@ int prepare(void)
 		}
 	}
 
+	/* try to mount /tmp if not mounted, if not mountable, use ramfs as tmpfs */
+	mkdir("/tmp", 0755);
+	mount("none", "/tmp", "tmpfs", 0, 0);
+
 	return 0;
 }
 
-- 
2.25.1

[PATCH v3 13/14] selftests/nolibc: add chmod_tmpdir test

[Zhangjin Wu]

create a temp directory to test chmod with tmpfs.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 906b70ddec79..be2a18cd5bd5 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -699,6 +699,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(chdir_dot);         EXPECT_SYSZR(1, chdir(".")); break;
 		CASE_TEST(chdir_blah);        EXPECT_SYSER(1, chdir("/blah"), -1, ENOENT); break;
 		CASE_TEST(chmod_self);        EXPECT_SYSER(proc, chmod("/proc/self", 0555), -1, EPERM); break;
+		CASE_TEST(chmod_tmpdir);      mkdir("/tmp/blah", 0755); EXPECT_SYSZR(1, chmod("/tmp/blah", 0555)); rmdir("/tmp/blah"); break;
 		CASE_TEST(chown_self);        EXPECT_SYSER(proc, chown("/proc/self", 0, 0), -1, EPERM); break;
 		CASE_TEST(chroot_root);       EXPECT_SYSZR(euid0, chroot("/")); break;
 		CASE_TEST(chroot_blah);       EXPECT_SYSER(1, chroot("/proc/self/blah"), -1, ENOENT); break;
-- 
2.25.1

[PATCH v3 14/14] selftests/nolibc: vfprintf: remove MEMFD_CREATE dependency

[Zhangjin Wu]

The vfprintf test case require to open a temporary file to write, the
old memfd_create() method is perfect but has strong dependency on
MEMFD_CREATE and also TMPFS or HUGETLBFS (see fs/Kconfig):

    config MEMFD_CREATE
	def_bool TMPFS || HUGETLBFS

And from v6.2, MFD_NOEXEC_SEAL must be passed for the non-executable
memfd, otherwise, The kernel warning will be output to the test result
like this:

        Running test 'vfprintf'
        0 emptymemfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=1 'init'
         "" = ""                                                  [OK]

To avoid such warning and also to remove the MEMFD_CREATE dependency,
let's open a file from tmpfs directly.

The /tmp directory is used to detect the existing of tmpfs, if not
there, skip instead of fail.

And further, for pid == 1, the initramfs is loaded as ramfs, which can
be used as tmpfs, so, it is able to further remove TMPFS dependency too.

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/9ad51430-b7c0-47dc-80af-20c86539498d@t-8ch.de
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index be2a18cd5bd5..714252518595 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -868,10 +868,10 @@ static int expect_vfprintf(int llen, size_t c, const char *expected, const char
 	FILE *memfile;
 	va_list args;
 
-	fd = memfd_create("vfprintf", 0);
+	fd = open("/tmp", O_TMPFILE | O_EXCL | O_RDWR, 0600);
 	if (fd == -1) {
-		pad_spc(llen, 64, "[FAIL]\n");
-		return 1;
+		pad_spc(llen, 64, "[SKIPPED]\n");
+		return 0;
 	}
 
 	memfile = fdopen(fd, "w+");
-- 
2.25.1