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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 21:25:27 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 21:25:27 +0300
commit475d4df82719225510625b4263baa1105665f4b3 (patch)
tree41dfcac836db2241fe81b49b50557d4908654a3d
parent511fb5bafed197ff76d9adf5448de67f1d0558ae (diff)
parent71214379532794b5a05ea760524cdfb1c4ddbfcb (diff)
downloadlinux-475d4df82719225510625b4263baa1105665f4b3.tar.xz
Merge tag 'v6.6-vfs.fchmodat2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull fchmodat2 system call from Christian Brauner: "This adds the fchmodat2() system call. It is a revised version of the fchmodat() system call, adding a missing flag argument. Support for both AT_SYMLINK_NOFOLLOW and AT_EMPTY_PATH are included. Adding this system call revision has been a longstanding request but so far has always fallen through the cracks. While the kernel implementation of fchmodat() does not have a flag argument the libc provided POSIX-compliant fchmodat(3) version does. Both glibc and musl have to implement a workaround in order to support AT_SYMLINK_NOFOLLOW (see [1] and [2]). The workaround is brittle because it relies not just on O_PATH and O_NOFOLLOW semantics and procfs magic links but also on our rather inconsistent symlink semantics. This gives userspace a proper fchmodat2() system call that libcs can use to properly implement fchmodat(3) and allows them to get rid of their hacks. In this case it will immediately benefit them as the current workaround is already defunct because of aformentioned inconsistencies. In addition to AT_SYMLINK_NOFOLLOW, give userspace the ability to use AT_EMPTY_PATH with fchmodat2(). This is already possible with fchownat() so there's no reason to not also support it for fchmodat2(). The implementation is simple and comes with selftests. Implementation of the system call and wiring up the system call are done as separate patches even though they could arguably be one patch. But in case there are merge conflicts from other system call additions it can be beneficial to have separate patches" Link: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/fchmodat.c;h=17eca54051ee28ba1ec3f9aed170a62630959143;hb=a492b1e5ef7ab50c6fdd4e4e9879ea5569ab0a6c#l35 [1] Link: https://git.musl-libc.org/cgit/musl/tree/src/stat/fchmodat.c?id=718f363bc2067b6487900eddc9180c84e7739f80#n28 [2] * tag 'v6.6-vfs.fchmodat2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests: fchmodat2: remove duplicate unneeded defines fchmodat2: add support for AT_EMPTY_PATH selftests: Add fchmodat2 selftest arch: Register fchmodat2, usually as syscall 452 fs: Add fchmodat2() Non-functional cleanup of a "__user * filename"
-rw-r--r--arch/alpha/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/arm/tools/syscall.tbl1
-rw-r--r--arch/arm64/include/asm/unistd.h2
-rw-r--r--arch/arm64/include/asm/unistd32.h2
-rw-r--r--arch/ia64/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/m68k/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/microblaze/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/mips/kernel/syscalls/syscall_n32.tbl1
-rw-r--r--arch/mips/kernel/syscalls/syscall_n64.tbl1
-rw-r--r--arch/mips/kernel/syscalls/syscall_o32.tbl1
-rw-r--r--arch/parisc/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/powerpc/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/s390/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/sh/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/sparc/kernel/syscalls/syscall.tbl1
-rw-r--r--arch/x86/entry/syscalls/syscall_32.tbl1
-rw-r--r--arch/x86/entry/syscalls/syscall_64.tbl1
-rw-r--r--arch/xtensa/kernel/syscalls/syscall.tbl1
-rw-r--r--fs/open.c23
-rw-r--r--include/linux/syscalls.h4
-rw-r--r--include/uapi/asm-generic/unistd.h5
-rw-r--r--tools/testing/selftests/Makefile1
-rw-r--r--tools/testing/selftests/fchmodat2/.gitignore2
-rw-r--r--tools/testing/selftests/fchmodat2/Makefile6
-rw-r--r--tools/testing/selftests/fchmodat2/fchmodat2_test.c142
25 files changed, 196 insertions, 7 deletions
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 1f13995d00d7..ad37569d0507 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -491,3 +491,4 @@
559 common futex_waitv sys_futex_waitv
560 common set_mempolicy_home_node sys_ni_syscall
561 common cachestat sys_cachestat
+562 common fchmodat2 sys_fchmodat2
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 8ebed8a13874..c572d6c3dee0 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -465,3 +465,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 64a514f90131..bd77253b62e0 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -39,7 +39,7 @@
#define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5)
#define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800)
-#define __NR_compat_syscalls 452
+#define __NR_compat_syscalls 453
#endif
#define __ARCH_WANT_SYS_CLONE
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index d952a28463e0..78b68311ec81 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -909,6 +909,8 @@ __SYSCALL(__NR_futex_waitv, sys_futex_waitv)
__SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node)
#define __NR_cachestat 451
__SYSCALL(__NR_cachestat, sys_cachestat)
+#define __NR_fchmodat2 452
+__SYSCALL(__NR_fchmodat2, sys_fchmodat2)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index f8c74ffeeefb..83d8609aec03 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -372,3 +372,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 4f504783371f..259ceb125367 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -451,3 +451,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 858d22bf275c..a3798c2637fd 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -457,3 +457,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 1976317d4e8b..152034b8e0a0 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -390,3 +390,4 @@
449 n32 futex_waitv sys_futex_waitv
450 n32 set_mempolicy_home_node sys_set_mempolicy_home_node
451 n32 cachestat sys_cachestat
+452 n32 fchmodat2 sys_fchmodat2
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index cfda2511badf..cb5e757f6621 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -366,3 +366,4 @@
449 n64 futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 n64 cachestat sys_cachestat
+452 n64 fchmodat2 sys_fchmodat2
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 7692234c3768..1a646813afdc 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -439,3 +439,4 @@
449 o32 futex_waitv sys_futex_waitv
450 o32 set_mempolicy_home_node sys_set_mempolicy_home_node
451 o32 cachestat sys_cachestat
+452 o32 fchmodat2 sys_fchmodat2
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index a0a9145b6dd4..e97c175b56f9 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -450,3 +450,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 8c0b08b7a80e..20e50586e8a2 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -538,3 +538,4 @@
449 common futex_waitv sys_futex_waitv
450 nospu set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index a6935af2235c..0122cc156952 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -454,3 +454,4 @@
449 common futex_waitv sys_futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2 sys_fchmodat2
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 97377e8c5025..e90d585c4d3e 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -454,3 +454,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index faa835f3c54a..4ed06c71c43f 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -497,3 +497,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index bc0a3c941b35..2d0b1bd866ea 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -456,3 +456,4 @@
449 i386 futex_waitv sys_futex_waitv
450 i386 set_mempolicy_home_node sys_set_mempolicy_home_node
451 i386 cachestat sys_cachestat
+452 i386 fchmodat2 sys_fchmodat2
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 227538b0ce80..814768249eae 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -373,6 +373,7 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
#
# Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 2b69c3c035b6..fc1a4f3c81d9 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -422,3 +422,4 @@
449 common futex_waitv sys_futex_waitv
450 common set_mempolicy_home_node sys_set_mempolicy_home_node
451 common cachestat sys_cachestat
+452 common fchmodat2 sys_fchmodat2
diff --git a/fs/open.c b/fs/open.c
index 023a20322f11..98f6601fbac6 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -671,11 +671,20 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
return err;
}
-static int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
+static int do_fchmodat(int dfd, const char __user *filename, umode_t mode,
+ unsigned int flags)
{
struct path path;
int error;
- unsigned int lookup_flags = LOOKUP_FOLLOW;
+ unsigned int lookup_flags;
+
+ if (unlikely(flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)))
+ return -EINVAL;
+
+ lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
+ if (flags & AT_EMPTY_PATH)
+ lookup_flags |= LOOKUP_EMPTY;
+
retry:
error = user_path_at(dfd, filename, lookup_flags, &path);
if (!error) {
@@ -689,15 +698,21 @@ retry:
return error;
}
+SYSCALL_DEFINE4(fchmodat2, int, dfd, const char __user *, filename,
+ umode_t, mode, unsigned int, flags)
+{
+ return do_fchmodat(dfd, filename, mode, flags);
+}
+
SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename,
umode_t, mode)
{
- return do_fchmodat(dfd, filename, mode);
+ return do_fchmodat(dfd, filename, mode, 0);
}
SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
{
- return do_fchmodat(AT_FDCWD, filename, mode);
+ return do_fchmodat(AT_FDCWD, filename, mode, 0);
}
/*
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 03e3d0121d5e..5690aef7b3a8 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -438,8 +438,10 @@ asmlinkage long sys_chdir(const char __user *filename);
asmlinkage long sys_fchdir(unsigned int fd);
asmlinkage long sys_chroot(const char __user *filename);
asmlinkage long sys_fchmod(unsigned int fd, umode_t mode);
-asmlinkage long sys_fchmodat(int dfd, const char __user * filename,
+asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
umode_t mode);
+asmlinkage long sys_fchmodat2(int dfd, const char __user *filename,
+ umode_t mode, unsigned int flags);
asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
gid_t group, int flag);
asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group);
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index fd6c1cb585db..abe087c53b4b 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -820,8 +820,11 @@ __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node)
#define __NR_cachestat 451
__SYSCALL(__NR_cachestat, sys_cachestat)
+#define __NR_fchmodat2 452
+__SYSCALL(__NR_fchmodat2, sys_fchmodat2)
+
#undef __NR_syscalls
-#define __NR_syscalls 452
+#define __NR_syscalls 453
/*
* 32 bit systems traditionally used different
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 666b56f22a41..8dca8acdb671 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -18,6 +18,7 @@ TARGETS += drivers/net/bonding
TARGETS += drivers/net/team
TARGETS += efivarfs
TARGETS += exec
+TARGETS += fchmodat2
TARGETS += filesystems
TARGETS += filesystems/binderfs
TARGETS += filesystems/epoll
diff --git a/tools/testing/selftests/fchmodat2/.gitignore b/tools/testing/selftests/fchmodat2/.gitignore
new file mode 100644
index 000000000000..82a4846cbc4b
--- /dev/null
+++ b/tools/testing/selftests/fchmodat2/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/*_test
diff --git a/tools/testing/selftests/fchmodat2/Makefile b/tools/testing/selftests/fchmodat2/Makefile
new file mode 100644
index 000000000000..20839f8e43f2
--- /dev/null
+++ b/tools/testing/selftests/fchmodat2/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined $(KHDR_INCLUDES)
+TEST_GEN_PROGS := fchmodat2_test
+
+include ../lib.mk
diff --git a/tools/testing/selftests/fchmodat2/fchmodat2_test.c b/tools/testing/selftests/fchmodat2/fchmodat2_test.c
new file mode 100644
index 000000000000..e0319417124d
--- /dev/null
+++ b/tools/testing/selftests/fchmodat2/fchmodat2_test.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <syscall.h>
+#include <unistd.h>
+
+#include "../kselftest.h"
+
+int sys_fchmodat2(int dfd, const char *filename, mode_t mode, int flags)
+{
+ int ret = syscall(__NR_fchmodat2, dfd, filename, mode, flags);
+
+ return ret >= 0 ? ret : -errno;
+}
+
+int setup_testdir(void)
+{
+ int dfd, ret;
+ char dirname[] = "/tmp/ksft-fchmodat2.XXXXXX";
+
+ /* Make the top-level directory. */
+ if (!mkdtemp(dirname))
+ ksft_exit_fail_msg("%s: failed to create tmpdir\n", __func__);
+
+ dfd = open(dirname, O_PATH | O_DIRECTORY);
+ if (dfd < 0)
+ ksft_exit_fail_msg("%s: failed to open tmpdir\n", __func__);
+
+ ret = openat(dfd, "regfile", O_CREAT | O_WRONLY | O_TRUNC, 0644);
+ if (ret < 0)
+ ksft_exit_fail_msg("%s: failed to create file in tmpdir\n",
+ __func__);
+ close(ret);
+
+ ret = symlinkat("regfile", dfd, "symlink");
+ if (ret < 0)
+ ksft_exit_fail_msg("%s: failed to create symlink in tmpdir\n",
+ __func__);
+
+ return dfd;
+}
+
+int expect_mode(int dfd, const char *filename, mode_t expect_mode)
+{
+ struct stat st;
+ int ret = fstatat(dfd, filename, &st, AT_SYMLINK_NOFOLLOW);
+
+ if (ret)
+ ksft_exit_fail_msg("%s: %s: fstatat failed\n",
+ __func__, filename);
+
+ return (st.st_mode == expect_mode);
+}
+
+void test_regfile(void)
+{
+ int dfd, ret;
+
+ dfd = setup_testdir();
+
+ ret = sys_fchmodat2(dfd, "regfile", 0640, 0);
+
+ if (ret < 0)
+ ksft_exit_fail_msg("%s: fchmodat2(noflag) failed\n", __func__);
+
+ if (!expect_mode(dfd, "regfile", 0100640))
+ ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2\n",
+ __func__);
+
+ ret = sys_fchmodat2(dfd, "regfile", 0600, AT_SYMLINK_NOFOLLOW);
+
+ if (ret < 0)
+ ksft_exit_fail_msg("%s: fchmodat2(AT_SYMLINK_NOFOLLOW) failed\n",
+ __func__);
+
+ if (!expect_mode(dfd, "regfile", 0100600))
+ ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n",
+ __func__);
+
+ ksft_test_result_pass("fchmodat2(regfile)\n");
+}
+
+void test_symlink(void)
+{
+ int dfd, ret;
+
+ dfd = setup_testdir();
+
+ ret = sys_fchmodat2(dfd, "symlink", 0640, 0);
+
+ if (ret < 0)
+ ksft_exit_fail_msg("%s: fchmodat2(noflag) failed\n", __func__);
+
+ if (!expect_mode(dfd, "regfile", 0100640))
+ ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2\n",
+ __func__);
+
+ if (!expect_mode(dfd, "symlink", 0120777))
+ ksft_exit_fail_msg("%s: wrong symlink mode bits after fchmodat2\n",
+ __func__);
+
+ ret = sys_fchmodat2(dfd, "symlink", 0600, AT_SYMLINK_NOFOLLOW);
+
+ /*
+ * On certain filesystems (xfs or btrfs), chmod operation fails. So we
+ * first check the symlink target but if the operation fails we mark the
+ * test as skipped.
+ *
+ * https://sourceware.org/legacy-ml/libc-alpha/2020-02/msg00467.html
+ */
+ if (ret == 0 && !expect_mode(dfd, "symlink", 0120600))
+ ksft_exit_fail_msg("%s: wrong symlink mode bits after fchmodat2 with nofollow\n",
+ __func__);
+
+ if (!expect_mode(dfd, "regfile", 0100640))
+ ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n",
+ __func__);
+
+ if (ret != 0)
+ ksft_test_result_skip("fchmodat2(symlink)\n");
+ else
+ ksft_test_result_pass("fchmodat2(symlink)\n");
+}
+
+#define NUM_TESTS 2
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+ ksft_set_plan(NUM_TESTS);
+
+ test_regfile();
+ test_symlink();
+
+ if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
+ ksft_exit_fail();
+ else
+ ksft_exit_pass();
+}