missing_syscall: drop unnecessary ifdefs for syscall number

Nowadays, we define syscall numbers for newer syscalls.
Hence the conditions are not necessary.

This also adds several comments about when syscalls are introduced.

diff --git a/src/basic/missing_syscall.h b/src/basic/missing_syscall.h
index af7aa528c6e7b796de66394c4debaa287908b2c6..6bf9c0d5ae47aad58122e3f9436355710a85dfa1 100644 (file)
--- a/src/basic/missing_syscall.h
+++ b/src/basic/missing_syscall.h
@@ -24,13 +24,9 @@
 /* ======================================================================= */
 
 #if !HAVE_FCHMODAT2
+/* since kernel v6.6 (78252deb023cf0879256fcfbafe37022c390762b) */
 static inline int missing_fchmodat2(int dirfd, const char *path, mode_t mode, int flags) {
-#  ifdef __NR_fchmodat2
         return syscall(__NR_fchmodat2, dirfd, path, mode, flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define fchmodat2 missing_fchmodat2
@@ -95,12 +91,16 @@ static inline long missing_keyctl(int cmd, unsigned long arg2, unsigned long arg
 #  define keyctl missing_keyctl
 }
 
+/* ======================================================================= */
+
 static inline key_serial_t missing_add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t ringid) {
         return syscall(__NR_add_key, type, description, payload, plen, ringid);
 
 #  define add_key missing_add_key
 }
 
+/* ======================================================================= */
+
 static inline key_serial_t missing_request_key(const char *type, const char *description, const char * callout_info, key_serial_t destringid) {
         return syscall(__NR_request_key, type, description, callout_info, destringid);
 
@@ -114,12 +114,7 @@ static inline key_serial_t missing_request_key(const char *type, const char *des
 union bpf_attr;
 
 static inline int missing_bpf(int cmd, union bpf_attr *attr, size_t size) {
-#ifdef __NR_bpf
         return (int) syscall(__NR_bpf, cmd, attr, size);
-#else
-        errno = ENOSYS;
-        return -1;
-#endif
 }
 
 #  define bpf missing_bpf
@@ -138,14 +133,7 @@ enum {
 
 static inline long missing_set_mempolicy(int mode, const unsigned long *nodemask,
                            unsigned long maxnode) {
-        long i;
-#  if defined __NR_set_mempolicy && __NR_set_mempolicy >= 0
-        i = syscall(__NR_set_mempolicy, mode, nodemask, maxnode);
-#  else
-        errno = ENOSYS;
-        i = -1;
-#  endif
-        return i;
+        return syscall(__NR_set_mempolicy, mode, nodemask, maxnode);
 }
 
 #  define set_mempolicy missing_set_mempolicy
@@ -155,14 +143,7 @@ static inline long missing_set_mempolicy(int mode, const unsigned long *nodemask
 static inline long missing_get_mempolicy(int *mode, unsigned long *nodemask,
                            unsigned long maxnode, void *addr,
                            unsigned long flags) {
-        long i;
-#  if defined __NR_get_mempolicy && __NR_get_mempolicy >= 0
-        i = syscall(__NR_get_mempolicy, mode, nodemask, maxnode, addr, flags);
-#  else
-        errno = ENOSYS;
-        i = -1;
-#  endif
-        return i;
+        return syscall(__NR_get_mempolicy, mode, nodemask, maxnode, addr, flags);
 }
 
 #  define get_mempolicy missing_get_mempolicy
@@ -171,6 +152,7 @@ static inline long missing_get_mempolicy(int *mode, unsigned long *nodemask,
 /* ======================================================================= */
 
 #if !HAVE_PIDFD_SEND_SIGNAL
+/* since kernel v5.1 (3eb39f47934f9d5a3027fe00d906a45fe3a15fad) */
 static inline int missing_pidfd_send_signal(int fd, int sig, siginfo_t *info, unsigned flags) {
         return syscall(__NR_pidfd_send_signal, fd, sig, info, flags);
 }
@@ -178,7 +160,10 @@ static inline int missing_pidfd_send_signal(int fd, int sig, siginfo_t *info, un
 #  define pidfd_send_signal missing_pidfd_send_signal
 #endif
 
+/* ======================================================================= */
+
 #if !HAVE_PIDFD_OPEN
+/* since kernel v5.3 (7615d9e1780e26e0178c93c55b73309a5dc093d7) */
 static inline int missing_pidfd_open(pid_t pid, unsigned flags) {
         return syscall(__NR_pidfd_open, pid, flags);
 }
@@ -190,11 +175,7 @@ static inline int missing_pidfd_open(pid_t pid, unsigned flags) {
 
 #if !HAVE_RT_TGSIGQUEUEINFO
 static inline int missing_rt_tgsigqueueinfo(pid_t tgid, pid_t tid, int sig, siginfo_t *info) {
-#  if defined __NR_rt_tgsigqueueinfo && __NR_rt_tgsigqueueinfo >= 0
         return syscall(__NR_rt_tgsigqueueinfo, tgid, tid, sig, info);
-#  else
-#    error "__NR_rt_tgsigqueueinfo not defined"
-#  endif
 }
 
 #  define rt_tgsigqueueinfo missing_rt_tgsigqueueinfo
@@ -203,15 +184,11 @@ static inline int missing_rt_tgsigqueueinfo(pid_t tgid, pid_t tid, int sig, sigi
 /* ======================================================================= */
 
 #if !HAVE_EXECVEAT
+/* since kernel v3.19 (51f39a1f0cea1cacf8c787f652f26dfee9611874) */
 static inline int missing_execveat(int dirfd, const char *pathname,
                                    char *const argv[], char *const envp[],
                                    int flags) {
-#  if defined __NR_execveat && __NR_execveat >= 0
         return syscall(__NR_execveat, dirfd, pathname, argv, envp, flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  undef AT_EMPTY_PATH
@@ -222,8 +199,8 @@ static inline int missing_execveat(int dirfd, const char *pathname,
 /* ======================================================================= */
 
 #if !HAVE_CLOSE_RANGE
+/* since kernel v5.9 (9b4feb630e8e9801603f3cab3a36369e3c1cf88d) */
 static inline int missing_close_range(unsigned first_fd, unsigned end_fd, unsigned flags) {
-#  ifdef __NR_close_range
         /* Kernel-side the syscall expects fds as unsigned integers (just like close() actually), while
          * userspace exclusively uses signed integers for fds. glibc chose to expose it 1:1 however, hence we
          * do so here too, even if we end up passing signed fds to it most of the time. */
@@ -231,10 +208,6 @@ static inline int missing_close_range(unsigned first_fd, unsigned end_fd, unsign
                        first_fd,
                        end_fd,
                        flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define close_range missing_close_range
@@ -243,6 +216,7 @@ static inline int missing_close_range(unsigned first_fd, unsigned end_fd, unsign
 /* ======================================================================= */
 
 #if !HAVE_MOUNT_SETATTR
+/* since kernel v5.12 (2a1867219c7b27f928e2545782b86daaf9ad50bd) */
 
 #if !HAVE_STRUCT_MOUNT_ATTR
 struct mount_attr {
@@ -314,12 +288,7 @@ static inline int missing_mount_setattr(
                 struct mount_attr *attr,
                 size_t size) {
 
-#  if defined __NR_mount_setattr && __NR_mount_setattr >= 0
         return syscall(__NR_mount_setattr, dfd, path, flags, attr, size);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define mount_setattr missing_mount_setattr
@@ -328,6 +297,7 @@ static inline int missing_mount_setattr(
 /* ======================================================================= */
 
 #if !HAVE_OPEN_TREE
+/* since kernel v5.2 (a07b20004793d8926f78d63eb5980559f7813404, d8076bdb56af5e5918376cd1573a6b0007fc1a89) */
 
 #ifndef OPEN_TREE_CLONE
 #define OPEN_TREE_CLONE 1
@@ -342,12 +312,7 @@ static inline int missing_open_tree(
                 const char *filename,
                 unsigned flags) {
 
-#  if defined __NR_open_tree && __NR_open_tree >= 0
         return syscall(__NR_open_tree, dfd, filename, flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define open_tree missing_open_tree
@@ -360,6 +325,7 @@ static inline int missing_open_tree(
 #endif
 
 #if !HAVE_MOVE_MOUNT
+/* since kernel v5.2 (2db154b3ea8e14b04fee23e3fdfd5e9d17fbc6ae, d8076bdb56af5e5918376cd1573a6b0007fc1a89) */
 
 #ifndef MOVE_MOUNT_F_EMPTY_PATH
 #define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
@@ -376,12 +342,7 @@ static inline int missing_move_mount(
                 const char *to_pathname,
                 unsigned flags) {
 
-#  if defined __NR_move_mount && __NR_move_mount >= 0
         return syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd, to_pathname, flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define move_mount missing_move_mount
@@ -390,18 +351,14 @@ static inline int missing_move_mount(
 /* ======================================================================= */
 
 #if !HAVE_FSOPEN
+/* since kernel v5.2 (24dcb3d90a1f67fe08c68a004af37df059d74005, d8076bdb56af5e5918376cd1573a6b0007fc1a89) */
 
 #ifndef FSOPEN_CLOEXEC
 #define FSOPEN_CLOEXEC 0x00000001
 #endif
 
 static inline int missing_fsopen(const char *fsname, unsigned flags) {
-#  if defined __NR_fsopen && __NR_fsopen >= 0
         return syscall(__NR_fsopen, fsname, flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define fsopen missing_fsopen
@@ -410,6 +367,7 @@ static inline int missing_fsopen(const char *fsname, unsigned flags) {
 /* ======================================================================= */
 
 #if !HAVE_FSCONFIG
+/* since kernel v5.2 (ecdab150fddb42fe6a739335257949220033b782, d8076bdb56af5e5918376cd1573a6b0007fc1a89) */
 
 #ifndef FSCONFIG_SET_FLAG
 #define FSCONFIG_SET_FLAG 0 /* Set parameter, supplying no value */
@@ -428,12 +386,7 @@ static inline int missing_fsopen(const char *fsname, unsigned flags) {
 #endif
 
 static inline int missing_fsconfig(int fd, unsigned cmd, const char *key, const void *value, int aux) {
-#  if defined __NR_fsconfig && __NR_fsconfig >= 0
         return syscall(__NR_fsconfig, fd, cmd, key, value, aux);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define fsconfig missing_fsconfig
@@ -442,18 +395,14 @@ static inline int missing_fsconfig(int fd, unsigned cmd, const char *key, const
 /* ======================================================================= */
 
 #if !HAVE_FSMOUNT
+/* since kernel v5.2 for (93766fbd2696c2c4453dd8e1070977e9cd4e6b6d, d8076bdb56af5e5918376cd1573a6b0007fc1a89) */
 
 #ifndef FSMOUNT_CLOEXEC
 #define FSMOUNT_CLOEXEC 0x00000001
 #endif
 
 static inline int missing_fsmount(int fd, unsigned flags, unsigned ms_flags) {
-#  if defined __NR_fsmount && __NR_fsmount >= 0
         return syscall(__NR_fsmount, fd, flags, ms_flags);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define fsmount missing_fsmount
@@ -462,14 +411,8 @@ static inline int missing_fsmount(int fd, unsigned flags, unsigned ms_flags) {
 /* ======================================================================= */
 
 #if !HAVE_GETDENTS64
-
 static inline ssize_t missing_getdents64(int fd, void *buffer, size_t length) {
-#  if defined __NR_getdents64 && __NR_getdents64 >= 0
         return syscall(__NR_getdents64, fd, buffer, length);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define getdents64 missing_getdents64
@@ -478,7 +421,7 @@ static inline ssize_t missing_getdents64(int fd, void *buffer, size_t length) {
 /* ======================================================================= */
 
 #if !HAVE_SCHED_SETATTR
-
+/* since kernel 3.14 (e6cfc0295c7d51b008999a8b13a44fb43f8685ea) */
 static inline ssize_t missing_sched_setattr(pid_t pid, struct sched_attr *attr, unsigned int flags) {
         return syscall(__NR_sched_setattr, pid, attr, flags);
 }
@@ -503,14 +446,9 @@ int __clone2(int (*fn)(void *), void *stack_base, size_t stack_size, int flags,
 /* ======================================================================= */
 
 #if !HAVE_QUOTACTL_FD
-
+/* since kernel v5.14 (64c2c2c62f92339b176ea24403d8db16db36f9e6) */
 static inline int missing_quotactl_fd(int fd, int cmd, int id, void *addr) {
-#  ifdef __NR_quotactl_fd
         return syscall(__NR_quotactl_fd, fd, cmd, id, addr);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define quotactl_fd missing_quotactl_fd
@@ -519,6 +457,7 @@ static inline int missing_quotactl_fd(int fd, int cmd, int id, void *addr) {
 /* ======================================================================= */
 
 #if !HAVE_SETXATTRAT
+/* since kernel v6.13 (6140be90ec70c39fa844741ca3cc807dd0866394) */
 struct xattr_args {
         _align_(8) uint64_t value;
         uint32_t size;
@@ -526,25 +465,18 @@ struct xattr_args {
 };
 
 static inline int missing_setxattrat(int fd, const char *path, int at_flags, const char *name, const struct xattr_args *args, size_t size) {
-#  ifdef __NR_setxattrat
         return syscall(__NR_setxattrat, fd, path, at_flags, name, args, size);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define setxattrat missing_setxattrat
 #endif
 
+/* ======================================================================= */
+
 #if !HAVE_REMOVEXATTRAT
+/* since kernel v6.13 (6140be90ec70c39fa844741ca3cc807dd0866394) */
 static inline int missing_removexattrat(int fd, const char *path, int at_flags, const char *name) {
-#  ifdef __NR_removexattrat
         return syscall(__NR_removexattrat, fd, path, at_flags, name);
-#  else
-        errno = ENOSYS;
-        return -1;
-#  endif
 }
 
 #  define removexattrat missing_removexattrat