| missing_syscall: when adding syscall replacements, use different names ( |
| |
| #8229) |
| |
| In meson.build we check that functions are available using: |
| meson.get_compiler('c').has_function('foo') |
| which checks the following: |
| - if __stub_foo or __stub___foo are defined, return false |
| - if foo is declared (a pointer to the function can be taken), return true |
| - otherwise check for __builtin_memfd_create |
| |
| _stub is documented by glibc as |
| It defines a symbol '__stub_FUNCTION' for each function |
| in the C library which is a stub, meaning it will fail |
| every time called, usually setting errno to ENOSYS. |
| |
| So if __stub is defined, we know we don't want to use the glibc version, but |
| this doesn't tell us if the name itself is defined or not. If it _is_ defined, |
| and we define our replacement as an inline static function, we get an error: |
| |
| In file included from ../src/basic/missing.h:1358:0, |
| from ../src/basic/util.h:47, |
| from ../src/basic/calendarspec.h:29, |
| from ../src/basic/calendarspec.c:34: |
| ../src/basic/missing_syscall.h:65:19: error: static declaration of 'memfd_create' follows non-static declaration |
| static inline int memfd_create(const char *name, unsigned int flags) { |
| ^~~~~~~~~~~~ |
| .../usr/include/bits/mman-shared.h:46:5: note: previous declaration of 'memfd_create' was here |
| int memfd_create (const char *__name, unsigned int __flags) __THROW; |
| ^~~~~~~~~~~~ |
| |
| To avoid this problem, call our inline functions different than glibc, |
| and use a #define to map the official name to our replacement. |
| |
| Fixes #8099. |
| |
| v2: |
| - use "missing_" as the prefix instead of "_" |
| |
| v3: |
| - rebase and update for statx() |
| |
| Unfortunately "statx" is also present in "struct statx", so the define |
| causes issues. Work around this by using a typedef. |
| |
| I checked that systemd compiles with current glibc |
| (glibc-devel-2.26-24.fc27.x86_64) if HAVE_MEMFD_CREATE, HAVE_GETTID, |
| HAVE_PIVOT_ROOT, HAVE_SETNS, HAVE_RENAMEAT2, HAVE_KCMP, HAVE_KEYCTL, |
| HAVE_COPY_FILE_RANGE, HAVE_BPF, HAVE_STATX are forced to 0. |
| |
| Setting HAVE_NAME_TO_HANDLE_AT to 0 causes an issue, but it's not because of |
| the define, but because of struct file_handle. |
| |
| |
| backport https://github.com/systemd/systemd/commit/5187dd2c403caf92d09f3491e41f1ceb3f10491f |
| |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| Upstream-Status: Backport [https://github.com/systemd/systemd/issues/8099] |
| Index: git/src/basic/missing_syscall.h |
| =================================================================== |
| --- git.orig/src/basic/missing_syscall.h |
| +++ git/src/basic/missing_syscall.h |
| @@ -26,9 +26,11 @@ |
| #include <sys/types.h> |
| |
| #if !HAVE_PIVOT_ROOT |
| -static inline int pivot_root(const char *new_root, const char *put_old) { |
| +static inline int missing_pivot_root(const char *new_root, const char *put_old) { |
| return syscall(SYS_pivot_root, new_root, put_old); |
| } |
| + |
| +# define pivot_root missing_pivot_root |
| #endif |
| |
| #if !HAVE_CANONICALIZE_FILE_NAME |
| @@ -68,7 +70,7 @@ static inline char *canonicalize_file_na |
| # endif |
| # endif |
| |
| -static inline int memfd_create(const char *name, unsigned int flags) { |
| +static inline int missing_memfd_create(const char *name, unsigned int flags) { |
| # ifdef __NR_memfd_create |
| return syscall(__NR_memfd_create, name, flags); |
| # else |
| @@ -76,6 +78,8 @@ static inline int memfd_create(const cha |
| return -1; |
| # endif |
| } |
| + |
| +# define memfd_create missing_memfd_create |
| #endif |
| |
| /* ======================================================================= */ |
| @@ -115,7 +119,7 @@ static inline int memfd_create(const cha |
| # endif |
| # endif |
| |
| -static inline int getrandom(void *buffer, size_t count, unsigned flags) { |
| +static inline int missing_getrandom(void *buffer, size_t count, unsigned flags) { |
| # ifdef __NR_getrandom |
| return syscall(__NR_getrandom, buffer, count, flags); |
| # else |
| @@ -123,14 +127,18 @@ static inline int getrandom(void *buffer |
| return -1; |
| # endif |
| } |
| + |
| +# define getrandom missing_getrandom |
| #endif |
| |
| /* ======================================================================= */ |
| |
| #if !HAVE_GETTID |
| -static inline pid_t gettid(void) { |
| +static inline pid_t missing_gettid(void) { |
| return (pid_t) syscall(SYS_gettid); |
| } |
| + |
| +# define gettid missing_gettid |
| #endif |
| |
| /* ======================================================================= */ |
| @@ -158,7 +166,7 @@ struct file_handle { |
| unsigned char f_handle[0]; |
| }; |
| |
| -static inline int name_to_handle_at(int fd, const char *name, struct file_handle *handle, int *mnt_id, int flags) { |
| +static inline int missing_name_to_handle_at(int fd, const char *name, struct file_handle *handle, int *mnt_id, int flags) { |
| # ifdef __NR_name_to_handle_at |
| return syscall(__NR_name_to_handle_at, fd, name, handle, mnt_id, flags); |
| # else |
| @@ -166,6 +174,8 @@ static inline int name_to_handle_at(int |
| return -1; |
| # endif |
| } |
| + |
| +# define name_to_handle_at missing_name_to_handle_at |
| #endif |
| |
| /* ======================================================================= */ |
| @@ -183,7 +193,7 @@ static inline int name_to_handle_at(int |
| # endif |
| # endif |
| |
| -static inline int setns(int fd, int nstype) { |
| +static inline int missing_setns(int fd, int nstype) { |
| # ifdef __NR_setns |
| return syscall(__NR_setns, fd, nstype); |
| # else |
| @@ -191,6 +201,8 @@ static inline int setns(int fd, int nsty |
| return -1; |
| # endif |
| } |
| + |
| +# define setns missing_setns |
| #endif |
| |
| /* ======================================================================= */ |
| @@ -236,7 +248,7 @@ static inline pid_t raw_getpid(void) { |
| # endif |
| # endif |
| |
| -static inline int renameat2(int oldfd, const char *oldname, int newfd, const char *newname, unsigned flags) { |
| +static inline int missing_renameat2(int oldfd, const char *oldname, int newfd, const char *newname, unsigned flags) { |
| # ifdef __NR_renameat2 |
| return syscall(__NR_renameat2, oldfd, oldname, newfd, newname, flags); |
| # else |
| @@ -244,12 +256,14 @@ static inline int renameat2(int oldfd, c |
| return -1; |
| # endif |
| } |
| + |
| +# define renameat2 missing_renameat2 |
| #endif |
| |
| /* ======================================================================= */ |
| |
| #if !HAVE_KCMP |
| -static inline int kcmp(pid_t pid1, pid_t pid2, int type, unsigned long idx1, unsigned long idx2) { |
| +static inline int missing_kcmp(pid_t pid1, pid_t pid2, int type, unsigned long idx1, unsigned long idx2) { |
| # ifdef __NR_kcmp |
| return syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2); |
| # else |
| @@ -257,36 +271,44 @@ static inline int kcmp(pid_t pid1, pid_t |
| return -1; |
| # endif |
| } |
| + |
| +# define kcmp missing_kcmp |
| #endif |
| |
| /* ======================================================================= */ |
| |
| #if !HAVE_KEYCTL |
| -static inline long keyctl(int cmd, unsigned long arg2, unsigned long arg3, unsigned long arg4,unsigned long arg5) { |
| +static inline long missing_keyctl(int cmd, unsigned long arg2, unsigned long arg3, unsigned long arg4,unsigned long arg5) { |
| # ifdef __NR_keyctl |
| return syscall(__NR_keyctl, cmd, arg2, arg3, arg4, arg5); |
| # else |
| errno = ENOSYS; |
| return -1; |
| # endif |
| + |
| +# define keyctl missing_keyctl |
| } |
| |
| -static inline key_serial_t add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t ringid) { |
| +static inline key_serial_t missing_add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t ringid) { |
| # ifdef __NR_add_key |
| return syscall(__NR_add_key, type, description, payload, plen, ringid); |
| # else |
| errno = ENOSYS; |
| return -1; |
| # endif |
| + |
| +# define add_key missing_add_key |
| } |
| |
| -static inline key_serial_t request_key(const char *type, const char *description, const char * callout_info, key_serial_t destringid) { |
| +static inline key_serial_t missing_request_key(const char *type, const char *description, const char * callout_info, key_serial_t destringid) { |
| # ifdef __NR_request_key |
| return syscall(__NR_request_key, type, description, callout_info, destringid); |
| # else |
| errno = ENOSYS; |
| return -1; |
| # endif |
| + |
| +# define request_key missing_request_key |
| } |
| #endif |
| |
| @@ -313,10 +335,10 @@ static inline key_serial_t request_key(c |
| # endif |
| # endif |
| |
| -static inline ssize_t copy_file_range(int fd_in, loff_t *off_in, |
| - int fd_out, loff_t *off_out, |
| - size_t len, |
| - unsigned int flags) { |
| +static inline ssize_t missing_copy_file_range(int fd_in, loff_t *off_in, |
| + int fd_out, loff_t *off_out, |
| + size_t len, |
| + unsigned int flags) { |
| # ifdef __NR_copy_file_range |
| return syscall(__NR_copy_file_range, fd_in, off_in, fd_out, off_out, len, flags); |
| # else |
| @@ -324,6 +346,8 @@ static inline ssize_t copy_file_range(in |
| return -1; |
| # endif |
| } |
| + |
| +# define copy_file_range missing_copy_file_range |
| #endif |
| |
| /* ======================================================================= */ |
| @@ -351,7 +375,7 @@ static inline ssize_t copy_file_range(in |
| |
| union bpf_attr; |
| |
| -static inline int bpf(int cmd, union bpf_attr *attr, size_t size) { |
| +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 |
| @@ -360,6 +384,7 @@ static inline int bpf(int cmd, union bpf |
| #endif |
| } |
| |
| +# define bpf missing_bpf |
| #endif |
| |
| /* ======================================================================= */ |