From 1c710c896eb461895d3c399e15bb5f20b39c9073 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 8 May 2007 00:33:25 -0700 Subject: [PATCH] utimensat implementation Implement utimensat(2) which is an extension to futimesat(2) in that it a) supports nano-second resolution for the timestamps b) allows to selectively ignore the atime/mtime value c) allows to selectively use the current time for either atime or mtime d) supports changing the atime/mtime of a symlink itself along the lines of the BSD lutimes(3) functions For this change the internally used do_utimes() functions was changed to accept a timespec time value and an additional flags parameter. Additionally the sys_utime function was changed to match compat_sys_utime which already use do_utimes instead of duplicating the work. Also, the completely missing futimensat() functionality is added. We have such a function in glibc but we have to resort to using /proc/self/fd/* which not everybody likes (chroot etc). Test application (the syscall number will need per-arch editing): #include #include #include #include #include #include #define __NR_utimensat 280 #define UTIME_NOW ((1l << 30) - 1l) #define UTIME_OMIT ((1l << 30) - 2l) int main(void) { int status = 0; int fd = open("ttt", O_RDWR|O_CREAT|O_EXCL, 0666); if (fd == -1) error (1, errno, "failed to create test file \"ttt\""); struct stat64 st1; if (fstat64 (fd, &st1) != 0) error (1, errno, "fstat failed"); struct timespec t[2]; t[0].tv_sec = 0; t[0].tv_nsec = 0; t[1].tv_sec = 0; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); struct stat64 st2; if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0) { puts ("atim not reset to zero"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("mtim not reset to zero"); status = 1; } if (status != 0) goto out; t[0] = st1.st_atim; t[1].tv_sec = 0; t[1].tv_nsec = UTIME_OMIT; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != st1.st_atim.tv_sec || st2.st_atim.tv_nsec != st1.st_atim.tv_nsec) { puts ("atim not set"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("mtim changed from zero"); status = 1; } if (status != 0) goto out; t[0].tv_sec = 0; t[0].tv_nsec = UTIME_OMIT; t[1] = st1.st_mtim; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != st1.st_atim.tv_sec || st2.st_atim.tv_nsec != st1.st_atim.tv_nsec) { puts ("mtim changed from original time"); status = 1; } if (st2.st_mtim.tv_sec != st1.st_mtim.tv_sec || st2.st_mtim.tv_nsec != st1.st_mtim.tv_nsec) { puts ("mtim not set"); status = 1; } if (status != 0) goto out; sleep (2); t[0].tv_sec = 0; t[0].tv_nsec = UTIME_NOW; t[1].tv_sec = 0; t[1].tv_nsec = UTIME_NOW; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); struct timeval tv; gettimeofday(&tv,NULL); if (st2.st_atim.tv_sec <= st1.st_atim.tv_sec || st2.st_atim.tv_sec > tv.tv_sec) { puts ("atim not set to NOW"); status = 1; } if (st2.st_mtim.tv_sec <= st1.st_mtim.tv_sec || st2.st_mtim.tv_sec > tv.tv_sec) { puts ("mtim not set to NOW"); status = 1; } if (symlink ("ttt", "tttsym") != 0) error (1, errno, "cannot create symlink"); t[0].tv_sec = 0; t[0].tv_nsec = 0; t[1].tv_sec = 0; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, AT_FDCWD, "tttsym", t, AT_SYMLINK_NOFOLLOW) != 0) error (1, errno, "utimensat failed"); if (lstat64 ("tttsym", &st2) != 0) error (1, errno, "lstat failed"); if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0) { puts ("symlink atim not reset to zero"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("symlink mtim not reset to zero"); status = 1; } if (status != 0) goto out; t[0].tv_sec = 1; t[0].tv_nsec = 0; t[1].tv_sec = 1; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, fd, NULL, t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != 1 || st2.st_atim.tv_nsec != 0) { puts ("atim not reset to one"); status = 1; } if (st2.st_mtim.tv_sec != 1 || st2.st_mtim.tv_nsec != 0) { puts ("mtim not reset to one"); status = 1; } if (status == 0) puts ("all OK"); out: close (fd); unlink ("ttt"); unlink ("tttsym"); return status; } [akpm@linux-foundation.org: add missing i386 syscall table entry] Signed-off-by: Ulrich Drepper Cc: Alexey Dobriyan Cc: Michael Kerrisk Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/alpha/kernel/osf_sys.c | 14 ++- arch/i386/kernel/syscall_table.S | 1 + arch/sparc64/kernel/sys_sparc32.c | 14 ++- arch/x86_64/ia32/ia32entry.S | 3 +- fs/compat.c | 43 ++++++-- fs/utimes.c | 162 +++++++++++++++++++----------- include/asm-i386/unistd.h | 3 +- include/asm-x86_64/unistd.h | 2 + include/linux/stat.h | 3 + include/linux/time.h | 2 +- 10 files changed, 172 insertions(+), 75 deletions(-) diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index ea405f5713ce..ce857158c1ea 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -953,15 +953,25 @@ osf_setitimer(int which, struct itimerval32 __user *in, struct itimerval32 __use asmlinkage int osf_utimes(char __user *filename, struct timeval32 __user *tvs) { - struct timeval ktvs[2]; + struct timespec tv[2]; if (tvs) { + struct timeval ktvs[2]; if (get_tv32(&ktvs[0], &tvs[0]) || get_tv32(&ktvs[1], &tvs[1])) return -EFAULT; + + if (ktvs[0].tv_usec < 0 || ktvs[0].tv_usec >= 1000000 || + ktvs[1].tv_usec < 0 || ktvs[1].tv_usec >= 1000000) + return -EINVAL; + + tv[0].tv_sec = ktvs[0].tv_sec; + tv[0].tv_nsec = 1000 * ktvs[0].tv_usec; + tv[1].tv_sec = ktvs[1].tv_sec; + tv[1].tv_nsec = 1000 * ktvs[1].tv_usec; } - return do_utimes(AT_FDCWD, filename, tvs ? ktvs : NULL); + return do_utimes(AT_FDCWD, filename, tvs ? tv : NULL, 0); } #define MAX_SELECT_SECONDS \ diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index 2697e9210e92..0772678ceecf 100644 --- a/arch/i386/kernel/syscall_table.S +++ b/arch/i386/kernel/syscall_table.S @@ -319,3 +319,4 @@ ENTRY(sys_call_table) .long sys_move_pages .long sys_getcpu .long sys_epoll_pwait + .long sys_utimensat /* 320 */ diff --git a/arch/sparc64/kernel/sys_sparc32.c b/arch/sparc64/kernel/sys_sparc32.c index 7876a0226285..692e46a6b8da 100644 --- a/arch/sparc64/kernel/sys_sparc32.c +++ b/arch/sparc64/kernel/sys_sparc32.c @@ -775,15 +775,25 @@ asmlinkage long sys32_settimeofday(struct compat_timeval __user *tv, asmlinkage long sys32_utimes(char __user *filename, struct compat_timeval __user *tvs) { - struct timeval ktvs[2]; + struct timespec tv[2]; if (tvs) { + struct timeval ktvs[2]; if (get_tv32(&ktvs[0], tvs) || get_tv32(&ktvs[1], 1+tvs)) return -EFAULT; + + if (ktvs[0].tv_usec < 0 || ktvs[0].tv_usec >= 1000000 || + ktvs[1].tv_usec < 0 || ktvs[1].tv_usec >= 1000000) + return -EINVAL; + + tv[0].tv_sec = ktvs[0].tv_sec; + tv[0].tv_nsec = 1000 * ktvs[0].tv_usec; + tv[1].tv_sec = ktvs[1].tv_sec; + tv[1].tv_nsec = 1000 * ktvs[1].tv_usec; } - return do_utimes(AT_FDCWD, filename, (tvs ? &ktvs[0] : NULL)); + return do_utimes(AT_FDCWD, filename, tvs ? tv : NULL); } /* These are here just in case some old sparc32 binary calls it. */ diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S index c48087db6f75..f21068378272 100644 --- a/arch/x86_64/ia32/ia32entry.S +++ b/arch/x86_64/ia32/ia32entry.S @@ -710,9 +710,10 @@ ia32_sys_call_table: .quad compat_sys_get_robust_list .quad sys_splice .quad sys_sync_file_range - .quad sys_tee + .quad sys_tee /* 315 */ .quad compat_sys_vmsplice .quad compat_sys_move_pages .quad sys_getcpu .quad sys_epoll_pwait + .quad compat_sys_utimensat /* 320 */ ia32_syscall_end: diff --git a/fs/compat.c b/fs/compat.c index 9f6248dfd9d9..9cf75df9b2bb 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -77,30 +77,57 @@ int compat_printk(const char *fmt, ...) */ asmlinkage long compat_sys_utime(char __user *filename, struct compat_utimbuf __user *t) { - struct timeval tv[2]; + struct timespec tv[2]; if (t) { if (get_user(tv[0].tv_sec, &t->actime) || get_user(tv[1].tv_sec, &t->modtime)) return -EFAULT; - tv[0].tv_usec = 0; - tv[1].tv_usec = 0; + tv[0].tv_nsec = 0; + tv[1].tv_nsec = 0; } - return do_utimes(AT_FDCWD, filename, t ? tv : NULL); + return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0); +} + +asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename, struct compat_timespec __user *t, int flags) +{ + struct timespec tv[2]; + + if (t) { + if (get_compat_timespec(&tv[0], &t[0]) || + get_compat_timespec(&tv[1], &t[1])) + return -EFAULT; + + if ((tv[0].tv_nsec == UTIME_OMIT || tv[0].tv_nsec == UTIME_NOW) + && tv[0].tv_sec != 0) + return -EINVAL; + if ((tv[1].tv_nsec == UTIME_OMIT || tv[1].tv_nsec == UTIME_NOW) + && tv[1].tv_sec != 0) + return -EINVAL; + + if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT) + return 0; + } + return do_utimes(dfd, filename, t ? tv : NULL, flags); } asmlinkage long compat_sys_futimesat(unsigned int dfd, char __user *filename, struct compat_timeval __user *t) { - struct timeval tv[2]; + struct timespec tv[2]; if (t) { if (get_user(tv[0].tv_sec, &t[0].tv_sec) || - get_user(tv[0].tv_usec, &t[0].tv_usec) || + get_user(tv[0].tv_nsec, &t[0].tv_usec) || get_user(tv[1].tv_sec, &t[1].tv_sec) || - get_user(tv[1].tv_usec, &t[1].tv_usec)) + get_user(tv[1].tv_nsec, &t[1].tv_usec)) return -EFAULT; + if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 || + tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0) + return -EINVAL; + tv[0].tv_nsec *= 1000; + tv[1].tv_nsec *= 1000; } - return do_utimes(dfd, filename, t ? tv : NULL); + return do_utimes(dfd, filename, t ? tv : NULL, 0); } asmlinkage long compat_sys_utimes(char __user *filename, struct compat_timeval __user *t) diff --git a/fs/utimes.c b/fs/utimes.c index 99cf2cb11fec..480f7c8c29da 100644 --- a/fs/utimes.c +++ b/fs/utimes.c @@ -1,8 +1,10 @@ #include +#include #include #include #include #include +#include #include #include #include @@ -20,54 +22,18 @@ * must be owner or have write permission. * Else, update from *times, must be owner or super user. */ -asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) +asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times) { - int error; - struct nameidata nd; - struct inode * inode; - struct iattr newattrs; + struct timespec tv[2]; - error = user_path_walk(filename, &nd); - if (error) - goto out; - inode = nd.dentry->d_inode; - - error = -EROFS; - if (IS_RDONLY(inode)) - goto dput_and_out; - - /* Don't worry, the checks are done in inode_change_ok() */ - newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; if (times) { - error = -EPERM; - if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) - goto dput_and_out; - - error = get_user(newattrs.ia_atime.tv_sec, ×->actime); - newattrs.ia_atime.tv_nsec = 0; - if (!error) - error = get_user(newattrs.ia_mtime.tv_sec, ×->modtime); - newattrs.ia_mtime.tv_nsec = 0; - if (error) - goto dput_and_out; - - newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; - } else { - error = -EACCES; - if (IS_IMMUTABLE(inode)) - goto dput_and_out; - - if (current->fsuid != inode->i_uid && - (error = vfs_permission(&nd, MAY_WRITE)) != 0) - goto dput_and_out; + if (get_user(tv[0].tv_sec, ×->actime) || + get_user(tv[1].tv_sec, ×->modtime)) + return -EFAULT; + tv[0].tv_nsec = 0; + tv[1].tv_nsec = 0; } - mutex_lock(&inode->i_mutex); - error = notify_change(nd.dentry, &newattrs); - mutex_unlock(&inode->i_mutex); -dput_and_out: - path_release(&nd); -out: - return error; + return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0); } #endif @@ -76,18 +42,38 @@ out: * must be owner or have write permission. * Else, update from *times, must be owner or super user. */ -long do_utimes(int dfd, char __user *filename, struct timeval *times) +long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags) { int error; struct nameidata nd; - struct inode * inode; + struct dentry *dentry; + struct inode *inode; struct iattr newattrs; + struct file *f = NULL; - error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); - - if (error) + error = -EINVAL; + if (flags & ~AT_SYMLINK_NOFOLLOW) goto out; - inode = nd.dentry->d_inode; + + if (filename == NULL && dfd != AT_FDCWD) { + error = -EINVAL; + if (flags & AT_SYMLINK_NOFOLLOW) + goto out; + + error = -EBADF; + f = fget(dfd); + if (!f) + goto out; + dentry = f->f_path.dentry; + } else { + error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd); + if (error) + goto out; + + dentry = nd.dentry; + } + + inode = dentry->d_inode; error = -EROFS; if (IS_RDONLY(inode)) @@ -100,11 +86,21 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times) if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) goto dput_and_out; - newattrs.ia_atime.tv_sec = times[0].tv_sec; - newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000; - newattrs.ia_mtime.tv_sec = times[1].tv_sec; - newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000; - newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; + if (times[0].tv_nsec == UTIME_OMIT) + newattrs.ia_valid &= ~ATTR_ATIME; + else if (times[0].tv_nsec != UTIME_NOW) { + newattrs.ia_atime.tv_sec = times[0].tv_sec; + newattrs.ia_atime.tv_nsec = times[0].tv_nsec; + newattrs.ia_valid |= ATTR_ATIME_SET; + } + + if (times[1].tv_nsec == UTIME_OMIT) + newattrs.ia_valid &= ~ATTR_MTIME; + else if (times[1].tv_nsec != UTIME_NOW) { + newattrs.ia_mtime.tv_sec = times[1].tv_sec; + newattrs.ia_mtime.tv_nsec = times[1].tv_nsec; + newattrs.ia_valid |= ATTR_MTIME_SET; + } } else { error = -EACCES; if (IS_IMMUTABLE(inode)) @@ -115,21 +111,67 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times) goto dput_and_out; } mutex_lock(&inode->i_mutex); - error = notify_change(nd.dentry, &newattrs); + error = notify_change(dentry, &newattrs); mutex_unlock(&inode->i_mutex); dput_and_out: - path_release(&nd); + if (f) + fput(f); + else + path_release(&nd); out: return error; } +asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags) +{ + struct timespec tstimes[2]; + + if (utimes) { + if (copy_from_user(&tstimes, utimes, sizeof(tstimes))) + return -EFAULT; + if ((tstimes[0].tv_nsec == UTIME_OMIT || + tstimes[0].tv_nsec == UTIME_NOW) && + tstimes[0].tv_sec != 0) + return -EINVAL; + if ((tstimes[1].tv_nsec == UTIME_OMIT || + tstimes[1].tv_nsec == UTIME_NOW) && + tstimes[1].tv_sec != 0) + return -EINVAL; + + /* Nothing to do, we must not even check the path. */ + if (tstimes[0].tv_nsec == UTIME_OMIT && + tstimes[1].tv_nsec == UTIME_OMIT) + return 0; + } + + return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags); +} + asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes) { struct timeval times[2]; + struct timespec tstimes[2]; + + if (utimes) { + if (copy_from_user(×, utimes, sizeof(times))) + return -EFAULT; + + /* This test is needed to catch all invalid values. If we + would test only in do_utimes we would miss those invalid + values truncated by the multiplication with 1000. Note + that we also catch UTIME_{NOW,OMIT} here which are only + valid for utimensat. */ + if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 || + times[1].tv_usec >= 1000000 || times[1].tv_usec < 0) + return -EINVAL; + + tstimes[0].tv_sec = times[0].tv_sec; + tstimes[0].tv_nsec = 1000 * times[0].tv_usec; + tstimes[1].tv_sec = times[1].tv_sec; + tstimes[1].tv_nsec = 1000 * times[1].tv_usec; + } - if (utimes && copy_from_user(×, utimes, sizeof(times))) - return -EFAULT; - return do_utimes(dfd, filename, utimes ? times : NULL); + return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0); } asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes) diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h index 833fa1704ff9..bd21e795197c 100644 --- a/include/asm-i386/unistd.h +++ b/include/asm-i386/unistd.h @@ -325,10 +325,11 @@ #define __NR_move_pages 317 #define __NR_getcpu 318 #define __NR_epoll_pwait 319 +#define __NR_utimensat 320 #ifdef __KERNEL__ -#define NR_syscalls 320 +#define NR_syscalls 321 #define __ARCH_WANT_IPC_PARSE_VERSION #define __ARCH_WANT_OLD_READDIR diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h index 26e23e01c54a..595703949df3 100644 --- a/include/asm-x86_64/unistd.h +++ b/include/asm-x86_64/unistd.h @@ -619,6 +619,8 @@ __SYSCALL(__NR_sync_file_range, sys_sync_file_range) __SYSCALL(__NR_vmsplice, sys_vmsplice) #define __NR_move_pages 279 __SYSCALL(__NR_move_pages, sys_move_pages) +#define __NR_utimensat 280 +__SYSCALL(__NR_utimensat, sys_utimensat) #ifndef __NO_STUBS #define __ARCH_WANT_OLD_READDIR diff --git a/include/linux/stat.h b/include/linux/stat.h index 679ef0d70b6b..611c398dab72 100644 --- a/include/linux/stat.h +++ b/include/linux/stat.h @@ -53,6 +53,9 @@ #define S_IWUGO (S_IWUSR|S_IWGRP|S_IWOTH) #define S_IXUGO (S_IXUSR|S_IXGRP|S_IXOTH) +#define UTIME_NOW ((1l << 30) - 1l) +#define UTIME_OMIT ((1l << 30) - 2l) + #include #include diff --git a/include/linux/time.h b/include/linux/time.h index 50e31b1659a7..dda9be685ab6 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -109,7 +109,7 @@ extern void do_gettimeofday(struct timeval *tv); extern int do_settimeofday(struct timespec *tv); extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz); #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts) -extern long do_utimes(int dfd, char __user *filename, struct timeval *times); +extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags); struct itimerval; extern int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue); -- 2.30.2