1 //===-- Wrapper over SYS_statx syscall ------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_LIBC_SRC_SYS_STAT_LINUX_KERNEL_STATX_H 10 #define LLVM_LIBC_SRC_SYS_STAT_LINUX_KERNEL_STATX_H 11 12 #include "src/__support/OSUtil/syscall.h" // For internal syscall function. 13 #include "src/__support/common.h" 14 #include "src/__support/macros/config.h" 15 16 #include <stdint.h> 17 #include <sys/stat.h> 18 #include <sys/syscall.h> // For syscall numbers. 19 20 // It is safe to include this kernel header as it is designed to be 21 // included from user programs without causing any name pollution. 22 #include <linux/kdev_t.h> 23 24 namespace { 25 26 // The type definitions in the internal namespace match kernel's definition of 27 // the statx_timestamp and statx types in linux/stat.h. We define equivalent 28 // types here instead of including that header file to avoid name mixup between 29 // linux/stat.h and the libc's stat.h. 30 struct statx_timestamp { 31 int64_t tv_sec; 32 uint32_t tv_nsec; 33 int32_t __reserved; 34 }; 35 36 struct statx_buf { 37 uint32_t stx_mask; // What results were written 38 uint32_t stx_blksize; // Preferred general I/O size 39 uint64_t stx_attributes; // Flags conveying information about the file 40 uint32_t stx_nlink; // Number of hard links 41 uint32_t stx_uid; // User ID of owner 42 uint32_t stx_gid; // Group ID of owner 43 uint16_t stx_mode; // File mode 44 uint16_t __spare0[1]; 45 uint64_t stx_ino; // Inode number 46 uint64_t stx_size; // File size 47 uint64_t stx_blocks; // Number of 512-byte blocks allocated 48 uint64_t stx_attributes_mask; // Mask to show what's supported in 49 // stx_attributes 50 struct statx_timestamp stx_atime; // Last access time 51 struct statx_timestamp stx_btime; // File creation time 52 struct statx_timestamp stx_ctime; // Last attribute change time 53 struct statx_timestamp stx_mtime; // Last data modification time 54 uint32_t stx_rdev_major; // Device ID of special file 55 uint32_t stx_rdev_minor; 56 uint32_t stx_dev_major; // ID of device containing file 57 uint32_t stx_dev_minor; 58 uint64_t stx_mnt_id; 59 uint64_t __spare2; 60 uint64_t __spare3[12]; // Spare space for future expansion 61 }; 62 63 // The below mask value is based on the definition of a similarly 64 // named macro in linux/stat.h. When this flag is passed for the 65 // mask argument to the statx syscall, all fields except the 66 // stx_btime field will be filled in. 67 constexpr unsigned int STATX_BASIC_STATS_MASK = 0x7FF; 68 69 } // Anonymous namespace 70 71 namespace LIBC_NAMESPACE_DECL { 72 73 LIBC_INLINE int statx(int dirfd, const char *__restrict path, int flags, 74 struct stat *__restrict statbuf) { 75 // We make a statx syscall and copy out the result into the |statbuf|. 76 ::statx_buf xbuf; 77 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_statx, dirfd, path, flags, 78 ::STATX_BASIC_STATS_MASK, &xbuf); 79 if (ret < 0) 80 return -ret; 81 82 statbuf->st_dev = MKDEV(xbuf.stx_dev_major, xbuf.stx_dev_minor); 83 statbuf->st_ino = static_cast<decltype(statbuf->st_ino)>(xbuf.stx_ino); 84 statbuf->st_mode = xbuf.stx_mode; 85 statbuf->st_nlink = xbuf.stx_nlink; 86 statbuf->st_uid = xbuf.stx_uid; 87 statbuf->st_gid = xbuf.stx_gid; 88 statbuf->st_rdev = MKDEV(xbuf.stx_rdev_major, xbuf.stx_rdev_minor); 89 statbuf->st_size = xbuf.stx_size; 90 statbuf->st_atim.tv_sec = xbuf.stx_atime.tv_sec; 91 statbuf->st_atim.tv_nsec = xbuf.stx_atime.tv_nsec; 92 statbuf->st_mtim.tv_sec = xbuf.stx_mtime.tv_sec; 93 statbuf->st_mtim.tv_nsec = xbuf.stx_mtime.tv_nsec; 94 statbuf->st_ctim.tv_sec = xbuf.stx_ctime.tv_sec; 95 statbuf->st_ctim.tv_nsec = xbuf.stx_ctime.tv_nsec; 96 statbuf->st_blksize = xbuf.stx_blksize; 97 statbuf->st_blocks = 98 static_cast<decltype(statbuf->st_blocks)>(xbuf.stx_blocks); 99 100 return 0; 101 } 102 103 } // namespace LIBC_NAMESPACE_DECL 104 105 #endif // LLVM_LIBC_SRC_SYS_STAT_LINUX_KERNEL_STATX_H 106