Fix the dirfd issue when path is absolute

src/libos/src/fs/file_ops/access.rs

@@ -47,10 +47,6 @@ pub fn do_faccessat(
         "faccessat: dirfd: {:?}, path: {:?}, mode: {:?}, flags: {:?}",
         dirfd, path, mode, flags
     );
-    if Path::new(path).is_absolute() {
-        // Path is absolute, so dirfd is ignored
-        return Ok(do_access(path, mode, flags)?);
-    }
     let path = match dirfd {
         DirFd::Fd(dirfd) => {
             let dir_path = get_dir_path(dirfd)?;

src/libos/src/fs/file_ops/open.rs

@@ -19,10 +19,6 @@ pub fn do_openat(dirfd: DirFd, path: &str, flags: u32, mode: u32) -> Result<File
         "openat: dirfd: {:?}, path: {:?}, flags: {:#o}, mode: {:#o}",
         dirfd, path, flags, mode
     );
-    if Path::new(path).is_absolute() {
-        // Path is absolute, so dirfd is ignored
-        return Ok(do_open(path, flags, mode)?);
-    }
     let path = match dirfd {
         DirFd::Fd(dirfd) => {
             let dir_path = get_dir_path(dirfd)?;

src/libos/src/fs/file_ops/stat.rs

@@ -171,10 +171,6 @@ pub fn do_fstatat(dirfd: DirFd, path: &str, flags: StatFlags) -> Result<Stat> {
     if path.len() == 0 && !flags.contains(StatFlags::AT_EMPTY_PATH) {
         return_errno!(ENOENT, "path is an empty string");
     }
-    if Path::new(path).is_absolute() {
-        // Path is absolute, so dirfd is ignored
-        return Ok(do_stat(path)?);
-    }
     match dirfd {
         DirFd::Fd(dirfd) => {
             if path.len() == 0 {

src/libos/src/fs/syscalls.rs

@@ -43,10 +43,15 @@ pub fn do_open(path: *const i8, flags: u32, mode: u32) -> Result<isize> {
 }
 
 pub fn do_openat(dirfd: i32, path: *const i8, flags: u32, mode: u32) -> Result<isize> {
-    let dirfd = DirFd::from_i32(dirfd)?;
     let path = from_user::clone_cstring_safely(path)?
         .to_string_lossy()
         .into_owned();
+    let dirfd = if Path::new(&path).is_absolute() {
+        // Path is absolute, dirfd is treated as Cwd
+        DirFd::Cwd
+    } else {
+        DirFd::from_i32(dirfd)?
+    };
     let fd = file_ops::do_openat(dirfd, &path, flags, mode)?;
     Ok(fd as isize)
 }
@@ -179,10 +184,15 @@ pub fn do_lstat(path: *const i8, stat_buf: *mut Stat) -> Result<isize> {
 }
 
 pub fn do_fstatat(dirfd: i32, path: *const i8, stat_buf: *mut Stat, flags: u32) -> Result<isize> {
-    let dirfd = DirFd::from_i32(dirfd)?;
     let path = from_user::clone_cstring_safely(path)?
         .to_string_lossy()
         .into_owned();
+    let dirfd = if Path::new(&path).is_absolute() {
+        // Path is absolute, dirfd is treated as Cwd
+        DirFd::Cwd
+    } else {
+        DirFd::from_i32(dirfd)?
+    };
     from_user::check_mut_ptr(stat_buf)?;
     let flags = StatFlags::from_bits_truncate(flags);
     let stat = file_ops::do_fstatat(dirfd, &path, flags)?;
@@ -202,10 +212,15 @@ pub fn do_access(path: *const i8, mode: u32) -> Result<isize> {
 }
 
 pub fn do_faccessat(dirfd: i32, path: *const i8, mode: u32, flags: u32) -> Result<isize> {
-    let dirfd = DirFd::from_i32(dirfd)?;
     let path = from_user::clone_cstring_safely(path)?
         .to_string_lossy()
         .into_owned();
+    let dirfd = if Path::new(&path).is_absolute() {
+        // Path is absolute, dirfd is treated as Cwd
+        DirFd::Cwd
+    } else {
+        DirFd::from_i32(dirfd)?
+    };
     let mode = AccessibilityCheckMode::from_u32(mode)?;
     let flags = AccessibilityCheckFlags::from_u32(flags)?;
     file_ops::do_faccessat(dirfd, &path, mode, flags).map(|_| 0)

test/access/main.c

@@ -62,6 +62,9 @@ static int __test_faccessat_with_abs_path(const char *file_path) {
     if (faccessat(AT_FDCWD, file_path, F_OK, 0) < 0) {
         THROW_ERROR("failed to faccessat file with abs path");
     }
+    if (faccessat(-1, file_path, F_OK, 0) < 0) {
+        THROW_ERROR("failed to faccessat file with abs path and invalid dirfd");
+    }
     if (remove_file(file_path) < 0) {
         return -1;
     }

test/open/main.c

@@ -37,6 +37,12 @@ static int __test_openat_with_abs_path(const char *file_path, int flags, int mod
         THROW_ERROR("failed to openat a file with abs path");
     }
     close(fd);
+
+    fd = openat(-1, file_path, flags, mode);
+    if (fd < 0) {
+        THROW_ERROR("failed to openat a file with abs path and invalid dirfd");
+    }
+    close(fd);
     return 0;
 }
 

test/stat/main.c

@@ -79,12 +79,14 @@ static int __test_lstat(const char *file_path) {
 
 static int __test_fstatat_with_abs_path(const char *file_path) {
     struct stat stat_buf;
-    int ret;
 
-    ret = fstatat(AT_FDCWD, file_path, &stat_buf, 0);
-    if (ret < 0) {
+    if (fstatat(AT_FDCWD, file_path, &stat_buf, 0) < 0) {
         THROW_ERROR("failed to fstatat file with abs path");
     }
+
+    if (fstatat(-1, file_path, &stat_buf, 0) < 0) {
+        THROW_ERROR("failed to fstatat file with abs path and invalid dirfd");
+    }
     return 0;
 }