From a7ef3d06f74c8131b04b41cdf902e3c59f61769f Mon Sep 17 00:00:00 2001 From: Anton Kling Date: Sun, 8 Dec 2024 19:43:31 +0100 Subject: vfs: Force truncation even without permissions O_TRUNC as a mode does not seem to imply write permissions but we still wish to truncate the file before giving back a file descriptor. Therefore the kernel can now override any permission checks if it wishes to do a truncation while still using the "ordinary path". --- kernel/fs/vfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/fs/vfs.c') diff --git a/kernel/fs/vfs.c b/kernel/fs/vfs.c index c06c71f..3b912ce 100644 --- a/kernel/fs/vfs.c +++ b/kernel/fs/vfs.c @@ -289,7 +289,7 @@ int vfs_open(const char *file, int flags, int mode) { // FIXME: Maybe it is sometimes a TTY? int rc = vfs_create_fd(flags, mode, 0 /*is_tty*/, inode, NULL); if (flags & O_TRUNC) { - vfs_ftruncate(rc, 0); + vfs_ftruncate(rc, 0, 1); } return rc; } @@ -488,12 +488,12 @@ int vfs_dup2(int org_fd, int new_fd) { return 1; } -int vfs_ftruncate(int fd, size_t length) { +int vfs_ftruncate(int fd, size_t length, int force_truncate) { vfs_fd_t *fd_ptr = get_vfs_fd(fd, NULL); if (!fd_ptr) { return -EBADF; } - if (!(fd_ptr->flags & O_READ)) { + if (!(fd_ptr->flags & O_WRITE) && !force_truncate) { return -EINVAL; } vfs_inode_t *inode = fd_ptr->inode; -- cgit v1.2.3