readdir.c: get compat_filldir() more or less in sync with filldir() (82af599b) · Commits · 戴 / test

fs/readdir.c

+27 −24

Original line number	Diff line number	Diff line
		@@ -473,7 +473,7 @@ struct compat_linux_dirent {
		struct compat_getdents_callback {
		struct dir_context ctx;
		struct compat_linux_dirent __user *current_dir;
		struct compat_linux_dirent __user *previous;
		int prev_reclen;
		int count;
		int error;
		};
		@@ -481,13 +481,17 @@ struct compat_getdents_callback {
		static int compat_filldir(struct dir_context ctx, const char name, int namlen,
		loff_t offset, u64 ino, unsigned int d_type)
		{
		struct compat_linux_dirent __user * dirent;
		struct compat_linux_dirent __user dirent, prev;
		struct compat_getdents_callback *buf =
		container_of(ctx, struct compat_getdents_callback, ctx);
		compat_ulong_t d_ino;
		int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
		namlen + 2, sizeof(compat_long_t));
		int prev_reclen;

		buf->error = verify_dirent_name(name, namlen);
		if (unlikely(buf->error))
		return buf->error;
		buf->error = -EINVAL; /* only used if we fail.. */
		if (reclen > buf->count)
		return -EINVAL;
		@@ -496,29 +500,27 @@ static int compat_filldir(struct dir_context ctx, const char name, int namlen,
		buf->error = -EOVERFLOW;
		return -EOVERFLOW;
		}
		dirent = buf->previous;
		if (dirent) {
		if (signal_pending(current))
		prev_reclen = buf->prev_reclen;
		if (prev_reclen && signal_pending(current))
		return -EINTR;
		if (__put_user(offset, &dirent->d_off))
		goto efault;
		}
		dirent = buf->current_dir;
		if (__put_user(d_ino, &dirent->d_ino))
		goto efault;
		if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
		if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
		if (__put_user(0, dirent->d_name + namlen))
		goto efault;
		if (__put_user(d_type, (char __user *) dirent + reclen - 1))
		prev = (void __user *) dirent - prev_reclen;
		if (!user_write_access_begin(prev, reclen + prev_reclen))
		goto efault;
		buf->previous = dirent;
		dirent = (void __user *)dirent + reclen;
		buf->current_dir = dirent;

		unsafe_put_user(offset, &prev->d_off, efault_end);
		unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
		unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
		unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
		unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
		user_write_access_end();

		buf->prev_reclen = reclen;
		buf->current_dir = (void __user *)dirent + reclen;
		buf->count -= reclen;
		return 0;
		efault_end:
		user_write_access_end();
		efault:
		buf->error = -EFAULT;
		return -EFAULT;
		@@ -528,7 +530,6 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
		struct compat_linux_dirent __user *, dirent, unsigned int, count)
		{
		struct fd f;
		struct compat_linux_dirent __user * lastdirent;
		struct compat_getdents_callback buf = {
		.ctx.actor = compat_filldir,
		.current_dir = dirent,
		@@ -546,8 +547,10 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
		error = iterate_dir(f.file, &buf.ctx);
		if (error >= 0)
		error = buf.error;
		lastdirent = buf.previous;
		if (lastdirent) {
		if (buf.prev_reclen) {
		struct compat_linux_dirent __user * lastdirent;
		lastdirent = (void __user *)buf.current_dir - buf.prev_reclen;

		if (put_user(buf.ctx.pos, &lastdirent->d_off))
		error = -EFAULT;
		else

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