fs: remove various compat readv/writev helpers

Now that import_iovec handles compat iovecs as well, all the duplicated
code in the compat readv/writev helpers is not needed.  Remove them
and switch the compat syscall handlers to use the native helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/read_write.c b/fs/read_write.c
index 0a68037..eab427b 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1068,226 +1068,107 @@ SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
        return do_pwritev(fd, vec, vlen, pos, flags);
 }
 
+/*
+ * Various compat syscalls.  Note that they all pretend to take a native
+ * iovec - import_iovec will properly treat those as compat_iovecs based on
+ * in_compat_syscall().
+ */
 #ifdef CONFIG_COMPAT
-static size_t compat_readv(struct file *file,
-                          const struct compat_iovec __user *vec,
-                          unsigned long vlen, loff_t *pos, rwf_t flags)
-{
-       struct iovec iovstack[UIO_FASTIOV];
-       struct iovec *iov = iovstack;
-       struct iov_iter iter;
-       ssize_t ret;
-
-       ret = import_iovec(READ, (const struct iovec __user *)vec, vlen,
-                          UIO_FASTIOV, &iov, &iter);
-       if (ret >= 0) {
-               ret = do_iter_read(file, &iter, pos, flags);
-               kfree(iov);
-       }
-       if (ret > 0)
-               add_rchar(current, ret);
-       inc_syscr(current);
-       return ret;
-}
-
-static size_t do_compat_readv(compat_ulong_t fd,
-                                const struct compat_iovec __user *vec,
-                                compat_ulong_t vlen, rwf_t flags)
-{
-       struct fd f = fdget_pos(fd);
-       ssize_t ret;
-       loff_t pos;
-
-       if (!f.file)
-               return -EBADF;
-       pos = f.file->f_pos;
-       ret = compat_readv(f.file, vec, vlen, &pos, flags);
-       if (ret >= 0)
-               f.file->f_pos = pos;
-       fdput_pos(f);
-       return ret;
-
-}
-
 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                compat_ulong_t, vlen)
 {
-       return do_compat_readv(fd, vec, vlen, 0);
-}
-
-static long do_compat_preadv64(unsigned long fd,
-                                 const struct compat_iovec __user *vec,
-                                 unsigned long vlen, loff_t pos, rwf_t flags)
-{
-       struct fd f;
-       ssize_t ret;
-
-       if (pos < 0)
-               return -EINVAL;
-       f = fdget(fd);
-       if (!f.file)
-               return -EBADF;
-       ret = -ESPIPE;
-       if (f.file->f_mode & FMODE_PREAD)
-               ret = compat_readv(f.file, vec, vlen, &pos, flags);
-       fdput(f);
-       return ret;
+       return do_readv(fd, vec, vlen, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                unsigned long, vlen, loff_t, pos)
 {
-       return do_compat_preadv64(fd, vec, vlen, pos, 0);
+       return do_preadv(fd, vec, vlen, pos, 0);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-       return do_compat_preadv64(fd, vec, vlen, pos, 0);
+       return do_preadv(fd, vec, vlen, pos, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                unsigned long, vlen, loff_t, pos, rwf_t, flags)
 {
        if (pos == -1)
-               return do_compat_readv(fd, vec, vlen, flags);
-
-       return do_compat_preadv64(fd, vec, vlen, pos, flags);
+               return do_readv(fd, vec, vlen, flags);
+       return do_preadv(fd, vec, vlen, pos, flags);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
                rwf_t, flags)
 {
        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
        if (pos == -1)
-               return do_compat_readv(fd, vec, vlen, flags);
-
-       return do_compat_preadv64(fd, vec, vlen, pos, flags);
-}
-
-static size_t compat_writev(struct file *file,
-                           const struct compat_iovec __user *vec,
-                           unsigned long vlen, loff_t *pos, rwf_t flags)
-{
-       struct iovec iovstack[UIO_FASTIOV];
-       struct iovec *iov = iovstack;
-       struct iov_iter iter;
-       ssize_t ret;
-
-       ret = import_iovec(WRITE, (const struct iovec __user *)vec, vlen,
-                          UIO_FASTIOV, &iov, &iter);
-       if (ret >= 0) {
-               file_start_write(file);
-               ret = do_iter_write(file, &iter, pos, flags);
-               file_end_write(file);
-               kfree(iov);
-       }
-       if (ret > 0)
-               add_wchar(current, ret);
-       inc_syscw(current);
-       return ret;
-}
-
-static size_t do_compat_writev(compat_ulong_t fd,
-                                 const struct compat_iovec __user* vec,
-                                 compat_ulong_t vlen, rwf_t flags)
-{
-       struct fd f = fdget_pos(fd);
-       ssize_t ret;
-       loff_t pos;
-
-       if (!f.file)
-               return -EBADF;
-       pos = f.file->f_pos;
-       ret = compat_writev(f.file, vec, vlen, &pos, flags);
-       if (ret >= 0)
-               f.file->f_pos = pos;
-       fdput_pos(f);
-       return ret;
+               return do_readv(fd, vec, vlen, flags);
+       return do_preadv(fd, vec, vlen, pos, flags);
 }
 
 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
-               const struct compat_iovec __user *, vec,
+               const struct iovec __user *, vec,
                compat_ulong_t, vlen)
 {
-       return do_compat_writev(fd, vec, vlen, 0);
-}
-
-static long do_compat_pwritev64(unsigned long fd,
-                                  const struct compat_iovec __user *vec,
-                                  unsigned long vlen, loff_t pos, rwf_t flags)
-{
-       struct fd f;
-       ssize_t ret;
-
-       if (pos < 0)
-               return -EINVAL;
-       f = fdget(fd);
-       if (!f.file)
-               return -EBADF;
-       ret = -ESPIPE;
-       if (f.file->f_mode & FMODE_PWRITE)
-               ret = compat_writev(f.file, vec, vlen, &pos, flags);
-       fdput(f);
-       return ret;
+       return do_writev(fd, vec, vlen, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                unsigned long, vlen, loff_t, pos)
 {
-       return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+       return do_pwritev(fd, vec, vlen, pos, 0);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *,vec,
                compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-       return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+       return do_pwritev(fd, vec, vlen, pos, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *, vec,
                unsigned long, vlen, loff_t, pos, rwf_t, flags)
 {
        if (pos == -1)
-               return do_compat_writev(fd, vec, vlen, flags);
-
-       return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+               return do_writev(fd, vec, vlen, flags);
+       return do_pwritev(fd, vec, vlen, pos, flags);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
-               const struct compat_iovec __user *,vec,
+               const struct iovec __user *,vec,
                compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
 {
        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
        if (pos == -1)
-               return do_compat_writev(fd, vec, vlen, flags);
-
-       return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+               return do_writev(fd, vec, vlen, flags);
+       return do_pwritev(fd, vec, vlen, pos, flags);
 }
-
-#endif
+#endif /* CONFIG_COMPAT */
 
 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
                           size_t count, loff_t max)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index cebcaac..36b5842 100644 (file)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -546,25 +546,25 @@ asmlinkage long compat_sys_getdents(unsigned int fd,
 /* fs/read_write.c */
 asmlinkage long compat_sys_lseek(unsigned int, compat_off_t, unsigned int);
 asmlinkage ssize_t compat_sys_readv(compat_ulong_t fd,
-               const struct compat_iovec __user *vec, compat_ulong_t vlen);
+               const struct iovec __user *vec, compat_ulong_t vlen);
 asmlinkage ssize_t compat_sys_writev(compat_ulong_t fd,
-               const struct compat_iovec __user *vec, compat_ulong_t vlen);
+               const struct iovec __user *vec, compat_ulong_t vlen);
 /* No generic prototype for pread64 and pwrite64 */
 asmlinkage ssize_t compat_sys_preadv(compat_ulong_t fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                compat_ulong_t vlen, u32 pos_low, u32 pos_high);
 asmlinkage ssize_t compat_sys_pwritev(compat_ulong_t fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                compat_ulong_t vlen, u32 pos_low, u32 pos_high);
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
 asmlinkage long compat_sys_preadv64(unsigned long fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                unsigned long vlen, loff_t pos);
 #endif
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
 asmlinkage long compat_sys_pwritev64(unsigned long fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                unsigned long vlen, loff_t pos);
 #endif
 
@@ -800,20 +800,20 @@ asmlinkage long compat_sys_execveat(int dfd, const char __user *filename,
                     const compat_uptr_t __user *argv,
                     const compat_uptr_t __user *envp, int flags);
 asmlinkage ssize_t compat_sys_preadv2(compat_ulong_t fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                compat_ulong_t vlen, u32 pos_low, u32 pos_high, rwf_t flags);
 asmlinkage ssize_t compat_sys_pwritev2(compat_ulong_t fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                compat_ulong_t vlen, u32 pos_low, u32 pos_high, rwf_t flags);
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
 asmlinkage long  compat_sys_preadv64v2(unsigned long fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                unsigned long vlen, loff_t pos, rwf_t flags);
 #endif
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
 asmlinkage long compat_sys_pwritev64v2(unsigned long fd,
-               const struct compat_iovec __user *vec,
+               const struct iovec __user *vec,
                unsigned long vlen, loff_t pos, rwf_t flags);
 #endif