[PATCH 5/9] fs: remove various compat readv/writev helpers
Christoph Hellwig
hch at lst.de
Fri Sep 25 14:51:42 AEST 2020
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 at lst.de>
---
fs/read_write.c | 179 +++++++----------------------------------
include/linux/compat.h | 20 ++---
2 files changed, 40 insertions(+), 159 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 0a68037580b455..eab427b7cc0a3f 100644
--- 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 b930de791ff16b..306ea7e1172d8d 100644
--- 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
--
2.28.0
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