iov_iter: transparently handle compat iovecs in import_iovec

Use in compat_syscall to import either native or the compat iovecs, and
remove the now superflous compat_import_iovec.

This removes the need for special compat logic in most callers, and
the remaining ones can still be simplified by using __import_iovec
with a bool compat parameter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2020-09-25 06:51:41 +02:00 committed by Al Viro
parent bfdc59701d
commit 89cd35c58b
11 changed files with 26 additions and 65 deletions

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@ -333,16 +333,8 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
struct iov_iter i; struct iov_iter i;
struct iovec *iov = NULL; struct iovec *iov = NULL;
#ifdef CONFIG_COMPAT ret = import_iovec(rq_data_dir(rq), hdr->dxferp,
if (in_compat_syscall()) hdr->iovec_count, 0, &iov, &i);
ret = compat_import_iovec(rq_data_dir(rq),
hdr->dxferp, hdr->iovec_count,
0, &iov, &i);
else
#endif
ret = import_iovec(rq_data_dir(rq),
hdr->dxferp, hdr->iovec_count,
0, &iov, &i);
if (ret < 0) if (ret < 0)
goto out_free_cdb; goto out_free_cdb;

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@ -1820,14 +1820,7 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
struct iovec *iov = NULL; struct iovec *iov = NULL;
struct iov_iter i; struct iov_iter i;
#ifdef CONFIG_COMPAT res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
if (in_compat_syscall())
res = compat_import_iovec(rw, hp->dxferp, iov_count,
0, &iov, &i);
else
#endif
res = import_iovec(rw, hp->dxferp, iov_count,
0, &iov, &i);
if (res < 0) if (res < 0)
return res; return res;

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@ -1489,12 +1489,8 @@ static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
*iovec = NULL; *iovec = NULL;
return ret; return ret;
} }
#ifdef CONFIG_COMPAT
if (compat) return __import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter, compat);
return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec,
iter);
#endif
return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter);
} }
static inline void aio_rw_done(struct kiocb *req, ssize_t ret) static inline void aio_rw_done(struct kiocb *req, ssize_t ret)

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@ -2846,13 +2846,8 @@ static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
return ret; return ret;
} }
#ifdef CONFIG_COMPAT return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
if (req->ctx->compat) req->ctx->compat);
return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
iovec, iter);
#endif
return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter);
} }
static ssize_t io_import_iovec(int rw, struct io_kiocb *req, static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
@ -4166,8 +4161,9 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
sr->len); sr->len);
iomsg->iov = NULL; iomsg->iov = NULL;
} else { } else {
ret = import_iovec(READ, uiov, iov_len, UIO_FASTIOV, ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
&iomsg->iov, &iomsg->msg.msg_iter); &iomsg->iov, &iomsg->msg.msg_iter,
false);
if (ret > 0) if (ret > 0)
ret = 0; ret = 0;
} }
@ -4207,9 +4203,9 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
sr->len = iomsg->iov[0].iov_len; sr->len = iomsg->iov[0].iov_len;
iomsg->iov = NULL; iomsg->iov = NULL;
} else { } else {
ret = compat_import_iovec(READ, uiov, len, UIO_FASTIOV, ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
&iomsg->iov, UIO_FASTIOV, &iomsg->iov,
&iomsg->msg.msg_iter); &iomsg->msg.msg_iter, true);
if (ret < 0) if (ret < 0)
return ret; return ret;
} }

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@ -1078,7 +1078,8 @@ static size_t compat_readv(struct file *file,
struct iov_iter iter; struct iov_iter iter;
ssize_t ret; ssize_t ret;
ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter); ret = import_iovec(READ, (const struct iovec __user *)vec, vlen,
UIO_FASTIOV, &iov, &iter);
if (ret >= 0) { if (ret >= 0) {
ret = do_iter_read(file, &iter, pos, flags); ret = do_iter_read(file, &iter, pos, flags);
kfree(iov); kfree(iov);
@ -1186,7 +1187,8 @@ static size_t compat_writev(struct file *file,
struct iov_iter iter; struct iov_iter iter;
ssize_t ret; ssize_t ret;
ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter); ret = import_iovec(WRITE, (const struct iovec __user *)vec, vlen,
UIO_FASTIOV, &iov, &iter);
if (ret >= 0) { if (ret >= 0) {
file_start_write(file); file_start_write(file);
ret = do_iter_write(file, &iter, pos, flags); ret = do_iter_write(file, &iter, pos, flags);

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@ -1387,7 +1387,7 @@ COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, io
if (error) if (error)
return error; return error;
error = compat_import_iovec(type, iov32, nr_segs, error = import_iovec(type, (struct iovec __user *)iov32, nr_segs,
ARRAY_SIZE(iovstack), &iov, &iter); ARRAY_SIZE(iovstack), &iov, &iter);
if (error >= 0) { if (error >= 0) {
error = do_vmsplice(f.file, &iter, flags); error = do_vmsplice(f.file, &iter, flags);

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@ -275,14 +275,6 @@ ssize_t import_iovec(int type, const struct iovec __user *uvec,
ssize_t __import_iovec(int type, const struct iovec __user *uvec, ssize_t __import_iovec(int type, const struct iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
struct iov_iter *i, bool compat); struct iov_iter *i, bool compat);
#ifdef CONFIG_COMPAT
struct compat_iovec;
ssize_t compat_import_iovec(int type, const struct compat_iovec __user * uvector,
unsigned nr_segs, unsigned fast_segs,
struct iovec **iov, struct iov_iter *i);
#endif
int import_single_range(int type, void __user *buf, size_t len, int import_single_range(int type, void __user *buf, size_t len,
struct iovec *iov, struct iov_iter *i); struct iovec *iov, struct iov_iter *i);

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@ -1806,21 +1806,11 @@ ssize_t import_iovec(int type, const struct iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs, unsigned nr_segs, unsigned fast_segs,
struct iovec **iovp, struct iov_iter *i) struct iovec **iovp, struct iov_iter *i)
{ {
return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, false); return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i,
in_compat_syscall());
} }
EXPORT_SYMBOL(import_iovec); EXPORT_SYMBOL(import_iovec);
#ifdef CONFIG_COMPAT
ssize_t compat_import_iovec(int type, const struct compat_iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
struct iov_iter *i)
{
return __import_iovec(type, (const struct iovec __user *)uvec, nr_segs,
fast_segs, iovp, i, true);
}
EXPORT_SYMBOL(compat_import_iovec);
#endif
int import_single_range(int rw, void __user *buf, size_t len, int import_single_range(int rw, void __user *buf, size_t len,
struct iovec *iov, struct iov_iter *i) struct iovec *iov, struct iov_iter *i)
{ {

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@ -326,7 +326,8 @@ compat_process_vm_rw(compat_pid_t pid,
if (flags != 0) if (flags != 0)
return -EINVAL; return -EINVAL;
rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter); rc = import_iovec(dir, (const struct iovec __user *)lvec, liovcnt,
UIO_FASTIOV, &iov_l, &iter);
if (rc < 0) if (rc < 0)
return rc; return rc;
if (!iov_iter_count(&iter)) if (!iov_iter_count(&iter))

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@ -98,8 +98,8 @@ int get_compat_msghdr(struct msghdr *kmsg,
if (err) if (err)
return err; return err;
err = compat_import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len,
len, UIO_FASTIOV, iov, &kmsg->msg_iter); UIO_FASTIOV, iov, &kmsg->msg_iter);
return err < 0 ? err : 0; return err < 0 ? err : 0;
} }

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@ -33,9 +33,8 @@ static long compat_keyctl_instantiate_key_iov(
if (!_payload_iov) if (!_payload_iov)
ioc = 0; ioc = 0;
ret = compat_import_iovec(WRITE, _payload_iov, ioc, ret = import_iovec(WRITE, (const struct iovec __user *)_payload_iov,
ARRAY_SIZE(iovstack), &iov, ioc, ARRAY_SIZE(iovstack), &iov, &from);
&from);
if (ret < 0) if (ret < 0)
return ret; return ret;