* [PATCH 1/9 next] mm:process_vm_access Call import_iovec() instead of rw_copy_check_uvector()
@ 2020-09-15 14:55 David Laight
2020-09-21 14:09 ` Christoph Hellwig
0 siblings, 1 reply; 2+ messages in thread
From: David Laight @ 2020-09-15 14:55 UTC (permalink / raw)
To: [email protected], [email protected],
[email protected], Jens Axboe, David S. Miller, Al Viro,
linux-fsdevel
This is the only direct call of rw_copy_check_uvector().
Removing it lets rw_copy_check_uvector() be inlined into
import_iovec() and the horrid calling conventions fixed.
Signed-off-by: David Laight <[email protected]>
---
mm/process_vm_access.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 29c052099aff..1cc3d6f66b31 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -264,7 +264,7 @@ static ssize_t process_vm_rw(pid_t pid,
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
- struct iov_iter iter;
+ struct iov_iter iter_l, iter_r;
ssize_t rc;
int dir = vm_write ? WRITE : READ;
@@ -272,23 +272,24 @@ static ssize_t process_vm_rw(pid_t pid,
return -EINVAL;
/* Check iovecs */
- rc = import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter);
+ rc = import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter_l);
if (rc < 0)
return rc;
- if (!iov_iter_count(&iter))
+ if (!iov_iter_count(&iter_l))
goto free_iovecs;
- rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
- iovstack_r, &iov_r);
+ rc = import_iovec(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV, &iov_r, &iter_r);
if (rc <= 0)
goto free_iovecs;
- rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
+ rc = process_vm_rw_core(pid, &iter_l, iter_r.iov, iter_r.nr_segs,
+ flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)
kfree(iov_r);
- kfree(iov_l);
+ if (iov_l != iovstack_l)
+ kfree(iov_l);
return rc;
}
@@ -322,30 +323,30 @@ compat_process_vm_rw(compat_pid_t pid,
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
- struct iov_iter iter;
+ struct iov_iter iter_l, iter_r;
ssize_t rc = -EFAULT;
int dir = vm_write ? WRITE : READ;
if (flags != 0)
return -EINVAL;
- rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter);
+ rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter_l);
if (rc < 0)
return rc;
- if (!iov_iter_count(&iter))
+ if (!iov_iter_count(&iter_l))
goto free_iovecs;
- rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
- UIO_FASTIOV, iovstack_r,
- &iov_r);
+ rc = compat_import_iovec(0, rvec, riovcnt, UIO_FASTIOV, &iov_r, &iter_r);
if (rc <= 0)
goto free_iovecs;
- rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
+ rc = process_vm_rw_core(pid, &iter_l, iter_r.iov, iter_r.nr_segs,
+ flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)
kfree(iov_r);
- kfree(iov_l);
+ if (iov_l != iovstack_l)
+ kfree(iov_l);
return rc;
}
--
2.25.1
-
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 1/9 next] mm:process_vm_access Call import_iovec() instead of rw_copy_check_uvector()
2020-09-15 14:55 [PATCH 1/9 next] mm:process_vm_access Call import_iovec() instead of rw_copy_check_uvector() David Laight
@ 2020-09-21 14:09 ` Christoph Hellwig
0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2020-09-21 14:09 UTC (permalink / raw)
To: David Laight
Cc: [email protected], [email protected],
[email protected], Jens Axboe, David S. Miller, Al Viro,
linux-fsdevel
On Tue, Sep 15, 2020 at 02:55:08PM +0000, David Laight wrote:
>
> This is the only direct call of rw_copy_check_uvector().
> Removing it lets rw_copy_check_uvector() be inlined into
> import_iovec() and the horrid calling conventions fixed.
This looks sensible, but as-is will create a warning when actually
this code.
This is the variant I picked up as a prep patch for the compat
iovec handling, which passes the relevant LTP tests:
http://git.infradead.org/users/hch/misc.git/commitdiff/9e3cf5d0f13572310354bf6c62e1feb9fb232266
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