path: root/drivers/xen
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2019-01-04 02:57:57 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-04 02:57:57 (GMT)
commit96d4f267e40f9509e8a66e2b39e8b95655617693 (patch)
treedf03d142d405652392707b1b80c284d68d6ea6ab /drivers/xen
parent135143b2cac43d2a1ec73b53033b9473fbbcce6d (diff)
Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/xen')
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 7e6e6821..b24ddac 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -459,14 +459,14 @@ static long privcmd_ioctl_mmap_batch(
return -EFAULT;
/* Returns per-frame error in m.arr. */
m.err = NULL;
- if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr)))
+ if (!access_ok(m.arr, m.num * sizeof(*m.arr)))
return -EFAULT;
case 2:
if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2)))
return -EFAULT;
/* Returns per-frame error code in m.err. */
- if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err))))
+ if (!access_ok(m.err, m.num * (sizeof(*m.err))))
return -EFAULT;
@@ -661,7 +661,7 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata)
goto out;
- if (!access_ok(VERIFY_WRITE, kbufs[i].uptr,
+ if (!access_ok(kbufs[i].uptr,
kbufs[i].size)) {
rc = -EFAULT;
goto out;

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