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authorLinus Torvalds <torvalds@linux-foundation.org>2019-01-03 18:57:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-03 18:57:57 -0800
commit96d4f267e40f9509e8a66e2b39e8b95655617693 (patch)
treedf03d142d405652392707b1b80c284d68d6ea6ab /kernel/compat.c
parent135143b2cac43d2a1ec73b53033b9473fbbcce6d (diff)
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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 'kernel/compat.c')
-rw-r--r--kernel/compat.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/compat.c b/kernel/compat.c
index 089d00d0da9c..705d4ae6c018 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -95,28 +95,28 @@ int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
{
- return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
+ return (!access_ok(ctv, sizeof(*ctv)) ||
__get_user(tv->tv_sec, &ctv->tv_sec) ||
__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
}
static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv)
{
- return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
+ return (!access_ok(ctv, sizeof(*ctv)) ||
__put_user(tv->tv_sec, &ctv->tv_sec) ||
__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
}
static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts)
{
- return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
+ return (!access_ok(cts, sizeof(*cts)) ||
__get_user(ts->tv_sec, &cts->tv_sec) ||
__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}
static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts)
{
- return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
+ return (!access_ok(cts, sizeof(*cts)) ||
__put_user(ts->tv_sec, &cts->tv_sec) ||
__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}
@@ -335,7 +335,7 @@ int get_compat_sigevent(struct sigevent *event,
const struct compat_sigevent __user *u_event)
{
memset(event, 0, sizeof(*event));
- return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
+ return (!access_ok(u_event, sizeof(*u_event)) ||
__get_user(event->sigev_value.sival_int,
&u_event->sigev_value.sival_int) ||
__get_user(event->sigev_signo, &u_event->sigev_signo) ||
@@ -354,7 +354,7 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
+ if (!access_ok(umask, bitmap_size / 8))
return -EFAULT;
user_access_begin();
@@ -384,7 +384,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
+ if (!access_ok(umask, bitmap_size / 8))
return -EFAULT;
user_access_begin();
@@ -438,7 +438,7 @@ void __user *compat_alloc_user_space(unsigned long len)
ptr = arch_compat_alloc_user_space(len);
- if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
+ if (unlikely(!access_ok(ptr, len)))
return NULL;
return ptr;