Hi Andrew,
Around 2.6.11-mm1 Yoichi Yuasa found a user of verify_area that I had
missed when converting everything to access_ok. The patch below still
applies cleanly to 2.6.11-mm4.
Please apply (unless of course you already picked it up back then and
have it in a queue somewhere :) .
--
Jesper Juhl
---------- Forwarded message ----------
Date: Mon, 7 Mar 2005 00:55:30 +0100 (CET)
From: Jesper Juhl <[EMAIL PROTECTED]>
To: Yoichi Yuasa <[EMAIL PROTECTED]>
Cc: Andrew Morton <[EMAIL PROTECTED]>, linux-kernel
<linux-kernel@vger.kernel.org>,
Ralf Baechle <[EMAIL PROTECTED]>
Subject: Re: [PATCH 2.6.11-mm1] mips: more convert verify_area to access_ok
On Sun, 6 Mar 2005, Yoichi Yuasa wrote:
> This patch converts verify_area to access_ok for include/asm-mips.
>
Yeah, that's one of the few bits I had not done yet. Thank you for taking
a look at that.
I don't believe your patch is correct though. See below for what I think
is a better one.
> Yoichi
>
> Signed-off-by: Yoichi Yuasa <[EMAIL PROTECTED]>
>
> diff -urN -X dontdiff a-orig/include/asm-mips/uaccess.h
> a/include/asm-mips/uaccess.h
> --- a-orig/include/asm-mips/uaccess.h Sat Mar 5 04:15:22 2005
> +++ a/include/asm-mips/uaccess.h Sun Mar 6 15:51:02 2005
> @@ -254,13 +254,11 @@
> ({ \
> __typeof__(*(ptr)) __gu_val = 0; \
> long __gu_addr; \
> - long __gu_err; \
> + long __gu_err = -EFAULT; \
> \
> might_sleep(); \
> __gu_addr = (long) (ptr); \
> - __gu_err = verify_area(VERIFY_READ, (void *) __gu_addr, size); \
> - \
> - if (likely(!__gu_err)) { \
> + if (access_ok(VERIFY_READ, (void *) __gu_addr, size)) { \
> switch (size) { \
> case 1: __get_user_asm("lb", __gu_err); break; \
> case 2: __get_user_asm("lh", __gu_err); break; \
with this change, __gu_err will always be -EFAULT. With the original code
it was either -EFAULT or 0 depending on the return value from verify_area.
Same goes for the next hunk in your patch.
I believe a more correct patch would be this :
Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]>
diff -up linux-2.6.11-mm1-orig/include/asm-mips/uaccess.h
linux-2.6.11-mm1/include/asm-mips/uaccess.h
--- linux-2.6.11-mm1-orig/include/asm-mips/uaccess.h 2005-03-05
00:39:40.000000000 +0100
+++ linux-2.6.11-mm1/include/asm-mips/uaccess.h 2005-03-07 00:49:24.000000000
+0100
@@ -258,7 +258,8 @@ struct __large_struct { unsigned long bu
\
might_sleep(); \
__gu_addr = (long) (ptr); \
- __gu_err = verify_area(VERIFY_READ, (void *) __gu_addr, size); \
+ __gu_err = access_ok(VERIFY_READ, (void *) __gu_addr, size) \
+ ? 0 : -EFAULT; \
\
if (likely(!__gu_err)) { \
switch (size) { \
@@ -353,7 +354,8 @@ extern void __get_user_unknown(void);
might_sleep(); \
__pu_val = (x); \
__pu_addr = (long) (ptr); \
- __pu_err = verify_area(VERIFY_WRITE, (void *) __pu_addr, size); \
+ __pu_err = access_ok(VERIFY_WRITE, (void *) __pu_addr, size) \
+ ? 0 : -EFAULT; \
\
if (likely(!__pu_err)) { \
switch (size) { \
It preserves the exact behaviour of the original.
--
Jesper
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