From: Al Viro <viro@zeniv.linux.org.uk>
To: kbuild test robot <lkp@intel.com>
Cc: kbuild-all@lists.01.org, linux-fsdevel@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [vfs:uaccess.net 16/19] net/atm/ioctl.c:180:29: sparse: sparse: Using plain integer as NULL pointer
Date: Fri, 22 May 2020 15:23:21 +0100 [thread overview]
Message-ID: <20200522142321.GP23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <202005222158.Heq0Iqum%lkp@intel.com>
On Fri, May 22, 2020 at 09:58:00PM +0800, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git uaccess.net
> head: 0edecc020b33f8e31d8baa80735b45e8e8434700
> commit: a3929484af75ee524419edbbc4e9ce012c3d67c9 [16/19] atm: move copyin from atm_getnames() into the caller
> config: arm64-randconfig-s002-20200521 (attached as .config)
> compiler: aarch64-linux-gcc (GCC) 9.3.0
> reproduce:
> # apt-get install sparse
> # sparse version: v0.6.1-193-gb8fad4bc-dirty
> git checkout a3929484af75ee524419edbbc4e9ce012c3d67c9
> # save the attached .config to linux build tree
> make W=1 C=1 ARCH=arm64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kbuild test robot <lkp@intel.com>
>
>
> sparse warnings: (new ones prefixed by >>)
>
> >> net/atm/ioctl.c:180:29: sparse: sparse: Using plain integer as NULL pointer
Huh?
> > 180 if (get_user(buf, &iobuf->buffer))
_what_ use of plain integer as a NULL pointer? <looks>
Misannotated get_user() on arm64 - should be
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 32fc8061aa76..bc5c7b091152 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -304,7 +304,7 @@ do { \
__p = uaccess_mask_ptr(__p); \
__raw_get_user((x), __p, (err)); \
} else { \
- (x) = 0; (err) = -EFAULT; \
+ (x) = (__force __typeof__(x))0; (err) = -EFAULT; \
} \
} while (0)
and that's a _lot_ of noise in sparse logs on arm64, obviously - one for
each get_user() of a pointer...
next prev parent reply other threads:[~2020-05-22 14:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-22 13:58 [vfs:uaccess.net 16/19] net/atm/ioctl.c:180:29: sparse: sparse: Using plain integer as NULL pointer kbuild test robot
2020-05-22 14:23 ` Al Viro [this message]
2020-05-22 14:44 ` Catalin Marinas
2020-05-22 15:04 ` Al Viro
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