From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>,
linux-arch@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Thierry Reding <treding@nvidia.com>,
linux-ia64@vger.kernel.org
Subject: [PATCH v2 19/40] ia64: fix put_user sparse errors
Date: Tue, 06 Jan 2015 15:44:34 +0000 [thread overview]
Message-ID: <1420558883-10131-20-git-send-email-mst@redhat.com> (raw)
In-Reply-To: <1420558883-10131-1-git-send-email-mst@redhat.com>
virtio wants to write bitwise types to userspace using put_user.
At the moment this triggers sparse errors, since the value is passed
through an integer.
For example:
__le32 __user *p;
__le32 x;
put_user(x, p);
is safe, but currently triggers a sparse warning.
Fix that up using __force.
Note: this does not suppress any useful sparse checks since callers
do a cast (__typeof__(*(ptr))) (x) which in turn forces all the
necessary type checks.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
arch/ia64/include/asm/uaccess.h | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/ia64/include/asm/uaccess.h b/arch/ia64/include/asm/uaccess.h
index 967c312..4f3fb6cc 100644
--- a/arch/ia64/include/asm/uaccess.h
+++ b/arch/ia64/include/asm/uaccess.h
@@ -169,10 +169,11 @@ do { \
(err) = ia64_getreg(_IA64_REG_R8); \
(val) = ia64_getreg(_IA64_REG_R9); \
} while (0)
-# define __put_user_size(val, addr, n, err) \
-do { \
- __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, (unsigned long) (val)); \
- (err) = ia64_getreg(_IA64_REG_R8); \
+# define __put_user_size(val, addr, n, err) \
+do { \
+ __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, \
+ (__force unsigned long) (val)); \
+ (err) = ia64_getreg(_IA64_REG_R8); \
} while (0)
#endif /* !ASM_SUPPORTED */
--
MST
prev parent reply other threads:[~2015-01-06 15:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1420558883-10131-1-git-send-email-mst@redhat.com>
2015-01-06 15:43 ` [PATCH v2 07/40] ia64/uaccess: fix sparse errors Michael S. Tsirkin
2015-01-06 15:44 ` Michael S. Tsirkin [this message]
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