linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	clang-built-linux@googlegroups.com,
	Anton Blanchard <anton@samba.org>,
	linuxppc-dev@lists.ozlabs.org, Joel Stanley <joel@jms.id.au>
Subject: [PATCH AUTOSEL 4.14 013/109] powerpc: Fix duplicate const clang warning in user access code
Date: Sat,  9 Nov 2019 21:44:05 -0500	[thread overview]
Message-ID: <20191110024541.31567-13-sashal@kernel.org> (raw)
In-Reply-To: <20191110024541.31567-1-sashal@kernel.org>

From: Anton Blanchard <anton@samba.org>

[ Upstream commit e00d93ac9a189673028ac125a74b9bc8ae73eebc ]

This re-applies commit b91c1e3e7a6f ("powerpc: Fix duplicate const
clang warning in user access code") (Jun 2015) which was undone in
commits:
  f2ca80905929 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017)
  d466f6c5cac1 ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017)
  f84ed59a612d ("powerpc/sparse: Constify the address pointer in __get_user_check()") (Feb 2017)

We see a large number of duplicate const errors in the user access
code when building with llvm/clang:

  include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
        ret = __get_user(c, uaddr);

The problem is we are doing const __typeof__(*(ptr)), which will hit
the warning if ptr is marked const.

Removing const does not seem to have any effect on GCC code
generation.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/uaccess.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 51f00c00d7e49..3865d1d235976 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -234,7 +234,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	__long_type(*(ptr)) __gu_val;				\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	if (!is_kernel_addr((unsigned long)__gu_addr))		\
 		might_fault();					\
@@ -248,7 +248,7 @@ do {								\
 ({									\
 	long __gu_err = -EFAULT;					\
 	__long_type(*(ptr)) __gu_val = 0;				\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
 	might_fault();							\
 	if (access_ok(VERIFY_READ, __gu_addr, (size))) {		\
 		barrier_nospec();					\
@@ -262,7 +262,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	__long_type(*(ptr)) __gu_val;				\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	barrier_nospec();					\
 	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
-- 
2.20.1


  parent reply	other threads:[~2019-11-10  3:39 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191110024541.31567-1-sashal@kernel.org>
2019-11-10  2:44 ` [PATCH AUTOSEL 4.14 010/109] powerpc/iommu: Avoid derefence before pointer check Sasha Levin
2019-11-10  2:44 ` [PATCH AUTOSEL 4.14 011/109] powerpc/64s/hash: Fix stab_rr off by one initialization Sasha Levin
2019-11-10  2:44 ` [PATCH AUTOSEL 4.14 012/109] powerpc/pseries: Disable CPU hotplug across migrations Sasha Levin
2019-11-10  2:44 ` Sasha Levin [this message]
2019-11-10  2:44 ` [PATCH AUTOSEL 4.14 016/109] libfdt: Ensure INT_MAX is defined in libfdt_env.h Sasha Levin
2019-11-10  2:44 ` [PATCH AUTOSEL 4.14 019/109] net: toshiba: fix return type of ndo_start_xmit function Sasha Levin
2019-11-10  2:44 ` [PATCH AUTOSEL 4.14 045/109] net: freescale: " Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191110024541.31567-13-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=anton@samba.org \
    --cc=clang-built-linux@googlegroups.com \
    --cc=joel@jms.id.au \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=ndesaulniers@google.com \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).