Commit e00d93ac authored Sep 14, 2018 by Anton Blanchard Committed by Michael Ellerman Sep 19, 2018

powerpc: Fix duplicate const clang warning in user access code



This re-applies commit b91c1e3e ("powerpc: Fix duplicate const
clang warning in user access code") (Jun 2015) which was undone in
commits:
  f2ca8090 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017)
  d466f6c5 ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017)
  f84ed59a ("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>

parent ee9d21b3

arch/powerpc/include/asm/uaccess.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -260,7 +260,7 @@ 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(); \
		@@ -274,7 +274,7 @@ 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(); \
		@@ -288,7 +288,7 @@ 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); \

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