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	Starting with recent GCC 8 builds, objtool and perf fail to build with
the following error:
  ../str_error_r.c: In function ‘str_error_r’:
  ../str_error_r.c:25:3: error: passing argument 1 to restrict-qualified parameter aliases with argument 5 [-Werror=restrict]
     snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err);
The code seems harmless, but there's probably no benefit in printing the
'buf' pointer in this situation anyway, so just remove it to make GCC
happy.
Reported-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20180316031154.juk2uncs7baffctp@treble
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
		
	
			
		
			
				
	
	
		
			27 lines
		
	
	
	
		
			1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			27 lines
		
	
	
	
		
			1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#undef _GNU_SOURCE
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#include <string.h>
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#include <stdio.h>
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#include <linux/string.h>
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/*
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 * The tools so far have been using the strerror_r() GNU variant, that returns
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 * a string, be it the buffer passed or something else.
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 *
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 * But that, besides being tricky in cases where we expect that the function
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 * using strerror_r() returns the error formatted in a provided buffer (we have
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 * to check if it returned something else and copy that instead), breaks the
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 * build on systems not using glibc, like Alpine Linux, where musl libc is
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 * used.
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 *
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 * So, introduce yet another wrapper, str_error_r(), that has the GNU
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 * interface, but uses the portable XSI variant of strerror_r(), so that users
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 * rest asured that the provided buffer is used and it is what is returned.
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 */
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char *str_error_r(int errnum, char *buf, size_t buflen)
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{
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	int err = strerror_r(errnum, buf, buflen);
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	if (err)
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		snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, [buf], %zd)=%d", errnum, buflen, err);
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	return buf;
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}
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