Re: [PATCH] perf tools: fix type mismatch - long vs __statfs_word

From: Vineet Gupta
Date: Thu Sep 04 2014 - 01:45:31 EST


+CC acme, Peter


On Wednesday 13 August 2014 10:34 PM, Alexey Brodkin wrote:
> From "include/uapi/asm-generic/statfs.h" it is seen that "statfs.f_type" is of
> type "__statfs_word" which in its turn is "__u32" (unsigned int) for 32-bit
> systems.
>
> So in case of compilation with "-Werror" following breakage happens:
> --->---
> fs.c: In function ‘fs__valid_mount’:
> fs.c:76:24: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
> else if (st_fs.f_type != magic)
> ^
> cc1: all warnings being treated as errors
> --->---
>
> Note that now when fs.c is in "lib/api/fs" and in "tools/lib/api/Makefile"
> CFLAGS has hard-coded "-Werror" this is inevitable even if one builds "perf"
> with "WERROR=0".
>
> Signed-off-by: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
>
> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Cody P Schafer <dev@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
> tools/lib/api/fs/fs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
> index c1b49c3..4b2fa7b 100644
> --- a/tools/lib/api/fs/fs.c
> +++ b/tools/lib/api/fs/fs.c
> @@ -75,7 +75,7 @@ static int fs__valid_mount(const char *fs, long magic)
>
> if (statfs(fs, &st_fs) < 0)
> return -ENOENT;
> - else if (st_fs.f_type != magic)
> + else if ((long)st_fs.f_type != magic)
> return -ENOENT;
>
> return 0;

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