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| author | Nathan Chancellor <natechancellor@gmail.com> | 2019-09-26 09:22:59 -0700 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-09-28 17:13:39 -0400 |
| commit | 968e5170939662341242812b9c82ef51cf140a33 (patch) | |
| tree | 55b5f965485179f55046d23c82426240baf62f4d | |
| parent | d2aea95a1a4d195d939d16303700921be318a2b9 (diff) | |
| download | linux-968e5170939662341242812b9c82ef51cf140a33.tar.gz linux-968e5170939662341242812b9c82ef51cf140a33.tar.xz | |
tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro
After r372664 in clang, the IF_ASSIGN macro causes a couple hundred
warnings along the lines of:
kernel/trace/trace_output.c:1331:2: warning: converting the enum
constant to a boolean [-Wint-in-bool-context]
kernel/trace/trace.h:409:3: note: expanded from macro
'trace_assign_type'
IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,
^
kernel/trace/trace.h:371:14: note: expanded from macro 'IF_ASSIGN'
WARN_ON(id && (entry)->type != id); \
^
264 warnings generated.
This warning can catch issues with constructs like:
if (state == A || B)
where the developer really meant:
if (state == A || state == B)
This is currently the only occurrence of the warning in the kernel
tree across defconfig, allyesconfig, allmodconfig for arm32, arm64,
and x86_64. Add the implicit '!= 0' to the WARN_ON statement to fix
the warnings and find potential issues in the future.
Link: https://github.com/llvm/llvm-project/commit/28b38c277a2941e9e891b2db30652cfd962f070b
Link: https://github.com/ClangBuiltLinux/linux/issues/686
Link: http://lkml.kernel.org/r/20190926162258.466321-1-natechancellor@gmail.com
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 26b0a08f3c7d..f801d154ff6a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -365,11 +365,11 @@ static inline struct trace_array *top_trace_array(void) __builtin_types_compatible_p(typeof(var), type *) #undef IF_ASSIGN -#define IF_ASSIGN(var, entry, etype, id) \ - if (FTRACE_CMP_TYPE(var, etype)) { \ - var = (typeof(var))(entry); \ - WARN_ON(id && (entry)->type != id); \ - break; \ +#define IF_ASSIGN(var, entry, etype, id) \ + if (FTRACE_CMP_TYPE(var, etype)) { \ + var = (typeof(var))(entry); \ + WARN_ON(id != 0 && (entry)->type != id); \ + break; \ } /* Will cause compile errors if type is not found. */ |