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tracing: Use address-of operator on section symbols 

Clang warns:

../kernel/trace/trace.c:9335:33: warning: array comparison always
evaluates to true [-Wtautological-compare]
        if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
                                       ^
1 warning generated.

These are not true arrays, they are linker defined symbols, which are
just addresses. Using the address of operator silences the warning and
does not change the runtime result of the check (tested with some print
statements compiled in with clang + ld.lld and gcc + ld.bfd in QEMU).

Link: http://lkml.kernel.org/r/20200220051011.26113-1-natechancellor@gmail.com

Link: https://github.com/ClangBuiltLinux/linux/issues/893
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Nathan Chancellor 2020-02-19 22:10:12 -07:00 committed by Steven Rostedt (VMware)
parent bbd9d05618
commit bf2cbe044d
1 changed files with 1 additions and 1 deletions
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2
kernel/trace/trace.c
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@ -9334,7 +9334,7 @@ __init static int tracer_alloc_buffers(void)
goto out_free_buffer_mask;
/* Only allocate trace_printk buffers if a trace_printk exists */
if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt)
/* Must be called before global_trace.buffer is allocated */
trace_printk_init_buffers();