From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <natechancellor@gmail.com>
Subject: [for-next][PATCH 01/21] tracing: Use address-of operator on section symbols
Date: Sun, 29 Mar 2020 14:42:53 -0400 [thread overview]
Message-ID: <20200329184315.677608653@goodmis.org> (raw)
In-Reply-To: 20200329184252.289087453@goodmis.org
From: Nathan Chancellor <natechancellor@gmail.com>
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>
---
kernel/trace/trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6b11e4e2150c..02be4ddd4ad5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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();
--
2.25.1
next prev parent reply other threads:[~2020-03-29 18:44 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-29 18:42 [for-next][PATCH 00/21] tracing: Updates for v5.7 Steven Rostedt
2020-03-29 18:42 ` Steven Rostedt [this message]
2020-03-29 18:42 ` [for-next][PATCH 02/21] selftest/ftrace: Fix function trigger test to handle trace not disabling the tracer Steven Rostedt
2020-03-29 18:42 ` [for-next][PATCH 03/21] tracing: Save off entry when peeking at next entry Steven Rostedt
2020-03-29 18:42 ` [for-next][PATCH 04/21] ring-buffer: Have ring_buffer_empty() not depend on tracing stopped Steven Rostedt
2020-03-29 18:42 ` [for-next][PATCH 05/21] ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance() Steven Rostedt
2020-03-29 18:42 ` [for-next][PATCH 06/21] ring-buffer: Add page_stamp to iterator for synchronization Steven Rostedt
2020-03-29 18:42 ` [for-next][PATCH 07/21] ring-buffer: Have rb_iter_head_event() handle concurrent writer Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 08/21] ring-buffer: Do not die if rb_iter_peek() fails more than thrice Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 09/21] ring-buffer: Optimize rb_iter_head_event() Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 10/21] ring-buffer: Make resize disable per cpu buffer instead of total buffer Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 11/21] ring-buffer: Do not disable recording when there is an iterator Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 12/21] tracing: Do not disable tracing when reading the trace file Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 13/21] ring-buffer/tracing: Have iterator acknowledge dropped events Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 14/21] tracing: Have the document reflect that the trace file keeps tracing enabled Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 15/21] ftrace/kprobe: Show the maxactive number on kprobe_events Steven Rostedt
2020-03-31 13:11 ` Sasha Levin
2020-03-29 18:43 ` [for-next][PATCH 16/21] ftrace: Make function trace pid filtering a bit more exact Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 17/21] ftrace: Create set_ftrace_notrace_pid to not trace tasks Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 18/21] tracing: Create set_event_notrace_pid " Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 19/21] selftests/ftrace: Add test to test new set_ftrace_notrace_pid file Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 20/21] selftests/ftrace: Add test to test new set_event_notrace_pid file Steven Rostedt
2020-03-29 18:43 ` [for-next][PATCH 21/21] tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid Steven Rostedt
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