linux-kernel - [PATCH] stacktrace: get rid of unneeded !!

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Date:   Mon, 11 Nov 2019 10:26:47 +0100
From:   Jiri Slaby <jslaby@...e.cz>
To:     tglx@...utronix.de
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org,
        Jiri Slaby <jslaby@...e.cz>, Joe Perches <joe@...ches.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [PATCH] stacktrace: get rid of unneeded !!

My commit b0c51f158455 ("stacktrace: Don't skip first entry on
noncurrent tasks") adds one or zero to skipnr by "!!(current == tsk)".
But the C99 standard says:
  The == (equal to) and != (not equal to) operators are
  ...
  Each of the operators yields 1 if the specified relation is true and 0
  if it is false.

So there is no need to prepend the above expression by "!!" -- remove
it.

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Reported-by: Joe Perches <joe@...ches.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: x86@...nel.org
---
 kernel/stacktrace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index c9ea7eb2cb1a..2af66e449aa6 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -142,7 +142,7 @@ unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store,
 		.store	= store,
 		.size	= size,
 		/* skip this function if they are tracing us */
-		.skip	= skipnr + !!(current == tsk),
+		.skip	= skipnr + (current == tsk),
 	};
 
 	if (!try_get_task_stack(tsk))
@@ -300,7 +300,7 @@ unsigned int stack_trace_save_tsk(struct task_struct *task,
 		.entries	= store,
 		.max_entries	= size,
 		/* skip this function if they are tracing us */
-		.skip	= skipnr + !!(current == task),
+		.skip	= skipnr + (current == task),
 	};
 
 	save_stack_trace_tsk(task, &trace);
-- 
2.24.0