linux-kernel - [PATCH v2 4/5] binder: convert logging macros into functions

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Date:   Fri, 29 Apr 2022 23:56:43 +0000
From:   Carlos Llamas <cmllamas@...gle.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Arve Hjønnevåg" <arve@...roid.com>,
        Todd Kjos <tkjos@...roid.com>,
        Martijn Coenen <maco@...roid.com>,
        Christian Brauner <brauner@...nel.org>,
        Suren Baghdasaryan <surenb@...gle.com>
Cc:     Joel Fernandes <joel@...lfernandes.org>,
        Hridya Valsaraju <hridya@...gle.com>, kernel-team@...roid.com,
        linux-kernel@...r.kernel.org, Shuah Khan <shuah@...nel.org>,
        Arnd Bergmann <arnd@...db.de>, Li Li <dualli@...gle.com>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Carlos Llamas <cmllamas@...gle.com>,
        linux-kselftest@...r.kernel.org
Subject: [PATCH v2 4/5] binder: convert logging macros into functions

Converting binder_debug() and binder_user_error() macros into functions
reduces the overall object size by 16936 bytes when cross-compiled with
aarch64-linux-gnu-gcc 11.2.0:

$ size drivers/android/binder.o.{old,new}
   text	   data	    bss	    dec	    hex	filename
  77935	   6168	  20264	 104367	  197af	drivers/android/binder.o.old
  65551	   1616	  20264	  87431	  15587	drivers/android/binder.o.new

This is particularly beneficial to functions binder_transaction() and
binder_thread_write() which repeatedly use these macros and are both
part of the critical path for all binder transactions.

$ nm --size vmlinux.{old,new} |grep ' binder_transaction$'
0000000000002f60 t binder_transaction
0000000000002358 t binder_transaction

$ nm --size vmlinux.{old,new} |grep binder_thread_write
0000000000001c54 t binder_thread_write
00000000000014a8 t binder_thread_write

Signed-off-by: Carlos Llamas <cmllamas@...gle.com>
---
 drivers/android/binder.c | 41 ++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index b9df0c8a68d3..bfb21e258427 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -133,19 +133,36 @@ static int binder_set_stop_on_user_error(const char *val,
 module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
 	param_get_int, &binder_stop_on_user_error, 0644);
 
-#define binder_debug(mask, x...) \
-	do { \
-		if (binder_debug_mask & mask) \
-			pr_info_ratelimited(x); \
-	} while (0)
+static __printf(2, 3) void binder_debug(int mask, const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
 
-#define binder_user_error(x...) \
-	do { \
-		if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) \
-			pr_info_ratelimited(x); \
-		if (binder_stop_on_user_error) \
-			binder_stop_on_user_error = 2; \
-	} while (0)
+	if (binder_debug_mask & mask) {
+		va_start(args, format);
+		vaf.va = &args;
+		vaf.fmt = format;
+		pr_info_ratelimited("%pV", &vaf);
+		va_end(args);
+	}
+}
+
+static __printf(1, 2) void binder_user_error(const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) {
+		va_start(args, format);
+		vaf.va = &args;
+		vaf.fmt = format;
+		pr_info_ratelimited("%pV", &vaf);
+		va_end(args);
+	}
+
+	if (binder_stop_on_user_error)
+		binder_stop_on_user_error = 2;
+}
 
 #define binder_set_extended_error(ee, _id, _command, _param) \
 	do { \
-- 
2.36.0.464.gb9c8b46e94-goog