linux-kernel - [PATCH v2] [2/2] powerpc: Switch to generic WARN_ON()/BUG

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20071019020345.GB28359@lixom.net>
Date:	Thu, 18 Oct 2007 21:03:45 -0500
From:	Olof Johansson <olof@...om.net>
To:	linux-kernel@...r.kernel.org
Cc:	akpm@...ux-foundation.org, paulus@...abs.org, lethal@...ux-sh.org,
	kyle@...isc-linux.org, grundler@...isc-linux.org,
	linuxppc-dev@...abs.org
Subject: [PATCH v2] [2/2] powerpc: Switch to generic WARN_ON()/BUG_ON()

[POWERPC] Switch to generic WARN_ON()/BUG_ON()

Not using the ppc-specific WARN_ON/BUG_ON constructs actually saves about
4K text on a ppc64_defconfig. The main reason seems to be that prepping
the arguments to the conditional trap instructions is more work than
just doing a compare and branch.

Signed-off-by: Olof Johansson <olof@...om.net>

Index: k.org/include/asm-powerpc/bug.h
===================================================================
--- k.org.orig/include/asm-powerpc/bug.h
+++ k.org/include/asm-powerpc/bug.h
@@ -54,12 +54,6 @@
 	".previous\n"
 #endif
 
-/*
- * BUG_ON() and WARN_ON() do their best to cooperate with compile-time
- * optimisations. However depending on the complexity of the condition
- * some compiler versions may not produce optimal results.
- */
-
 #define BUG() do {						\
 	__asm__ __volatile__(					\
 		"1:	twi 31,0,0\n"				\
@@ -69,20 +63,6 @@
 	for(;;) ;						\
 } while (0)
 
-#define BUG_ON(x) do {						\
-	if (__builtin_constant_p(x)) {				\
-		if (x)						\
-			BUG();					\
-	} else {						\
-		__asm__ __volatile__(				\
-		"1:	"PPC_TLNEI"	%4,0\n"			\
-		_EMIT_BUG_ENTRY					\
-		: : "i" (__FILE__), "i" (__LINE__), "i" (0),	\
-		  "i" (sizeof(struct bug_entry)),		\
-		  "r" ((__force long)(x)));			\
-	}							\
-} while (0)
-
 #define __WARN() do {						\
 	__asm__ __volatile__(					\
 		"1:	twi 31,0,0\n"				\
@@ -92,23 +72,6 @@
 		  "i" (sizeof(struct bug_entry)));		\
 } while (0)
 
-#define WARN_ON(x) ({						\
-	int __ret_warn_on = !!(x);				\
-	if (__builtin_constant_p(__ret_warn_on)) {		\
-		if (__ret_warn_on)				\
-			__WARN();				\
-	} else {						\
-		__asm__ __volatile__(				\
-		"1:	"PPC_TLNEI"	%4,0\n"			\
-		_EMIT_BUG_ENTRY					\
-		: : "i" (__FILE__), "i" (__LINE__),		\
-		  "i" (BUGFLAG_WARNING),			\
-		  "i" (sizeof(struct bug_entry)),		\
-		  "r" (__ret_warn_on));				\
-	}							\
-	unlikely(__ret_warn_on);				\
-})
-
 #endif /* __ASSEMBLY __ */
 #endif /* CONFIG_BUG */
 
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/