[PATCH 19/20] lto, module: Warn about modules that are not fully LTOed

From: Andi Kleen <andi@firstfloor.org>
To: linux-kernel@vger.kernel.org
Cc: sam@ravnborg.org, x86@kernel.org, linux-kbuild@vger.kernel.org,
	Andi Kleen <ak@linux.intel.com>,
	rusty@rustcorp.com.au
Subject: [PATCH 19/20] lto, module: Warn about modules that are not fully LTOed
Date: Tue, 18 Feb 2014 15:28:57 +0100	[thread overview]
Message-ID: <1392733738-8290-20-git-send-email-andi@firstfloor.org> (raw)
In-Reply-To: <1392733738-8290-1-git-send-email-andi@firstfloor.org>

From: Andi Kleen <ak@linux.intel.com>

When __gnu_lto_* is present that means that the module hasn't run with
LTO yet.

Cc: rusty@rustcorp.com.au
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 kernel/module.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/module.c b/kernel/module.c
index b99e801..4f3eff7 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1949,8 +1949,11 @@ static int simplify_symbols(struct module *mod, const struct load_info *info)
 		switch (sym[i].st_shndx) {
 		case SHN_COMMON:
 			/* Ignore common symbols */
-			if (!strncmp(name, "__gnu_lto", 9))
+			if (!strncmp(name, "__gnu_lto", 9)) {
+				pr_info("%s: module not link time optimized\n",
+				       mod->name);
 				break;
+			}
 
 			/* We compiled with -fno-common.  These are not
 			   supposed to happen.  */
-- 
1.8.5.2

