[arm-perf:delay 3/3] ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!

[arm-perf:delay 3/3] ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!

[Fengguang Wu]

Hi Jonathan,

FYI, kernel build failed on

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git delay
head:   d9ed51a6b84c5724fd047a4715449356fffca83f
commit: d9ed51a6b84c5724fd047a4715449356fffca83f [3/3] ARM: delay: add registration mechanism for delay timer sources
config: arm-s3c2410_defconfig

All error/warnings:

ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu, Yuanhan Liu                              Intel Corporation

Re: [arm-perf:delay 3/3] ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!

[Jonathan Austin]

Hi Fengguang,

Thanks for the report,

On 01/10/12 12:40, Fengguang Wu wrote:

> Hi Jonathan,
> 
> FYI, kernel build failed on
> 
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git delay
> head:   d9ed51a6b84c5724fd047a4715449356fffca83f
> commit: d9ed51a6b84c5724fd047a4715449356fffca83f [3/3] ARM: delay: add registration mechanism for delay timer sources
> config: arm-s3c2410_defconfig
> 
> All error/warnings:
> 
> ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!

I've fixed this and sent a patch (included below) to Will for his delay branch,

Jonny

-------8<---------

From: Jonathan Austin <jonathan.austin@arm.com>
Date: Mon, 1 Oct 2012 16:48:59 +0100
Subject: [PATCH] ARM: delay: export read_current_timer to fix get_cycles

On ARM, get_cycles() is implemented in terms of read_current_timer(), but
the latter is not exported to modules, resulting in failure to link:

  ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!

This patch exports the symbol as required.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
---
 arch/arm/kernel/armksyms.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 60d3b73..6a37f8d 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -50,6 +50,7 @@ extern void fpundefinstr(void);
 
        /* platform dependent support */
 EXPORT_SYMBOL(arm_delay_ops);
+EXPORT_SYMBOL(read_current_timer);
 
        /* networking */
 EXPORT_SYMBOL(csum_partial);
-- 
1.7.1