Re: [PATCH] m32r: add __ucmpdi2 to fix build failure

From: Sudip Mukherjee
Date: Fri Jun 10 2016 - 03:08:53 EST


On Thursday 09 June 2016 11:16 PM, Andrew Morton wrote:
On Thu, 9 Jun 2016 22:53:33 +0100 Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> wrote:

We are having build failure with m32r and the error message being:
ERROR: "__ucmpdi2" [lib/842/842_decompress.ko] undefined!
ERROR: "__ucmpdi2" [fs/btrfs/btrfs.ko] undefined!
ERROR: "__ucmpdi2" [drivers/scsi/sd_mod.ko] undefined!
ERROR: "__ucmpdi2" [drivers/media/i2c/adv7842.ko] undefined!
ERROR: "__ucmpdi2" [drivers/md/bcache/bcache.ko] undefined!
ERROR: "__ucmpdi2" [drivers/iio/imu/inv_mpu6050/inv-mpu6050.ko] undefined!

__ucmpdi2 is introduced to m32r architecture taking example from other
architectures like h8300, microblaze, mips.

--- a/arch/m32r/kernel/m32r_ksyms.c
+++ b/arch/m32r/kernel/m32r_ksyms.c
@@ -41,6 +41,9 @@ EXPORT_SYMBOL(cpu_data);
EXPORT_SYMBOL(smp_flush_tlb_page);
#endif

+extern int __ucmpdi2(unsigned long long a, unsigned long long b);
+EXPORT_SYMBOL(__ucmpdi2);
+

This would be neater. Does it work?


From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: m32r-add-__ucmpdi2-to-fix-build-failure-fix

avoid extern declaration in .c file

Cc: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
Cc: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

--- a/arch/m32r/kernel/m32r_ksyms.c~m32r-add-__ucmpdi2-to-fix-build-failure-fix
+++ a/arch/m32r/kernel/m32r_ksyms.c
@@ -41,7 +41,6 @@ EXPORT_SYMBOL(cpu_data);
EXPORT_SYMBOL(smp_flush_tlb_page);
#endif

-extern int __ucmpdi2(unsigned long long a, unsigned long long b);
EXPORT_SYMBOL(__ucmpdi2);

/* compiler generated symbol */
--- a/arch/m32r/lib/libgcc.h~m32r-add-__ucmpdi2-to-fix-build-failure-fix
+++ a/arch/m32r/lib/libgcc.h
@@ -22,3 +22,4 @@ typedef union {

#endif /* __ASM_LIBGCC_H */

+extern int __ucmpdi2(unsigned long long a, unsigned long long b);



Nope.
In file included from ../include/linux/linkage.h:6:0,
from ../include/linux/kernel.h:6,
from ../include/linux/list.h:8,
from ../include/linux/module.h:9,
from ../arch/m32r/kernel/m32r_ksyms.c:1:
../arch/m32r/kernel/m32r_ksyms.c:44:15: error: '__ucmpdi2' undeclared here (not in a function)
EXPORT_SYMBOL(__ucmpdi2);
^
../include/linux/export.h:57:16: note: in definition of macro '___EXPORT_SYMBOL'
extern typeof(sym) sym; \
^
../arch/m32r/kernel/m32r_ksyms.c:44:1: note: in expansion of macro 'EXPORT_SYMBOL'
EXPORT_SYMBOL(__ucmpdi2);
^
make[2]: *** [arch/m32r/kernel/m32r_ksyms.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [arch/m32r/kernel] Error 2
make[1]: *** Waiting for unfinished jobs....

m32r_ksyms.c is not having any reference to the name. If you want to remove the extern from the C file then I think we should declare it in some header file and include that in the m32r_ksyms.c. And if that works then that can be applied to all the other arch also, as almost all of them have these externs in *_ksyms.c.

Regards
Sudip