kpatch-build failed (fc19)

[lulinqing]

$ kpatch-build foo.patch
Using cache at /home/lilu/.kpatch/3.13.6-100.fc19.x86_64/src
Testing patch file
patching file fs/proc/meminfo.c
Building original kernel
Building patched kernel
Detecting changed objects
Rebuilding changed objects
Extracting new and modified ELF sections
changed function: meminfo_proc_show
Building patch module: kpatch-foo.ko
ERROR: kpatch build failed. Check /tmp/kpatch-build-1395733172.log for more details.

The last few lines from log file(110KB in total):
https://github.com/lulinqing/misc/blob/master/kpatch-build-1395733172.log

... ...
found patched function meminfo_proc_show
original function at address ffffffff81227a90 (length 1312)
patches_nr = 1
patches_size = 24
relas_size = 24
patches_offset = 71
relas_offset = 80
make -C /home/lilu/.kpatch/3.13.6-100.fc19.x86_64/src M=/tmp/tmp.wAw8XBHOYT/patch kpatch-foo.ko
make[1]: Entering directory `/home/lilu/.kpatch/3.13.6-100.fc19.x86_64/src'
  CC [M]  /tmp/tmp.wAw8XBHOYT/patch/kpatch-patch-hook.o
  LD [M]  /tmp/tmp.wAw8XBHOYT/patch/kpatch-foo.o
/tmp/tmp.wAw8XBHOYT/patch/output.o: file not recognized: File format not recognized
make[3]: *** [/tmp/tmp.wAw8XBHOYT/patch/kpatch-foo.o] Error 1
make[2]: *** [kpatch-foo.ko] Error 2
make[1]: *** [sub-make] Error 2
make[1]: Leaving directory `/home/lilu/.kpatch/3.13.6-100.fc19.x86_64/src'
make: *** [kpatch-foo.ko] Error 2

Test patch I used:

Index: src/fs/proc/meminfo.c
===================================================================
--- src.orig/fs/proc/meminfo.c
+++ src/fs/proc/meminfo.c
@@ -95,7 +95,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
        "Committed_AS:   %8lu kB\n"
        "VmallocTotal:   %8lu kB\n"
        "VmallocUsed:    %8lu kB\n"
-       "VmallocChunk:   %8lu kB\n"
+       "VMALLOCCHUNK:   %8lu kB\n"
 #ifdef CONFIG_MEMORY_FAILURE
        "HardwareCorrupted: %5lu kB\n"
 #endif

Thanks!

[sjenning]

What version of elfutils do you have installed? It needs to be 0.158 (or greater).

[ryanmiao]

I agree with Seth.
And I tried this patch on fedora19 with elfutils-0.156-5.fc19.x86_64, ld failed to generate kpatch-meminfo.o.

[lulinqing]

I have 0.156-5 installed, and it's the latest I can get from yum update.

$ rpm -qa | grep elf
elfutils-0.156-5.fc19.x86_64
elfutils-libelf-0.156-5.fc19.x86_64
elfutils-libs-0.156-5.fc19.x86_64
elfutils-devel-0.156-5.fc19.x86_64
elfutils-libelf-devel-0.156-5.fc19.x86_64

I'll install 0.158+ manually and try again.
Thanks!

[lulinqing]

Tested on fc20 and this issue was gone.
Hit another error and reported in issue #87