error in android kernel compilation

Question

I am trying to compile android kernel (cyanogen) for Samsung Galaxy mini , according to these instructions:

I am using CM-7.

I performed these steps:

1. Download kernel source code.

2. Configure the build :

   adb pull /proc/config.gz /home/user_name/android/kernel/cm-kernel/config.gz 
   cat config.gz | gunzip > .config 
   make ARCH=arm CROSS_COMPILE=$CCOMPILER menuconfig
   

3. Make the build:

    make ARCH=arm CROSS_COMPILE=$CCOMPILER -j4
   

After this kernel starts compiling and everything works fine but then it reports an error which appear to be an error in the source code, here is the output in the terminal.

 kernel/cpuset.c:1385: error: ‘task’ undeclared (first use in this
 function)
 kernel/cpuset.c:1385: error: (Each undeclared identifier is reported
 only once
 kernel/cpuset.c:1385: error: for each function it appears in.)
 kernel/cpuset.c: In function ‘cpuset_print_task_mems_allowed’: 
  CC [M]  fs/ceph/snap.o
  CC [M]  crypto/seed.o
  CC [M]  fs/btrfs/disk-io.o
  CC [M]  fs/cifs/connect.o
  CC [M]  fs/ceph/xattr.o
  CC [M]  crypto/salsa20_generic.o
  CC [M]  crypto/deflate.o
  CC [M]  fs/ceph/mds_client.o
  CC [M]  crypto/zlib.o
  CC [M]  fs/btrfs/transaction.o
  CC [M]  crypto/michael_mic.o
  CC [M]  crypto/authenc.o
  CC [M]  fs/ceph/mdsmap.o
  CC [M]  fs/cifs/dir.o
  CC [M]  fs/ceph/strings.o
  CC [M]  fs/btrfs/inode.o
  CC [M]  fs/ceph/ceph_frag.o
  CC [M]  crypto/lzo.o
  CC [M]  fs/ceph/debugfs.o
  CC [M]  crypto/ansi_cprng.o
  CC [M]  fs/cifs/file.o
  LD [M]  fs/ceph/ceph.o
  LD      fs/coda/built-in.o
  CC [M]  fs/coda/psdev.o
  CC [M]  crypto/tcrypt.o
fs/cifs/file.c: In function 'cifs_write':
fs/cifs/file.c:1036: warning: format '%zd' expects type 'signed size_t', but argument     3     has type 'size_t'
In file included from fs/coda/psdev.c:45:
include/linux/coda.h:223: error: expected specifier-qualifier-list before 'u_quad_t'
make[2]: *** [fs/coda/psdev.o] Error 1
make[1]: *** [fs/coda] Error 2
make[1]: *** Waiting for unfinished jobs....
CC [M]  crypto/ghash-generic.o
CC [M]  crypto/xor.o
include/asm-generic/xor.h:696: warning: 'xor_block_8regs_p' defined but not used
include/asm-generic/xor.h:704: warning: 'xor_block_32regs_p' defined but not used
CC [M]  fs/cifs/inode.o
LD      crypto/async_tx/built-in.o
CC [M]  crypto/async_tx/async_tx.o
CC [M]  crypto/async_tx/async_memcpy.o
CC [M]  fs/btrfs/file.o
CC [M]  fs/btrfs/tree-defrag.o
crypto/async_tx/async_memcpy.c: In function 'async_memcpy':
crypto/async_tx/async_memcpy.c:72: warning: format '%zu' expects type 'size_t', but         argument 3 has type 'unsigned int'
crypto/async_tx/async_memcpy.c:76: warning: format '%zu' expects type 'size_t', but     argument 3 has type 'unsigned int'
CC [M]  crypto/async_tx/async_xor.o
CC [M]  fs/btrfs/extent_map.o
crypto/async_tx/async_xor.c: In function 'async_xor':
crypto/async_tx/async_xor.c:202: warning: format '%zu' expects type 'size_t', but         argument 3 has type 'unsigned int'
crypto/async_tx/async_xor.c:208: warning: format '%zu' expects type 'size_t', but     argument 3 has type 'unsigned int'
crypto/async_tx/async_xor.c: In function 'async_xor_val':
crypto/async_tx/async_xor.c:286: warning: format '%zu' expects type 'size_t', but argument 3 has type 'unsigned int'
crypto/async_tx/async_xor.c:314: warning: format '%zu' expects type 'size_t', but argument 3 has type 'unsigned int'
CC [M]  crypto/async_tx/async_pq.o
CC [M]  fs/btrfs/sysfs.o
crypto/async_tx/async_pq.c: In function 'async_gen_syndrome':
crypto/async_tx/async_pq.c:218: warning: format '%zu' expects type 'size_t', but  argument 4 has type 'unsigned int'
crypto/async_tx/async_pq.c:225: warning: format '%zu' expects type 'size_t', but  argument 4 has type 'unsigned int'
crypto/async_tx/async_pq.c: In function 'async_syndrome_val':
crypto/async_tx/async_pq.c:295: warning: format '%zu' expects type 'size_t', but  argument 4 has type 'unsigned int'
crypto/async_tx/async_pq.c:344: warning: format '%zu' expects type 'size_t', but argument 4 has type 'unsigned int'
CC [M]  fs/btrfs/struct-funcs.o
CC [M]  fs/cifs/link.o
CC [M]  fs/btrfs/xattr.o
CC [M]  crypto/async_tx/async_raid6_recov.o
crypto/async_tx/async_raid6_recov.c: In function 'async_raid6_2data_recov':
crypto/async_tx/async_raid6_recov.c:334: warning: format '%zu' expects type 'size_t', but argument 4 has type 'unsigned int'
crypto/async_tx/async_raid6_recov.c: In function 'async_raid6_datap_recov':
crypto/async_tx/async_raid6_recov.c:410: warning: format '%zu' expects type 'size_t', but argument 4 has type 'unsigned int'
CC [M]  fs/cifs/misc.o
CC [M]  fs/btrfs/ordered-data.o
CC [M]  crypto/async_tx/raid6test.o
LD      crypto/crypto.o
LD      crypto/built-in.o
CC [M]  fs/btrfs/extent_io.o
CC [M]  fs/btrfs/volumes.o
CC [M]  fs/cifs/netmisc.o
CC [M]  fs/cifs/smbdes.o
CC [M]  fs/cifs/smbencrypt.o
CC  [M]  fs/cifs/transport.o
CC [M]  fs/cifs/asn1.o
CC [M]  fs/btrfs/async-thread.o
CC [M]  fs/cifs/md4.o
CC [M]  fs/cifs/md5.o
CC [M]  fs/cifs/cifs_unicode.o
CC [M]  fs/btrfs/ioctl.o
CC [M]  fs/btrfs/locking.o
CC [M]  fs/cifs/nterr.o
CC [M]  fs/cifs/xattr.o
CC [M]  fs/cifs/cifsencrypt.o
CC [M]  fs/btrfs/orphan.o
CC [M]  fs/cifs/readdir.o
CC [M]  fs/btrfs/export.o
CC [M]  fs/cifs/ioctl.o
CC [M]  fs/btrfs/tree-log.o
CC [M]  fs/btrfs/acl.o
CC [M]  fs/btrfs/free-space-cache.o
CC [M]  fs/cifs/sess.o
CC [M]  fs/btrfs/zlib.o
CC [M]  fs/btrfs/compression.o
CC [M]  fs/cifs/export.o
CC [M]  fs/btrfs/delayed-ref.o
CC [M]  fs/btrfs/relocation.o
CC [M]  fs/cifs/cifs_spnego.o
CC [M]  fs/cifs/dns_resolve.o
CC [M]  fs/cifs/cifs_dfs_ref.o
LD [M]  fs/cifs/cifs.o
LD [M]  fs/btrfs/btrfs.o
make: *** [fs] Error 2

If anyone can please tell how to resolve this issue.

Answer 1

There was error in the source code, in the file , kernel/cpuset.c on line 1385, 'task' was used, where as it should be 'tsk' , moreover it was used later without being assigned the value. It should have been assigned the value in this way : __task_cred(tsk).

This is the original code:

/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
             struct task_struct *tsk, bool threadgroup)
{
int ret;
struct cpuset *cs = cgroup_cs(cont);

if ((current != task) && (!capable(CAP_SYS_ADMIN))) {
    const struct cred *cred = current_cred(), *tcred;

    if (cred->euid != tcred->uid && cred->euid != tcred->suid)
        return -EPERM;
}

......................

This is the modified code:

/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
             struct task_struct *tsk, bool threadgroup)
{
int ret;
struct cpuset *cs = cgroup_cs(cont);

if ((current != tsk) && (!capable(CAP_SYS_ADMIN))) {
    const struct cred *cred = current_cred(), *tcred;
    tcred = __task_cred(tsk); 

    if (cred->euid != tcred->uid && cred->euid != tcred->suid)
        return -EPERM;
}

This link explains different possible errors which can occur while android kernel compilation.