Commit a65e7bfc broke the UML build with
the following error -

  In file included from fs/proc/kcore.c:17:
  include/linux/elfcore.h: In function 'elf_core_copy_task_regs':
  include/linux/elfcore.h:129: error: implicit declaration of function 'task_pt_regs'

Fix this by restoring the previous behavior of returning 0 for all arches
like UML that don't define task_pt_regs.
Signed-off-by: NParag Warudkar <parag.lkml@gmail.com>
Acked-by: NAmerigo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the multithread program core thread message error.

This issue affects arches with neither has CORE_DUMP_USE_REGSET nor
ELF_CORE_COPY_TASK_REGS, ARM is one of them.

The thread message of core file is generated in elf_dump_thread_status.
The register values is set by elf_core_copy_task_regs in this function.

If an arch doesn't define ELF_CORE_COPY_TASK_REGS,
elf_core_copy_task_regs() will do nothing.  Then the core file will not
have the register message of thread.

So add elf_core_copy_regs to set regiser values if ELF_CORE_COPY_TASK_REGS
doesn't define.

The following is how to reproduce this issue:

cat 1.c
#include <stdio.h>
#include <pthread.h>
#include <assert.h>

void td1(void * i)
{
       while (1)
       {
               printf ("1\n");
               sleep (1);
       }

       return;
}

void td2(void * i)
{
       while (1)
       {
               printf ("2\n");
               sleep (1);
       }

       return;
}

int
main(int argc,char *argv[],char *envp[])
{
       pthread_t       t1,t2;

       pthread_create(&t1, NULL, (void*)td1, NULL);
       pthread_create(&t2, NULL, (void*)td2, NULL);

       sleep (10);

       assert(0);

       return (0);
}
arm-xxx-gcc -g -lpthread 1.c -o 1
copy 1.c and 1 to a arm board.
Goto this board.
ulimit -c 1800000
./1
# ./1
1
2
1
...
...
1
1: 1.c:37: main: Assertion `0' failed.
Aborted (core dumped)
Then you can get a core file.
gdb 1 core.xxx
Without the patch:
(gdb) info threads
 3 process 909  0x00000000 in ?? ()
 2 process 908  0x00000000 in ?? ()
* 1 process 907  0x4a6e2238 in raise () from /lib/libc.so.6
You can found that the pc of 909 and 908 is 0x00000000.
With the patch:
(gdb) info threads
 3 process 885  0x4a749974 in nanosleep () from /lib/libc.so.6
 2 process 884  0x4a749974 in nanosleep () from /lib/libc.so.6
* 1 process 883  0x4a6e2238 in raise () from /lib/libc.so.6
The pc of 885 and 884 is right.
Signed-off-by: NHui Zhu <teawater@gmail.com>
Cc: Amerigo Wang <xiyou.wangcong@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ELF core dump is used for both user land core dump and kernel crash
dump.  Depending on architecture, register might need to be accessed
differently for userland and kernel.  Allow architectures to define
ELF_CORE_COPY_KERNEL_REGS() and use different operation for kernel
register dump.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Do not export asm/elf.h during make headers_install.
Signed-off-by: NKirill A. Shutemov <k.shutemov@gmail.com>
Reviewed-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Do not export asm/user.h and linux/user.h during make headers_install.
Signed-off-by: NKirill A. Shutemov <k.shutemov@gmail.com>
Reviewed-by: NDavid Woodhouse <dwmw2@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add coredump capability for the ELF-FDPIC binfmt.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The compilation of kexec/kdump seems to be broken for x86_64.  Remove the
dependency of kexec on CONFIG_IA32_EMULATION.
Signed-off-by: NFernando Vazquez <fernando@intellilink.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!