crash: remove dependency of FA_DUMP on CRASH_DUMP

In kdump kernel, /proc/vmcore is an elf file mapping the crashed kernel's
old memory content. Its elf header is constructed in 1st kernel and passed
to kdump kernel via elfcorehdr_addr. Config CRASH_DUMP enables the code
of 1st kernel's old memory accessing in different architectures.

Currently, config FA_DUMP has dependency on CRASH_DUMP because fadump
needs access global variable 'elfcorehdr_addr' to judge if it's in
kdump kernel within function is_kdump_kernel(). In the current
kernel/crash_dump.c, variable 'elfcorehdr_addr' is defined, and function
setup_elfcorehdr() used to parse kernel parameter to fetch the passed
value of elfcorehdr_addr. Only for accessing elfcorehdr_addr, FA_DUMP
really doesn't have to depends on CRASH_DUMP.

To remove the dependency of FA_DUMP on CRASH_DUMP to avoid confusion,
rename kernel/crash_dump.c to kernel/elfcorehdr.c, and build it when
CONFIG_VMCORE_INFO is ebabled. With this, FA_DUMP doesn't need to depend
on CRASH_DUMP.

[[email protected]: power/fadump: make FA_DUMP select CRASH_DUMP]
  Link: https://lkml.kernel.org/r/Zb8D1ASrgX0qVm9z@MiWiFi-R3L-srv
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Baoquan He <[email protected]>
Acked-by: Hari Bathini <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: Klara Modin <[email protected]>
Cc: Michael Kelley <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Yang Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions