kexec: add dmesg log symbols to /proc/vmcoreinfo lists

It would be nice to be able to extract the dmesg log from a vmcore file
without needing to keep the debug symbols for the running kernel handy all
the time.  We have a facility to do this in /proc/vmcore.  This patch adds
the log_buf and log_end symbols to the vmcoreinfo area so that tools (like
makedumpfile) can easily extract the dmesg logs from a vmcore image.

[akpm@linux-foundation.org: several fixes and cleanups]
[akpm@linux-foundation.org: fix unused log_buf_kexec_setup()]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Simon Horman <horms@verge.net.au>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 93eed85fe017..589832aac41f 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1409,6 +1409,7 @@ static int __init crash_save_vmcoreinfo_init(void)
         VMCOREINFO_OFFSET(list_head, prev);
         VMCOREINFO_OFFSET(vm_struct, addr);
         VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
+        log_buf_kexec_setup();
         VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
         VMCOREINFO_NUMBER(NR_FREE_PAGES);
         VMCOREINFO_NUMBER(PG_lru);