vmcore: continue vmcore initialization if PT_NOTE is found empty
Currently when an empty PT_NOTE is detected, vmcore initialization
fails. It sounds too harsh. Because PT_NOTE could be empty, for
example, one offlined a cpu but never restarted kdump service, and after
crash, PT_NOTE program header is there but no data contains. It's
better to warn about the empty PT_NOTE and continue to initialise
vmcore.
And ultimately the multiple PT_NOTE are merged into a single one, all
empty PT_NOTE are discarded naturally during the merge. So empty
PT_NOTE is not visible to user space and vmcore is as good as expected.
Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Greg Pearson <greg.pearson@hp.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index ab852715..6a8e785 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -484,7 +484,6 @@
phdr_ptr->p_memsz = real_sz;
if (real_sz == 0) {
pr_warn("Warning: Zero PT_NOTE entries found\n");
- return -EINVAL;
}
}
@@ -671,7 +670,6 @@
phdr_ptr->p_memsz = real_sz;
if (real_sz == 0) {
pr_warn("Warning: Zero PT_NOTE entries found\n");
- return -EINVAL;
}
}