[Devel] [PATCH RHEL7 COMMIT] mm: issue panic() on bad page/pte bugs if panic_on_warn is set

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-693.1.1.vz7.37.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.1.1.vz7.37.12
------>
commit aeb779949e1d0df996d4382ac5ec5372288800ec
Author: Andrey Ryabinin <aryabinin at virtuozzo.com>
Date:   Thu Oct 12 12:51:26 2017 +0300

    mm: issue panic() on bad page/pte bugs if panic_on_warn is set
    
    Bad page state bugs is serious issue. It's worth issue panic if
    panic_on_warn is set to collect crash dump and catch issue earlier.
    
    https://jira.sw.ru/browse/PSBM-70168
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 mm/memory.c     | 2 ++
 mm/page_alloc.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/mm/memory.c b/mm/memory.c
index c30a042..b1c6968 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -733,6 +733,8 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
 		       vma->vm_file->f_op->mmap);
 	dump_stack();
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
+	if (panic_on_warn)
+		panic("panic_on_warn set ...\n");
 }
 
 /*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0ee5e9a..137d1d8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -463,6 +463,8 @@ static void bad_page(struct page *page, char *reason, unsigned long bad_flags)
 	/* Leave bad fields for debug, except PageBuddy could make trouble */
 	page_mapcount_reset(page); /* remove PageBuddy */
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
+	if (panic_on_warn)
+		panic("panic_on_warn set ...\n");
 }
 
 /*