[Crash-utility] [PATCH v2] memory: Handle crash failure in linux-next caused by struct kmem_cache changes
Since kernel commit cf338283652f ("slab: remove struct kmem_cache_cpu")
in linux-next there is no more 'cpu_slab' member in struct kmem_cache.
Pick 'cpu_sheaves' as an alternative kmem_cache member for kernel-next to
identify the SLUB case.
Without the patch, crash fails to start on kernel-next with the error
message:
crash: invalid structure member offset: kmem_cache_s_num
FILE: memory.c LINE: 9988 FUNCTION: kmem_cache_init()
This fix:
- allows the crash to start with no errors for kernel-next.
- make the 'kmap -s' command working again for kernel-next.
- throws an error message on 'kmem -S' command if no 'cpu_slab' member
presents in struct kmem_cache:
kmem: -S not supported for this kernel
Signed-off-by: Mikhail Zaslonko <zaslonko(a)linux.ibm.com>
---
memory.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/memory.c b/memory.c
index cbc8d2f..17423a5 100644
--- a/memory.c
+++ b/memory.c
@@ -672,6 +672,7 @@ vm_init(void)
} else if (!VALID_STRUCT(kmem_slab_s) &&
!VALID_STRUCT(slab_s) &&
!MEMBER_EXISTS("kmem_cache", "cpu_slab") &&
+ !MEMBER_EXISTS("kmem_cache", "cpu_sheaves") &&
(VALID_STRUCT(slab) || (vt->flags & SLAB_OVERLOAD_PAGE))) {
vt->flags |= PERCPU_KMALLOC_V2;
@@ -816,7 +817,7 @@ vm_init(void)
if (INVALID_MEMBER(page_first_page))
ANON_MEMBER_OFFSET_INIT(page_first_page, "page", "first_page");
- } else if (MEMBER_EXISTS("kmem_cache", "cpu_slab") &&
+ } else if ((MEMBER_EXISTS("kmem_cache", "cpu_slab") ||
MEMBER_EXISTS("kmem_cache", "cpu_sheaves")) &&
STRUCT_EXISTS("kmem_cache_node")) {
vt->flags |= KMALLOC_SLUB;
@@ -5270,6 +5271,9 @@ cmd_kmem(void)
if (sflag || Sflag || rflag || !(vt->flags & KMEM_CACHE_INIT))
kmem_cache_init();
+ if (Sflag && !MEMBER_EXISTS("kmem_cache", "cpu_slab"))
+ error(FATAL, "-S not supported for this kernel\n");
+
while (args[optind]) {
if (hexadecimal(args[optind], 0)) {
value[spec_addr++] =
@@ -20401,7 +20405,6 @@ get_cpu_slab_ptr(struct meminfo *si, int cpu, ulong
*cpu_freelist)
default:
cpu_slab_ptr = 0;
- error(FATAL, "cannot determine location of kmem_cache.cpu_slab page\n");
}
return cpu_slab_ptr;
--
2.52.0