Date: Fri, 30 Aug 2024 10:33:03 -0000 From: qiwu.chen(a)transsion.com Subject: [Crash-utility] [PATCH] kmem: fix the determination for slab page To: devel(a)lists.crash-utility.osci.io Message-ID: <20240830103303.2824.23557(a)lists.crash-utility.osci.io&gt; Content-Type: text/plain; charset="utf-8" The determination for a slab page is changed since kernel commit 8db00ad564617 which migrates PG_slab flag from page flags to the lower 16 bit of the page type.

Before apply this patch: crash> kmem -s ffff000002aa4100 kmem: address is not allocated in slab subsystem: ffff000002aa4100 After apply this patch: crash> kmem -s ffff000002aa4100 CACHE OBJSIZE ALLOCATED TOTAL SLABS SSIZE NAME ffff00000140f900 4096 94 126 18 32k task_struct SLAB MEMORY NODE TOTAL ALLOCATED FREE fffffdffc00aa800 ffff000002aa0000 0 7 5 2 FREE / [ALLOCATED] [ffff000002aa4100] Signed-off-by: qiwu.chen <qiwu.chen(a)transsion.com&gt; --- defs.h | 1 + memory.c | 23 +++++++++++++++++++---- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/defs.h b/defs.h index e9eb9e3..9ef7f97 100644 --- a/defs.h +++ b/defs.h @@ -2289,6 +2289,7 @@ struct offset_table { /* stash of commonly-used offsets */ long track_cpu; long track_when; long track_handle; + long page_page_type; }; struct size_table { /* stash of commonly-used sizes */ diff --git a/memory.c b/memory.c index 7bf8f86..f9ad6e4 100644 --- a/memory.c +++ b/memory.c @@ -509,6 +509,8 @@ vm_init(void) ANON_MEMBER_OFFSET_INIT(page_compound_head, "page", "compound_head"); MEMBER_OFFSET_INIT(page_private, "page", "private"); MEMBER_OFFSET_INIT(page_freelist, "page", "freelist"); + if (MEMBER_EXISTS("page", "page_type")) + MEMBER_OFFSET_INIT(page_page_type, "page", "page_type"); MEMBER_OFFSET_INIT(mm_struct_pgd, "mm_struct", "pgd"); @@ -10114,7 +10116,7 @@ static char * vaddr_to_kmem_cache(ulong vaddr, char *buf, int verbose) { physaddr_t paddr; - ulong page, cache, page_flags; + ulong page, cache, page_flags, page_type; if (!kvtop(NULL, vaddr, &paddr, 0)) { if (verbose) @@ -10143,7 +10145,10 @@ vaddr_to_kmem_cache(ulong vaddr, char *buf, int verbose) readmem(compound_head(page)+OFFSET(page_flags), KVADDR, &page_flags, sizeof(ulong), "page.flags", FAULT_ON_ERROR); - if (!(page_flags & (1 << vt->PG_slab))) + readmem(page + OFFSET(page_page_type), KVADDR, &page_type, + sizeof(ulong), "page type", FAULT_ON_ERROR); + if (!(page_flags & (1 << vt->PG_slab)) && + !(page_type & (1 << vt->PG_slab))) return NULL; } else return NULL; @@ -20688,7 +20693,7 @@ char * is_slab_page(struct meminfo *si, char *buf) { int i, cnt; - ulong page_slab, page_flags, name; + ulong page_slab, page_flags, page_type, name; ulong *cache_list; char *retval; @@ -20703,7 +20708,17 @@ is_slab_page(struct meminfo *si, char *buf) RETURN_ON_ERROR|QUIET)) return NULL; - if (!(page_flags & (1 << vt->PG_slab))) + if (!readmem(si->spec_addr + OFFSET(page_page_type), KVADDR, + &page_type, sizeof(ulong), "page.page_type", + RETURN_ON_ERROR|QUIET)) + return NULL; + + /* + * PG_slab is migrated from the page flags to the lower 16 bit + * of the page type since linux commit 8db00ad564617. + */ + if (!(page_flags & (1 << vt->PG_slab)) && + !(page_type & (1 << vt->PG_slab))) return NULL; if (!readmem(si->spec_addr + OFFSET(page_slab), KVADDR, -- 2.25.1