On Fri, Sep 20, 2024 at 9:30 AM <devel-requ...@lists.crash-utility.osci.io>
wrote:
> Date: Fri, 20 Sep 2024 01:28:32 -0000
> From: qiwu.c...@transsion.com
> Subject: [Crash-utility] [PATCH v3] kmem: fix the determination for
> slab page
> To: devel@lists.crash-utility.osci.io
> Message-ID: <20240920012832.29184.28...@lists.crash-utility.osci.io>
> Content-Type: text/plain; charset="utf-8"
>
> The determination for a slab page has changed due to changing
> PG_slab from a page flag to a page type since kernel commit
> 46df8e73a4a3.
>
> 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.c...@transsion.com>
> ---
> defs.h | 7 ++++++
> memory.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++---------
> symbols.c | 2 ++
> 3 files changed, 66 insertions(+), 11 deletions(-)
>
>
Thank you for the update, qiwu.
I have no other issues, for the v3: Ack
Thanks
Lianbo
> diff --git a/defs.h b/defs.h
> index 2231cb6..e2a9278 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -2243,6 +2243,7 @@ struct offset_table { /* stash of
> commonly-used offsets */
> long vmap_node_busy;
> long rb_list_head;
> long file_f_inode;
> + long page_page_type;
> };
>
> struct size_table { /* stash of commonly-used sizes */
> @@ -2651,6 +2652,7 @@ struct vm_table { /* kernel
> VM-related data */
> ulong max_mem_section_nr;
> ulong zero_paddr;
> ulong huge_zero_paddr;
> + uint page_type_base;
> };
>
> #define NODES (0x1)
> @@ -2684,6 +2686,11 @@ struct vm_table { /* kernel
> VM-related data */
> #define SLAB_CPU_CACHE (0x10000000)
> #define SLAB_ROOT_CACHES (0x20000000)
> #define USE_VMAP_NODES (0x40000000)
> +/*
> + * The SLAB_PAGEFLAGS flag is introduced to detect the change of
> + * PG_slab's type from a page flag to a page type.
> + */
> +#define SLAB_PAGEFLAGS (0x80000000)
>
> #define IS_FLATMEM() (vt->flags & FLATMEM)
> #define IS_DISCONTIGMEM() (vt->flags & DISCONTIGMEM)
> diff --git a/memory.c b/memory.c
> index 967a9cf..8befe8c 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -351,6 +351,43 @@ static ulong handle_each_vm_area(struct
> handle_each_vm_area_args *);
>
> static ulong DISPLAY_DEFAULT;
>
> +/*
> + * Before kernel commit ff202303c398e, the value is defined as a macro,
> so copy it here;
> + * After this commit, the value is defined as an enum, which can be
> evaluated at runtime.
> + */
> +#define PAGE_TYPE_BASE 0xf0000000
> +#define PageType(page_type, flag)
> \
> + ((page_type & (vt->page_type_base | flag)) == vt->page_type_base)
> +
> +static void page_type_init(void)
> +{
> + if (!enumerator_value("PAGE_TYPE_BASE", (long
> *)&vt->page_type_base))
> + vt->page_type_base = PAGE_TYPE_BASE;
> +}
> +
> +/*
> + * The PG_slab's type has changed from a page flag to a page type
> + * since kernel commit 46df8e73a4a3.
> + */
> +static bool page_slab(ulong page, ulong flags)
> +{
> + if (vt->flags & SLAB_PAGEFLAGS) {
> + if ((flags >> vt->PG_slab) & 1)
> + return TRUE;
> + }
> +
> + if (VALID_MEMBER(page_page_type)) {
> + uint page_type;
> +
> + readmem(page+OFFSET(page_page_type), KVADDR, &page_type,
> + sizeof(page_type), "page_type", FAULT_ON_ERROR);
> + if (PageType(page_type, (uint)vt->PG_slab))
> + return TRUE;
> + }
> +
> + return FALSE;
> +}
> +
> /*
> * Verify that the sizeof the primitive types are reasonable.
> */
> @@ -504,6 +541,7 @@ 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");
> + MEMBER_OFFSET_INIT(page_page_type, "page", "page_type");
>
> MEMBER_OFFSET_INIT(mm_struct_pgd, "mm_struct", "pgd");
>
> @@ -1278,6 +1316,8 @@ vm_init(void)
>
> page_flags_init();
>
> + page_type_init();
> +
> rss_page_types_init();
>
> vt->flags |= VM_INIT;
> @@ -5931,7 +5971,7 @@ dump_mem_map_SPARSEMEM(struct meminfo *mi)
> if ((flags >> v22_PG_Slab) & 1)
> slabs++;
> } else if (vt->PG_slab) {
> - if ((flags >> vt->PG_slab) & 1)
> + if (page_slab(pp, flags))
> slabs++;
> } else {
> if ((flags >> v24_PG_slab) & 1)
> @@ -6381,7 +6421,7 @@ dump_mem_map(struct meminfo *mi)
> if ((flags >> v22_PG_Slab) & 1)
> slabs++;
> } else if (vt->PG_slab) {
> - if ((flags >> vt->PG_slab) & 1)
> + if (page_slab(pp, flags))
> slabs++;
> } else {
> if ((flags >> v24_PG_slab) & 1)
> @@ -6694,7 +6734,6 @@ dump_hstates()
> FREEBUF(hstate);
> }
>
> -
> static void
> page_flags_init(void)
> {
> @@ -6775,6 +6814,9 @@ page_flags_init_from_pageflag_names(void)
> vt->pageflags_data[i].name = nameptr;
> vt->pageflags_data[i].mask = mask;
>
> + if (!strncmp(nameptr, "slab", 4))
> + vt->flags |= SLAB_PAGEFLAGS;
> +
> if (CRASHDEBUG(1)) {
> fprintf(fp, " %08lx %s\n",
> vt->pageflags_data[i].mask,
> @@ -6835,8 +6877,9 @@ page_flags_init_from_pageflags_enum(void)
> }
> strcpy(nameptr, arglist[0] + strlen("PG_"));
> vt->pageflags_data[p].name = nameptr;
> - vt->pageflags_data[p].mask = 1 <<
> atoi(arglist[2]);
> -
> + vt->pageflags_data[p].mask = 1 << atoi(arglist[2]);
> + if (!strncmp(nameptr, "slab", 4))
> + vt->flags |= SLAB_PAGEFLAGS;
> p++;
> }
> } else
> @@ -9736,14 +9779,14 @@ vaddr_to_kmem_cache(ulong vaddr, char *buf, int
> verbose)
> readmem(page+OFFSET(page_flags), KVADDR,
> &page_flags, sizeof(ulong), "page.flags",
> FAULT_ON_ERROR);
> - if (!(page_flags & (1 << vt->PG_slab))) {
> + if (!page_slab(page, page_flags)) {
> if (((vt->flags & KMALLOC_SLUB) ||
> VALID_MEMBER(page_compound_head)) ||
> ((vt->flags & KMALLOC_COMMON) &&
> VALID_MEMBER(page_slab) &&
> VALID_MEMBER(page_first_page))) {
>
> readmem(compound_head(page)+OFFSET(page_flags), KVADDR,
> &page_flags, sizeof(ulong),
> "page.flags",
> FAULT_ON_ERROR);
> - if (!(page_flags & (1 << vt->PG_slab)))
> + if (!page_slab(compound_head(page),
> page_flags))
> return NULL;
> } else
> return NULL;
> @@ -14108,6 +14151,8 @@ dump_vm_table(int verbose)
> fprintf(fp, "%sNODELISTS_IS_PTR", others++ ? "|" : "");\
> if (vt->flags & VM_INIT)
> fprintf(fp, "%sVM_INIT", others++ ? "|" : "");\
> + if (vt->flags & SLAB_PAGEFLAGS)
> + fprintf(fp, "%sSLAB_PAGEFLAGS", others++ ? "|" : "");\
>
> fprintf(fp, ")\n");
> if (vt->kernel_pgd[0] == vt->kernel_pgd[1])
> @@ -14237,6 +14282,7 @@ dump_vm_table(int verbose)
> vt->pageflags_data[i].mask,
> vt->pageflags_data[i].name);
> }
> + fprintf(fp, " page_type_base: %x\n", vt->page_type_base);
>
> dump_vma_cache(VERBOSE);
> }
> @@ -20195,7 +20241,7 @@ char *
> is_slab_page(struct meminfo *si, char *buf)
> {
> int i, cnt;
> - ulong page_slab, page_flags, name;
> + ulong pg_slab, page_flags, name;
> ulong *cache_list;
> char *retval;
>
> @@ -20210,11 +20256,11 @@ is_slab_page(struct meminfo *si, char *buf)
> RETURN_ON_ERROR|QUIET))
> return NULL;
>
> - if (!(page_flags & (1 << vt->PG_slab)))
> + if (!page_slab(si->spec_addr, page_flags))
> return NULL;
>
> if (!readmem(si->spec_addr + OFFSET(page_slab), KVADDR,
> - &page_slab, sizeof(ulong), "page.slab",
> + &pg_slab, sizeof(ulong), "page.slab",
> RETURN_ON_ERROR|QUIET))
> return NULL;
>
> @@ -20222,7 +20268,7 @@ is_slab_page(struct meminfo *si, char *buf)
> cnt = get_kmem_cache_list(&cache_list);
>
> for (i = 0; i < cnt; i++) {
> - if (page_slab == cache_list[i]) {
> + if (pg_slab == cache_list[i]) {
> if (!readmem(cache_list[i] +
> OFFSET(kmem_cache_name),
> KVADDR, &name, sizeof(char *),
> "kmem_cache.name", QUIET|RETURN_ON_ERROR))
> diff --git a/symbols.c b/symbols.c
> index 69a1fbb..014cd29 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -10339,6 +10339,8 @@ dump_offset_table(char *spec, ulong makestruct)
> fprintf(fp, " page_compound_head: %ld\n",
> OFFSET(page_compound_head));
> fprintf(fp, " page_private: %ld\n",
> OFFSET(page_private));
> + fprintf(fp, " page_page_type: %ld\n",
> + OFFSET(page_page_type));
>
> fprintf(fp, " trace_print_flags_mask: %ld\n",
> OFFSET(trace_print_flags_mask));
> --
> 2.25.1
>
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