Date: Wed, 5 Jun 2024 07:30:03 +0000 From: HAGIO KAZUHITO(萩尾　一仁)&lt;k-hagio-ab(a)nec.com&gt; Subject: [Crash-utility] [PATCH] Fix "kmem -v" option on Linux 6.9 and later kernels To:"devel@lists.crash-utility.osci.io" <devel(a)lists.crash-utility.osci.io&gt; Message-ID:<1717572599-30426-1-git-send-email-k-hagio-ab@nec.com> Content-Type: text/plain; charset="iso-2022-jp" The following kernel commits removed vmap_area_list and vmap_area_root rb-tree, and introduced vmap_nodes. 55c49fee57af mm/vmalloc: remove vmap_area_list d093602919ad mm: vmalloc: remove global vmap_area_root rb-tree Without the patch, the "kmem -v" option and functions that use dump_vmlist() fail with or without an error: crash> kmem -v VM_STRUCT ADDRESS RANGE SIZE kmem: invalid kernel virtual address: ccccccccccccccd4 type: "vmlist addr" crash> kmem -v crash> Signed-off-by: Kazuhito Hagio&lt;k-hagio-ab(a)nec.com&gt; --- defs.h | 4 ++ memory.c | 135 +++++++++++++++++++++++++++++++++++++++++++++--------- symbols.c | 3 ++ 3 files changed, 120 insertions(+), 22 deletions(-) diff --git a/defs.h b/defs.h index 01f316e67dde..95de33188070 100644 --- a/defs.h +++ b/defs.h @@ -2240,6 +2240,8 @@ struct offset_table { /* stash of commonly-used offsets */ long mnt_namespace_nr_mounts; long mount_mnt_node; long log_caller_id; + long vmap_node_busy; + long rb_list_head; }; struct size_table { /* stash of commonly-used sizes */ @@ -2414,6 +2416,7 @@ struct size_table { /* stash of commonly-used sizes */ long maple_tree; long maple_node; long module_memory; + long vmap_node; }; struct array_table { @@ -2678,6 +2681,7 @@ struct vm_table { /* kernel VM-related data */ #define SLAB_OVERLOAD_PAGE (0x8000000) #define SLAB_CPU_CACHE (0x10000000) #define SLAB_ROOT_CACHES (0x20000000) +#define USE_VMAP_NODES (0x40000000) #define IS_FLATMEM() (vt->flags & FLATMEM) #define IS_DISCONTIGMEM() (vt->flags & DISCONTIGMEM) diff --git a/memory.c b/memory.c index 34ed646b5d1e..acb8507cfb75 100644 --- a/memory.c +++ b/memory.c @@ -235,6 +235,7 @@ static void dump_slab_objects(struct meminfo *); static void dump_slab_objects_percpu(struct meminfo *); static void dump_vmlist(struct meminfo *); static void dump_vmap_area(struct meminfo *); +static int get_vmap_area_list_from_nodes(ulong **); static int dump_page_lists(struct meminfo *); static void dump_kmeminfo(void); static int page_to_phys(ulong, physaddr_t *); @@ -433,9 +434,15 @@ vm_init(void) if (VALID_MEMBER(vmap_area_va_start) && VALID_MEMBER(vmap_area_va_end) && VALID_MEMBER(vmap_area_list) && - VALID_MEMBER(vmap_area_vm) && - kernel_symbol_exists("vmap_area_list")) - vt->flags |= USE_VMAP_AREA; + VALID_MEMBER(vmap_area_vm)) { + if (kernel_symbol_exists("vmap_nodes")) { + STRUCT_SIZE_INIT(vmap_node, "vmap_node"); + MEMBER_OFFSET_INIT(vmap_node_busy, "vmap_node", "busy"); + MEMBER_OFFSET_INIT(rb_list_head, "rb_list", "head"); + vt->flags |= USE_VMAP_NODES; + } else if (kernel_symbol_exists("vmap_area_list")) + vt->flags |= USE_VMAP_AREA; + } if (kernel_symbol_exists("hstates")) { STRUCT_SIZE_INIT(hstate, "hstate"); @@ -8957,7 +8964,7 @@ dump_vmlist(struct meminfo *vi) physaddr_t paddr; int mod_vmlist; - if (vt->flags & USE_VMAP_AREA) { + if (vt->flags & (USE_VMAP_AREA|USE_VMAP_NODES)) { dump_vmap_area(vi); return; } @@ -9067,6 +9074,77 @@ next_entry: vi->retval = verified; } +static int +sort_by_va_start(const void *arg1, const void *arg2) +{ + ulong va_start1, va_start2; + + readmem(*(ulong *)arg1 + OFFSET(vmap_area_va_start), KVADDR, &va_start1, + sizeof(void *), "vmap_area.va_start", FAULT_ON_ERROR); + readmem(*(ulong *)arg2 + OFFSET(vmap_area_va_start), KVADDR, &va_start2, + sizeof(void *), "vmap_area.va_start", FAULT_ON_ERROR); + + return va_start1 < va_start2 ? -1 : (va_start1 == va_start2 ? 0 : 1); +} + +/* Linux 6.9 and later kernels use "vmap_nodes". */ +static int +get_vmap_area_list_from_nodes(ulong **list_ptr) +{ + int i, cnt, c; + struct list_data list_data, *ld = &list_data; + uint nr_vmap_nodes; + ulong vmap_nodes, list_head; + ulong *list, *ptr; + + get_symbol_data("nr_vmap_nodes", sizeof(uint), &nr_vmap_nodes); + get_symbol_data("vmap_nodes", sizeof(ulong), &vmap_nodes); + + /* count up all vmap_areas. */ + cnt = 0; + for (i = 0; i < nr_vmap_nodes; i++) { + BZERO(ld, sizeof(struct list_data)); + list_head = vmap_nodes + SIZE(vmap_node) * i + + OFFSET(vmap_node_busy) + OFFSET(rb_list_head); + readmem(list_head, KVADDR, &ld->start, sizeof(void *), + "rb_list.head", FAULT_ON_ERROR); + ld->list_head_offset = OFFSET(vmap_area_list); + ld->end = list_head; + c = do_list(ld); + if (c < 0) + return -1; + + cnt += c; + } + + list = ptr = (ulong *)GETBUF(sizeof(void *) * cnt); + + /* gather all vmap_areas into a list. */ + for (i = 0; i < nr_vmap_nodes; i++) { + BZERO(ld, sizeof(struct list_data)); + ld->flags = LIST_ALLOCATE; + list_head = vmap_nodes + SIZE(vmap_node) * i + + OFFSET(vmap_node_busy) + OFFSET(rb_list_head); + readmem(list_head, KVADDR, &ld->start, sizeof(void *), + "rb_list.head", FAULT_ON_ERROR); + ld->list_head_offset = OFFSET(vmap_area_list); + ld->end = list_head; + c = do_list(ld); + if (c < 0) + return -1; + + memcpy(ptr, ld->list_ptr, sizeof(void *) * c); + ptr += c; + + FREEBUF(ld->list_ptr); + }

+ + qsort(list, cnt, sizeof(void *), sort_by_va_start); + + *list_ptr = list; + return cnt; +} + static void dump_vmap_area(struct meminfo *vi) { @@ -9080,26 +9158,37 @@ dump_vmap_area(struct meminfo *vi) char buf2[BUFSIZE]; char buf3[BUFSIZE]; char buf4[BUFSIZE]; + ulong *list_ptr; #define VM_VM_AREA 0x4 /* mm/vmalloc.c */ - vmap_area_buf = GETBUF(SIZE(vmap_area)); start = count = verified = size = 0; - ld = &list_data; - BZERO(ld, sizeof(struct list_data)); - ld->flags = LIST_HEAD_FORMAT|LIST_HEAD_POINTER|LIST_ALLOCATE; - get_symbol_data("vmap_area_list", sizeof(void *), &ld->start); - ld->list_head_offset = OFFSET(vmap_area_list); - ld->end = symbol_value("vmap_area_list"); - cnt = do_list(ld); - if (cnt < 0) { - FREEBUF(vmap_area_buf); - error(WARNING, "invalid/corrupt vmap_area_list\n"); - vi->retval = 0; - return; + if (vt->flags & USE_VMAP_NODES) { + cnt = get_vmap_area_list_from_nodes(&list_ptr); + if (cnt < 0) { + error(WARNING, "invalid/corrupt vmap_nodes.busy list\n"); + vi->retval = 0; + return; + } + } else { + ld = &list_data; + BZERO(ld, sizeof(struct list_data)); + ld->flags = LIST_HEAD_FORMAT|LIST_HEAD_POINTER|LIST_ALLOCATE; + get_symbol_data("vmap_area_list", sizeof(void *), &ld->start); + ld->list_head_offset = OFFSET(vmap_area_list); + ld->end = symbol_value("vmap_area_list"); + cnt = do_list(ld); + if (cnt < 0) { + error(WARNING, "invalid/corrupt vmap_area_list\n"); + vi->retval = 0; + return; + } + list_ptr = ld->list_ptr; } + vmap_area_buf = GETBUF(SIZE(vmap_area)); + for (i = 0; i < cnt; i++) { if (!(pc->curcmd_flags & HEADER_PRINTED) && (i == 0) && !(vi->flags & (GET_HIGHEST|GET_PHYS_TO_VMALLOC| @@ -9116,7 +9205,7 @@ dump_vmap_area(struct meminfo *vi) pc->curcmd_flags |= HEADER_PRINTED; } - readmem(ld->list_ptr[i], KVADDR, vmap_area_buf, + readmem(list_ptr[i], KVADDR, vmap_area_buf, SIZE(vmap_area), "vmap_area struct", FAULT_ON_ERROR); if (VALID_MEMBER(vmap_area_flags) && @@ -9158,7 +9247,7 @@ dump_vmap_area(struct meminfo *vi) } fprintf(fp, "%s%s %s%s %s - %s %7ld\n", mkstring(buf1,VADDR_PRLEN, LONG_HEX|CENTER|LJUST, - MKSTR(ld->list_ptr[i])), space(MINSPACE-1), + MKSTR(list_ptr[i])), space(MINSPACE-1), mkstring(buf2,VADDR_PRLEN, LONG_HEX|CENTER|LJUST, MKSTR(vm_struct)), space(MINSPACE-1), mkstring(buf3, VADDR_PRLEN, LONG_HEX|RJUST, @@ -9179,14 +9268,14 @@ dump_vmap_area(struct meminfo *vi) if (vi->flags & GET_PHYS_TO_VMALLOC) { vi->retval = pcheck + PAGEOFFSET(vi->spec_addr); - FREEBUF(ld->list_ptr); + FREEBUF(list_ptr); return; } else fprintf(fp, "%s%s %s%s %s - %s %7ld\n", mkstring(buf1,VADDR_PRLEN, LONG_HEX|CENTER|LJUST, - MKSTR(ld->list_ptr[i])), + MKSTR(list_ptr[i])), space(MINSPACE-1), mkstring(buf2, VADDR_PRLEN, LONG_HEX|CENTER|LJUST, @@ -9204,7 +9293,7 @@ dump_vmap_area(struct meminfo *vi) } FREEBUF(vmap_area_buf); - FREEBUF(ld->list_ptr); + FREEBUF(list_ptr); if (vi->flags & GET_HIGHEST) vi->retval = start+size; @@ -14001,6 +14090,8 @@ dump_vm_table(int verbose) fprintf(fp, "%sSLAB_ROOT_CACHES", others++ ? "|" : "");\ if (vt->flags & USE_VMAP_AREA) fprintf(fp, "%sUSE_VMAP_AREA", others++ ? "|" : "");\ + if (vt->flags & USE_VMAP_NODES) + fprintf(fp, "%sUSE_VMAP_NODES", others++ ? "|" : "");\ if (vt->flags & CONFIG_NUMA) fprintf(fp, "%sCONFIG_NUMA", others++ ? "|" : "");\ if (vt->flags & VM_EVENT) diff --git a/symbols.c b/symbols.c index b7627a83587a..ded34412ff41 100644 --- a/symbols.c +++ b/symbols.c @@ -10167,6 +10167,8 @@ dump_offset_table(char *spec, ulong makestruct) fprintf(fp, " vmap_area_flags: %ld\n", OFFSET(vmap_area_flags)); fprintf(fp, " vmap_area_purge_list: %ld\n", OFFSET(vmap_area_purge_list)); + fprintf(fp, " vmap_node_busy: %ld\n", OFFSET(vmap_node_busy)); + fprintf(fp, " rb_list_head: %ld\n", OFFSET(rb_list_head)); fprintf(fp, " module_size_of_struct: %ld\n", OFFSET(module_size_of_struct)); @@ -12040,6 +12042,7 @@ dump_offset_table(char *spec, ulong makestruct) SIZE(task_group)); fprintf(fp, " vmap_area: %ld\n", SIZE(vmap_area)); + fprintf(fp, " vmap_node: %ld\n", SIZE(vmap_node)); fprintf(fp, " hrtimer_clock_base: %ld\n", SIZE(hrtimer_clock_base)); fprintf(fp, " hrtimer_base: %ld\n", -- 2.31.1