[Crash-utility] [PATCH] Fix for an abort in vm_stat_init() without CONFIG_NUMA

With recent kernels without CONFIG_NUMA (including Fedora 32-bit), the vm_stat_init() function aborts when getting numa_stat_item enum items, (probably) because it is not defined. crash> kmem -V double free or corruption (!prev) Aborted (core dumped) We can avoid the abort by checking whether the length of the vm_numa_stat array is also not zero. This patch tested OK with the following kernels: 4.17.0-0.rc5.git3.1.fc29.i686 4.18.0-0.rc5.git4.1.fc29.x86_64 3.10.0-862.el7.x86_64 Signed-off-by: Kazuhito Hagio <k-hagio(a)ab.jp.nec.com&gt; --- defs.h | 1 + memory.c | 10 ++++++---- symbols.c | 4 ++++ 3 files changed, 11 insertions(+), 4 deletions(-) diff --git a/defs.h b/defs.h index f569a62..6fdb478 100644 --- a/defs.h +++ b/defs.h @@ -2220,6 +2220,7 @@ struct array_table { int height_to_maxnodes; int task_struct_rlim; int signal_struct_rlim; + int vm_numa_stat; }; /* diff --git a/memory.c b/memory.c index 7c0cb5f..e02ba68 100644 --- a/memory.c +++ b/memory.c @@ -17454,11 +17454,12 @@ vm_stat_init(void) } else if (symbol_exists("vm_zone_stat") && get_symbol_type("vm_zone_stat", NULL, NULL) == TYPE_CODE_ARRAY) { - if (symbol_exists("vm_numa_stat")) { + if (symbol_exists("vm_numa_stat") && + get_array_length("vm_numa_stat", NULL, 0)) { vt->nr_vm_stat_items = get_array_length("vm_zone_stat", NULL, 0) + get_array_length("vm_node_stat", NULL, 0) - + get_array_length("vm_numa_stat", NULL, 0); + + ARRAY_LENGTH(vm_numa_stat); split_vmstat = 2; enumerator_value("NR_VM_ZONE_STAT_ITEMS", &zone_cnt); enumerator_value("NR_VM_NODE_STAT_ITEMS", &node_cnt); @@ -17599,7 +17600,7 @@ dump_vm_stat(char *item, long *retval, ulong zone) buf = GETBUF(sizeof(ulong) * vt->nr_vm_stat_items); if (symbol_exists("vm_node_stat") && symbol_exists("vm_zone_stat") && - symbol_exists("vm_numa_stat")) + symbol_exists("vm_numa_stat") && ARRAY_LENGTH(vm_numa_stat)) split_vmstat = 2; else if (symbol_exists("vm_node_stat") && symbol_exists("vm_zone_stat")) split_vmstat = 1; @@ -17666,7 +17667,8 @@ dump_vm_stat(char *item, long *retval, ulong zone) if (!zone) { if ((i == node_start) && symbol_exists("vm_node_stat")) fprintf(fp, "\n VM_NODE_STAT:\n"); - if ((i == numa_start) && symbol_exists("vm_numa_stat")) + if ((i == numa_start) && symbol_exists("vm_numa_stat") + && ARRAY_LENGTH(vm_numa_stat)) fprintf(fp, "\n VM_NUMA_STAT:\n"); } fprintf(fp, "%s%s: %ld\n", diff --git a/symbols.c b/symbols.c index df84ee2..bee60ba 100644 --- a/symbols.c +++ b/symbols.c @@ -8457,6 +8457,8 @@ builtin_array_length(char *s, int len, int *two_dim) lenptr = &array_table.task_struct_rlim; else if (STREQ(s, "signal_struct.rlim")) lenptr = &array_table.signal_struct_rlim; + else if (STREQ(s, "vm_numa_stat")) + lenptr = &array_table.vm_numa_stat; if (!lenptr) /* not stored */ return(len); @@ -10594,6 +10596,8 @@ dump_offset_table(char *spec, ulong makestruct) ARRAY_LENGTH(task_struct_rlim)); fprintf(fp, " signal_struct_rlim: %d\n", ARRAY_LENGTH(signal_struct_rlim)); + fprintf(fp, " vm_numa_stat: %d\n", + ARRAY_LENGTH(vm_numa_stat)); if (spec) { int in_size_table, in_array_table, arrays, offsets, sizes; -- 1.8.3.1