[PATCH RFC][makedumpfile 04/10] Add btf/kallsyms support for symbol type/address resolving
Tao Liu
ltao at redhat.com
Tue Jun 10 02:57:37 PDT 2025
btf data contains symbols' type and size, which is essential to determine a
structure/member size & offset. kallsyms contains symbols' address. All the
data can provide complete info for symbol resolving.
To initialize, we will:
1st) read vmcore info and parse kernel's kallsyms data;
2nd) read kernel data range of "__start/stop_BTF" and parse kernel's btf data,
now we have complete type/address info for kernel symbols;
3rd) iterate kernel's module and parse all kernel modules' kallsyms data;
4th) iterate btf_modules and parse all kernel modules' btf data, now we have
complete type/address info for kernel and modules symbols.
Also to speed up the converting of symbol name to address/type, the parsed
btf/kallsyms data are stored in hash tables.
Signed-off-by: Tao Liu <ltao at redhat.com>
---
Makefile | 2 +-
btf.c | 919 +++++++++++++++++++++++++++++++++++++++++++++++++
btf.h | 176 ++++++++++
kallsyms.c | 371 ++++++++++++++++++++
kallsyms.h | 42 +++
makedumpfile.c | 3 +
makedumpfile.h | 11 +
7 files changed, 1523 insertions(+), 1 deletion(-)
create mode 100644 btf.c
create mode 100644 btf.h
create mode 100644 kallsyms.c
create mode 100644 kallsyms.h
diff --git a/Makefile b/Makefile
index 18d3a17..fbc9f5b 100644
--- a/Makefile
+++ b/Makefile
@@ -45,7 +45,7 @@ CFLAGS_ARCH += -m32
endif
SRC_BASE = makedumpfile.c makedumpfile.h diskdump_mod.h sadump_mod.h sadump_info.h
-SRC_PART = print_info.c dwarf_info.c elf_info.c erase_info.c sadump_info.c cache.c tools.c printk.c detect_cycle.c
+SRC_PART = print_info.c dwarf_info.c elf_info.c erase_info.c sadump_info.c cache.c tools.c printk.c detect_cycle.c kallsyms.c btf.c
OBJ_PART=$(patsubst %.c,%.o,$(SRC_PART))
SRC_ARCH = arch/arm.c arch/arm64.c arch/x86.c arch/x86_64.c arch/ia64.c arch/ppc64.c arch/s390x.c arch/ppc.c arch/sparc64.c arch/mips64.c arch/loongarch64.c arch/riscv64.c
OBJ_ARCH=$(patsubst %.c,%.o,$(SRC_ARCH))
diff --git a/btf.c b/btf.c
new file mode 100644
index 0000000..c91c841
--- /dev/null
+++ b/btf.c
@@ -0,0 +1,919 @@
+#include "btf.h"
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <libelf.h>
+#include <gelf.h>
+#include <dirent.h>
+#include "kallsyms.h"
+#include "makedumpfile.h"
+
+// btf_files_array[0] must be kernel itself
+// btf_files_array[1..] are kernel modules
+static struct btf_file **btf_files_array = NULL;
+static int btf_files_array_index = 0;
+
+static const char *kind_names[NR_BTF_KINDS] = {
+ [BTF_KIND_UNKN] = "UNKN",
+ [BTF_KIND_INT] = "INT",
+ [BTF_KIND_PTR] = "PTR",
+ [BTF_KIND_ARRAY] = "ARRAY",
+ [BTF_KIND_STRUCT] = "STRUCT",
+ [BTF_KIND_UNION] = "UNION",
+ [BTF_KIND_ENUM] = "ENUM",
+ [BTF_KIND_FWD] = "FWD",
+ [BTF_KIND_TYPEDEF] = "TYPEDEF",
+ [BTF_KIND_VOLATILE] = "VOLATILE",
+ [BTF_KIND_CONST] = "CONST",
+ [BTF_KIND_RESTRICT] = "RESTRICT",
+ [BTF_KIND_FUNC] = "FUNC",
+ [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
+ [BTF_KIND_VAR] = "VAR",
+ [BTF_KIND_DATASEC] = "DATASEC",
+ [BTF_KIND_FLOAT] = "FLOAT",
+ [BTF_KIND_DECL_TAG] = "DECL_TAG",
+ [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
+ [BTF_KIND_ENUM64] = "ENUM64",
+};
+
+static inline uint16_t btf_vlen(uint32_t info)
+{
+ return info & 0xFFFF;
+}
+
+static inline uint32_t btf_kind_flag(uint32_t info)
+{
+ return info & (1 << 31);
+}
+
+static inline uint32_t btf_member_bit_offset(uint32_t value)
+{
+ return value & 0xffffff;
+}
+
+static inline uint32_t btf_member_bitfield_size(uint32_t value)
+{
+ return value >> 24;
+}
+
+static struct btf_type *btf_next(struct btf_type *tp)
+{
+ uintptr_t next = (uintptr_t)&tp[1];
+
+ switch (btf_kind(tp->info)) {
+ case BTF_KIND_INT:
+ next += sizeof(uint32_t);
+ break;
+
+ case BTF_KIND_ARRAY:
+ next += sizeof(struct btf_array);
+ break;
+
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ next += btf_vlen(tp->info) * sizeof(struct btf_member);
+ break;
+
+ case BTF_KIND_ENUM:
+ next += btf_vlen(tp->info) * sizeof(struct btf_enum);
+ break;
+
+ case BTF_KIND_FUNC_PROTO:
+ next += btf_vlen(tp->info) * sizeof(struct btf_param);
+ break;
+
+ case BTF_KIND_VAR:
+ next += sizeof(struct btf_var);
+ break;
+
+ case BTF_KIND_DATASEC:
+ next += btf_vlen(tp->info) * sizeof(struct btf_var_secinfo);
+ break;
+
+ case BTF_KIND_DECL_TAG:
+ next += sizeof(struct btf_decl_tag);
+ break;
+
+ case BTF_KIND_ENUM64:
+ next += btf_vlen(tp->info) * sizeof(struct btf_enum64);
+ break;
+
+ case BTF_KIND_PTR:
+ case BTF_KIND_FWD:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_CONST:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_FUNC:
+ case BTF_KIND_FLOAT:
+ case BTF_KIND_TYPE_TAG:
+ break; // no extra data
+
+ default:
+ __builtin_unreachable();
+ }
+ return (struct btf_type *)next;
+}
+
+#define NAME_HASH 512
+static struct name_entry *name_hash_table[NAME_HASH] = {0};
+
+static void *get_name_entry_next(void *entry)
+{
+ return ((struct name_entry *)entry)->name_hash_next;
+}
+
+static void set_name_entry_next(void *entry, void *next)
+{
+ ((struct name_entry *)entry)->name_hash_next = next;
+}
+
+static void name_hash_install(struct name_entry *en)
+{
+ hash_install((void **)name_hash_table, NAME_HASH, en, en->name,
+ get_name_entry_next, set_name_entry_next);
+}
+
+static unsigned int name_hash_index(char *name)
+{
+ return hash_index(name, NAME_HASH);
+}
+
+static int read_file_at_offset(char *f, int f_off, int r_size, void *buf)
+{
+ int got = 0;
+ int r, fd, ret = -1;
+
+ fd = open(f, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, "%s: Failed to open file %s\n", __func__, f);
+ goto out;
+ }
+
+ while (got < r_size) {
+ r = pread(fd, buf + got, r_size - got, f_off + got);
+ if (r < 0) {
+ fprintf(stderr, "%s: Failed to read file %s\n", __func__, f);
+ goto clean_fd;
+ }
+ got += r;
+ }
+ ret = got;
+
+clean_fd:
+ close(fd);
+out:
+ return ret;
+}
+
+static char *get_str_by_name_off(struct btf_file *bf, uint32_t name_off)
+{
+ struct btf_file *bf_vmlinux = btf_files_array[0];
+
+ if (bf != bf_vmlinux && name_off >= bf_vmlinux->str_cache_len)
+ return bf->str_cache + name_off - bf_vmlinux->str_cache_len;
+ else
+ return bf_vmlinux->str_cache + name_off;
+}
+
+int get_btf_type_by_type_id(struct btf_file *bf_in, uint32_t id_in,
+ struct btf_type *bt_out, struct name_entry **en_out)
+{
+ struct name_entry *en;
+ struct btf_file *bf_vmlinux = btf_files_array[0];
+
+ if (bf_in != bf_vmlinux && id_in > bf_vmlinux->array_len) {
+ en = bf_in->array[id_in - bf_vmlinux->array_len - 1];
+ } else {
+ en = bf_vmlinux->array[id_in - 1];
+ }
+ if (en_out)
+ *en_out = en;
+ return read_file_at_offset(en->bf->file_name,
+ en->btf_type_offset + en->bf->types_data_offset,
+ sizeof(*bt_out), bt_out);
+}
+
+/*
+* Parse the btf data and install elements into hashtable and array for quick
+* reference.
+*/
+static int parse_btf_data(char *file_path, char *data_start, uint32_t data_len)
+{
+ struct btf_header *hdr = (struct btf_header *)data_start;
+ struct btf_file *bf = NULL;
+ void *type_start;
+ char *str_start;
+ struct btf_type *tp;
+ struct name_entry *en;
+ int i, j, scale;
+
+ /* We do some check first */
+ if (hdr->magic != BTF_MAGIC) {
+ fprintf(stderr, "%s: Invalid BTF magic in %s\n",
+ __func__, file_path);
+ goto out;
+ }
+ if (hdr->hdr_len != sizeof(*hdr)) {
+ fprintf(stderr, "%s: Invalid BTF header length in %s\n",
+ __func__, file_path);
+ goto out;
+ }
+ if (hdr->hdr_len + hdr->str_off + hdr->str_len > data_len) {
+ fprintf(stderr, "%s: String section exceeds data length in %s\n",
+ __func__, file_path);
+ goto out;
+ }
+ if (hdr->hdr_len + hdr->type_off + hdr->type_len > data_len) {
+ fprintf(stderr, "%s: Type section exceeds data length in %s\n",
+ __func__, file_path);
+ goto out;
+ }
+
+ /* Let's start parsing */
+ bf = (struct btf_file *)malloc(sizeof(*bf));
+ if (!bf)
+ goto no_mem;
+ memset(bf, 0, sizeof(*bf));
+
+ /* Enlarge array when reach power of 2 */
+ btf_files_array[btf_files_array_index++] = bf;
+ if ((btf_files_array_index & (btf_files_array_index - 1)) == 0) {
+ struct btf_file **tmp = (struct btf_file **)reallocarray(btf_files_array,
+ btf_files_array_index << 1,
+ sizeof(struct btf_file *));
+ if (!tmp)
+ goto no_mem;
+ btf_files_array = tmp;
+ }
+
+ type_start = data_start + hdr->hdr_len + hdr->type_off;
+ str_start = data_start + hdr->hdr_len + hdr->str_off;
+
+ bf->str_cache = malloc(hdr->str_len);
+ if (!bf->str_cache)
+ goto no_mem;
+ memcpy(bf->str_cache, str_start, hdr->str_len);
+ bf->str_cache_len = hdr->str_len;
+
+ bf->array_len = 64;
+ bf->array = (struct name_entry **)calloc(bf->array_len,
+ sizeof(struct name_entry *));
+ if (!bf->array)
+ goto no_mem;
+
+ bf->file_name = strdup(file_path);
+ if (!bf->file_name)
+ goto no_mem;
+ bf->types_data_offset = (char *)type_start - data_start;
+
+ for (tp = (struct btf_type *)type_start, i = 0;
+ (void *)tp < type_start + hdr->type_len;
+ tp = btf_next(tp), i++) {
+ en = (struct name_entry *)malloc(sizeof(struct name_entry));
+ if (!en) {
+ bf->array_len = i;
+ goto no_mem;
+ }
+ memset(en, 0, sizeof(struct name_entry));
+
+ en->btf_type_offset = (void *)tp - type_start;
+ en->id = i + 1;
+ en->bf = bf;
+ if (tp->name_off) {
+ en->name = get_str_by_name_off(bf, tp->name_off);
+ if (en->name[0])
+ name_hash_install(en);
+ }
+ bf->array[i] = en;
+
+ /* Now deal with sub elements which also have a name */
+ if (btf_kind(tp->info) == BTF_KIND_ENUM ||
+ btf_kind(tp->info) == BTF_KIND_ENUM64) {
+ scale = btf_kind(tp->info) == BTF_KIND_ENUM ?
+ sizeof(struct btf_enum) : sizeof(struct btf_enum64);
+ for (j = 0; j < btf_vlen(tp->info); j++) {
+ en = (struct name_entry *)malloc(sizeof(struct name_entry));
+ if (!en) {
+ bf->array_len = i + 1;
+ goto no_mem;
+ }
+ memset(en, 0, sizeof(struct name_entry));
+ en->id = 0;
+ en->p_id = i + 1;
+ en->p_id += btf_files_array_index == 1 ?
+ 0 : btf_files_array[0]->array_len;
+ en->bf = bf;
+ en->name = get_str_by_name_off(bf,
+ *(uint32_t *)((char *)&tp[1] + j * scale));
+ // printf("%s\n", en->name);
+ name_hash_install(en);
+ }
+ }
+
+ /* Enlarge array when over 3/4 */
+ if (i > (bf->array_len >> 2) * 3) {
+ struct name_entry **tmp = (struct name_entry **)reallocarray(bf->array,
+ bf->array_len << 1, sizeof(struct name_entry *));
+ if (!tmp)
+ goto no_mem;
+ bf->array = tmp;
+ bf->array_len <<= 1;
+ }
+ }
+ bf->array_len = i;
+ return 0;
+no_mem:
+ /* All the memory free will be dealed later. */
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+out:
+ return -1;
+}
+
+/*
+ * Used by search_name_by_cond() for searching specific type:
+ * such as struct/union/typedef
+ */
+static bool is_type(struct name_entry *sp, void *data_in, void *data_out)
+{
+ struct btf_type *bt = (struct btf_type *)data_out;
+ int type = *(int *)data_in;
+ if (sp->id) {
+ read_file_at_offset(sp->bf->file_name,
+ sp->btf_type_offset + sp->bf->types_data_offset,
+ sizeof(*bt), bt);
+ return btf_kind(bt->info) == type;
+ }
+ return false;
+}
+
+static struct name_entry *search_name_by_cond(char *name,
+ bool (*fn)(struct name_entry *, void *, void *),
+ void *data_in, void *data_out)
+{
+ unsigned int index;
+ struct name_entry *sp;
+
+ index = name_hash_index(name);
+ for (sp = name_hash_table[index]; sp; sp = sp->name_hash_next) {
+ if (!strcmp(name, sp->name) && fn(sp, data_in, data_out)) {
+ return sp;
+ }
+ }
+ return sp;
+}
+
+// caller should prepare bt
+void resolve_typedef(struct name_entry *en_in, struct name_entry **en_out,
+ struct btf_type *bt)
+{
+ uint32_t id;
+ struct name_entry *en;
+
+ read_file_at_offset(en_in->bf->file_name,
+ en_in->btf_type_offset + en_in->bf->types_data_offset,
+ sizeof(*bt), bt);
+ if (btf_kind(bt->info) == BTF_KIND_TYPEDEF) {
+ id = bt->type;
+ get_btf_type_by_type_id(en_in->bf, id, bt, &en);
+ return resolve_typedef(en, en_out, bt);
+ } else {
+ *en_out = en_in;
+ }
+}
+
+struct cond_args {
+ int index;
+ char *name;
+};
+
+static bool cond(struct cond_args *c1, struct cond_args *c2)
+{
+ if (c1->name && c2->name)
+ /* Check if the member name is what we want */
+ return !strcmp(c1->name, c2->name);
+ else
+ /* Check if the member index is what we want */
+ return c1->index == c2->index;
+}
+
+static bool get_internal_member_info(struct name_entry *en, int base_position,
+ int *global_index, struct cond_args *tar_arg,
+ struct member_info *mi, bool initial_dive)
+{
+ struct btf_type bt, sub_bt;
+ int member_num;
+ char *member_array_buf = NULL;
+ int i;
+ struct btf_member *bm;
+ struct btf_array *ba;
+ int bm_position;
+ struct name_entry *sub_en;
+ bool res;
+ struct cond_args cur_arg = {0};
+
+ read_file_at_offset(en->bf->file_name,
+ en->btf_type_offset + en->bf->types_data_offset,
+ sizeof(bt), &bt); // this struct
+ if (initial_dive ||
+ ((!en->name || en->name[0] == '\0') &&
+ ((btf_kind(bt.info) == BTF_KIND_STRUCT) ||
+ (btf_kind(bt.info) == BTF_KIND_UNION)))) {
+ /* anonymous struct/union, dive into */
+ member_num = btf_vlen(bt.info);
+ member_array_buf = calloc(member_num, sizeof(struct btf_member));
+ if (!member_array_buf) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ return false;
+ }
+ read_file_at_offset(en->bf->file_name,
+ en->btf_type_offset + en->bf->types_data_offset + sizeof(bt),
+ member_num *sizeof(struct btf_member), member_array_buf);
+ for (i = 0, bm = (struct btf_member *)member_array_buf;
+ i < member_num; i++) {
+ if (btf_kind_flag(bt.info)) {
+ bm_position = base_position +
+ btf_member_bit_offset(bm[i].offset);
+ mi->bits = btf_member_bitfield_size(bm[i].offset);
+ } else {
+ bm_position = base_position +
+ bm[i].offset;
+ }
+ mi->sname = get_str_by_name_off(en->bf, bm[i].name_off);
+ get_btf_type_by_type_id(en->bf, bm[i].type,
+ &sub_bt, &sub_en);
+ // Dive into this member
+ res = get_internal_member_info(sub_en, bm_position, global_index,
+ tar_arg, mi, false);
+ if (res) {
+ free(member_array_buf);
+ return res;
+ }
+ }
+ free(member_array_buf);
+ return false;
+ }
+
+ cur_arg.index = *global_index;
+ cur_arg.name = mi->sname;
+ if (cond(&cur_arg, tar_arg)) {
+ mi->bit_pos = base_position;
+ resolve_typedef(en, &sub_en, &bt);
+ mi->uniq_id = id_to_uniq_id(sub_en->id, sub_en->bf);
+ if (btf_kind(bt.info) == BTF_KIND_PTR) {
+ /*
+ * BUG? No pointer size in btf,
+ * 32bit btf target on 64bit machine
+ */
+ mi->size = sizeof(void *);
+ mi->type = "char *";
+ } else if (btf_kind(bt.info) == BTF_KIND_ARRAY) {
+ en = sub_en;
+ ba = (struct btf_array *)malloc(sizeof(struct btf_array));
+ if (!ba) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ return false;
+ }
+ read_file_at_offset(en->bf->file_name,
+ en->btf_type_offset + en->bf->types_data_offset + sizeof(bt),
+ sizeof(struct btf_array), ba);
+ mi->size = ba->nelems; // array elements
+ get_btf_type_by_type_id(en->bf, ba->type, &sub_bt, &sub_en);
+ resolve_typedef(sub_en, &en, &bt);
+ free(ba);
+ mi->size *= bt.size; // element size
+ mi->type = NULL; // "char [64]? Leave it NULL for now"
+ } else {
+ mi->size = bt.size;
+ mi->type = get_str_by_name_off(sub_en->bf, bt.name_off);
+ }
+ return true;
+ } else {
+ (*global_index)++;
+ return false;
+ }
+}
+
+static bool get_member_info_by_index(struct name_entry *en, int target_index,
+ struct member_info *mi)
+{
+ int g_index = 1;
+ struct cond_args args = {0};
+ args.index = target_index;
+ memset(mi, 0, sizeof(*mi));
+ return get_internal_member_info(en, 0, &g_index, &args, mi, true);
+}
+
+static bool get_member_info_by_member_name(struct name_entry *en, char *member_name,
+ struct member_info *mi)
+{
+ int g_index = 1;
+ struct cond_args args = {0};
+ args.name = member_name;
+ memset(mi, 0, sizeof(*mi));
+ return get_internal_member_info(en, 0, &g_index, &args, mi, true);
+}
+
+/*
+ * Entry for query struct members
+ * Return: struct size, mi_out: member details
+ */
+uint32_t get_struct_member_by_name(char *struct_name, char *member_name,
+ struct member_info *mi_out)
+{
+ struct name_entry *en;
+ struct btf_type bt = {0};
+ int type = BTF_KIND_STRUCT;
+
+ en = search_name_by_cond(struct_name, is_type, (void *)&type, (void *)&bt);
+ if (!en)
+ goto out;
+ if (get_member_info_by_member_name(en, member_name, mi_out))
+ return bt.size;
+out:
+ return 0;
+}
+
+/*
+ * Entry for query type members, similar as above
+ * Return: found-the-type, mi_out: member details
+ */
+static uint32_t uniq_id_to_id(uint32_t, struct btf_file **);
+bool get_type_member_by_index(uint64_t type_uniq_id, int member_index,
+ struct member_info *mi_out)
+{
+ uint32_t id;
+ struct btf_file *bf;
+
+ id = uniq_id_to_id((uint32_t)type_uniq_id, &bf);
+ return get_member_info_by_index(bf->array[id - 1], member_index, mi_out);
+}
+
+uint32_t id_to_uniq_id(uint32_t id, struct btf_file *bf)
+{
+ int i;
+ uint32_t uniq_id = 0;
+ for (i = 0; i < btf_files_array_index; i++) {
+ if (btf_files_array[i] != bf)
+ uniq_id += btf_files_array[i]->array_len;
+ else
+ return id + uniq_id;
+ }
+ __builtin_unreachable();
+ assert(false);
+}
+
+static uint32_t uniq_id_to_id(uint32_t uid, struct btf_file **bf)
+{
+ int i;
+
+ for (i = 0; i < btf_files_array_index; i++) {
+ if (uid > btf_files_array[i]->array_len) {
+ uid -= btf_files_array[i]->array_len;
+ } else {
+ if (bf)
+ *bf = btf_files_array[i];
+ return uid;
+ }
+
+ }
+ __builtin_unreachable();
+ assert(false);
+}
+
+// api for eppic
+uint32_t get_type_size_by_name(char *type_name, int type, uint32_t *uniq_id)
+{
+ struct name_entry *en;
+ struct btf_type bt = {0};
+
+ en = search_name_by_cond(type_name, is_type, (void *)&type, (void *)&bt);
+ if (!en)
+ goto out;
+ if (uniq_id)
+ *uniq_id = id_to_uniq_id(en->id, en->bf);
+ return bt.size;
+out:
+ return 0;
+}
+
+// Caller should prepare bt_out
+struct name_entry *get_en_by_uniq_id(uint32_t uniq_id, struct btf_type *bt_out)
+{
+ uint32_t id;
+ struct btf_file *bf;
+ struct name_entry *en;
+ struct name_entry *en_sub;
+
+ id = uniq_id_to_id((uint32_t)uniq_id, &bf);
+ en = bf->array[id - 1];
+ resolve_typedef(en, &en_sub, bt_out);
+ return en_sub;
+}
+
+/* Deal with btf file */
+static int btf_file_init(int fd)
+{
+ struct stat f_stat;
+ char *buf = NULL;
+ char proc_path[32];
+ char real_path[512];
+ int ret = -1;
+
+ memset(real_path, 0, sizeof(real_path));
+ if (fstat(fd, &f_stat) < 0) {
+ fprintf(stderr, "%s: fstat fail!\n", __func__);
+ goto out;
+ }
+ buf = malloc(f_stat.st_size);
+ if (!buf) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ goto out;
+ }
+
+ snprintf(proc_path, sizeof(proc_path), "/proc/self/fd/%d", fd);
+ readlink(proc_path, real_path, sizeof(real_path) - 1);
+ if (read_file_at_offset(real_path, 0, f_stat.st_size, buf) < 0)
+ goto out;
+
+ ret = parse_btf_data(real_path, buf, f_stat.st_size);
+out:
+ if (buf)
+ free(buf);
+ return ret;
+}
+
+/* Deal with elf file which contains .BTF section */
+static int elf_file_init(int fd)
+{
+ char proc_path[32];
+ char real_path[512];
+ Elf *elf = NULL;
+ Elf_Scn *scn = NULL;
+ size_t shstrndx;
+ GElf_Shdr shdr;
+ Elf_Data *data = NULL;
+ char *str, *databuf = NULL;
+ int ret = -1;
+
+ snprintf(proc_path, sizeof(proc_path), "/proc/self/fd/%d", fd);
+ readlink(proc_path, real_path, sizeof(real_path) - 1);
+
+ if (elf_version(EV_CURRENT) == EV_NONE)
+ goto elf_err;
+ elf = elf_begin(fd, ELF_C_READ, NULL);
+ if (!elf || elf_getshdrstrndx(elf, &shstrndx))
+ goto elf_err;
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ if (!gelf_getshdr(scn, &shdr))
+ continue;
+ str = elf_strptr(elf, shstrndx, shdr.sh_name);
+ if (!strcmp(str, ".BTF"))
+ break;
+ }
+ if (!scn) {
+ fprintf(stderr, "%s: No .BTF found in %s!\n", __func__, real_path);
+ goto out;
+ }
+
+ data = elf_rawdata(scn, data);
+ databuf = malloc(data->d_size);
+ if (!databuf) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ goto out;
+ }
+ memcpy(databuf, data->d_buf, data->d_size);
+ elf_end(elf);
+ elf = NULL;
+ ret = parse_btf_data(real_path, databuf, data->d_size);
+ goto out;
+
+elf_err:
+ fprintf(stderr, "%s: elf error in %s!\n", __func__, real_path);
+out:
+ if (databuf)
+ free(databuf);
+ if (elf)
+ elf_end(elf);
+ return ret;
+}
+
+/*
+ * Entry for parse btf file and elf file.
+ */
+static int file_init(char *name)
+{
+ int fd = 0, ret = -1;
+ char buf[4] = {0};
+
+ /* Will be enlarged automatically */
+ if (!btf_files_array) {
+ btf_files_array = calloc(1, sizeof(struct btf_file *));
+ if (!btf_files_array) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ goto out;
+ }
+ }
+
+ fd = open(name, O_RDONLY);
+ if (read_file_at_offset(name, 0, sizeof(buf), buf) < 0)
+ goto out;
+ if (*(u_int16_t *)&buf == BTF_MAGIC) {
+ ret = btf_file_init(fd);
+ } else if (*(u_int32_t *)&buf == (((u_int32_t)ELFMAG0 << 24) |
+ ((u_int32_t)ELFMAG1 << 16) |
+ ((u_int32_t)ELFMAG2 << 8) |
+ ((u_int32_t)ELFMAG3 << 0))) {
+ ret = elf_file_init(fd);
+ } else {
+ __builtin_unreachable();
+ }
+
+out:
+ if (fd)
+ close(fd);
+ return ret;
+}
+
+/* For pure buffer data, wrap it as a file, and handover to file_init() */
+char temp[] = "/tmp/btf_XXXXXX";
+static int init_btf_from_buf(char *mod_name, char *buf, int size)
+{
+ int fd;
+ char name_buf[64];
+ int w, got = 0;
+ static char *temp_dir = NULL;
+
+ if (!temp_dir)
+ temp_dir = mkdtemp(temp);
+ snprintf(name_buf, sizeof(name_buf), "%s/%s", temp_dir, mod_name);
+ fd = open(name_buf, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+ if (fd < 0) {
+ fprintf(stderr, "%s: open fail in %s!\n", __func__, name_buf);
+ return -1;
+ }
+
+ while (got < size) {
+ w = pwrite(fd, buf + got, size - got, got);
+ if (w < 0) {
+ fprintf(stderr, "%s: pwrite fail in %s!\n", __func__, name_buf);
+ return -1;
+ }
+ got += w;
+ }
+ close(fd);
+ return file_init(name_buf);
+}
+
+int init_kernel_btf(void)
+{
+ uint64_t size;
+ char *buf;
+ int ret;
+
+ uint64_t start_btf = get_kallsyms_value_by_name("__start_BTF");
+ uint64_t stop_btf = get_kallsyms_value_by_name("__stop_BTF");
+ if (!start_btf || !stop_btf) {
+ fprintf(stderr, "%s: symbol __start/stop_BTF not found!\n", __func__);
+ return -1;
+ }
+
+ size = stop_btf - start_btf;
+ buf = (char *)malloc(size);
+ if (!buf) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ return -1;
+ }
+ readmem(VADDR, start_btf, buf, size);
+ ret = init_btf_from_buf("vmlinux", buf, size);
+ free(buf);
+
+ return ret;
+}
+
+int init_module_btf(void)
+{
+ uint64_t btf_modules, list;
+ struct member_info mi;
+ uint64_t btf = 0, data = 0, module = 0;
+ int data_size = 0;
+ char *btf_buf = NULL;
+ char *modname = NULL;
+
+ btf_modules = get_kallsyms_value_by_name("btf_modules");
+ if (!btf_modules)
+ /* Maybe module is not enabled, this is not an error */
+ return 0;
+
+ INIT_MEMBER_OFF_SIZE(btf_module, list);
+ INIT_MEMBER_OFF_SIZE(btf_module, btf);
+ INIT_MEMBER_OFF_SIZE(btf_module, module);
+ INIT_MEMBER_OFF_SIZE(module, name);
+ INIT_MEMBER_OFF_SIZE(btf, data);
+ INIT_MEMBER_OFF_SIZE(btf, data_size);
+ modname = (char *)malloc(GET_MEMBER_SIZE(module, name));
+ if (!modname) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ goto out;
+ }
+
+ for (list = next_list(btf_modules); list != btf_modules; list = next_list(list)) {
+ readmem(VADDR, list - GET_MEMBER_OFF(btf_module, list) +
+ GET_MEMBER_OFF(btf_module, btf),
+ &btf, GET_MEMBER_SIZE(btf_module, btf));
+ readmem(VADDR, list - GET_MEMBER_OFF(btf_module, list) +
+ GET_MEMBER_OFF(btf_module, module),
+ &module, GET_MEMBER_SIZE(btf_module, module));
+ readmem(VADDR, module + GET_MEMBER_OFF(module, name),
+ modname, GET_MEMBER_SIZE(module, name));
+ readmem(VADDR, btf + GET_MEMBER_OFF(btf, data),
+ &data, GET_MEMBER_SIZE(btf, data));
+ readmem(VADDR, btf + GET_MEMBER_OFF(btf, data_size),
+ &data_size, GET_MEMBER_SIZE(btf, data_size));
+ btf_buf = (char *)malloc(data_size);
+ if (!btf_buf) {
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+ goto out;
+ }
+ readmem(VADDR, data, btf_buf, data_size);
+ if (init_btf_from_buf(modname, btf_buf, data_size))
+ goto out;
+ free(btf_buf);
+ }
+ return 0;
+out:
+ if (modname)
+ free(modname);
+ if (btf_buf)
+ free(btf_buf);
+ return -1;
+}
+
+void cleanup_btf(void)
+{
+ int bf_index, i;
+ struct btf_file *bf;
+ struct name_entry *en, *en_tmp;
+ DIR *temp_dir;
+ struct dirent *entry;
+ char path[512];
+
+ /* Free no-hashtable-installed elements */
+ for (bf_index = 0; bf_index < btf_files_array_index; bf_index++) {
+ bf = btf_files_array[bf_index];
+ if (bf && bf->array) {
+ for (i = 0; i < bf->array_len; i++) {
+ if (!bf->array[i]->name || !bf->array[i]->name[0])
+ free(bf->array[i]);
+ }
+ }
+ }
+
+ /* Free the hashtable-installed elements */
+ for (i = 0; i < NAME_HASH; i++) {
+ for (en = name_hash_table[i]; en;) {
+ en_tmp = en;
+ en = en->name_hash_next;
+ free(en_tmp);
+ }
+ }
+
+ /* Cleanup anything else */
+ for (bf_index = 0; bf_index < btf_files_array_index; bf_index++) {
+ bf = btf_files_array[bf_index];
+ if (bf && bf->array) {
+ free(bf->array);
+ }
+ if (bf && bf->file_name)
+ free(bf->file_name);
+ if (bf && bf->str_cache)
+ free(bf->str_cache);
+ if (bf)
+ free(bf);
+ }
+
+ if (btf_files_array)
+ free(btf_files_array);
+
+ /* Cleanup the dir /tmp/btf_XXXXXX */
+ temp_dir = opendir(temp);
+ if (!temp_dir)
+ return;
+ while ((entry = readdir(temp_dir)) != NULL) {
+ if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, ".."))
+ continue;
+ snprintf(path, sizeof(path), "%s/%s", temp, entry->d_name);
+ if (remove(path)) {
+ fprintf(stderr, "%s: fail del %s!\n", __func__, path);
+ /* In case too many fail messages of files in the dir */
+ return;
+ }
+ }
+ closedir(temp_dir);
+ rmdir(temp);
+}
diff --git a/btf.h b/btf.h
new file mode 100644
index 0000000..a0d13e6
--- /dev/null
+++ b/btf.h
@@ -0,0 +1,176 @@
+#ifndef _BTF_H
+#define _BTF_H
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef uint8_t __u8;
+typedef uint16_t __u16;
+typedef uint32_t __u32;
+typedef int32_t __s32;
+
+#define BTF_MAGIC 0xeb9f
+
+enum {
+ BTF_KIND_UNKN = 0, /* Unknown */
+ BTF_KIND_INT = 1, /* Integer */
+ BTF_KIND_PTR = 2, /* Pointer */
+ BTF_KIND_ARRAY = 3, /* Array */
+ BTF_KIND_STRUCT = 4, /* Struct */
+ BTF_KIND_UNION = 5, /* Union */
+ BTF_KIND_ENUM = 6, /* Enumeration */
+ BTF_KIND_FWD = 7, /* Forward */
+ BTF_KIND_TYPEDEF = 8, /* Typedef */
+ BTF_KIND_VOLATILE = 9, /* Volatile */
+ BTF_KIND_CONST = 10, /* Const */
+ BTF_KIND_RESTRICT = 11, /* Restrict */
+ BTF_KIND_FUNC = 12, /* Function */
+ BTF_KIND_FUNC_PROTO = 13, /* Function Proto */
+ BTF_KIND_VAR = 14, /* Variable */
+ BTF_KIND_DATASEC = 15, /* Section */
+ BTF_KIND_FLOAT = 16, /* Floating point */
+ BTF_KIND_DECL_TAG = 17, /* Decl Tag */
+ BTF_KIND_TYPE_TAG = 18, /* Type Tag */
+ BTF_KIND_ENUM64 = 19, /* Enumeration up to 64-bit values */
+
+ NR_BTF_KINDS,
+ BTF_KIND_MAX = NR_BTF_KINDS - 1,
+};
+
+struct btf_type {
+ __u32 name_off;
+
+ /* "info" bits arrangement
+ * bits 0-15: vlen (e.g. # of struct's members)
+ * bits 16-23: unused
+ * bits 24-27: kind (e.g. int, ptr, array...etc)
+ * bits 28-30: unused
+ * bit 31: kind_flag, currently used by
+ * struct, union and fwd
+ */
+ __u32 info;
+
+ /* "size" is used by INT, ENUM, STRUCT, UNION and DATASEC.
+ * "size" tells the size of the type it is describing.
+ *
+ * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
+ * FUNC, FUNC_PROTO, VAR, DECL_TAG and TYPE_TAG.
+ * "type" is a type_id referring to another type.
+ */
+ union {
+ __u32 size;
+ __u32 type;
+ };
+};
+
+struct btf_header {
+ __u16 magic;
+ __u8 version;
+ __u8 flags;
+ __u32 hdr_len;
+
+ /* All offsets are in bytes relative to the end of this header */
+ __u32 type_off; /* offset of type section */
+ __u32 type_len; /* length of type section */
+ __u32 str_off; /* offset of string section */
+ __u32 str_len; /* length of string section */
+};
+
+struct btf_array {
+ __u32 type;
+ __u32 index_type;
+ __u32 nelems;
+};
+
+struct btf_member {
+ __u32 name_off;
+ __u32 type;
+ /* If the type info kind_flag is set, the btf_member offset
+ * contains both member bitfield size and bit offset. The
+ * bitfield size is set for bitfield members. If the type
+ * info kind_flag is not set, the offset contains only bit
+ * offset.
+ */
+ __u32 offset;
+};
+
+struct btf_enum {
+ __u32 name_off;
+ __s32 val;
+};
+
+struct btf_enum64 {
+ __u32 name_off;
+ __u32 val_lo32;
+ __u32 val_hi32;
+};
+
+struct btf_param {
+ __u32 name_off;
+ __u32 type;
+};
+
+struct btf_var {
+ __u32 linkage;
+};
+
+struct btf_var_secinfo {
+ __u32 type;
+ __u32 offset;
+ __u32 size;
+};
+
+struct btf_decl_tag {
+ __s32 component_idx;
+};
+
+/*************************************/
+struct btf_file {
+ char *file_name;
+ char *str_cache;
+ uint32_t str_cache_len;
+ uint32_t types_data_offset;
+ uint32_t array_len;
+ struct name_entry **array;
+};
+
+struct name_entry {
+ union {
+ uint32_t btf_type_offset;
+ uint32_t p_id;
+ };
+
+ uint32_t id;
+ char *name;
+ struct btf_file *bf;
+ struct name_entry *name_hash_next;
+};
+
+struct member_info {
+ char *sname; // member name
+ char *type; // member type: int, long etc
+ uint32_t bit_pos; // member position in bits
+ uint32_t bits; // member width in bits
+ uint32_t size; // member size in bytes
+ int uniq_id; // uniq_id of btf
+};
+
+/*************************************/
+
+int init_kernel_btf(void);
+uint32_t get_struct_member_by_name(char *, char *, struct member_info *);
+bool get_type_member_by_index(uint64_t, int, struct member_info *);
+uint32_t get_type_size_by_name(char *, int, uint32_t *);
+struct name_entry *get_en_by_uniq_id(uint32_t, struct btf_type *);
+void resolve_typedef(struct name_entry *, struct name_entry **, struct btf_type *);
+int get_btf_type_by_type_id(struct btf_file *, uint32_t,
+ struct btf_type *, struct name_entry **);
+uint32_t id_to_uniq_id(uint32_t, struct btf_file *);
+int init_module_btf(void);
+void cleanup_btf(void);
+
+static inline uint32_t btf_kind(uint32_t info)
+{
+ return (info & 0x1F000000) >> 24;
+}
+
+#endif /* _BTF_H */
diff --git a/kallsyms.c b/kallsyms.c
new file mode 100644
index 0000000..89f6bfa
--- /dev/null
+++ b/kallsyms.c
@@ -0,0 +1,371 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include "makedumpfile.h"
+#include "kallsyms.h"
+#include "btf.h"
+
+static uint32_t *kallsyms_offsets = NULL;
+static uint16_t *kallsyms_token_index = NULL;
+static uint8_t *kallsyms_token_table = NULL;
+static uint8_t *kallsyms_names = NULL;
+static unsigned long kallsyms_relative_base = 0;
+static unsigned int kallsyms_num_syms = 0;
+
+#define NAME_HASH 512
+static struct syment *symtable = NULL;
+static struct syment *name_hash_table[NAME_HASH] = {0};
+
+static uint64_t absolute_percpu(uint64_t base, int32_t val)
+{
+ if (val >= 0)
+ return (uint64_t)val;
+ else
+ return base - 1 - val;
+}
+
+static void *get_syment_next(void *entry)
+{
+ return ((struct syment *)entry)->name_hash_next;
+}
+
+static void set_syment_next(void *entry, void *next)
+{
+ ((struct syment *)entry)->name_hash_next = next;
+}
+
+static unsigned int name_hash_index(char *name)
+{
+ return hash_index(name, NAME_HASH);
+}
+
+static void name_hash_install(struct syment *en)
+{
+ hash_install((void **)name_hash_table, NAME_HASH, en, en->name,
+ get_syment_next, set_syment_next);
+}
+
+struct syment *search_kallsyms_by_name(char *name)
+{
+ unsigned int index;
+ struct syment *sp;
+
+ index = name_hash_index(name);
+ for (sp = name_hash_table[index]; sp; sp = sp->name_hash_next) {
+ if (!strcmp(name, sp->name)) {
+ return sp;
+ }
+ }
+ return sp;
+}
+
+uint64_t get_kallsyms_value_by_name(char *name)
+{
+ struct syment *sp;
+
+ sp = search_kallsyms_by_name(name);
+ if (!sp)
+ return 0;
+ return sp->value;
+}
+
+#define BUFLEN 512
+int parse_kernel_kallsyms(void)
+{
+ char buf[BUFLEN];
+ int len = 0;
+ int index = 0, i;
+ uint8_t *compressd_data;
+ uint8_t *uncompressd_data;
+ uint64_t stext;
+
+ symtable = calloc(kallsyms_num_syms, sizeof(struct syment));
+ if (!symtable)
+ goto no_mem;
+
+ for (i = 0; i < kallsyms_num_syms; i++) {
+ memset(buf, 0, BUFLEN);
+ len = kallsyms_names[index++];
+ compressd_data = &kallsyms_names[index];
+ index += len;
+ while (len--) {
+ uncompressd_data = &kallsyms_token_table[kallsyms_token_index[*compressd_data]];
+ assert(strlen(buf) + strlen((char *)uncompressd_data) < BUFLEN);
+ strcat(buf, (char *)uncompressd_data);
+ compressd_data++;
+ }
+ symtable[i].value = kallsyms_offsets[i];
+ symtable[i].type = buf[0];
+ symtable[i].name = strdup(&buf[1]);
+ if (!symtable[i].name)
+ goto no_mem;
+ name_hash_install(&symtable[i]);
+ }
+
+ /* Now refresh the absolute each kallsyms address */
+ stext = get_kallsyms_value_by_name("_stext");
+ if (SYMBOL(_stext) == absolute_percpu(kallsyms_relative_base, stext)) {
+ for (i = 0; i < kallsyms_num_syms; i++) {
+ symtable[i].value = absolute_percpu(kallsyms_relative_base,
+ symtable[i].value);
+ }
+ } else if (SYMBOL(_stext) == kallsyms_relative_base + stext) {
+ for (i = 0; i < kallsyms_num_syms; i++) {
+ symtable[i].value += kallsyms_relative_base;
+ }
+ } else {
+ fprintf(stderr, "%s: Wrong calculate kallsyms symbol value!\n", __func__);
+ goto out;
+ }
+
+ return 0;
+no_mem:
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+out:
+ return -1;
+}
+
+static bool vmcore_info_ready = false;
+
+int read_vmcoreinfo_kallsyms(void)
+{
+ READ_SYMBOL("kallsyms_names", kallsyms_names);
+ READ_SYMBOL("kallsyms_num_syms", kallsyms_num_syms);
+ READ_SYMBOL("kallsyms_token_table", kallsyms_token_table);
+ READ_SYMBOL("kallsyms_token_index", kallsyms_token_index);
+ READ_SYMBOL("kallsyms_offsets", kallsyms_offsets);
+ READ_SYMBOL("kallsyms_relative_base", kallsyms_relative_base);
+ vmcore_info_ready = true;
+ return true;
+}
+
+int init_kernel_kallsyms(void)
+{
+ const int token_index_size = (UINT8_MAX + 1) * sizeof(uint16_t);
+ uint64_t last_token, len;
+ char data;
+ int i;
+ int ret = -1;
+
+ if (vmcore_info_ready == false) {
+ fprintf(stderr, "%s: vmcoreinfo not ready for kallsyms!\n",
+ __func__);
+ return ret;
+ }
+
+ readmem(VADDR, SYMBOL(kallsyms_num_syms), &kallsyms_num_syms,
+ sizeof(kallsyms_num_syms));
+ readmem(VADDR, SYMBOL(kallsyms_relative_base), &kallsyms_relative_base,
+ sizeof(kallsyms_relative_base));
+
+ kallsyms_offsets = malloc(sizeof(uint32_t) * kallsyms_num_syms);
+ if (!kallsyms_offsets)
+ goto no_mem;
+ readmem(VADDR, SYMBOL(kallsyms_offsets), kallsyms_offsets,
+ kallsyms_num_syms * sizeof(uint32_t));
+
+ kallsyms_token_index = malloc(token_index_size);
+ if (!kallsyms_token_index)
+ goto no_mem;
+ readmem(VADDR, SYMBOL(kallsyms_token_index), kallsyms_token_index,
+ token_index_size);
+
+ last_token = SYMBOL(kallsyms_token_table) + kallsyms_token_index[UINT8_MAX];
+ do {
+ readmem(VADDR, last_token++, &data, 1);
+ } while(data);
+ len = last_token - SYMBOL(kallsyms_token_table);
+ kallsyms_token_table = malloc(len);
+ if (!kallsyms_token_table)
+ goto no_mem;
+ readmem(VADDR, SYMBOL(kallsyms_token_table), kallsyms_token_table, len);
+
+ for (len = 0, i = 0; i < kallsyms_num_syms; i++) {
+ readmem(VADDR, SYMBOL(kallsyms_names) + len, &data, 1);
+ if (data & 0x80) {
+ printf("BUG! long sym name");
+ goto out;
+ }
+ len += data + 1;
+ }
+ kallsyms_names = malloc(len);
+ if (!kallsyms_names)
+ goto no_mem;
+ readmem(VADDR, SYMBOL(kallsyms_names), kallsyms_names, len);
+
+ ret = parse_kernel_kallsyms();
+ goto out;
+
+no_mem:
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+out:
+ if (kallsyms_offsets)
+ free(kallsyms_offsets);
+ if (kallsyms_token_index)
+ free(kallsyms_token_index);
+ if (kallsyms_token_table)
+ free(kallsyms_token_table);
+ if (kallsyms_names)
+ free(kallsyms_names);
+ return ret;
+}
+
+uint64_t next_list(uint64_t list)
+{
+ static int list_head_next_offset = 0;
+ static int list_head_next_size = 0;
+
+ struct member_info mi;
+ uint64_t next = 0;
+
+ if (!list_head_next_size) {
+ get_struct_member_by_name("list_head", "next", &mi);
+ list_head_next_size = mi.size;
+ list_head_next_offset = mi.bit_pos / 8;
+ }
+ readmem(VADDR, list + list_head_next_offset, &next, list_head_next_size);
+ return next;
+}
+
+int init_module_kallsyms(void)
+{
+ struct member_info mi;
+ uint64_t modules, list, value = 0, symtab = 0,
+ strtab = 0, typetab = 0;
+ uint32_t st_name = 0;
+ int num_symtab, i, j;
+ struct syment *mod_syment;
+ char symname[512], ch;
+ int ret = -1;
+
+ modules = get_kallsyms_value_by_name("modules");
+ if (!modules) {
+ /* Not a failure if no module enabled */
+ ret = 0;
+ goto out;
+ }
+
+ INIT_MEMBER_OFF_SIZE(module, list);
+ INIT_MEMBER_OFF_SIZE(module, core_kallsyms);
+ INIT_MEMBER_OFF_SIZE(mod_kallsyms, symtab);
+ INIT_MEMBER_OFF_SIZE(mod_kallsyms, num_symtab);
+ INIT_MEMBER_OFF_SIZE(mod_kallsyms, strtab);
+ INIT_MEMBER_OFF_SIZE(mod_kallsyms, typetab);
+ INIT_MEMBER_OFF_SIZE(elf64_sym, st_name);
+ INIT_MEMBER_OFF_SIZE(elf64_sym, st_value);
+
+ for (list = next_list(modules); list != modules; list = next_list(list)) {
+ readmem(VADDR, list - GET_MEMBER_OFF(module, list) +
+ GET_MEMBER_OFF(module, core_kallsyms) +
+ GET_MEMBER_OFF(mod_kallsyms, num_symtab),
+ &num_symtab, GET_MEMBER_SIZE(mod_kallsyms, num_symtab));
+ readmem(VADDR, list - GET_MEMBER_OFF(module, list) +
+ GET_MEMBER_OFF(module, core_kallsyms) +
+ GET_MEMBER_OFF(mod_kallsyms, symtab),
+ &symtab, GET_MEMBER_SIZE(mod_kallsyms, symtab));
+ readmem(VADDR, list - GET_MEMBER_OFF(module, list) +
+ GET_MEMBER_OFF(module, core_kallsyms) +
+ GET_MEMBER_OFF(mod_kallsyms, strtab),
+ &strtab, GET_MEMBER_SIZE(mod_kallsyms, strtab));
+ readmem(VADDR, list - GET_MEMBER_OFF(module, list) +
+ GET_MEMBER_OFF(module, core_kallsyms) +
+ GET_MEMBER_OFF(mod_kallsyms, typetab),
+ &typetab, GET_MEMBER_SIZE(mod_kallsyms, typetab));
+ for (i = 0; i < num_symtab; i++) {
+ j = 0;
+ readmem(VADDR, symtab + i * GET_STRUCT_SIZE(elf64_sym, st_value) +
+ GET_MEMBER_OFF(elf64_sym, st_value),
+ &value, GET_MEMBER_SIZE(elf64_sym, st_value));
+ readmem(VADDR, symtab + i * GET_STRUCT_SIZE(elf64_sym, st_name) +
+ GET_MEMBER_OFF(elf64_sym, st_name),
+ &st_name, GET_MEMBER_SIZE(elf64_sym, st_name));
+ do {
+ readmem(VADDR, strtab + st_name + j++, &ch, 1);
+ } while (ch != '\0');
+ if (j == 1)
+ /* Skip empty string */
+ continue;
+ assert(j <= sizeof(symname));
+ mod_syment = (struct syment *)calloc(1, sizeof(struct syment));
+ if (!mod_syment)
+ goto no_mem;
+ readmem(VADDR, strtab + st_name, symname, j);
+ mod_syment->name = strdup(symname);
+ if (!mod_syment->name) {
+ free(mod_syment);
+ goto no_mem;
+ }
+ mod_syment->value = value;
+ readmem(VADDR, typetab + i, &mod_syment->type, 1);
+ name_hash_install(mod_syment);
+ }
+ }
+ ret = 0;
+ goto out;
+no_mem:
+ /* Hashtable will be cleaned later */
+ fprintf(stderr, "%s: Not enough memory!\n", __func__);
+out:
+ return ret;
+}
+
+void cleanup_kallsyms(void)
+{
+ struct syment *en, *en_tmp;
+ int i;
+
+ /* Free the module's kallsyms first */
+ for (i = 0; i < NAME_HASH; i++) {
+ for (en = name_hash_table[i]; en;) {
+ en_tmp = en;
+ en = en->name_hash_next;
+ if (en_tmp <= &symtable[kallsyms_num_syms - 1] &&
+ en_tmp >= &symtable[0])
+ continue;
+ free(en_tmp->name);
+ free(en_tmp);
+ }
+ }
+
+ /* Free the kernel ones */
+ for (i = 0; i < kallsyms_num_syms; i++) {
+ if (symtable[i].name)
+ free(symtable[i].name);
+ }
+ free(symtable);
+}
+
+/* Hash table utils */
+unsigned int hash_index(const char *name, unsigned int hash_size)
+{
+ unsigned int len, value;
+
+ len = strlen(name);
+ value = name[len - 1] * name[len / 2];
+
+ return (name[0] ^ value) % hash_size;
+}
+
+void hash_install(void **hash_table, unsigned int hash_size,
+ void *entry, const char *name,
+ void *(*get_next)(void *),
+ void (*set_next)(void *, void *))
+{
+ unsigned int index = hash_index(name, hash_size);
+ void *sp = hash_table[index];
+
+ assert(index < hash_size);
+ if (sp == NULL) {
+ hash_table[index] = entry;
+ } else {
+ while (sp) {
+ if (get_next(sp)) {
+ sp = get_next(sp);
+ } else {
+ set_next(sp, entry);
+ break;
+ }
+ }
+ }
+}
\ No newline at end of file
diff --git a/kallsyms.h b/kallsyms.h
new file mode 100644
index 0000000..96ea970
--- /dev/null
+++ b/kallsyms.h
@@ -0,0 +1,42 @@
+#ifndef _KALLSYMS_H
+#define _KALLSYMS_H
+
+#include <stdint.h>
+
+struct syment {
+ uint64_t value;
+ char *name;
+ struct syment *name_hash_next;
+ char type;
+};
+
+int init_kernel_kallsyms(void);
+int read_vmcoreinfo_kallsyms(void);
+int parse_kernel_kallsyms(void);
+struct syment *search_kallsyms_by_name(char *);
+uint64_t next_list(uint64_t);
+uint64_t get_kallsyms_value_by_name(char *);
+int init_module_kallsyms(void);
+void cleanup_kallsyms(void);
+int read_vmcoreinfo_kallsyms(void);
+
+struct member_off_size {
+ int m_off;
+ int m_size;
+ int s_size;
+};
+#define QUATE(x) #x
+#define INIT_MEMBER_OFF_SIZE(S, M) \
+ struct member_off_size S##_##M; \
+ S##_##M.s_size = get_struct_member_by_name(QUATE(S), QUATE(M), &mi); \
+ S##_##M.m_off = mi.bit_pos / 8; \
+ S##_##M.m_size = mi.size;
+#define GET_MEMBER_OFF(S, M) (S##_##M.m_off)
+#define GET_MEMBER_SIZE(S, M) (S##_##M.m_size)
+#define GET_STRUCT_SIZE(S, M) (S##_##M.s_size)
+
+unsigned int hash_index(const char *, unsigned int);
+void hash_install(void **, unsigned int, void *, const char *,
+ void *(*)(void *), void (*)(void *, void *));
+
+#endif /* _KALLSYMS_H */
\ No newline at end of file
diff --git a/makedumpfile.c b/makedumpfile.c
index 33fad32..cdfcfeb 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -27,6 +27,7 @@
#include <limits.h>
#include <assert.h>
#include <zlib.h>
+#include "kallsyms.h"
struct symbol_table symbol_table;
struct size_table size_table;
@@ -3103,6 +3104,8 @@ read_vmcoreinfo_from_vmcore(off_t offset, unsigned long size, int flag_xen_hv)
if (!read_vmcoreinfo())
goto out;
}
+ read_vmcoreinfo_kallsyms();
+
close_vmcoreinfo();
ret = TRUE;
diff --git a/makedumpfile.h b/makedumpfile.h
index 944397a..cc474ad 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -257,6 +257,7 @@ static inline int string_exists(char *s) { return (s ? TRUE : FALSE); }
#define UINT(ADDR) *((unsigned int *)(ADDR))
#define ULONG(ADDR) *((unsigned long *)(ADDR))
#define ULONGLONG(ADDR) *((unsigned long long *)(ADDR))
+#define VOID_PTR(ADDR) *((void **)(ADDR))
/*
@@ -1917,6 +1918,16 @@ struct symbol_table {
* symbols on sparc64 arch
*/
unsigned long long vmemmap_table;
+
+ /*
+ * kallsyms related
+ */
+ unsigned long long kallsyms_names;
+ unsigned long long kallsyms_num_syms;
+ unsigned long long kallsyms_token_table;
+ unsigned long long kallsyms_token_index;
+ unsigned long long kallsyms_offsets;
+ unsigned long long kallsyms_relative_base;
};
struct size_table {
--
2.47.0
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