|  | /* | 
|  | * Backtrace debugging | 
|  | * Copyright (c) 2009, Jouni Malinen <j@w1.fi> | 
|  | * | 
|  | * This software may be distributed under the terms of the BSD license. | 
|  | * See README for more details. | 
|  | */ | 
|  |  | 
|  | #ifdef WPA_TRACE_BFD | 
|  | #define _GNU_SOURCE | 
|  | #include <link.h> | 
|  | #endif /* WPA_TRACE_BCD */ | 
|  | #include "includes.h" | 
|  |  | 
|  | #include "common.h" | 
|  | #include "trace.h" | 
|  |  | 
|  | #ifdef WPA_TRACE | 
|  |  | 
|  | static struct dl_list active_references = | 
|  | { &active_references, &active_references }; | 
|  |  | 
|  | #ifdef WPA_TRACE_BFD | 
|  | #include <bfd.h> | 
|  |  | 
|  | #define DMGL_PARAMS      (1 << 0) | 
|  | #define DMGL_ANSI        (1 << 1) | 
|  |  | 
|  | static char *prg_fname = NULL; | 
|  | static bfd *cached_abfd = NULL; | 
|  | static asymbol **syms = NULL; | 
|  | static unsigned long start_offset; | 
|  | static int start_offset_looked_up; | 
|  |  | 
|  |  | 
|  | static int callback(struct dl_phdr_info *info, size_t size, void *data) | 
|  | { | 
|  | /* | 
|  | * dl_iterate_phdr(3): | 
|  | * "The first object visited by callback is the main program." | 
|  | */ | 
|  | start_offset = info->dlpi_addr; | 
|  |  | 
|  | /* | 
|  | * dl_iterate_phdr(3): | 
|  | * "The dl_iterate_phdr() function walks through the list of an | 
|  | *  application's shared objects and calls the function callback | 
|  | *  once for each object, until either all shared objects have | 
|  | *  been processed or callback returns a nonzero value." | 
|  | */ | 
|  | return 1; | 
|  | } | 
|  |  | 
|  |  | 
|  | static void get_prg_fname(void) | 
|  | { | 
|  | char exe[50], fname[512]; | 
|  | int len; | 
|  | os_snprintf(exe, sizeof(exe) - 1, "/proc/%u/exe", getpid()); | 
|  | len = readlink(exe, fname, sizeof(fname) - 1); | 
|  | if (len < 0 || len >= (int) sizeof(fname)) { | 
|  | wpa_printf(MSG_ERROR, "readlink: %s", strerror(errno)); | 
|  | return; | 
|  | } | 
|  | fname[len] = '\0'; | 
|  | prg_fname = strdup(fname); | 
|  | } | 
|  |  | 
|  |  | 
|  | static bfd * open_bfd(const char *fname) | 
|  | { | 
|  | bfd *abfd; | 
|  | char **matching; | 
|  |  | 
|  | abfd = bfd_openr(prg_fname, NULL); | 
|  | if (abfd == NULL) { | 
|  | wpa_printf(MSG_INFO, "bfd_openr failed"); | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | if (bfd_check_format(abfd, bfd_archive)) { | 
|  | wpa_printf(MSG_INFO, "bfd_check_format failed"); | 
|  | bfd_close(abfd); | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | if (!bfd_check_format_matches(abfd, bfd_object, &matching)) { | 
|  | wpa_printf(MSG_INFO, "bfd_check_format_matches failed"); | 
|  | free(matching); | 
|  | bfd_close(abfd); | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | return abfd; | 
|  | } | 
|  |  | 
|  |  | 
|  | static void read_syms(bfd *abfd) | 
|  | { | 
|  | long storage, symcount; | 
|  | bfd_boolean dynamic = FALSE; | 
|  |  | 
|  | if (syms) | 
|  | return; | 
|  |  | 
|  | if (!(bfd_get_file_flags(abfd) & HAS_SYMS)) { | 
|  | wpa_printf(MSG_INFO, "No symbols"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | storage = bfd_get_symtab_upper_bound(abfd); | 
|  | if (storage == 0) { | 
|  | storage = bfd_get_dynamic_symtab_upper_bound(abfd); | 
|  | dynamic = TRUE; | 
|  | } | 
|  | if (storage < 0) { | 
|  | wpa_printf(MSG_INFO, "Unknown symtab upper bound"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | syms = malloc(storage); | 
|  | if (syms == NULL) { | 
|  | wpa_printf(MSG_INFO, "Failed to allocate memory for symtab " | 
|  | "(%ld bytes)", storage); | 
|  | return; | 
|  | } | 
|  | if (dynamic) | 
|  | symcount = bfd_canonicalize_dynamic_symtab(abfd, syms); | 
|  | else | 
|  | symcount = bfd_canonicalize_symtab(abfd, syms); | 
|  | if (symcount < 0) { | 
|  | wpa_printf(MSG_INFO, "Failed to canonicalize %ssymtab", | 
|  | dynamic ? "dynamic " : ""); | 
|  | free(syms); | 
|  | syms = NULL; | 
|  | return; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | struct bfd_data { | 
|  | bfd_vma pc; | 
|  | bfd_boolean found; | 
|  | const char *filename; | 
|  | const char *function; | 
|  | unsigned int line; | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * binutils removed the bfd parameter and renamed things but | 
|  | * those were macros so we can detect their absence. | 
|  | * Cf. https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;h=fd3619828e94a24a92cddec42cbc0ab33352eeb4;hp=5dfda3562a69686c43aad4fb0269cc9d5ec010d5 | 
|  | */ | 
|  | #ifndef bfd_get_section_vma | 
|  | #define bfd_get_section_vma(bfd, section) bfd_section_vma(section) | 
|  | #endif | 
|  | #ifndef bfd_get_section_size | 
|  | #define bfd_get_section_size bfd_section_size | 
|  | #endif | 
|  |  | 
|  | static void find_addr_sect(bfd *abfd, asection *section, void *obj) | 
|  | { | 
|  | struct bfd_data *data = obj; | 
|  | bfd_vma vma; | 
|  | bfd_size_type size; | 
|  |  | 
|  | if (data->found) | 
|  | return; | 
|  |  | 
|  | if (!(bfd_get_section_vma(abfd, section))) | 
|  | return; | 
|  |  | 
|  | vma = bfd_get_section_vma(abfd, section); | 
|  | if (data->pc < vma) | 
|  | return; | 
|  |  | 
|  | size = bfd_get_section_size(section); | 
|  | if (data->pc >= vma + size) | 
|  | return; | 
|  |  | 
|  | data->found = bfd_find_nearest_line(abfd, section, syms, | 
|  | data->pc - vma, | 
|  | &data->filename, | 
|  | &data->function, | 
|  | &data->line); | 
|  | } | 
|  |  | 
|  |  | 
|  | static void wpa_trace_bfd_addr(void *pc) | 
|  | { | 
|  | bfd *abfd = cached_abfd; | 
|  | struct bfd_data data; | 
|  | const char *name; | 
|  | char *aname = NULL; | 
|  | const char *filename; | 
|  |  | 
|  | if (abfd == NULL) | 
|  | return; | 
|  |  | 
|  | data.pc = (bfd_hostptr_t) ((u8 *) pc - start_offset); | 
|  | data.found = FALSE; | 
|  | bfd_map_over_sections(abfd, find_addr_sect, &data); | 
|  |  | 
|  | if (!data.found) | 
|  | return; | 
|  |  | 
|  | do { | 
|  | if (data.function) | 
|  | aname = bfd_demangle(abfd, data.function, | 
|  | DMGL_ANSI | DMGL_PARAMS); | 
|  | name = aname ? aname : data.function; | 
|  | filename = data.filename; | 
|  | if (filename) { | 
|  | char *end = os_strrchr(filename, '/'); | 
|  | int i = 0; | 
|  | while (*filename && *filename == prg_fname[i] && | 
|  | filename <= end) { | 
|  | filename++; | 
|  | i++; | 
|  | } | 
|  | } | 
|  | wpa_printf(MSG_INFO, "     %s() %s:%u", | 
|  | name, filename, data.line); | 
|  | free(aname); | 
|  | aname = NULL; | 
|  |  | 
|  | data.found = bfd_find_inliner_info(abfd, &data.filename, | 
|  | &data.function, &data.line); | 
|  | } while (data.found); | 
|  | } | 
|  |  | 
|  |  | 
|  | static const char * wpa_trace_bfd_addr2func(void *pc) | 
|  | { | 
|  | bfd *abfd = cached_abfd; | 
|  | struct bfd_data data; | 
|  |  | 
|  | if (abfd == NULL) | 
|  | return NULL; | 
|  |  | 
|  | data.pc = (bfd_hostptr_t) ((u8 *) pc - start_offset); | 
|  | data.found = FALSE; | 
|  | bfd_map_over_sections(abfd, find_addr_sect, &data); | 
|  |  | 
|  | if (!data.found) | 
|  | return NULL; | 
|  |  | 
|  | return data.function; | 
|  | } | 
|  |  | 
|  |  | 
|  | static void wpa_trace_bfd_init(void) | 
|  | { | 
|  | if (!prg_fname) { | 
|  | get_prg_fname(); | 
|  | if (!prg_fname) | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (!cached_abfd) { | 
|  | cached_abfd = open_bfd(prg_fname); | 
|  | if (!cached_abfd) { | 
|  | wpa_printf(MSG_INFO, "Failed to open bfd"); | 
|  | return; | 
|  | } | 
|  | } | 
|  |  | 
|  | read_syms(cached_abfd); | 
|  | if (!syms) { | 
|  | wpa_printf(MSG_INFO, "Failed to read symbols"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (!start_offset_looked_up) { | 
|  | dl_iterate_phdr(callback, NULL); | 
|  | start_offset_looked_up = 1; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | void wpa_trace_dump_funcname(const char *title, void *pc) | 
|  | { | 
|  | wpa_printf(MSG_INFO, "WPA_TRACE: %s: %p", title, pc); | 
|  | wpa_trace_bfd_init(); | 
|  | wpa_trace_bfd_addr(pc); | 
|  | } | 
|  |  | 
|  |  | 
|  | size_t wpa_trace_calling_func(const char *buf[], size_t len) | 
|  | { | 
|  | bfd *abfd; | 
|  | void *btrace_res[WPA_TRACE_LEN]; | 
|  | int i, btrace_num; | 
|  | size_t pos = 0; | 
|  |  | 
|  | if (len == 0) | 
|  | return 0; | 
|  | if (len > WPA_TRACE_LEN) | 
|  | len = WPA_TRACE_LEN; | 
|  |  | 
|  | wpa_trace_bfd_init(); | 
|  | abfd = cached_abfd; | 
|  | if (!abfd) | 
|  | return 0; | 
|  |  | 
|  | btrace_num = backtrace(btrace_res, len); | 
|  | if (btrace_num < 1) | 
|  | return 0; | 
|  |  | 
|  | for (i = 0; i < btrace_num; i++) { | 
|  | struct bfd_data data; | 
|  |  | 
|  | data.pc = (bfd_hostptr_t) ((u8 *) btrace_res[i] - start_offset); | 
|  | data.found = FALSE; | 
|  | bfd_map_over_sections(abfd, find_addr_sect, &data); | 
|  |  | 
|  | while (data.found) { | 
|  | if (data.function && | 
|  | (pos > 0 || | 
|  | os_strcmp(data.function, __func__) != 0)) { | 
|  | buf[pos++] = data.function; | 
|  | if (pos == len) | 
|  | return pos; | 
|  | } | 
|  |  | 
|  | data.found = bfd_find_inliner_info(abfd, &data.filename, | 
|  | &data.function, | 
|  | &data.line); | 
|  | } | 
|  | } | 
|  |  | 
|  | return pos; | 
|  | } | 
|  |  | 
|  | #else /* WPA_TRACE_BFD */ | 
|  |  | 
|  | #define wpa_trace_bfd_init() do { } while (0) | 
|  | #define wpa_trace_bfd_addr(pc) do { } while (0) | 
|  | #define wpa_trace_bfd_addr2func(pc) NULL | 
|  |  | 
|  | #endif /* WPA_TRACE_BFD */ | 
|  |  | 
|  | void wpa_trace_dump_func(const char *title, void **btrace, int btrace_num) | 
|  | { | 
|  | char **sym; | 
|  | int i; | 
|  | enum { TRACE_HEAD, TRACE_RELEVANT, TRACE_TAIL } state; | 
|  |  | 
|  | wpa_trace_bfd_init(); | 
|  | wpa_printf(MSG_INFO, "WPA_TRACE: %s - START", title); | 
|  | sym = backtrace_symbols(btrace, btrace_num); | 
|  | state = TRACE_HEAD; | 
|  | for (i = 0; i < btrace_num; i++) { | 
|  | const char *func = wpa_trace_bfd_addr2func(btrace[i]); | 
|  | if (state == TRACE_HEAD && func && | 
|  | (os_strcmp(func, "wpa_trace_add_ref_func") == 0 || | 
|  | os_strcmp(func, "wpa_trace_check_ref") == 0 || | 
|  | os_strcmp(func, "wpa_trace_show") == 0)) | 
|  | continue; | 
|  | if (state == TRACE_TAIL && sym && sym[i] && | 
|  | os_strstr(sym[i], "__libc_start_main")) | 
|  | break; | 
|  | if (state == TRACE_HEAD) | 
|  | state = TRACE_RELEVANT; | 
|  | if (sym) | 
|  | wpa_printf(MSG_INFO, "[%d]: %s", i, sym[i]); | 
|  | else | 
|  | wpa_printf(MSG_INFO, "[%d]: ?? [%p]", i, btrace[i]); | 
|  | wpa_trace_bfd_addr(btrace[i]); | 
|  | if (state == TRACE_RELEVANT && func && | 
|  | os_strcmp(func, "main") == 0) | 
|  | state = TRACE_TAIL; | 
|  | } | 
|  | free(sym); | 
|  | wpa_printf(MSG_INFO, "WPA_TRACE: %s - END", title); | 
|  | } | 
|  |  | 
|  |  | 
|  | void wpa_trace_show(const char *title) | 
|  | { | 
|  | struct info { | 
|  | WPA_TRACE_INFO | 
|  | } info; | 
|  | wpa_trace_record(&info); | 
|  | wpa_trace_dump(title, &info); | 
|  | } | 
|  |  | 
|  |  | 
|  | void wpa_trace_add_ref_func(struct wpa_trace_ref *ref, const void *addr) | 
|  | { | 
|  | if (addr == NULL) | 
|  | return; | 
|  | ref->addr = addr; | 
|  | wpa_trace_record(ref); | 
|  | dl_list_add(&active_references, &ref->list); | 
|  | } | 
|  |  | 
|  |  | 
|  | void wpa_trace_check_ref(const void *addr) | 
|  | { | 
|  | struct wpa_trace_ref *ref; | 
|  | dl_list_for_each(ref, &active_references, struct wpa_trace_ref, list) { | 
|  | if (addr != ref->addr) | 
|  | continue; | 
|  | wpa_trace_show("Freeing referenced memory"); | 
|  | wpa_trace_dump("Reference registration", ref); | 
|  | abort(); | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | void wpa_trace_deinit(void) | 
|  | { | 
|  | #ifdef WPA_TRACE_BFD | 
|  | free(syms); | 
|  | syms = NULL; | 
|  | #endif /* WPA_TRACE_BFD */ | 
|  | } | 
|  |  | 
|  | #endif /* WPA_TRACE */ |