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authorTimothy Pearson <kb9vqf@pearsoncomputing.net>2012-12-01 22:14:28 -0600
committerTimothy Pearson <kb9vqf@pearsoncomputing.net>2012-12-01 22:14:28 -0600
commit786e248cea658856ef647b7ab8d3e8cf7c057918 (patch)
treed9aa63988d29e5b1837f6049c4806b191565407c /kdesktop/lock
parenta7c1897e9f5cc0aaca689227c25a6a70ec827cc0 (diff)
downloadtdebase-786e248cea658856ef647b7ab8d3e8cf7c057918.tar.gz
tdebase-786e248cea658856ef647b7ab8d3e8cf7c057918.zip
Add backtrace to kdesktop_lock exception handler
Diffstat (limited to 'kdesktop/lock')
-rw-r--r--kdesktop/lock/CMakeLists.txt4
-rw-r--r--kdesktop/lock/backtrace_symbols.c325
-rw-r--r--kdesktop/lock/lockprocess.cc22
3 files changed, 349 insertions, 2 deletions
diff --git a/kdesktop/lock/CMakeLists.txt b/kdesktop/lock/CMakeLists.txt
index caa655f59..6694f4315 100644
--- a/kdesktop/lock/CMakeLists.txt
+++ b/kdesktop/lock/CMakeLists.txt
@@ -32,11 +32,11 @@ set( target kdesktop_lock )
set( ${target}_SRCS
lockprocess.cc lockdlg.cc infodlg.cc querydlg.cc sakdlg.cc
- securedlg.cc autologout.cc main.cc
+ securedlg.cc autologout.cc main.cc backtrace_symbols.c
)
tde_add_executable( ${target} AUTOMOC
SOURCES ${${target}_SRCS}
- LINK kdesktopsettings-static dmctl-static kio-shared Xext ${GL_LIBRARY} "${LINKER_IMMEDIATE_BINDING_FLAGS}"
+ LINK kdesktopsettings-static dmctl-static kio-shared Xext bfd ${GL_LIBRARY} "${LINKER_IMMEDIATE_BINDING_FLAGS}"
DESTINATION ${BIN_INSTALL_DIR}
)
diff --git a/kdesktop/lock/backtrace_symbols.c b/kdesktop/lock/backtrace_symbols.c
new file mode 100644
index 000000000..69aa2d740
--- /dev/null
+++ b/kdesktop/lock/backtrace_symbols.c
@@ -0,0 +1,325 @@
+/*
+ A hacky replacement for backtrace_symbols in glibc
+
+ backtrace_symbols in glibc looks up symbols using dladdr which is limited in
+ the symbols that it sees. libbacktracesymbols opens the executable and shared
+ libraries using libbfd and will look up backtrace information using the symbol
+ table and the dwarf line information.
+
+ It may make more sense for this program to use libelf instead of libbfd.
+ However, I have not investigated that yet.
+
+ Derived from addr2line.c from GNU Binutils by Jeff Muizelaar
+
+ Copyright 2007 Jeff Muizelaar
+ Copyright 2012 Timothy Pearson
+*/
+
+/* addr2line.c -- convert addresses to line number and function name
+ Copyright 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+ Contributed by Ulrich Lauther <Ulrich.Lauther@mchp.siemens.de>
+
+ This file was part of GNU Binutils.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#define fatal(a, b) exit(1)
+#define bfd_fatal(a) exit(1)
+#define bfd_nonfatal(a) exit(1)
+#define list_matching_formats(a) exit(1)
+
+/* 2 characters for each byte, plus 1 each for 0, x, and NULL */
+#define PTRSTR_LEN (sizeof(void *) * 2 + 3)
+#define true 1
+#define false 0
+
+#define _GNU_SOURCE
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <execinfo.h>
+#include <bfd.h>
+#include <libiberty.h>
+#include <dlfcn.h>
+#include <link.h>
+#include <demangle.h>
+
+
+static asymbol **syms; /* Symbol table. */
+
+/* 150 isn't special; it's just an arbitrary non-ASCII char value. */
+#define OPTION_DEMANGLER (150)
+
+static void slurp_symtab(bfd * abfd);
+static void find_address_in_section(bfd *abfd, asection *section, void *data);
+
+/* Read in the symbol table. */
+
+static void slurp_symtab(bfd * abfd)
+{
+ long symcount;
+ unsigned int size;
+
+ if ((bfd_get_file_flags(abfd) & HAS_SYMS) == 0)
+ return;
+
+ symcount = (long)bfd_read_minisymbols(abfd, false, (void**) & syms, &size);
+ if (symcount == 0)
+ symcount = bfd_read_minisymbols(abfd, true /* dynamic */ ,
+ (void**) & syms, &size);
+
+ if (symcount < 0)
+ bfd_fatal(bfd_get_filename(abfd));
+}
+
+/* These global variables are used to pass information between
+ translate_addresses and find_address_in_section. */
+
+static bfd_vma pc;
+static const char *filename;
+static const char *functionname;
+static unsigned int line;
+static int found;
+
+/* Look for an address in a section. This is called via
+ bfd_map_over_sections. */
+
+static void find_address_in_section(bfd *abfd, asection *section, void *data __attribute__ ((__unused__)) )
+{
+ bfd_vma vma;
+ bfd_size_type size;
+
+ if (found)
+ return;
+
+ if ((bfd_get_section_flags(abfd, section) & SEC_ALLOC) == 0)
+ return;
+
+ vma = bfd_get_section_vma(abfd, section);
+ if (pc < vma)
+ return;
+
+ size = bfd_section_size(abfd, section);
+ if (pc >= vma + size)
+ return;
+
+ found = bfd_find_nearest_line(abfd, section, syms, pc - vma,
+ &filename, &functionname, &line);
+}
+
+/* Read hexadecimal addresses from stdin, translate into
+ file_name:line_number and optionally function name. */
+
+enum { Count, Print };
+
+static char** translate_addresses_buf(bfd * abfd, bfd_vma *addr, int naddr)
+{
+ int naddr_orig = naddr;
+ char b;
+ int total = 0;
+ int state;
+ char *buf = &b;
+ int len = 0;
+ char **ret_buf = NULL;
+
+ /* iterate over the formating twice.
+ * the first time we count how much space we need
+ * the second time we do the actual printing */
+ for (state=Count; state<=Print; state++) {
+ if (state == Print) {
+ ret_buf = (char**)malloc(total + sizeof(char*)*naddr);
+ buf = (char*)(ret_buf + naddr);
+ len = total;
+ }
+ while (naddr) {
+ if (state == Print)
+ ret_buf[naddr-1] = buf;
+ pc = addr[naddr-1];
+
+ found = false;
+ bfd_map_over_sections(abfd, find_address_in_section,
+ (PTR) NULL);
+
+ if (!found) {
+ total += snprintf(buf, len, "[0x%llx] \?\?() \?\?:0",(long long unsigned int) addr[naddr-1]) + 1;
+ } else {
+ const char *name;
+
+ name = functionname;
+ if (name == NULL || *name == '\0')
+ name = "??";
+ if (filename != NULL) {
+ const char *h;
+
+ h = strrchr(filename, '/');
+ if (h != NULL)
+ filename = h + 1;
+ }
+
+ char* funcname = cplus_demangle(name, DMGL_AUTO);
+ if (funcname) {
+ // demangling succeeded
+ total += snprintf(buf, len, "%s:%u\t%s()", filename ? filename : "??", line, funcname) + 1;
+ }
+ else {
+ // demangling failed
+ total += snprintf(buf, len, "%s:%u\t%s()", filename ? filename : "??", line, name) + 1;
+ }
+ }
+ if (state == Print) {
+ /* set buf just past the end of string */
+ buf = buf + total + 1;
+ }
+ naddr--;
+ }
+ naddr = naddr_orig;
+ }
+ return ret_buf;
+}
+/* Process a file. */
+
+static char **process_file(const char *file_name, bfd_vma *addr, int naddr)
+{
+ bfd *abfd;
+ char **matching;
+ char **ret_buf;
+
+ abfd = bfd_openr(file_name, NULL);
+
+ if (abfd == NULL)
+ bfd_fatal(file_name);
+
+ if (bfd_check_format(abfd, bfd_archive))
+ fatal("%s: can not get addresses from archive", file_name);
+
+ if (!bfd_check_format_matches(abfd, bfd_object, &matching)) {
+ bfd_nonfatal(bfd_get_filename(abfd));
+ if (bfd_get_error() ==
+ bfd_error_file_ambiguously_recognized) {
+ list_matching_formats(matching);
+ free(matching);
+ }
+ xexit(1);
+ }
+
+ slurp_symtab(abfd);
+
+ ret_buf = translate_addresses_buf(abfd, addr, naddr);
+
+ if (syms != NULL) {
+ free(syms);
+ syms = NULL;
+ }
+
+ bfd_close(abfd);
+ return ret_buf;
+}
+
+#define MAX_DEPTH 16
+
+struct file_match {
+ const char *file;
+ void *address;
+ void *base;
+ void *hdr;
+};
+
+static int find_matching_file(struct dl_phdr_info *info,
+ size_t size, void *data)
+{
+ struct file_match *match = data;
+ /* This code is modeled from Gfind_proc_info-lsb.c:callback() from libunwind */
+ long n;
+ const ElfW(Phdr) *phdr;
+ ElfW(Addr) load_base = info->dlpi_addr;
+ phdr = info->dlpi_phdr;
+ for (n = info->dlpi_phnum; --n >= 0; phdr++) {
+ if (phdr->p_type == PT_LOAD) {
+ ElfW(Addr) vaddr = phdr->p_vaddr + load_base;
+ if (match->address >= (void*)vaddr && match->address < (void*)(vaddr + phdr->p_memsz)) {
+ /* we found a match */
+ match->file = info->dlpi_name;
+ match->base = (void*)info->dlpi_addr;
+ }
+ }
+ }
+ return 0;
+}
+
+char **backtrace_symbols(void *const *buffer, int size)
+{
+ int stack_depth = size - 1;
+ int x,y;
+ /* discard calling function */
+ int total = 0;
+
+ char ***locations;
+ char **final;
+ char *f_strings;
+
+ locations = (char***)malloc(sizeof(char**) * (stack_depth+1));
+
+ bfd_init();
+ for(x=stack_depth, y=0; x>=0; x--, y++){
+ struct file_match match = { .address = buffer[x] };
+ char **ret_buf;
+ bfd_vma addr;
+ dl_iterate_phdr(find_matching_file, &match);
+ addr = buffer[x] - match.base;
+ if (match.file && strlen(match.file))
+ ret_buf = process_file(match.file, &addr, 1);
+ else
+ ret_buf = process_file("/proc/self/exe", &addr, 1);
+ locations[x] = ret_buf;
+ total += strlen(ret_buf[0]) + 1;
+ }
+
+ /* allocate the array of char* we are going to return and extra space for
+ * all of the strings */
+ final = (char**)malloc(total + (stack_depth + 1) * sizeof(char*));
+ /* get a pointer to the extra space */
+ f_strings = (char*)(final + stack_depth + 1);
+
+ /* fill in all of strings and pointers */
+ for(x=stack_depth; x>=0; x--){
+ strcpy(f_strings, locations[x][0]);
+ free(locations[x]);
+ final[x] = f_strings;
+ f_strings += strlen(f_strings) + 1;
+ }
+
+ free(locations);
+
+ return final;
+}
+
+void
+backtrace_symbols_fd(void *const *buffer, int size, int fd)
+{
+ int j;
+ char **strings;
+
+ strings = backtrace_symbols(buffer, size);
+ if (strings == NULL) {
+ perror("backtrace_symbols");
+ exit(EXIT_FAILURE);
+ }
+
+ for (j = 0; j < size; j++)
+ printf("%s\n", strings[j]);
+
+ free(strings);
+}
+
diff --git a/kdesktop/lock/lockprocess.cc b/kdesktop/lock/lockprocess.cc
index 3c37090a6..70836c26c 100644
--- a/kdesktop/lock/lockprocess.cc
+++ b/kdesktop/lock/lockprocess.cc
@@ -18,6 +18,8 @@
#include <config.h>
+#include <execinfo.h>
+
#include "lockprocess.h"
#include "lockdlg.h"
#include "infodlg.h"
@@ -129,9 +131,29 @@ static Window gVRootData = 0;
static Atom gXA_VROOT;
static Atom gXA_SCREENSAVER_VERSION;
+void print_trace()
+{
+ void *array[10];
+ size_t size;
+ char **strings;
+ size_t i;
+
+ size = backtrace (array, 10);
+ strings = backtrace_symbols (array, size);
+
+ printf ("[kdesktop_lock] Obtained %zd stack frames.\n\r", size);
+
+ for (i = 0; i < size; i++) {
+ printf ("[kdesktop_lock] %s\n\r", strings[i]);
+ }
+
+ free (strings);
+}
+
static void segv_handler(int)
{
printf("[kdesktop_lock] WARNING: A fatal exception was encountered. Trapping and ignoring it so as not to compromise desktop security...\n\r");
+ print_trace();
sleep(1);
}