(long gdb output, you’ve been warned)
Okay. So, the libdovecot shared library in /usr/local was stripped. Replaced that, and got farther. gdb walk below.
It looks to me like it gets deep into the OS’s vfork/execv where it catches a trap/crashes. Is this a problem I can catch, or something wrong with running in gdb? I notice this is a SIGTRAP, where the binary when run out of gdb gets a SIGSEGV, and that’s what a loaded core shows.
Thanks for any assistance.
- ChrisBreakpoint 3, master_service_exec_config (service=0x41030000, input=0x7fdfffff5a8) at master-service-settings.c:125 125 const char **conf_argv, *binary_path = service->argv[0]; (gdb) n 128 (void)t_binary_abspath(&binary_path); (gdb) n 130 if (!service->keep_environment && !input->preserve_environment) { (gdb) 131 if (input->preserve_home) (gdb) 133 if (input->preserve_user) (gdb) 135 if ((service->flags & MASTER_SERVICE_FLAG_STANDALONE) != 0) (gdb) 136 master_service_import_environment("LOG_STDERR_TIMESTAMP"); (gdb) 140 if (getenv(DOVECOT_PRESERVE_ENVS_ENV) == NULL) (gdb) 146 if (input->use_sysexits) (gdb) 150 i = 0; (gdb) 151 argv_max_count = 11 + (service->argc + 1) + 1; (gdb) 152 conf_argv = t_new(const char *, argv_max_count); (gdb) 153 conf_argv[i++] = DOVECOT_CONFIG_BIN_PATH; (gdb) 154 if (input->service != NULL) { (gdb) 158 conf_argv[i++] = "-c"; (gdb) 159 conf_argv[i++] = service->config_path; (gdb) 160 if (input->module != NULL) { (gdb) 161 conf_argv[i++] = "-m"; (gdb) 162 conf_argv[i++] = input->module; (gdb) 163 if (service->want_ssl_settings) { (gdb) 168 if (input->parse_full_config) (gdb) 171 conf_argv[i++] = "-e"; (gdb) 172 conf_argv[i++] = binary_path; (gdb) 173 memcpy(conf_argv+i, service->argv + 1, (gdb) 175 i += service->argc; (gdb) 177 i_assert(i < argv_max_count); (gdb) 178 execv_const(conf_argv[0], conf_argv); (gdb) p conf_argv $3 = (const char **) 0x41016e48 (gdb) p conf_argv[0] $4 = 0x4064f6d8 "/usr/local/bin/doveconf" (gdb) p *conf_argv $5 = 0x4064f6d8 "/usr/local/bin/doveconf" (gdb) s execv_const (path=0x4064f6d8 "/usr/local/bin/doveconf", argv=0x41016e48) at execv-const.c:23 23 (void)execv(path, argv_drop_const(argv)); (gdb) p parth No symbol "parth" in current context. (gdb) p path $6 = 0x4064f6d8 "/usr/local/bin/doveconf" (gdb) s argv_drop_const (argv=0x41016e48) at execv-const.c:13 13 for (count = 0; argv[count] != NULL; count++) ; (gdb) p argv $7 = (const char * const *) 0x41016e48 (gdb) p argv[0] $8 = 0x4064f6d8 "/usr/local/bin/doveconf" (gdb) p argv[1] $9 = 0x4064f708 "-c" (gdb) p argv[2] $10 = 0x41040000 "/usr/local/etc/dovecot/dovecot.conf" (gdb) p argv[3] $11 = 0x4064f710 "-m" (gdb) p argv[4] $12 = 0x16ad70 "auth" (gdb) p argv[5] $13 = 0x4064f728 "-e" (gdb) p argv[6] $14 = 0x7fdfffffd18 "/usr/ports/mail/dovecot/work/stage/usr/local/libexec/dovecot/auth" (gdb) p argv[7] $15 = 0x0 (gdb) n 15 ret = t_new(char *, count + 1); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 17 ret[i] = t_strdup_noconst(argv[i]); (gdb) 16 for (i = 0; i < count; i++) (gdb) 18 return ret; (gdb) 19 } (gdb)
Program received signal SIGTRAP, Trace/breakpoint trap. Cannot remove breakpoints because program is no longer writable. It might be running in another process. Further execution is probably impossible. 0x000000004022a380 in ?? () (gdb) b argv_drop_const Breakpoint 4 at 0x405d50b8: file execv-const.c, line 13. (gdb) run The program being debugged has been started already. Start it from the beginning? (y or n) y
Starting program: /usr/ports/mail/dovecot/work/stage/usr/local/libexec/dovecot/auth Error in re-setting breakpoint 3: No source file named master-service-settings.c. Error in re-setting breakpoint 4: No source file named execv-const.c.
Breakpoint 3, master_service_exec_config (service=0x41030000, input=0x7fdfffff5a8) at master-service-settings.c:125 125 const char **conf_argv, *binary_path = service->argv[0]; (gdb) n 128 (void)t_binary_abspath(&binary_path); (gdb) c Continuing.
Breakpoint 4, argv_drop_const (argv=0x41016e48) at execv-const.c:13
13 for (count = 0; argv[count] != NULL; count++) ;
(gdb) p argv
$16 = (const char * const *) 0x41016e48
(gdb) p argv[1]
$17 = 0x4064f708 "-c"
(gdb) p argv[6]
$18 = 0x7fdfffffd18 "/usr/ports/mail/dovecot/work/stage/usr/local/libexec/dovecot/auth"
(gdb) p argv[7]
$19 = 0x0
(gdb) n
15 ret = t_new(char *, count + 1);
(gdb) n
16 for (i = 0; i < count; i++)
(gdb) p ret
$20 = (char **) 0x41016eb8
(gdb) p ret[0]
$21 = 0x0
(gdb) p ret[1]
$22 = 0x0
(gdb) n
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb) p i,ret[i]
$23 = 0x0
(gdb) p i
$24 = 0
(gdb) p ret[i]
$25 = 0x0
(gdb) p argv[i]
$26 = 0x4064f6d8 "/usr/local/bin/doveconf"
(gdb) n
16 for (i = 0; i < count; i++)
(gdb) p i
$27 = 0
(gdb) p ret[i]
$28 = 0x41016ef8 "/usr/local/bin/doveconf"
(gdb) p ret[i+1]
$29 = 0x0
(gdb) n
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb) n
16 for (i = 0; i < count; i++)
(gdb)
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb)
16 for (i = 0; i < count; i++)
(gdb)
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb)
16 for (i = 0; i < count; i++)
(gdb)
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb)
16 for (i = 0; i < count; i++)
(gdb)
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb)
16 for (i = 0; i < count; i++)
(gdb)
17 ret[i] = t_strdup_noconst(argv[i]);
(gdb)
16 for (i = 0; i < count; i++)
(gdb)
18 return ret;
(gdb) p ret
$30 = (char **) 0x41016eb8
(gdb) p ret[]
A syntax error in expression, near ]'. (gdb) p *ret $31 = 0x41016ef8 "/usr/local/bin/doveconf" (gdb) p *ret[] A syntax error in expression, near ]'.
(gdb) p ret[0]
$32 = 0x41016ef8 "/usr/local/bin/doveconf"
(gdb) p ret[1]
$33 = 0x41016f10 "-c"
(gdb) p ret[2]
$34 = 0x41016f18 "/usr/local/etc/dovecot/dovecot.conf"
(gdb) p ret[3]
$35 = 0x41016f40 "-m"
(gdb) p ret[4]
$36 = 0x41016f48 "auth"
(gdb) p ret[5]
$37 = 0x41016f50 "-e"
(gdb) p ret[6]
$38 = 0x41016f58 "/usr/ports/mail/dovecot/work/stage/usr/local/libexec/dovecot/auth"
(gdb) p ret[7]
$39 = 0x0
(gdb) s
19 }
(gdb)
execv (name=0x4064f6d8 "/usr/local/bin/doveconf", argv=0x41016eb8)
at /usr/src/lib/libc/gen/exec.c:135
135 (void)_execve(name, argv, environ);
(gdb) p name
$40 = 0x4064f6d8 "/usr/local/bin/doveconf"
(gdb) p argv
$41 = (char * const *) 0x41016eb8
(gdb) p *argv
$42 = 0x41016ef8 "/usr/local/bin/doveconf"
(gdb) p environ
$43 = (char **) 0x4106e000
(gdb) p *environ
$44 = 0x4105f048 "DOVECOT_PRESERVE_ENVS=LOG_STDERR_TIMESTAMP"
(gdb) p environ[0]
$45 = 0x4105f048 "DOVECOT_PRESERVE_ENVS=LOG_STDERR_TIMESTAMP"
(gdb) p environ[1]
$46 = 0x4102f000 "COLUMNS=80"
(gdb) p environ[2]
$47 = 0x4102f020 "LINES=34"
(gdb) p environ[3]
$48 = 0x41028040 "LANG=en_US.UTF-8"
(gdb) p environ[4]
$49 = 0x4103b0a0 "PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/root/bin"
(gdb) p environ[5]
$50 = 0x41028060 "TERM=xterm-256color"
(gdb) p environ[6]
$51 = 0x4102f030 "LOGNAME=cross"
(gdb) p environ[7]
$52 = 0x4102f040 "USER=cross"
(gdb) p environ[8]
$53 = 0x4102f050 "USERNAME=cross"
(gdb) p environ[9]
$54 = 0x41028080 "MAIL=/var/mail/root"
(gdb) p environ[10]
$55 = 0x4102f060 "HOME=/root"
(gdb) p environ[11]
$56 = 0x4102f070 "SHELL=/bin/csh"
(gdb) p environ[12]
$57 = 0x4103b0f0 "SUDO_COMMAND=/usr/bin/gdb work/stage/usr/local/libexec/dovecot//auth"
(gdb) p environ[13]
$58 = 0x4102f080 "SUDO_USER=cross"
(gdb) p environ[14]
$59 = 0x4102f090 "SUDO_UID=1001"
(gdb) p environ[15]
$60 = 0x4102f0a0 "SUDO_GID=20"
(gdb) p environ[16]
$61 = 0x410280a0 "HOSTTYPE=FreeBSD"
(gdb) p environ[17]
$62 = 0x4102f0b0 "VENDOR=sun"
(gdb) p environ[18]
$63 = 0x4102f0c0 "OSTYPE=FreeBSD"
(gdb) p environ[19]
$64 = 0x4102f0d0 "MACHTYPE=sparc"
(gdb) p environ[20]
$65 = 0x410280c0 "PWD=/usr/ports/mail/dovecot"
(gdb) p environ[21]
$66 = 0x4102f0e0 "GROUP=wheel"
(gdb) p environ[22]
$67 = 0x410280e0 "HOST=westeros.distal.com"
(gdb) p environ[23]
$68 = 0x4102f0f0 "REMOTEHOST=2001"
(gdb) p environ[24]
$69 = 0x4102f100 "EDITOR=vi"
(gdb) p environ[25]
$70 = 0x4102f110 "PAGER=more"
(gdb) p environ[26]
$71 = 0x4102f120 "BLOCKSIZE=K"
(gdb) p environ[27]
$72 = 0x0
(gdb) s
134 {
(gdb) s
0x0000000040ab2800 in vfork () at /usr/src/lib/libc/gen/exec.c:133
133 execv(const char *name, char * const *argv)
(gdb)
0x0000000040ab2804 133 execv(const char *name, char * const *argv)
(gdb) print argv
No symbol "argv" in current context.
(gdb) s
execv (name=0x4064f6d8 "/usr/local/bin/doveconf", argv=0x41016eb8)
at /usr/src/lib/libc/gen/exec.c:135
135 (void)_execve(name, argv, environ);
(gdb) s
137 }
(gdb) s
135 (void)_execve(name, argv, environ);
(gdb) s
Program received signal SIGTRAP, Trace/breakpoint trap. Cannot remove breakpoints because program is no longer writable. It might be running in another process. Further execution is probably impossible. 0x000000004022a380 in ?? () (gdb)
On Feb 22, 2018, at 10:21, Chris Ross <cross+dovecot@distal.com> wrote:
Okay. Got to the next bit pretty quickly.: 524 if (master_service_settings_read(master_service, &input, (gdb) list 519 520
(gdb) s
Program received signal SIGTRAP, Trace/breakpoint trap. Cannot remove breakpoints because program is no longer writable. It might be running in another process. Further execution is probably impossible. 0x000000004022a380 in ?? () (gdb)
Any ideas here? I’m not sure where to look next…