blob: 07624ca5a47097ee8f69c3922fe272b11e797139 [file] [log] [blame]
/*
* Process debugging functions.
*
* Copyright 2000-2019 Willy Tarreau <willy@haproxy.org>.
*
* 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 of the License, or (at your option) any later version.
*
*/
#include <signal.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <common/buf.h>
#include <common/config.h>
#include <common/debug.h>
#include <common/hathreads.h>
#include <common/initcall.h>
#include <common/standard.h>
#include <types/global.h>
#include <proto/cli.h>
#include <proto/fd.h>
#include <proto/stream_interface.h>
#include <proto/task.h>
/* Dumps to the buffer some known information for the desired thread, and
* optionally extra info for the current thread. The dump will be appended to
* the buffer, so the caller is responsible for preliminary initializing it.
* The calling thread ID needs to be passed in <calling_tid> to display a star
* in front of the calling thread's line (usually it's tid). Any stuck thread
* is also prefixed with a '>'.
*/
void ha_thread_dump(struct buffer *buf, int thr, int calling_tid)
{
unsigned long thr_bit = 1UL << thr;
unsigned long long p = thread_info[thr].prev_cpu_time;
unsigned long long n = now_cpu_time_thread(&thread_info[thr]);
int stuck = !!(thread_info[thr].flags & TI_FL_STUCK);
chunk_appendf(buf,
"%c%cThread %-2u: act=%d glob=%d wq=%d rq=%d tl=%d tlsz=%d rqsz=%d\n"
" stuck=%d fdcache=%d prof=%d",
(thr == calling_tid) ? '*' : ' ', stuck ? '>' : ' ', thr + 1,
thread_has_tasks(),
!!(global_tasks_mask & thr_bit),
!eb_is_empty(&task_per_thread[thr].timers),
!eb_is_empty(&task_per_thread[thr].rqueue),
!LIST_ISEMPTY(&task_per_thread[thr].task_list),
task_per_thread[thr].task_list_size,
task_per_thread[thr].rqueue_size,
stuck,
!!(fd_cache_mask & thr_bit),
!!(task_profiling_mask & thr_bit));
chunk_appendf(buf,
" harmless=%d wantrdv=%d",
!!(threads_harmless_mask & thr_bit),
!!(threads_want_rdv_mask & thr_bit));
chunk_appendf(buf, "\n");
chunk_appendf(buf, " cpu_ns: poll=%llu now=%llu diff=%llu\n", p, n, n-p);
/* this is the end of what we can dump from outside the thread */
if (thr != tid)
return;
chunk_appendf(buf, " curr_task=");
ha_task_dump(buf, curr_task, " ");
}
/* dumps into the buffer some information related to task <task> (which may
* either be a task or a tasklet, and prepend each line except the first one
* with <pfx>. The buffer is only appended and the first output starts by the
* pointer itself. The caller is responsible for making sure the task is not
* going to vanish during the dump.
*/
void ha_task_dump(struct buffer *buf, const struct task *task, const char *pfx)
{
const struct stream *s = NULL;
if (!task) {
chunk_appendf(buf, "0\n");
return;
}
if (TASK_IS_TASKLET(task))
chunk_appendf(buf,
"%p (tasklet) calls=%u\n",
task,
task->calls);
else
chunk_appendf(buf,
"%p (task) calls=%u last=%llu%s\n",
task,
task->calls,
task->call_date ? (unsigned long long)(now_mono_time() - task->call_date) : 0,
task->call_date ? " ns ago" : "");
chunk_appendf(buf, "%s"
" fct=%p (%s) ctx=%p\n",
pfx,
task->process,
task->process == process_stream ? "process_stream" :
task->process == task_run_applet ? "task_run_applet" :
task->process == si_cs_io_cb ? "si_cs_io_cb" :
"?",
task->context);
if (task->process == process_stream && task->context)
s = (struct stream *)task->context;
else if (task->process == task_run_applet && task->context)
s = si_strm(((struct appctx *)task->context)->owner);
else if (task->process == si_cs_io_cb && task->context)
s = si_strm((struct stream_interface *)task->context);
if (s)
stream_dump(buf, s, pfx, '\n');
}
/* This function dumps all profiling settings. It returns 0 if the output
* buffer is full and it needs to be called again, otherwise non-zero.
*/
static int cli_io_handler_show_threads(struct appctx *appctx)
{
struct stream_interface *si = appctx->owner;
int thr;
if (unlikely(si_ic(si)->flags & (CF_WRITE_ERROR|CF_SHUTW)))
return 1;
if (appctx->st0)
thr = appctx->st1;
else
thr = 0;
chunk_reset(&trash);
ha_thread_dump_all_to_trash();
if (ci_putchk(si_ic(si), &trash) == -1) {
/* failed, try again */
si_rx_room_blk(si);
appctx->st1 = thr;
return 0;
}
return 1;
}
/* dumps a state of all threads into the trash and on fd #2, then aborts. */
void ha_panic()
{
chunk_reset(&trash);
chunk_appendf(&trash, "Thread %u is about to kill the process.\n", tid + 1);
ha_thread_dump_all_to_trash();
shut_your_big_mouth_gcc(write(2, trash.area, trash.data));
for (;;)
abort();
}
#if defined(DEBUG_DEV)
/* parse a "debug dev exit" command. It always returns 1, though it should never return. */
static int debug_parse_cli_exit(char **args, char *payload, struct appctx *appctx, void *private)
{
int code = atoi(args[3]);
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
exit(code);
return 1;
}
/* parse a "debug dev close" command. It always returns 1. */
static int debug_parse_cli_close(char **args, char *payload, struct appctx *appctx, void *private)
{
int fd;
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
if (!*args[3]) {
appctx->ctx.cli.msg = "Missing file descriptor number.\n";
goto reterr;
}
fd = atoi(args[3]);
if (fd < 0 || fd >= global.maxsock) {
appctx->ctx.cli.msg = "File descriptor out of range.\n";
goto reterr;
}
if (!fdtab[fd].owner) {
appctx->ctx.cli.msg = "File descriptor was already closed.\n";
goto retinfo;
}
fd_delete(fd);
return 1;
retinfo:
appctx->ctx.cli.severity = LOG_INFO;
appctx->st0 = CLI_ST_PRINT;
return 1;
reterr:
appctx->ctx.cli.severity = LOG_ERR;
appctx->st0 = CLI_ST_PRINT;
return 1;
}
/* parse a "debug dev delay" command. It always returns 1. */
static int debug_parse_cli_delay(char **args, char *payload, struct appctx *appctx, void *private)
{
int delay = atoi(args[3]);
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
usleep((long)delay * 1000);
return 1;
}
/* parse a "debug dev log" command. It always returns 1. */
static int debug_parse_cli_log(char **args, char *payload, struct appctx *appctx, void *private)
{
int arg;
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
chunk_reset(&trash);
for (arg = 3; *args[arg]; arg++) {
if (arg > 3)
chunk_strcat(&trash, " ");
chunk_strcat(&trash, args[arg]);
}
send_log(NULL, LOG_INFO, "%s\n", trash.area);
return 1;
}
/* parse a "debug dev loop" command. It always returns 1. */
static int debug_parse_cli_loop(char **args, char *payload, struct appctx *appctx, void *private)
{
struct timeval deadline, curr;
int loop = atoi(args[3]);
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
gettimeofday(&curr, NULL);
tv_ms_add(&deadline, &curr, loop);
while (tv_ms_cmp(&curr, &deadline) < 0)
gettimeofday(&curr, NULL);
return 1;
}
/* parse a "debug dev panic" command. It always returns 1, though it should never return. */
static int debug_parse_cli_panic(char **args, char *payload, struct appctx *appctx, void *private)
{
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
ha_panic();
return 1;
}
/* parse a "debug dev exec" command. It always returns 1. */
static int debug_parse_cli_exec(char **args, char *payload, struct appctx *appctx, void *private)
{
FILE *f;
int arg;
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
chunk_reset(&trash);
for (arg = 3; *args[arg]; arg++) {
if (arg > 3)
chunk_strcat(&trash, " ");
chunk_strcat(&trash, args[arg]);
}
f = popen(trash.area, "re");
if (!f) {
appctx->ctx.cli.severity = LOG_ERR;
appctx->ctx.cli.msg = "Failed to execute command.\n";
appctx->st0 = CLI_ST_PRINT;
return 1;
}
chunk_reset(&trash);
while (1) {
size_t ret = fread(trash.area + trash.data, 1, trash.size - 20 - trash.data, f);
if (!ret)
break;
trash.data += ret;
if (trash.data + 20 == trash.size) {
chunk_strcat(&trash, "\n[[[TRUNCATED]]]\n");
break;
}
}
fclose(f);
trash.area[trash.data] = 0;
appctx->ctx.cli.severity = LOG_INFO;
appctx->ctx.cli.msg = trash.area;
appctx->st0 = CLI_ST_PRINT;
return 1;
}
/* parse a "debug dev hex" command. It always returns 1. */
static int debug_parse_cli_hex(char **args, char *payload, struct appctx *appctx, void *private)
{
unsigned long start, len;
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
if (!*args[3]) {
appctx->ctx.cli.msg = "Missing memory address to dump from.\n";
goto reterr;
}
start = strtoul(args[3], NULL, 0);
if (!start) {
appctx->ctx.cli.msg = "Will not dump from NULL address.\n";
goto reterr;
}
/* by default, dump ~128 till next block of 16 */
len = strtoul(args[4], NULL, 0);
if (!len)
len = ((start + 128) & -16) - start;
chunk_reset(&trash);
dump_hex(&trash, " ", (const void *)start, len, 1);
trash.area[trash.data] = 0;
appctx->ctx.cli.severity = LOG_INFO;
appctx->ctx.cli.msg = trash.area;
appctx->st0 = CLI_ST_PRINT;
return 1;
reterr:
appctx->ctx.cli.severity = LOG_ERR;
appctx->st0 = CLI_ST_PRINT;
return 1;
}
/* parse a "debug dev tkill" command. It always returns 1. */
static int debug_parse_cli_tkill(char **args, char *payload, struct appctx *appctx, void *private)
{
int thr = 0;
int sig = SIGABRT;
if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
return 1;
if (*args[3])
thr = atoi(args[3]);
if (thr < 0 || thr > global.nbthread) {
appctx->ctx.cli.severity = LOG_ERR;
appctx->ctx.cli.msg = "Thread number out of range (use 0 for current).\n";
appctx->st0 = CLI_ST_PRINT;
return 1;
}
if (*args[4])
sig = atoi(args[4]);
if (thr)
ha_tkill(thr - 1, sig);
else
raise(sig);
return 1;
}
#endif
#ifndef USE_THREAD_DUMP
/* This function dumps all threads' state to the trash. This version is the
* most basic one, which doesn't inspect other threads.
*/
void ha_thread_dump_all_to_trash()
{
unsigned int thr;
for (thr = 0; thr < global.nbthread; thr++)
ha_thread_dump(&trash, thr, tid);
}
#else /* below USE_THREAD_DUMP is set */
/* The signal to trigger a debug dump on a thread is SIGURG. It has the benefit
* of not stopping gdb by default, so that issuing "show threads" in a process
* being debugged has no adverse effect.
*/
#define DEBUGSIG SIGURG
/* mask of threads still having to dump, used to respect ordering */
static volatile unsigned long threads_to_dump;
/* ID of the thread requesting the dump */
static unsigned int thread_dump_tid;
/* points to the buffer where the dump functions should write. It must
* have already been initialized by the requester. Nothing is done if
* it's NULL.
*/
struct buffer *thread_dump_buffer = NULL;
void ha_thread_dump_all_to_trash()
{
unsigned long old;
while (1) {
old = 0;
if (HA_ATOMIC_CAS(&threads_to_dump, &old, all_threads_mask))
break;
ha_thread_relax();
}
thread_dump_buffer = &trash;
thread_dump_tid = tid;
ha_tkillall(DEBUGSIG);
}
/* handles DEBUGSIG to dump the state of the thread it's working on */
void debug_handler(int sig, siginfo_t *si, void *arg)
{
/* There are 4 phases in the dump process:
* 1- wait for our turn, i.e. when all lower bits are gone.
* 2- perform the action if our bit is set
* 3- remove our bit to let the next one go, unless we're
* the last one and have to put them all as a signal
* 4- wait out bit to re-appear, then clear it and quit.
*/
/* wait for all previous threads to finish first */
while (threads_to_dump & (tid_bit - 1))
ha_thread_relax();
/* dump if needed */
if (threads_to_dump & tid_bit) {
if (thread_dump_buffer)
ha_thread_dump(thread_dump_buffer, tid, thread_dump_tid);
if ((threads_to_dump & all_threads_mask) == tid_bit) {
/* last one */
HA_ATOMIC_STORE(&threads_to_dump, all_threads_mask);
thread_dump_buffer = NULL;
}
else
HA_ATOMIC_AND(&threads_to_dump, ~tid_bit);
}
/* now wait for all others to finish dumping. The last one will set all
* bits again to broadcast the leaving condition so we'll see ourselves
* present again. This way the threads_to_dump variable never passes to
* zero until all visitors have stopped waiting.
*/
while (!(threads_to_dump & tid_bit))
ha_thread_relax();
HA_ATOMIC_AND(&threads_to_dump, ~tid_bit);
/* mark the current thread as stuck to detect it upon next invocation
* if it didn't move.
*/
if (!((threads_harmless_mask|sleeping_thread_mask) & tid_bit))
ti->flags |= TI_FL_STUCK;
}
static int init_debug_per_thread()
{
sigset_t set;
/* unblock the DEBUGSIG signal we intend to use */
sigemptyset(&set);
sigaddset(&set, DEBUGSIG);
ha_sigmask(SIG_UNBLOCK, &set, NULL);
return 1;
}
static int init_debug()
{
struct sigaction sa;
sa.sa_handler = NULL;
sa.sa_sigaction = debug_handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
sigaction(DEBUGSIG, &sa, NULL);
return 0;
}
REGISTER_POST_CHECK(init_debug);
REGISTER_PER_THREAD_INIT(init_debug_per_thread);
#endif /* USE_THREAD_DUMP */
/* register cli keywords */
static struct cli_kw_list cli_kws = {{ },{
#if defined(DEBUG_DEV)
{{ "debug", "dev", "close", NULL }, "debug dev close <fd> : close this file descriptor", debug_parse_cli_close, NULL },
{{ "debug", "dev", "delay", NULL }, "debug dev delay [ms] : sleep this long", debug_parse_cli_delay, NULL },
{{ "debug", "dev", "exec", NULL }, "debug dev exec [cmd] ... : show this command's output", debug_parse_cli_exec, NULL },
{{ "debug", "dev", "exit", NULL }, "debug dev exit [code] : immediately exit the process", debug_parse_cli_exit, NULL },
{{ "debug", "dev", "hex", NULL }, "debug dev hex <addr> [len]: dump a memory area", debug_parse_cli_hex, NULL },
{{ "debug", "dev", "log", NULL }, "debug dev log [msg] ... : send this msg to global logs", debug_parse_cli_log, NULL },
{{ "debug", "dev", "loop", NULL }, "debug dev loop [ms] : loop this long", debug_parse_cli_loop, NULL },
{{ "debug", "dev", "panic", NULL }, "debug dev panic : immediately trigger a panic", debug_parse_cli_panic, NULL },
{{ "debug", "dev", "tkill", NULL }, "debug dev tkill [thr] [sig] : send signal to thread", debug_parse_cli_tkill, NULL },
#endif
{ { "show", "threads", NULL }, "show threads : show some threads debugging information", NULL, cli_io_handler_show_threads, NULL },
{{},}
}};
INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);