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/*
* 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 <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <unistd.h>
#ifdef USE_EPOLL
#include <sys/epoll.h>
#endif
#include <haproxy/api.h>
#include <haproxy/applet.h>
#include <haproxy/buf.h>
#include <haproxy/cfgparse.h>
#include <haproxy/cli.h>
#include <haproxy/clock.h>
#ifdef USE_CPU_AFFINITY
#include <haproxy/cpu_topo.h>
#endif
#include <haproxy/debug.h>
#include <haproxy/fd.h>
#include <haproxy/global.h>
#include <haproxy/hlua.h>
#include <haproxy/http_ana.h>
#include <haproxy/limits.h>
#if defined(USE_LINUX_CAP)
#include <haproxy/linuxcap.h>
#endif
#include <haproxy/log.h>
#include <haproxy/net_helper.h>
#include <haproxy/sc_strm.h>
#include <haproxy/proxy.h>
#include <haproxy/stconn.h>
#include <haproxy/sym.h>
#include <haproxy/task.h>
#include <haproxy/thread.h>
#include <haproxy/time.h>
#include <haproxy/tools.h>
#include <haproxy/trace.h>
#include <haproxy/version.h>
#include <import/ist.h>
/* The dump state is made of:
* - num_thread on the lowest 15 bits
* - a SYNC flag on bit 15 (waiting for sync start)
* - number of participating threads on bits 16-30
* Initiating a dump consists in setting it to SYNC and incrementing the
* num_thread part when entering the function. The first thread periodically
* recounts active threads and compares it to the ready ones, and clears SYNC
* and sets the number of participants to the value found, which serves as a
* start signal. A thread finished dumping looks up the TID of the next active
* thread after it and writes it in the lowest part. If there's none, it sets
* the thread counter to the number of participants and resets that part,
* which serves as an end-of-dump signal. All threads decrement the num_thread
* part. Then all threads wait for the value to reach zero. Only used when
* USE_THREAD_DUMP is set.
*/
#define THREAD_DUMP_TMASK 0x00007FFFU
#define THREAD_DUMP_FSYNC 0x00008000U
#define THREAD_DUMP_PMASK 0x7FFF0000U
/* Description of a component with name, version, path, build options etc. E.g.
* one of them is haproxy. Others might be some clearly identified shared libs.
* They're intentionally self-contained and to be placed into an array to make
* it easier to find them in a core. The important fields (name and version)
* are locally allocated, other ones are dynamic.
*/
struct post_mortem_component {
char name[32]; // symbolic short name
char version[32]; // exact version
char *toolchain; // compiler and version (e.g. gcc-11.4.0)
char *toolchain_opts; // optims, arch-specific options (e.g. CFLAGS)
char *build_settings; // build options (e.g. USE_*, TARGET, etc)
char *path; // path if known.
};
/* This is a collection of information that are centralized to help with core
* dump analysis. It must be used with a public variable and gather elements
* as much as possible without dereferences so that even when identified in a
* core dump it's possible to get the most out of it even if the core file is
* not much exploitable. It's aligned to 256 so that it's easy to spot, given
* that being that large it will not change its size much.
*/
struct post_mortem {
/* platform-specific information */
char post_mortem_magic[32]; // "POST-MORTEM STARTS HERE+7654321\0"
struct {
struct utsname utsname; // OS name+ver+arch+hostname
char distro[64]; // Distro name and version from os-release file if exists
char hw_vendor[64]; // hardware/hypervisor vendor when known
char hw_family[64]; // hardware/hypervisor product family when known
char hw_model[64]; // hardware/hypervisor product/model when known
char brd_vendor[64]; // mainboard vendor when known
char brd_model[64]; // mainboard model when known
char soc_vendor[64]; // SoC/CPU vendor from cpuinfo
char soc_model[64]; // SoC model when known and relevant
char cpu_model[64]; // CPU model when different from SoC
char virt_techno[16]; // when provided by cpuid
char cont_techno[16]; // empty, "no", "yes", "docker" or others
} platform;
/* process-specific information */
struct {
pid_t pid;
uid_t boot_uid;
gid_t boot_gid;
uid_t run_uid;
gid_t run_gid;
#if defined(USE_LINUX_CAP)
struct {
// initial process capabilities
struct __user_cap_data_struct boot[_LINUX_CAPABILITY_U32S_3];
int err_boot; // errno, if capget() syscall fails at boot
// runtime process capabilities
struct __user_cap_data_struct run[_LINUX_CAPABILITY_U32S_3];
int err_run; // errno, if capget() syscall fails at runtime
} caps;
#endif
struct rlimit boot_lim_fd; // RLIMIT_NOFILE at startup
struct rlimit boot_lim_ram; // RLIMIT_DATA at startup
struct rlimit run_lim_fd; // RLIMIT_NOFILE just before enter in polling loop
struct rlimit run_lim_ram; // RLIMIT_DATA just before enter in polling loop
char **argv;
unsigned char argc;
} process;
#if defined(HA_HAVE_DUMP_LIBS)
/* information about dynamic shared libraries involved */
char *libs; // dump of one addr / path per line, or NULL
#endif
struct tgroup_info *tgroup_info; // pointer to ha_tgroup_info
struct thread_info *thread_info; // pointer to ha_thread_info
struct tgroup_ctx *tgroup_ctx; // pointer to ha_tgroup_ctx
struct thread_ctx *thread_ctx; // pointer to ha_thread_ctx
struct list *pools; // pointer to the head of the pools list
struct list *proxies; // pointer to the head of the proxies list
struct global *global; // pointer to the struct global
struct fdtab **fdtab; // pointer to the fdtab array
struct activity *activity; // pointer to the activity[] per-thread array
/* info about identified distinct components (executable, shared libs, etc).
* These can be all listed at once in gdb using:
* p *post_mortem.components@post_mortem.nb_components
*/
uint nb_components; // # of components below
struct post_mortem_component *components; // NULL or array
} post_mortem ALIGNED(256) HA_SECTION("_post_mortem") = { };
unsigned int debug_commands_issued = 0;
unsigned int warn_blocked_issued = 0;
unsigned int debug_enable_counters = (DEBUG_COUNTERS >= 2);
/* dumps a backtrace of the current thread that is appended to buffer <buf>.
* Lines are prefixed with the string <prefix> which may be empty (used for
* indenting). It is recommended to use this at a function's tail so that
* the function does not appear in the call stack. The <dump> argument
* indicates what dump state to start from, and should usually be zero. It
* may be among the following values:
* - 0: search usual callers before step 1, or directly jump to 2
* - 1: skip usual callers before step 2
* - 2: dump until polling loop, scheduler, or main() (excluded)
* - 3: end
* - 4-7: like 0 but stops *after* main.
*/
void ha_dump_backtrace(struct buffer *buf, const char *prefix, int dump)
{
sigset_t new_mask, old_mask;
struct buffer bak;
char pfx2[100];
void *callers[100];
int j, nptrs;
const void *addr;
/* make sure we don't re-enter from debug coming from other threads,
* as some libc's backtrace() are not re-entrant. We'll block these
* sensitive signals while possibly dumping a backtrace.
*/
sigemptyset(&new_mask);
#ifdef WDTSIG
sigaddset(&new_mask, WDTSIG);
#endif
#ifdef DEBUGSIG
sigaddset(&new_mask, DEBUGSIG);
#endif
ha_sigmask(SIG_BLOCK, &new_mask, &old_mask);
nptrs = my_backtrace(callers, sizeof(callers)/sizeof(*callers));
if (!nptrs)
goto leave;
if (snprintf(pfx2, sizeof(pfx2), "%s| ", prefix) > sizeof(pfx2))
pfx2[0] = 0;
/* The call backtrace_symbols_fd(callers, nptrs, STDOUT_FILENO would
* produce similar output to the following:
*/
chunk_appendf(buf, "%scall trace(%d):\n", prefix, nptrs);
for (j = 0; (j < nptrs || (dump & 3) < 2); j++) {
if (j == nptrs && !(dump & 3)) {
/* we failed to spot the starting point of the
* dump, let's start over dumping everything we
* have.
*/
dump += 2;
j = 0;
}
bak = *buf;
dump_addr_and_bytes(buf, pfx2, callers[j], -8);
addr = resolve_sym_name(buf, ": ", callers[j]);
#if defined(__i386__) || defined(__x86_64__)
/* Try to decode a relative call (0xe8 + 32-bit signed ofs) */
if (may_access(callers[j] - 5) && may_access(callers[j] - 1) &&
*((uchar*)(callers[j] - 5)) == 0xe8) {
int ofs = *((int *)(callers[j] - 4));
const void *addr2 = callers[j] + ofs;
resolve_sym_name(buf, " > ", addr2);
}
#elif defined(__aarch64__)
/* Try to decode a relative call (0x9X + 26-bit signed ofs) */
if (may_access(callers[j] - 4) && may_access(callers[j] - 1) &&
(*((int*)(callers[j] - 4)) & 0xFC000000) == 0x94000000) {
int ofs = (*((int *)(callers[j] - 4)) << 6) >> 4; // 26-bit signed immed*4
const void *addr2 = callers[j] - 4 + ofs;
resolve_sym_name(buf, " > ", addr2);
}
#endif
if ((dump & 3) == 0) {
/* dump not started, will start *after* ha_thread_dump_one(),
* ha_panic and ha_backtrace_to_stderr
*/
if (addr == ha_panic ||
addr == ha_backtrace_to_stderr || addr == ha_thread_dump_one)
dump++;
*buf = bak;
continue;
}
if ((dump & 3) == 1) {
/* starting */
if (addr == ha_panic ||
addr == ha_backtrace_to_stderr || addr == ha_thread_dump_one) {
*buf = bak;
continue;
}
dump++;
}
if ((dump & 3) == 2) {
/* still dumping */
if (dump == 6) {
/* we only stop *after* main and we must send the LF */
if (addr == main) {
j = nptrs;
dump++;
}
}
else if (addr == run_poll_loop || addr == main || addr == run_tasks_from_lists) {
dump++;
*buf = bak;
break;
}
}
/* OK, line dumped */
chunk_appendf(buf, "\n");
}
leave:
/* unblock temporarily blocked signals */
ha_sigmask(SIG_SETMASK, &old_mask, NULL);
}
/* dump a backtrace of current thread's stack to stderr. Displays the hint about
* the core if hint & 1.
*/
__attribute__((noinline)) void ha_backtrace_to_stderr(int hint)
{
char area[8192];
struct buffer b = b_make(area, sizeof(area), 0, 0);
const char *msg;
ha_dump_backtrace(&b, " ", 4);
if (b.data)
DISGUISE(write(2, b.area, b.data));
if (hint & 1) {
msg = "\n"
"Hint: when reporting this bug to developers, please check if a core file was\n"
" produced, open it with 'gdb', issue 'bt' to produce a backtrace for the\n"
" current thread only, then join it with the bug report.\n";
DISGUISE(write(2, msg, strlen(msg)));
}
}
/* Dumps some known information about the current thread into its dump buffer,
* and optionally extra info when it's considered safe to do so. The dump will
* be appended to the buffer, so the caller is responsible for preliminary
* initializing it. The <is_caller> argument will indicate if the thread is the
* one requesting the dump (e.g. watchdog, panic etc), in order to display a
* star ('*') in front of the thread to indicate the requesting one. Any stuck
* thread is also prefixed with a '>'. The caller is responsible for atomically
* setting up the thread's dump buffer to point to a valid buffer with enough
* room. Output will be truncated if it does not fit. When the dump is complete
* the dump buffer will have bit 0 set to 1 to tell the caller it's done, and
* the caller will then change that value to indicate it's done once the
* contents are collected.
*/
void ha_thread_dump_one(struct buffer *buf, int is_caller)
{
unsigned long long p = th_ctx->prev_cpu_time;
unsigned long long n = now_cpu_time();
int stuck = !!(th_ctx->flags & TH_FL_STUCK);
/* keep a copy of the dump pointer for post-mortem analysis */
HA_ATOMIC_STORE(&th_ctx->last_dump_buffer, buf);
chunk_appendf(buf,
"%c%cThread %-2u: id=0x%llx act=%d glob=%d wq=%d rq=%d tl=%d tlsz=%d rqsz=%d\n"
" %2u/%-2u loops=%u ctxsw=%u stuck=%d prof=%d",
(is_caller) ? '*' : ' ', stuck ? '>' : ' ', tid + 1,
ha_get_pthread_id(tid),
thread_has_tasks(),
!eb_is_empty(&th_ctx->rqueue_shared),
!eb_is_empty(&th_ctx->timers),
!eb_is_empty(&th_ctx->rqueue),
!(LIST_ISEMPTY(&th_ctx->tasklets[TL_URGENT]) &&
LIST_ISEMPTY(&th_ctx->tasklets[TL_NORMAL]) &&
LIST_ISEMPTY(&th_ctx->tasklets[TL_BULK]) &&
MT_LIST_ISEMPTY(&th_ctx->shared_tasklet_list)),
th_ctx->tasks_in_list,
th_ctx->rq_total,
ti->tgid, ti->ltid + 1,
activity[tid].loops, activity[tid].ctxsw,
stuck,
!!(th_ctx->flags & TH_FL_TASK_PROFILING));
#if defined(USE_THREAD)
chunk_appendf(buf,
" harmless=%d isolated=%d",
!!(_HA_ATOMIC_LOAD(&tg_ctx->threads_harmless) & ti->ltid_bit),
isolated_thread == tid);
#endif
#if (DEBUG_THREAD > 0) || defined(DEBUG_FULL)
chunk_appendf(buf, " locks=%d", th_ctx->lock_level);
#endif
chunk_appendf(buf, "\n");
chunk_appendf(buf, " cpu_ns: poll=%llu now=%llu diff=%llu\n", p, n, n-p);
/* also try to indicate for how long we've entered the current task.
* Note that the task's wake date only contains the 32 lower bits of
* the current time.
*/
if (th_ctx->current && tick_isset(th_ctx->sched_wake_date)) {
unsigned long long now = now_mono_time();
chunk_appendf(buf, " current call: wake=%u ns ago, call=%llu ns ago\n",
(uint)(now - th_ctx->sched_wake_date),
(now - th_ctx->sched_call_date));
}
/* report the execution context when known */
chunk_append_thread_ctx(buf, &th_ctx->exec_ctx, " exec_ctx: ", "\n");
/* this is the end of what we can dump from outside the current thread */
chunk_appendf(buf, " curr_task=");
ha_task_dump(buf, th_ctx->current, " ");
#if defined(USE_THREAD) && ((DEBUG_THREAD > 0) || defined(DEBUG_FULL))
/* List the lock history */
if (th_ctx->lock_history) {
int lkh, lkl, lbl;
int done;
chunk_appendf(buf, " lock_hist:");
for (lkl = 7; lkl >= 0; lkl--) {
lkh = (th_ctx->lock_history >> (lkl * 8)) & 0xff;
if (!lkh)
continue;
chunk_appendf(buf, " %c:%s",
"URSW"[lkh & 3], lock_label((lkh >> 2) - 1));
}
/* now rescan the list to only show those that remain */
done = 0;
for (lbl = 0; lbl < LOCK_LABELS; lbl++) {
/* find the latest occurrence of each label */
for (lkl = 0; lkl < 8; lkl++) {
lkh = (th_ctx->lock_history >> (lkl * 8)) & 0xff;
if (!lkh)
continue;
if ((lkh >> 2) == lbl)
break;
}
if (lkl == 8) // not found
continue;
if ((lkh & 3) == _LK_UN)
continue;
if (!done)
chunk_appendf(buf, " locked:");
chunk_appendf(buf, " %s(%c)",
lock_label((lkh >> 2) - 1),
"URSW"[lkh & 3]);
done++;
}
chunk_appendf(buf, "\n");
}
#endif
if (!(HA_ATOMIC_LOAD(&tg_ctx->threads_idle) & ti->ltid_bit)) {
/* only dump the stack of active threads */
#ifdef USE_LUA
if (th_ctx->current &&
th_ctx->current->process == process_stream && th_ctx->current->context) {
const struct stream *s = (const struct stream *)th_ctx->current->context;
struct hlua *hlua = NULL;
if (s) {
if (s->hlua[0] && HLUA_IS_BUSY(s->hlua[0]))
hlua = s->hlua[0];
else if (s->hlua[1] && HLUA_IS_BUSY(s->hlua[1]))
hlua = s->hlua[1];
}
if (hlua) {
mark_tainted(TAINTED_LUA_STUCK);
if (hlua->state_id == 0)
mark_tainted(TAINTED_LUA_STUCK_SHARED);
}
}
#endif
if (HA_ATOMIC_LOAD(&pool_trim_in_progress))
mark_tainted(TAINTED_MEM_TRIMMING_STUCK);
ha_dump_backtrace(buf, " ", 0);
}
leave:
return;
}
/* Triggers a thread dump from thread <thr>, either directly if it's the
* current thread or if thread dump signals are not implemented, or by sending
* a signal if it's a remote one and the feature is supported. The buffer <buf>
* will get the dump appended, and the caller is responsible for making sure
* there is enough room otherwise some contents will be truncated. The function
* waits for the called thread to fill the buffer before returning (or cancelling
* by reporting NULL). It does not release the called thread yet, unless it's the
* current one, which in this case is always available. It returns a pointer to
* the buffer used if the dump was done, otherwise NULL. When the dump starts, it
* marks the current thread as dumping, which will only be released via a failure
* (returns NULL) or via a call to ha_dump_thread_done().
*/
struct buffer *ha_thread_dump_fill(struct buffer *buf, int thr)
{
#ifdef USE_THREAD_DUMP
/* silence bogus warning in gcc 11 without threads */
ASSUME(0 <= thr && thr < MAX_THREADS);
if (thr != tid) {
struct buffer *old = NULL;
/* try to impose our dump buffer and to reserve the target thread's
* next dump for us.
*/
do {
if (old)
ha_thread_relax();
old = NULL;
} while (!HA_ATOMIC_CAS(&ha_thread_ctx[thr].thread_dump_buffer, &old, buf));
/* asking the remote thread to dump itself allows to get more details
* including a backtrace.
*/
ha_tkill(thr, DEBUGSIG);
/* now wait for the dump to be done (or cancelled) */
while (1) {
buf = HA_ATOMIC_LOAD(&ha_thread_ctx[thr].thread_dump_buffer);
if ((ulong)buf & 0x1)
break;
if (!buf)
return buf;
ha_thread_relax();
}
}
else
ha_thread_dump_one(buf, 1);
#else /* !USE_THREAD_DUMP below, we're on the target thread */
/* when thread-dump is not supported, we can only dump our own thread */
if (thr != tid)
return NULL;
/* the buffer might not be valid in case of a panic, since we
* have to allocate it ourselves in this case.
*/
if ((ulong)buf == 0x2UL)
buf = get_trash_chunk();
HA_ATOMIC_STORE(&th_ctx->thread_dump_buffer, buf);
ha_thread_dump_one(buf, 1);
#endif
return (struct buffer *)((ulong)buf & ~0x1UL);
}
/* Indicates to the called thread that the dumped data are collected by
* clearing the thread_dump_buffer pointer. It waits for the dump to be
* completed if it was not the case, and can also leave if the pointer
* is already NULL (e.g. if a thread has aborted).
*/
void ha_thread_dump_done(int thr)
{
struct buffer *old;
/* silence bogus warning in gcc 11 without threads */
ASSUME(0 <= thr && thr < MAX_THREADS);
/* now wait for the dump to be done or cancelled, and release it */
do {
if (thr == tid)
break;
old = HA_ATOMIC_LOAD(&ha_thread_ctx[thr].thread_dump_buffer);
if (!((ulong)old & 0x1)) {
if (!old)
break;
ha_thread_relax();
continue;
}
} while (!HA_ATOMIC_CAS(&ha_thread_ctx[thr].thread_dump_buffer, &old, NULL));
}
/* 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;
const struct appctx __maybe_unused *appctx = NULL;
struct hlua __maybe_unused *hlua = NULL;
const struct stconn *sc;
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->wake_date ? (unsigned long long)(now_mono_time() - task->wake_date) : 0,
task->wake_date ? " ns ago" : "");
chunk_appendf(buf, "%s fct=%p(", pfx, task->process);
resolve_sym_name(buf, NULL, task->process);
chunk_appendf(buf,") ctx=%p", task->context);
if (task->process == task_run_applet && (appctx = task->context))
chunk_appendf(buf, "(%s)\n", appctx->applet->name);
else
chunk_appendf(buf, "\n");
if (task->process == process_stream && task->context)
s = (struct stream *)task->context;
else if (task->process == task_run_applet && task->context && (sc = appctx_sc((struct appctx *)task->context)))
s = sc_strm(sc);
else if (task->process == sc_conn_io_cb && task->context)
s = sc_strm(((struct stconn *)task->context));
if (s) {
chunk_appendf(buf, "%sstream=", pfx);
strm_dump_to_buffer(buf, s, pfx, HA_ATOMIC_LOAD(&global.anon_key));
}
#ifdef USE_LUA
hlua = NULL;
if (s && ((s->hlua[0] && HLUA_IS_BUSY(s->hlua[0])) ||
(s->hlua[1] && HLUA_IS_BUSY(s->hlua[1])))) {
hlua = (s->hlua[0] && HLUA_IS_BUSY(s->hlua[0])) ? s->hlua[0] : s->hlua[1];
chunk_appendf(buf, "%sCurrent executing Lua from a stream analyser -- ", pfx);
}
else if (task->process == hlua_process_task && (hlua = task->context)) {
chunk_appendf(buf, "%sCurrent executing a Lua task -- ", pfx);
}
else if (task->process == task_run_applet && (appctx = task->context) &&
(appctx->applet->fct == hlua_applet_tcp_fct)) {
chunk_appendf(buf, "%sCurrent executing a Lua TCP service -- ", pfx);
}
else if (task->process == task_run_applet && (appctx = task->context) &&
(appctx->applet->fct == hlua_applet_http_fct)) {
chunk_appendf(buf, "%sCurrent executing a Lua HTTP service -- ", pfx);
}
/* only dump the Lua stack on panic because the approach is often
* destructive and the running program might not recover from this
* if called during warnings or "show threads".
*/
if (hlua && hlua->T && (get_tainted() & TAINTED_PANIC)) {
chunk_appendf(buf, "stack traceback:\n ");
append_prefixed_str(buf, hlua_traceback(hlua->T, "\n "), pfx, '\n', 0);
}
/* we may need to terminate the current line */
if (*b_peek(buf, b_data(buf)-1) != '\n')
b_putchr(buf, '\n');
#endif
}
/* 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.
* Note: to not statify this one, it's hard to spot in backtraces!
*/
int cli_io_handler_show_threads(struct appctx *appctx)
{
int *thr = appctx->svcctx;
if (!thr)
thr = applet_reserve_svcctx(appctx, sizeof(*thr));
do {
chunk_reset(&trash);
if (ha_thread_dump_fill(&trash, *thr)) {
ha_thread_dump_done(*thr);
if (applet_putchk(appctx, &trash) == -1) {
/* failed, try again */
return 0;
}
}
(*thr)++;
} while (*thr < global.nbthread);
return 1;
}
#if defined(HA_HAVE_DUMP_LIBS)
/* parse a "show libs" command. It returns 1 if it emits anything otherwise zero. */
static int debug_parse_cli_show_libs(char **args, char *payload, struct appctx *appctx, void *private)
{
if (!cli_has_level(appctx, ACCESS_LVL_OPER))
return 1;
chunk_reset(&trash);
if (dump_libs(&trash, 1))
return cli_msg(appctx, LOG_INFO, trash.area);
else
return 0;
}
#endif
/* parse a "show dev" command. It returns 1 if it emits anything otherwise zero. */
static int debug_parse_cli_show_dev(char **args, char *payload, struct appctx *appctx, void *private)
{
const char **build_opt;
char *err = NULL;
int i;
if (*args[2])
return cli_err(appctx, "This command takes no argument.\n");
chunk_reset(&trash);
chunk_appendf(&trash, "HAProxy version %s\n", haproxy_version);
chunk_appendf(&trash, "Features:\n %s\n", build_features);
chunk_appendf(&trash, "Build options:\n");
for (build_opt = NULL; (build_opt = hap_get_next_build_opt(build_opt)); )
if (append_prefixed_str(&trash, *build_opt, " ", '\n', 0) == 0)
chunk_strcat(&trash, "\n");
chunk_appendf(&trash, "Platform info:\n");
if (*post_mortem.platform.hw_vendor)
chunk_appendf(&trash, " machine vendor: %s\n", post_mortem.platform.hw_vendor);
if (*post_mortem.platform.hw_family)
chunk_appendf(&trash, " machine family: %s\n", post_mortem.platform.hw_family);
if (*post_mortem.platform.hw_model)
chunk_appendf(&trash, " machine model: %s\n", post_mortem.platform.hw_model);
if (*post_mortem.platform.brd_vendor)
chunk_appendf(&trash, " board vendor: %s\n", post_mortem.platform.brd_vendor);
if (*post_mortem.platform.brd_model)
chunk_appendf(&trash, " board model: %s\n", post_mortem.platform.brd_model);
if (*post_mortem.platform.soc_vendor)
chunk_appendf(&trash, " soc vendor: %s\n", post_mortem.platform.soc_vendor);
if (*post_mortem.platform.soc_model)
chunk_appendf(&trash, " soc model: %s\n", post_mortem.platform.soc_model);
if (*post_mortem.platform.cpu_model)
chunk_appendf(&trash, " cpu model: %s\n", post_mortem.platform.cpu_model);
if (*post_mortem.platform.virt_techno)
chunk_appendf(&trash, " virtual machine: %s\n", post_mortem.platform.virt_techno);
if (*post_mortem.platform.cont_techno)
chunk_appendf(&trash, " container: %s\n", post_mortem.platform.cont_techno);
if (*post_mortem.platform.utsname.sysname)
chunk_appendf(&trash, " OS name: %s\n", post_mortem.platform.utsname.sysname);
if (*post_mortem.platform.utsname.release)
chunk_appendf(&trash, " OS release: %s\n", post_mortem.platform.utsname.release);
if (*post_mortem.platform.utsname.version)
chunk_appendf(&trash, " OS version: %s\n", post_mortem.platform.utsname.version);
if (*post_mortem.platform.utsname.machine)
chunk_appendf(&trash, " OS architecture: %s\n", post_mortem.platform.utsname.machine);
if (*post_mortem.platform.utsname.nodename)
chunk_appendf(&trash, " node name: %s\n", HA_ANON_CLI(post_mortem.platform.utsname.nodename));
if (*post_mortem.platform.distro)
chunk_appendf(&trash, " distro pretty name: %s\n", HA_ANON_CLI(post_mortem.platform.distro));
chunk_appendf(&trash, "Process info:\n");
chunk_appendf(&trash, " pid: %d\n", post_mortem.process.pid);
chunk_appendf(&trash, " cmdline: ");
for (i = 0; i < post_mortem.process.argc; i++)
chunk_appendf(&trash, "%s ", post_mortem.process.argv[i]);
chunk_appendf(&trash, "\n");
#if defined(USE_LINUX_CAP)
/* let's dump saved in feed_post_mortem() initial capabilities sets */
if(!post_mortem.process.caps.err_boot) {
chunk_appendf(&trash, " boot capabilities:\n");
chunk_appendf(&trash, " \tCapEff: 0x%016llx\n",
CAPS_TO_ULLONG(post_mortem.process.caps.boot[0].effective,
post_mortem.process.caps.boot[1].effective));
chunk_appendf(&trash, " \tCapPrm: 0x%016llx\n",
CAPS_TO_ULLONG(post_mortem.process.caps.boot[0].permitted,
post_mortem.process.caps.boot[1].permitted));
chunk_appendf(&trash, " \tCapInh: 0x%016llx\n",
CAPS_TO_ULLONG(post_mortem.process.caps.boot[0].inheritable,
post_mortem.process.caps.boot[1].inheritable));
} else
chunk_appendf(&trash, " capget() failed at boot with: %s.\n",
errname(post_mortem.process.caps.err_boot, &err));
/* let's print actual capabilities sets, could be useful in order to compare */
if (!post_mortem.process.caps.err_run) {
chunk_appendf(&trash, " runtime capabilities:\n");
chunk_appendf(&trash, " \tCapEff: 0x%016llx\n",
CAPS_TO_ULLONG(post_mortem.process.caps.run[0].effective,
post_mortem.process.caps.run[1].effective));
chunk_appendf(&trash, " \tCapPrm: 0x%016llx\n",
CAPS_TO_ULLONG(post_mortem.process.caps.run[0].permitted,
post_mortem.process.caps.run[1].permitted));
chunk_appendf(&trash, " \tCapInh: 0x%016llx\n",
CAPS_TO_ULLONG(post_mortem.process.caps.run[0].inheritable,
post_mortem.process.caps.run[1].inheritable));
} else
chunk_appendf(&trash, " capget() failed at runtime with: %s.\n",
errname(post_mortem.process.caps.err_run, &err));
#endif
chunk_appendf(&trash, " %-22s %-11s %-11s \n", "identity:", "-boot-", "-runtime-");
chunk_appendf(&trash, " %-22s %-11d %-11d \n", " uid:", post_mortem.process.boot_uid,
post_mortem.process.run_uid);
chunk_appendf(&trash, " %-22s %-11d %-11d \n", " gid:", post_mortem.process.boot_gid,
post_mortem.process.run_gid);
chunk_appendf(&trash, " %-22s %-11s %-11s \n", "limits:", "-boot-", "-runtime-");
chunk_appendf(&trash, " %-22s %-11s %-11s \n", " fd limit (soft):",
LIM2A(normalize_rlim((ulong)post_mortem.process.boot_lim_fd.rlim_cur), "unlimited"),
LIM2A(normalize_rlim((ulong)post_mortem.process.run_lim_fd.rlim_cur), "unlimited"));
chunk_appendf(&trash, " %-22s %-11s %-11s \n", " fd limit (hard):",
LIM2A(normalize_rlim((ulong)post_mortem.process.boot_lim_fd.rlim_max), "unlimited"),
LIM2A(normalize_rlim((ulong)post_mortem.process.run_lim_fd.rlim_max), "unlimited"));
chunk_appendf(&trash, " %-22s %-11s %-11s \n", " ram limit (soft):",
LIM2A(normalize_rlim((ulong)post_mortem.process.boot_lim_ram.rlim_cur), "unlimited"),
LIM2A(normalize_rlim((ulong)post_mortem.process.run_lim_ram.rlim_cur), "unlimited"));
chunk_appendf(&trash, " %-22s %-11s %-11s \n", " ram limit (hard):",
LIM2A(normalize_rlim((ulong)post_mortem.process.boot_lim_ram.rlim_max), "unlimited"),
LIM2A(normalize_rlim((ulong)post_mortem.process.run_lim_ram.rlim_max), "unlimited"));
#ifdef USE_CPU_AFFINITY
cpu_topo_dump_summary(ha_cpu_topo, &trash);
#endif
ha_free(&err);
return cli_msg(appctx, LOG_INFO, trash.area);
}
/* Dumps a state of all threads into the trash and on fd #2, then aborts. */
void ha_panic()
{
struct buffer *buf;
unsigned int thr;
if (mark_tainted(TAINTED_PANIC) & TAINTED_PANIC) {
/* a panic dump is already in progress, let's not disturb it,
* we'll be called via signal DEBUGSIG. By returning we may be
* able to leave a current signal handler (e.g. WDT) so that
* this will ensure more reliable signal delivery.
*/
return;
}
chunk_printf(&trash, "\nPANIC! Thread %u is about to kill the process (pid %d).\n", tid + 1, pid);
/* dump a few of the post-mortem info */
chunk_appendf(&trash, "\nHAProxy info:\n version: %s\n features: %s\n",
haproxy_version, build_features);
chunk_appendf(&trash, "\nOperating system info:\n");
if (*post_mortem.platform.virt_techno)
chunk_appendf(&trash, " virtual machine: %s\n", post_mortem.platform.virt_techno);
if (*post_mortem.platform.cont_techno)
chunk_appendf(&trash, " container: %s\n", post_mortem.platform.cont_techno);
if (*post_mortem.platform.utsname.sysname || *post_mortem.platform.utsname.release ||
*post_mortem.platform.utsname.version || *post_mortem.platform.utsname.machine)
chunk_appendf(&trash, " kernel: %s %s %s %s\n",
post_mortem.platform.utsname.sysname, post_mortem.platform.utsname.release,
post_mortem.platform.utsname.version, post_mortem.platform.utsname.machine);
if (*post_mortem.platform.distro)
chunk_appendf(&trash, " userland: %s\n", post_mortem.platform.distro);
chunk_appendf(&trash, "\n");
DISGUISE(write(2, trash.area, trash.data));
for (thr = 0; thr < global.nbthread; thr++) {
if (thr == tid)
buf = get_trash_chunk();
else
buf = (void *)0x2UL; // let the target thread allocate it
buf = ha_thread_dump_fill(buf, thr);
if (!buf)
continue;
DISGUISE(write(2, buf->area, buf->data));
/* restore the thread's dump pointer for easier post-mortem analysis */
ha_thread_dump_done(thr);
}
#ifdef USE_LUA
if (get_tainted() & TAINTED_LUA_STUCK_SHARED && global.nbthread > 1) {
chunk_printf(&trash,
"### Note: at least one thread was stuck in a Lua context loaded using the\n"
" 'lua-load' directive, which is known for causing heavy contention\n"
" when used with threads. Please consider using 'lua-load-per-thread'\n"
" instead if your code is safe to run in parallel on multiple threads.\n");
DISGUISE(write(2, trash.area, trash.data));
}
else if (get_tainted() & TAINTED_LUA_STUCK) {
chunk_printf(&trash,
"### Note: at least one thread was stuck in a Lua context in a way that suggests\n"
" heavy processing inside a dependency or a long loop that can't yield.\n"
" Please make sure any external code you may rely on is safe for use in\n"
" an event-driven engine.\n");
DISGUISE(write(2, trash.area, trash.data));
}
#endif
if (get_tainted() & TAINTED_MEM_TRIMMING_STUCK) {
chunk_printf(&trash,
"### Note: one thread was found stuck under malloc_trim(), which can run for a\n"
" very long time on large memory systems. You way want to disable this\n"
" memory reclaiming feature by setting 'no-memory-trimming' in the\n"
" 'global' section of your configuration to avoid this in the future.\n");
DISGUISE(write(2, trash.area, trash.data));
}
chunk_printf(&trash,
"\n"
"Hint: when reporting this bug to developers, please check if a core file was\n"
" produced, open it with 'gdb', issue 't a a bt full', check that the\n"
" output does not contain sensitive data, then join it with the bug report.\n"
" For more info, please see https://github.com/haproxy/haproxy/issues/2374\n");
DISGUISE(write(2, trash.area, trash.data));
for (;;)
abort();
}
/* Dumps a state of the current thread on fd #2 and returns. It takes a great
* care about not using any global state variable so as to gracefully recover.
* It is designed to be called exclusively from the watchdog signal handler,
* and takes care of not touching thread_dump_buffer so as not to interfere
* with any other parallel dump that could have been started.
*/
void ha_stuck_warning(void)
{
char msg_buf[8192];
struct buffer buf;
ullong n, p;
if (mark_tainted(TAINTED_WARN_BLOCKED_TRAFFIC) & TAINTED_PANIC) {
/* a panic dump is already in progress, let's not disturb it,
* we'll be called via signal DEBUGSIG. By returning we may be
* able to leave a current signal handler (e.g. WDT) so that
* this will ensure more reliable signal delivery.
*/
return;
}
HA_ATOMIC_INC(&warn_blocked_issued);
buf = b_make(msg_buf, sizeof(msg_buf), 0, 0);
p = HA_ATOMIC_LOAD(&th_ctx->prev_cpu_time);
n = now_cpu_time();
chunk_appendf(&buf,
"\nWARNING! thread %u has stopped processing traffic for %llu milliseconds\n"
" with %d streams currently blocked, prevented from making any progress.\n"
" While this may occasionally happen with inefficient configurations\n"
" involving excess of regular expressions, map_reg, or heavy Lua processing,\n"
" this must remain exceptional because the system's stability is now at risk.\n"
" Timers in logs may be reported incorrectly, spurious timeouts may happen,\n"
" some incoming connections may silently be dropped, health checks may\n"
" randomly fail, and accesses to the CLI may block the whole process. The\n"
" blocking delay before emitting this warning may be adjusted via the global\n"
" 'warn-blocked-traffic-after' directive. Please check the trace below for\n"
" any clues about configuration elements that need to be corrected:\n\n",
tid + 1, (n - p) / 1000000ULL,
HA_ATOMIC_LOAD(&ha_thread_ctx[tid].stream_cnt));
ha_thread_dump_one(&buf, 1);
#ifdef USE_LUA
if (get_tainted() & TAINTED_LUA_STUCK_SHARED && global.nbthread > 1) {
chunk_appendf(&buf,
"### Note: at least one thread was stuck in a Lua context loaded using the\n"
" 'lua-load' directive, which is known for causing heavy contention\n"
" when used with threads. Please consider using 'lua-load-per-thread'\n"
" instead if your code is safe to run in parallel on multiple threads.\n");
}
else if (get_tainted() & TAINTED_LUA_STUCK) {
chunk_appendf(&buf,
"### Note: at least one thread was stuck in a Lua context in a way that suggests\n"
" heavy processing inside a dependency or a long loop that can't yield.\n"
" Please make sure any external code you may rely on is safe for use in\n"
" an event-driven engine.\n");
}
#endif
if (get_tainted() & TAINTED_MEM_TRIMMING_STUCK) {
chunk_appendf(&buf,
"### Note: one thread was found stuck under malloc_trim(), which can run for a\n"
" very long time on large memory systems. You way want to disable this\n"
" memory reclaiming feature by setting 'no-memory-trimming' in the\n"
" 'global' section of your configuration to avoid this in the future.\n");
}
chunk_appendf(&buf, " => Trying to gracefully recover now (pid %d).\n", pid);
/* Note: it's important to dump the whole buffer at once to avoid
* interleaved outputs from multiple threads dumping in parallel.
*/
DISGUISE(write(2, buf.area, buf.data));
}
/* Complain with message <msg> on stderr with a '\n' at the begin and at the
* end. Depending on the fatality, and type of the event in <details>, a
* different prefix and suffix will be appended. Then the event type may result
* in some taining of the process to happen. If the string contains an RS char
* (\x1e) then it's used as a delimiter: the main message stops there, and what
* follows is a new line that will be appended after another LF (normally it's
* used to give extra info to the user about the issue's location). When <dbg>
* is non-null, it is used as a source for the message, file, line number, type
* etc.
*/
static void _complain(uint details, const char *msg, struct debug_count *dbg)
{
struct iovec iovec[20];
const char *pfx;
const char *rs;
int vec = 0;
iovec[vec].iov_base = "\n";
iovec[vec].iov_len = 1;
vec++;
pfx = NULL;
if (details & DBG_DET_TYP_ABT)
pfx = "ABORT at ";
else if (details & DBG_DET_FAT_FATL)
pfx = "FATAL: ";
else if (details & DBG_DET_FAT_WARN)
pfx = "WARNING: ";
if (pfx) {
iovec[vec].iov_base = (char *)pfx;
iovec[vec].iov_len = strlen(pfx);
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