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authorJosé Bollo <jose.bollo@iot.bzh>2019-02-14 19:43:29 +0100
committerJosé Bollo <jose.bollo@iot.bzh>2019-03-22 12:21:54 +0100
commitd58b8f4273c48026f22d91896c05d2a5013480b2 (patch)
tree0c48aeb1005398f49918c437e6d576ef9dbfe82a
parent3383c9cdfdf6b7169cc2bf80a0dc60ea807a9c09 (diff)
sig-monitor: Add compiling switches
The following new switches are added: - USE_SIG_MONITOR_DUMPSTACK activate dump stack on error - USE_SIG_MONITOR_SIGNALS activate handling of signals - USE_SIG_MONITOR_FOR_CALL activate monitoring of calls - USE_SIG_MONITOR_TIMERS activate monitoring of call expiration All enabled by default Change-Id: I2231e5f2a8db469b7258ce14530f72b4c5f38b00 Signed-off-by: José Bollo <jose.bollo@iot.bzh>
-rw-r--r--src/CMakeLists.txt29
-rw-r--r--src/sig-monitor.c259
-rw-r--r--src/sig-monitor.h2
3 files changed, 206 insertions, 84 deletions
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 2985db4b..1d5da5e8 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -24,6 +24,35 @@ ADD_DEFINITIONS(-DBINDING_INSTALL_DIR="${binding_install_dir}")
# Always add INFER_EXTENSION (more details in afb-hreq.c)
ADD_DEFINITIONS(-DINFER_EXTENSION)
+############################################################################
+# TODO: improve below setting
+set(USE_SIG_MONITOR_DUMPSTACK ON CACHE BOOL "activate dump stack on error")
+set(USE_SIG_MONITOR_SIGNALS ON CACHE BOOL "activate handling of signals")
+set(USE_SIG_MONITOR_FOR_CALL ON CACHE BOOL "activate monitoring of calls")
+set(USE_SIG_MONITOR_TIMERS ON CACHE BOOL "activate monitoring of call expiration")
+
+if(USE_SIG_MONITOR_DUMPSTACK)
+ add_definitions(-DUSE_SIG_MONITOR_DUMPSTACK=1)
+else()
+ add_definitions(-DUSE_SIG_MONITOR_DUMPSTACK=0)
+endif()
+if(USE_SIG_MONITOR_SIGNALS)
+ add_definitions(-DUSE_SIG_MONITOR_SIGNALS=1)
+else()
+ add_definitions(-DUSE_SIG_MONITOR_SIGNALS=0)
+endif()
+if(USE_SIG_MONITOR_FOR_CALL)
+ add_definitions(-DUSE_SIG_MONITOR_FOR_CALL=1)
+else()
+ add_definitions(-DUSE_SIG_MONITOR_FOR_CALL=0)
+endif()
+if(USE_SIG_MONITOR_TIMERS)
+ add_definitions(-DUSE_SIG_MONITOR_TIMERS=1)
+else()
+ add_definitions(-DUSE_SIG_MONITOR_TIMERS=0)
+endif()
+############################################################################
+
SET(AFB_LIB_SOURCES
afb-api.c
afb-api-so.c
diff --git a/src/sig-monitor.c b/src/sig-monitor.c
index 4bb69fe5..954dcf8b 100644
--- a/src/sig-monitor.c
+++ b/src/sig-monitor.c
@@ -17,34 +17,59 @@
#define _GNU_SOURCE
+/*******************************************************************************
+* sig-monitor is under the control of several compilation flags
+*******************************************************************************/
+
+/* controls whether to dump stack or not */
+#if !defined(USE_SIG_MONITOR_DUMPSTACK)
+# define USE_SIG_MONITOR_DUMPSTACK 1
+#endif
+
+/* control whether to monitor signals */
+#if !defined(USE_SIG_MONITOR_SIGNALS)
+# define USE_SIG_MONITOR_SIGNALS 1
+#endif
+
+/* controls whether to monitor calls */
+#if !defined(USE_SIG_MONITOR_FOR_CALL)
+# define USE_SIG_MONITOR_FOR_CALL 1
+#endif
+
+/* control whether to monitor timers */
+#if !defined(USE_SIG_MONITOR_TIMERS)
+# define USE_SIG_MONITOR_TIMERS 1
+#endif
+
+#if !USE_SIG_MONITOR_SIGNALS
+# undef USE_SIG_MONITOR_FOR_CALL
+# define USE_SIG_MONITOR_FOR_CALL 0
+#endif
+
+#if !USE_SIG_MONITOR_FOR_CALL
+# undef USE_SIG_MONITOR_TIMERS
+# define USE_SIG_MONITOR_TIMERS 0
+#endif
+
+/******************************************************************************/
+
#include <stdlib.h>
#include <stdio.h>
-#include <signal.h>
#include <string.h>
-#include <setjmp.h>
-#include <time.h>
#include <unistd.h>
-#include <sys/syscall.h>
-#include <execinfo.h>
#include "sig-monitor.h"
+
#include "verbose.h"
-#define SIG_FOR_TIMER SIGVTALRM
+/******************************************************************************/
+#if !USE_SIG_MONITOR_DUMPSTACK
-/* local handler */
-static _Thread_local sigjmp_buf *error_handler;
-static _Thread_local int in_safe_dumpstack;
+static inline void dumpstack(int crop, int signum) {}
-/* local timers */
-static _Thread_local int thread_timer_set;
-static _Thread_local timer_t thread_timerid;
+#else
-/* internal signal lists */
-static int sigerr[] = { SIG_FOR_TIMER, SIGSEGV, SIGFPE, SIGILL, SIGBUS, 0 };
-static int sigterm[] = { SIGINT, SIGABRT, SIGTERM, 0 };
-static int exiting = 0;
-static int enabled = 0;
+#include <execinfo.h>
/*
* Dumps the current stack
@@ -82,23 +107,28 @@ static void dumpstack(int crop, int signum)
}
}
-static void safe_dumpstack_cb(int signum, void *closure)
-{
- int *args = closure;
- if (signum)
- ERROR("Can't provide backtrace: raised signal %s", strsignal(signum));
- else
- dumpstack(args[0], args[1]);
-}
+#endif
+/******************************************************************************/
+#if !USE_SIG_MONITOR_TIMERS
-static void safe_dumpstack(int crop, int signum)
-{
- int args[2] = { crop + 3, signum };
+static inline int timeout_create() { return 0; }
+static inline int timeout_arm(int timeout) { return 0; }
+static inline void timeout_disarm() {}
+static inline void timeout_delete() {}
- in_safe_dumpstack = 1;
- sig_monitor(0, safe_dumpstack_cb, args);
- in_safe_dumpstack = 0;
-}
+#define SIG_FOR_TIMER 0
+
+#else
+
+#include <time.h>
+#include <sys/syscall.h>
+#include <signal.h>
+
+#define SIG_FOR_TIMER SIGVTALRM
+
+/* local per thread timers */
+static _Thread_local int thread_timer_set;
+static _Thread_local timer_t thread_timerid;
/*
* Creates a timer for the current thread
@@ -166,9 +196,67 @@ static inline void timeout_delete()
thread_timer_set = 0;
}
}
+#endif
+/******************************************************************************/
+#if !USE_SIG_MONITOR_FOR_CALL
+
+static inline void monitor_raise(int signum) {}
+
+#else
+
+#include <setjmp.h>
+
+/* local handler */
+static _Thread_local sigjmp_buf *error_handler;
+
+static void monitor(int timeout, void (*function)(int sig, void*), void *arg)
+{
+ volatile int signum, signum2;
+ sigjmp_buf jmpbuf, *older;
+
+ older = error_handler;
+ signum = setjmp(jmpbuf);
+ if (signum == 0) {
+ error_handler = &jmpbuf;
+ if (timeout) {
+ timeout_create();
+ timeout_arm(timeout);
+ }
+ function(0, arg);
+ } else {
+ signum2 = setjmp(jmpbuf);
+ if (signum2 == 0)
+ function(signum, arg);
+ }
+ if (timeout)
+ timeout_disarm();
+ error_handler = older;
+}
+
+static inline void monitor_raise(int signum)
+{
+ if (error_handler != NULL)
+ longjmp(*error_handler, signum);
+}
+#endif
+/******************************************************************************/
+#if !USE_SIG_MONITOR_SIGNALS
+
+static inline int enable_signal_handling() { return 0; }
+
+#else
+
+#include <signal.h>
+
+/* internal signal lists */
+static int sigerr[] = { SIGSEGV, SIGFPE, SIGILL, SIGBUS, SIG_FOR_TIMER, 0 };
+static int sigterm[] = { SIGINT, SIGABRT, SIGTERM, 0 };
+
+static int exiting = 0;
+static int enabled = 0;
/* install the handlers */
-static int install(void (*handler)(int), int *signals)
+static int set_signals_handler(void (*handler)(int), int *signals)
{
int result = 1;
struct sigaction sa;
@@ -200,12 +288,40 @@ static void on_rescue_exit(int signum)
*/
static void safe_exit(int code)
{
- install(on_rescue_exit, sigerr);
- install(on_rescue_exit, sigterm);
+ set_signals_handler(on_rescue_exit, sigerr);
+ set_signals_handler(on_rescue_exit, sigterm);
exiting = code;
exit(code);
}
+#if !USE_SIG_MONITOR_DUMPSTACK
+
+static inline void safe_dumpstack(int crop, int signum) {}
+#define in_safe_dumpstack (0)
+
+#else
+
+static _Thread_local int in_safe_dumpstack;
+
+static void safe_dumpstack_cb(int signum, void *closure)
+{
+ int *args = closure;
+ if (signum)
+ ERROR("Can't provide backtrace: raised signal %s", strsignal(signum));
+ else
+ dumpstack(args[0], args[1]);
+}
+
+static void safe_dumpstack(int crop, int signum)
+{
+ int args[2] = { crop + 3, signum };
+
+ in_safe_dumpstack = 1;
+ sig_monitor(0, safe_dumpstack_cb, args);
+ in_safe_dumpstack = 0;
+}
+#endif
+
/* Handles signals that terminate the process */
static void on_signal_terminate (int signum)
{
@@ -220,42 +336,43 @@ static void on_signal_terminate (int signum)
/* Handles monitored signals that can be continued */
static void on_signal_error(int signum)
{
- if (in_safe_dumpstack)
- longjmp(*error_handler, signum);
-
- ERROR("ALERT! signal %d received: %s", signum, strsignal(signum));
- if (error_handler == NULL && signum == SIG_FOR_TIMER)
- return;
-
- safe_dumpstack(3, signum);
+ if (!in_safe_dumpstack) {
+ ERROR("ALERT! signal %d received: %s", signum, strsignal(signum));
- // unlock signal to allow a new signal to come
- if (error_handler != NULL)
- longjmp(*error_handler, signum);
+ safe_dumpstack(3, signum);
+ }
+ monitor_raise(signum);
- ERROR("Unmonitored signal %d received: %s", signum, strsignal(signum));
- safe_exit(2);
+ if (signum != SIG_FOR_TIMER) {
+ ERROR("Unmonitored signal %d received: %s", signum, strsignal(signum));
+ safe_exit(2);
+ }
}
-void sig_monitor_disable()
+/*
+static void disable_signal_handling()
{
+ set_signals_handler(SIG_DFL, sigerr);
+ set_signals_handler(SIG_DFL, sigterm);
enabled = 0;
- install(SIG_DFL, sigerr);
- install(SIG_DFL, sigterm);
}
+*/
-int sig_monitor_enable()
+static int enable_signal_handling()
{
- enabled = install(on_signal_error, sigerr) && install(on_signal_terminate, sigterm);
- if (enabled)
- return 0;
- sig_monitor_disable();
- return -1;
+ if (!set_signals_handler(on_signal_error, sigerr)
+ || !set_signals_handler(on_signal_terminate, sigterm)) {
+ return -1;
+ }
+ enabled = 1;
+ return 0;
}
+#endif
+/******************************************************************************/
int sig_monitor_init(int enable)
{
- return enable ? sig_monitor_enable() : (sig_monitor_disable(), 0);
+ return enable ? enable_signal_handling() : 0;
}
int sig_monitor_init_timeouts()
@@ -268,35 +385,13 @@ void sig_monitor_clean_timeouts()
timeout_delete();
}
-static void monitor(int timeout, void (*function)(int sig, void*), void *arg)
-{
- volatile int signum, signum2;
- sigjmp_buf jmpbuf, *older;
-
- older = error_handler;
- signum = setjmp(jmpbuf);
- if (signum == 0) {
- error_handler = &jmpbuf;
- if (timeout) {
- timeout_create();
- timeout_arm(timeout);
- }
- function(0, arg);
- } else {
- signum2 = setjmp(jmpbuf);
- if (signum2 == 0)
- function(signum, arg);
- }
- if (timeout)
- timeout_disarm();
- error_handler = older;
-}
-
void sig_monitor(int timeout, void (*function)(int sig, void*), void *arg)
{
+#if USE_SIG_MONITOR_SIGNALS && USE_SIG_MONITOR_FOR_CALL
if (enabled)
monitor(timeout, function, arg);
else
+#endif
function(0, arg);
}
diff --git a/src/sig-monitor.h b/src/sig-monitor.h
index 9e3792f5..09f648fb 100644
--- a/src/sig-monitor.h
+++ b/src/sig-monitor.h
@@ -20,8 +20,6 @@
extern int sig_monitor_init(int enable);
extern void sig_monitor_clean_timeouts();
extern int sig_monitor_init_timeouts();
-extern void sig_monitor_disable();
-extern int sig_monitor_enable();
extern void sig_monitor(int timeout, void (*function)(int sig, void*), void *arg);