Some news... My issue was caused because of course I made a mistake with the way of registering my metrics Listener. I used the following code (see my previous post) in the constructor: + MyMetrics.RegisterListener(IDTAG.c_str(), "*", std::bind(&canlog::MetricListener, this, _1)); and for the destructor: + MyMetrics.DeregisterListener(IDTAG.c_str()); I had to use IDTAG because this class has multiple instances. The issue is passing IDTAG.c_str() as a parameter ; becauseMyMetrics.RegisterListener stores the value of this const char* parameter and uses it 1) as an immutable parameter and 2) as a value. Of course this does not work with my first way to call MyMetrics.RegisterListener : * the memory buffer returned by IDTAG.c_str() has no more existence after exiting the constructor, so this lead to memory corruption. * when calling IDTAG.c_str() again in the destructor, there is absolutely no chance that this c_str() call returns the same memory address as the call in the constructor, so the value comparison will never work. I rewrote the code this way by adding a new member (m_idtag) to the class: @ vehicle/OVMS.V3/components/can/src/canlog.cpp:352 @ canlog::canlog(const char* type, std::string format, canformat::canformat_serve_ m_dropcount = 0; m_filtercount = 0; + m_idtag = strdup(IDTAG.c_str()); + using std::placeholders::_1; using std::placeholders::_2; MyEvents.RegisterEvent(IDTAG, "*", std::bind(&canlog::EventListener, this, _1, _2)); + if (NULL != m_idtag) + { + MyMetrics.RegisterListener(m_idtag, "*", std::bind(&canlog::MetricListener, this, _1)); + } + else + { + ESP_LOGE(TAG,"Cannot allocate memory - not registering metrics listener"); + } int queuesize = MyConfig.GetParamValueInt("can", "log.queuesize",100); m_queue = xQueueCreate(queuesize, sizeof(CAN_log_message_t)); @ vehicle/OVMS.V3/components/can/src/canlog.cpp:374 @ canlog::canlog(const char* type, std::string format, canformat::canformat_serve_ canlog::~canlog() { MyEvents.DeregisterEvent(IDTAG); + if (NULL != m_idtag) + { + MyMetrics.DeregisterListener(m_idtag); + free((void*)m_idtag); + } if (m_task) { Another option is to change MyMetrics.RegisterListener so that it store *a copy* of the parameter, and does string comparison instead of a value comparison: modified: vehicle/OVMS.V3/main/ovms_metrics.cpp ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── @ vehicle/OVMS.V3/main/ovms_metrics.cpp:1019 @ void OvmsMetrics::RegisterListener(const char* caller, const char* name, MetricC return; } + const char * caller_copy = (const char *)strdup(caller); + + if (NULL == caller_copy) + { + ESP_LOGE(TAG, "Problem registering metric %s for caller %s - insufficient memory",name,caller); + return; + } + MetricCallbackList *ml = k->second; - ml->push_back(new MetricCallbackEntry(caller,callback)); + ml->push_back(new MetricCallbackEntry(caller_copy,callback)); } void OvmsMetrics::DeregisterListener(const char* caller) @ vehicle/OVMS.V3/main/ovms_metrics.cpp:1041 @ void OvmsMetrics::DeregisterListener(const char* caller) while (itc!=ml->end()) { MetricCallbackEntry* ec = *itc; - if (ec->m_caller == caller) + if (strcmp(ec->m_caller, caller) == 0) { + free((char *)ec->m_caller); itc = ml->erase(itc); delete ec; } I've tested both approaches and they both solve my issue : no more crashes and memory corruption. The second one is more "risky" (as it potentially impacts everyone) but I think that it should not cause much regression. Let me know what you think - should I make a PR for this second approach ? Regards, Le 16/11/2022 à 22:45, Ludovic LANGE a écrit :
Dear list,
You may remember that I'm trying to enhance the "datalogger" side of OVMS - in different ways.
One facet of this endeavour is to have (CAN) logs that also incorporate other data coming from OVMS. In particular, I'd like to have GNSS (GPS) data in the same log as my CAN data.
My first try is to slightly alter `canlog.cpp` and add the ability to `LogInfo` some chosen metrics, in the same spirit of the already logged subset of events. (With CRTD format, it appears as comments)
While doing this, I'm facing multiple crashes that are somehow strange:
* The crashes only occur when closing the logs (`can log stop`), never when logging * The cause of the crash is not always the same (LoadProhibited, InstrFetchProhibited) * Sometimes the PC is impacted / overwritten
The crashes seems to always occur in a window of 20s after the `can log stop` command (In general it's immediate, but sometime can take some more seconds).
(It lead me also to discover that the feature of our version of esp-idf that resolves the memory addresses in the serial output - `make monitor` - is broken, and that it's better to use GDB for that)
While I am doing my homework and try to solve this, I wanted to share it here also to see if you already encountered this and/or if my changes are not done properly / not on the right OS task / etc.... - for which I lack background and experience. (In the process I think I found a non-freed variable, but it's not causing my issue - cf https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/pull/774 )
Here are the changes - you'll see that the crash do occur as soon as I `LogInfo` something - after the log has been closed.
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modified: vehicle/OVMS.V3/components/can/src/canlog.cpp ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── @ vehicle/OVMS.V3/components/can/src/canlog.cpp:355 @ canlog::canlog(const char* type, std::string format, canformat::canformat_serve_ using std::placeholders::_1; using std::placeholders::_2; MyEvents.RegisterEvent(IDTAG, "*", std::bind(&canlog::EventListener, this, _1, _2)); + MyMetrics.RegisterListener(IDTAG.c_str(), "*", std::bind(&canlog::MetricListener, this, _1));
int queuesize = MyConfig.GetParamValueInt("can", "log.queuesize",100); m_queue = xQueueCreate(queuesize, sizeof(CAN_log_message_t)); @ vehicle/OVMS.V3/components/can/src/canlog.cpp:365 @ canlog::canlog(const char* type, std::string format, canformat::canformat_serve_ canlog::~canlog() { MyEvents.DeregisterEvent(IDTAG); + MyMetrics.DeregisterListener(IDTAG.c_str());
if (m_task) { @ vehicle/OVMS.V3/components/can/src/canlog.cpp:441 @ void canlog::EventListener(std::string event, void* data) LogInfo(NULL, CAN_LogInfo_Event, event.c_str()); }
+void canlog::MetricListener(OvmsMetric* metric) { + std::string name = metric->m_name; + ESP_LOGI(TAG,"MetricListener - enter : %s", name.c_str()); + if (startsWith(name, "v.p.gps") || (name == "v.p.latitude") || (name == "v.p.longitude") || (name == "v.p.altitude") || (name == "v.p.direction") || (name == "v.p.satcount") || (name == "m.net.wifi.sq") || (name == "m.freeram")) { + std::string metric_text = "metric: " + name; + ESP_LOGI(TAG,"MetricListener - keep : %s", metric_text.c_str()); + LogInfo(NULL, CAN_LogInfo_Event, metric_text.c_str()); + } +} + const char* canlog::GetType() { return m_type;
Note: "m.net.wifi.sq" / "m.freeram" are providing debugging data, so that I can quickly receive metrics after the boot. Not what I'm interested in for the final version of course, and the list will be configurable.
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Here are some example of panic handler infos:
Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled. Core 1 register dump: PC : 0x400d95f8 PS : 0x00060830 A0 : 0x8030d32c A1 : 0x3ffc4980 A2 : 0x3ffeb5a8 A3 : 0x00000000 A4 : 0xfefefefe A5 : 0x3ffb5200 A6 : 0x3f805e78 A7 : 0x000000fe A8 : 0x800d95f0 A9 : 0x3ffc4930 A10 : 0x3ffeb5a8 A11 : 0x00000000 A12 : 0x00000009 A13 : 0x73c80b46 A14 : 0x3ffc4930 A15 : 0x3f8b4164 SAR : 0x00000004 EXCCAUSE: 0x0000001c EXCVADDR: 0xfefeff2e LBEG : 0x4008abe4 LEND : 0x4008ac00 LCOUNT : 0xffffffff
ELF file SHA256: eb3e5ce8f67640c8
Backtrace: 0x400d95f8:0x3ffc4980 0x4030d329:0x3ffc49e0 0x4012122d:0x3ffc4a00 0x40121296:0x3ffc4a60 0x40120e6e:0x3ffc4a80 0x400ede1f:0x3ffc4aa0 0x400eed41:0x3ffc4ae0 0x400ecdc9:0x3ffc4b00 0x4011c5b6:0x3ffc4b40 0x4011c7b6:0x3ffc4b70 0x4011c8d8:0x3ffc4be0 0x0
0x400d95f8 is exactly the address of the call to LogInfo in my changes:
(gdb) list *0x400d95f8 0x400d95f8 is in canlog::MetricListener(OvmsMetric*) (vehicle/OVMS.V3/components/can/src/canlog.cpp:447). 442 std::string name = metric->m_name; 443 ESP_LOGI(TAG,"MetricListener - enter : %s", name.c_str()); 444 if (startsWith(name, "v.p.gps") || (name == "v.p.latitude") || (name == "v.p.longitude") || (name == "v.p.altitude") || (name == "v.p.direction") || (name == "v.p.satcount") || (name == "m.net.wifi.sq") || (name == "m.freeram")) { 445 std::string metric_text = "metric: " + name; 446 ESP_LOGI(TAG,"MetricListener - keep : %s", metric_text.c_str()); *447 LogInfo(NULL, CAN_LogInfo_Event, metric_text.c_str());* 448 } 449 } 450
0xfefe / 0xfefefefe seems related to some of the Heap Memory Debugging options I've activated (Cf https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/sy... ) and seems to indicate a possible use-after-free issue. I'll look to debug in that direction.
Another version (before Heap Memory Debugging activated) did that from time to time:
------------------------------------------------------------------------ Guru Meditation Error: Core 0 panic'ed (InstrFetchProhibited). Exception was unhandled. Core 0 register dump: PC : 0x00008100 PS : 0x00060530 A0 : 0x802f0cf0 A1 : 0x3ffd0f00 A2 : 0x3ffeb214 A3 : 0x00008100 A4 : 0x402f1df8 A5 : 0x00000000 A6 : 0x00000003 A7 : 0x3ffb556c A8 : 0x800d9540 A9 : 0x3ffd0ee0 A10 : 0x3ffeb214 A11 : 0x00000000 A12 : 0x00000009 A13 : 0x3f8b4a24 A14 : 0xffffffff A15 : 0x40404040 SAR : 0x00000018 EXCCAUSE: 0x00000014 EXCVADDR: 0x00008100 LBEG : 0x4008a848 LEND : 0x4008a864 LCOUNT : 0xffffffff
ELF file SHA256: f4d0c43aa48ef759
Backtrace: 0x00008100:0x3ffd0f00 0x402f0ced:0x3ffd0fb0 0x4011c56d:0x3ffd0fd0 0x4011c5c6:0x3ffd1020 0x4011c24a:0x3ffd1040 0x4014f51d:0x3ffd1060 0x4014f953:0x3ffd1080 0x4014e6e3:0x3ffd11d0 0x4014ef16:0x3ffd1210 0x4014f001:0x3ffd1230 0x4014f119:0x3ffd1260 0x4014e889:0x3ffd1290 0x4014e9ed:0x3ffd1310 0x4014ebf9:0x3ffd13f0
------------------------------------------------------------------------
Thanks for any hint or advices you may want to share.
Regards,
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