detachInterrupt crashes after using argument in __attachInterruptArg()

[dok-net]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
• I have filled out all fields below.

Platform

• Hardware: WEMOS D1 mini
• Core Version: 95fd7b5
• Development Env: Visual Micro IDE
• Operating System: Windows

Settings in IDE

• Module: LOLIN(WEMOS) D1 R2 & mini
• Flash Mode: [qio|dio|other]
• Flash Size: 4MB
• lwip Variant: v2 Lower Memory
• Reset Method: [ck|nodemcu]
• Flash Frequency: [40Mhz]
• CPU Frequency: 80Mhz
• Upload Using: SERIAL
• Upload Speed: 921600

Problem Description

Using detachInterrupt after __attachInterruptArg with a non-null argument, that's also not incidentally of type ArgStructure (as defined in FunctionalInterrupt.h), leads to a crash.

MCVE Sketch

class Interrupt
{
public:
	void ICACHE_RAM_ATTR isr() {}
	static void ICACHE_RAM_ATTR isr_static(void* self)
	{
		if (self) static_cast<Interrupt*>(self)->isr();
	}
};

Interrupt intr;

void setup()
{
	Serial.begin(9600);
	delay(1000);
	__attachInterruptArg(D6, Interrupt::isr_static, &intr, CHANGE);
	detachInterrupt(D6);
}

// Add the main program code into the continuous loop() function
void loop()
{


}

Debug Messages

Exception (9):
epc1=0x4020328b epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000017 depc=0x00000000

>>>stack>>>

ctx: cont
sp: 3ffffdd0 end: 3fffffc0 offset: 01a0
3fffff70:  4010637c 3ffee248 402010f8 3fffefa0  
3fffff80:  401003e4 3ffee2b4 3ffee348 4010043c  
3fffff90:  3fffdad0 00000000 3ffee219 40201061  
3fffffa0:  feefeffe feefeffe feefeffe 402011a0  
3fffffb0:  feefeffe feefeffe 3ffe84f4 40100739  
<<<stack<<<

:Error:9 -> LoadStoreAlignmentCause: Attempt to read/write memory with an unaligned address (for example, trying to read/write a 32-bit word at an address that is not a multiple of 4)
0x4020328b std
0x4010637c Interrupt
0x402010f8 esp_yield
0x401003e4 detachInterrupt
0x4010043c detachInterrupt
0x40201061 setup
0x402011a0 loop_wrapper()
0x40100739 cont_wrapper

[devyte]

@dok-net the __attachInterruptArg() call is not really exposed and hence not meant to be used by a user in its current form (notice the __ prefix).
That means that strictly speaking this is not a bug.
However, we do want to expose an attachInterruptArg() function that works correctly, and I think you have a PR about that, so I'm keeping this open as an enhancement.

[devyte]

BTW, I invited you to our serial gitter channel. Please join so we can better coordinate efforts. If you didn't receive the mention let me know and I'll send it again.

[dok-net]

@devyte Haven't seen any invite anywhere.

[dok-net]

This issue is fixed by #6048.
The other PRs with similar concerns make more sense if that PR is accepted first - it fixes a real bug plus adds an API that I am lobbying for because I need/desire for EspSoftwareSerial: the proper Arduino.h-exposed attachInterruptArg().