Re: Memory corruption (?) I don't understand

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Also when you print out the size in the make file, how much SRAM does it
indicate your program is using?

On Tue, Jun 22, 2021 at 2:10 PM Trampas Stern <[email protected]> wrote:

> So I would recommend that you put in the ASSERT for the LDL_PEDANTIC()
> macro.
>
> Secondly, you need to be careful with PROGMEM, that is with AVR being a
> Harvard machine you can burn up SRAM quickly by not using PROGMEM  for
> constants.  For example with the LDL library you need to be sure
> that LDL_ENABLE_AVR is defined.
>
> Note the AVR is a great processor, however I have personally not used one
> in about 15 years.  The price and ease of programming ARM Cortex M have
> gotten such AVR are no longer viable for new development as I can develop
> products so much faster with ARM Cortex M parts, and their power and pric=
e
> is comparable to AVR.
>
> Another trick you can do is inside a function do this:
>
> void printMem(void) {
>    uint8_t *ptr;
>    printf("stack 0x%X\n", &ptr); //this will be address on stack where pt=
r
> is.
>    ptr=3Dmalloc(10);
>    printf("heap 0x%X\n", ptr); //this will be address as to heap
>    free(ptr);
> }
>
> This will help as you can do some rough tracking of stack and heap usage,
> assuming the AVR linker script has stack growing from top of memory to en=
d
> of heap it will help you check for stack overflow.
>
>
>
>
>
> On Tue, Jun 22, 2021 at 1:39 PM BERTRAND Jo=C3=ABl <joel.bertrand@systell=
a.fr>
> wrote:
>
>>         Strange. Following function runs as expected.
>>
>> enum ldl_mac_status LDL_MAC_otaa(struct ldl_mac *self)
>> {
>>     enum ldl_mac_status retval;
>>     union ldl_mac_response_arg arg;
>>
>>     LDL_PEDANTIC(self !=3D NULL)
>>
>>     if(self->ctx.joined){
>>
>>         retval =3D LDL_STATUS_JOINED;
>>     }
>>     else if(self->op =3D=3D LDL_OP_NONE){
>>
>>         if(self->devNonce <=3D U32(UINT16_MAX)){
>>
>>             forgetNetwork(self);
>>
>>             self->trials =3D 0;
>>
>>             self->day =3D U32(60) * U32(60) * U32(24) * timeTPS;
>>
>> #if defined(LDL_ENABLE_L2_1_1)
>>             LDL_OPS_deriveJoinKeys(self);
>> #endif
>>             fillJoinBuffer(self, U16(self->devNonce));
>>
>>             self->devNonce++;
>>
>>             arg.dev_nonce_updated.nextDevNonce =3D self->devNonce;
>>
>> unsigned char t[80];
>> sprintf(t, "self->handler=3D%p\r\n", self->handler);
>>             self->handler(self->app, LDL_MAC_DEV_NONCE_UPDATED, &arg);
>>
>>             self->tx.power =3D 0;
>>
>>             self->op =3D LDL_OP_JOINING;
>>
>>             if(self->state =3D=3D LDL_STATE_IDLE){
>>
>>                 self->state =3D LDL_STATE_WAIT_OTAA;
>>                 LDL_MAC_timerSet(self, LDL_TIMER_WAITA, 0);
>>             }
>>
>>             retval =3D LDL_STATUS_OK;
>>
>>             LDL_DEBUG("OTAA is pending")
>>         }
>>         else{
>>
>>             /* need to re-init with a different JoinEUI */
>>             retval =3D LDL_STATUS_DEVNONCE;
>>         }
>>     }
>>     else{
>>
>>         retval =3D LDL_STATUS_BUSY;
>>     }
>>
>>     return retval;
>> }
>>
>>         If I comment out sprintf(), it crashes. If I deplace this debug
>> trace
>> before or _after_ self->handler call, firmware runs as expected. I don't
>> understand. If there is a memory corruption somewhere, I could
>> understand that a debug trace _before_ the line that triggers the bug
>> can change something. But I don't understand why the following function
>> runs as expected :
>>
>> enum ldl_mac_status LDL_MAC_otaa(struct ldl_mac *self)
>> {
>>     enum ldl_mac_status retval;
>>     union ldl_mac_response_arg arg;
>>
>>     LDL_PEDANTIC(self !=3D NULL)
>>
>>     if(self->ctx.joined){
>>
>>         retval =3D LDL_STATUS_JOINED;
>>     }
>>     else if(self->op =3D=3D LDL_OP_NONE){
>>
>>         if(self->devNonce <=3D U32(UINT16_MAX)){
>>
>>             forgetNetwork(self);
>>
>>             self->trials =3D 0;
>>
>>             self->day =3D U32(60) * U32(60) * U32(24) * timeTPS;
>>
>> #if defined(LDL_ENABLE_L2_1_1)
>>             LDL_OPS_deriveJoinKeys(self);
>> #endif
>>             fillJoinBuffer(self, U16(self->devNonce));
>>
>>             self->devNonce++;
>>
>>             arg.dev_nonce_updated.nextDevNonce =3D self->devNonce;
>>
>>             self->handler(self->app, LDL_MAC_DEV_NONCE_UPDATED, &arg);
>>
>>             self->tx.power =3D 0;
>>
>>             self->op =3D LDL_OP_JOINING;
>>
>>             if(self->state =3D=3D LDL_STATE_IDLE){
>>
>>                 self->state =3D LDL_STATE_WAIT_OTAA;
>>                 LDL_MAC_timerSet(self, LDL_TIMER_WAITA, 0);
>>             }
>>
>>             retval =3D LDL_STATUS_OK;
>>
>>             LDL_DEBUG("OTAA is pending")
>>         }
>>         else{
>>
>>             /* need to re-init with a different JoinEUI */
>>             retval =3D LDL_STATUS_DEVNONCE;
>>         }
>>     }
>>     else{
>>
>>         retval =3D LDL_STATUS_BUSY;
>>     }
>>
>> unsigned char t[80];
>> sprintf(t, "self->handler=3D%p\r\n", self->handler);
>>     return retval;
>> }
>>
>>         Of course, if I comment out :
>>
>> unsigned char t[80];
>> sprintf(t, "self->handler=3D%p\r\n", self->handler);
>>
>> it crashes again :
>>
>> hilbert:[~/cvs/firmware-antivol] > simavr -t -vvv -m atmega1284 -f
>> 16000000 firmware.elf
>> Loaded 95670 .text at address 0x0
>> Loaded 5654 .data
>> Loaded 2276 .eeprom
>> 01..
>> ..
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D..
>>  Systella L100-A..
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D..
>> ..
>> Booting firmware 2021062218..
>> SPI initialized..
>> Reset LORA..
>> Reset LORA done..
>> LoRaWAN 1.1..
>> Initialization SX1262..
>> Initialization SX1262 done..
>> 0000000000000000..
>> MAC initialization..
>> LDL_MAC_addChannel:790>chIndex=3D0 freq=3D868100000 minRate=3D0 maxRate=
=3D5..
>> LDL_MAC_addChannel:790>chIndex=3D1 freq=3D868300000 minRate=3D0 maxRate=
=3D5..
>> LDL_MAC_addChannel:790>chIndex=3D2 freq=3D868500000 minRate=3D0 maxRate=
=3D5..
>> cb type=3D11..
>> processInit:994>set radio reset: ticks=3D151..
>> processRadioReset:1009>clear radio reset: ticks=3D151..
>> MAC initialization done..
>> lora_send..
>> processStartRadioForEntropy:1061>listen for entropy: ticks=3D152..
>> processEntropy:1078>read entropy: ticks=3D152 entropy=3D0..
>> cb type=3D0..
>> LDL_MAC_ready..
>> LDL_MAC_otaa..
>> LDL_MAC_addChannel:790>chIndex=3D0 freq=3D868100000 minRate=3D0 maxRate=
=3D5..
>> LDL_MAC_addChannel:790>chIndex=3D1 freq=3D868300000 minRate=3D0 maxRate=
=3D5..
>> LDL_MAC_addChannel:790>chIndex=3D2 freq=3D868500000 minRate=3D0 maxRate=
=3D5..
>> avr_gdb_init listening on port 1234
>>
>>
>>

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<div dir=3D"ltr">Also when you print out the size in the make file, how muc=
h SRAM does it indicate your program is using?=C2=A0</div><br><div class=3D=
"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, Jun 22, 2021 at=
 2:10 PM Trampas Stern &lt;<a href=3D"mailto:[email protected]">[email protected]=
.com</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"mar=
gin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1=
ex"><div dir=3D"ltr">So I would recommend that you put in the ASSERT for th=
e=C2=A0LDL_PEDANTIC() macro.=C2=A0<div><br></div><div>Secondly, you need to=
 be careful with PROGMEM, that is with AVR being a Harvard machine you can =
burn up SRAM quickly by not using PROGMEM=C2=A0 for constants.=C2=A0 For ex=
ample with the LDL library you need to be sure that=C2=A0LDL_ENABLE_AVR is =
defined.=C2=A0 =C2=A0</div><div><br></div><div>Note the AVR is a great proc=
essor, however I have personally not used one in about 15 years.=C2=A0 The =
price and ease of programming ARM Cortex M have gotten such AVR are no long=
er viable for new development as I can develop products so much faster with=
 ARM Cortex M parts, and their power and price is comparable to AVR.=C2=A0<=
/div><div><br></div><div>Another trick you can do is inside a function do t=
his:=C2=A0</div><div><br></div><div>void printMem(void) {</div><div>=C2=A0 =
=C2=A0uint8_t *ptr;</div><div>=C2=A0 =C2=A0printf(&quot;stack 0x%X\n&quot;,=
 &amp;ptr); //this will be address on stack where ptr is.</div><div>=C2=A0 =
=C2=A0ptr=3Dmalloc(10);</div><div>=C2=A0=C2=A0

printf(&quot;heap 0x%X\n&quot;, ptr); //this will be address as to heap=C2=
=A0</div><div>=C2=A0 =C2=A0free(ptr);</div><div>}</div><div><br></div><div>=
This will help as you can do some rough tracking of stack and heap usage, a=
ssuming the AVR linker script has stack growing from top of memory to end o=
f heap it will help you check for stack overflow.=C2=A0</div><div><br></div=
><div><br></div><div>=C2=A0=C2=A0</div><div><br></div></div><br><div class=
=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, Jun 22, 2021=
 at 1:39 PM BERTRAND Jo=C3=ABl &lt;<a href=3D"mailto:joel.bertrand@systella=
.fr" target=3D"_blank">[email protected]</a>&gt; wrote:<br></div><b=
lockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-le=
ft:1px solid rgb(204,204,204);padding-left:1ex">=C2=A0 =C2=A0 =C2=A0 =C2=A0=
 Strange. Following function runs as expected.<br>
<br>
enum ldl_mac_status LDL_MAC_otaa(struct ldl_mac *self)<br>
{<br>
=C2=A0 =C2=A0 enum ldl_mac_status retval;<br>
=C2=A0 =C2=A0 union ldl_mac_response_arg arg;<br>
<br>
=C2=A0 =C2=A0 LDL_PEDANTIC(self !=3D NULL)<br>
<br>
=C2=A0 =C2=A0 if(self-&gt;ctx.joined){<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_JOINED;<br>
=C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 else if(self-&gt;op =3D=3D LDL_OP_NONE){<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 if(self-&gt;devNonce &lt;=3D U32(UINT16_MAX)){<=
br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 forgetNetwork(self);<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;trials =3D 0;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;day =3D U32(60) * U32(60=
) * U32(24) * timeTPS;<br>
<br>
#if defined(LDL_ENABLE_L2_1_1)<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LDL_OPS_deriveJoinKeys(self);<br>
#endif<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 fillJoinBuffer(self, U16(self-&gt=
;devNonce));<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;devNonce++;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 arg.dev_nonce_updated.nextDevNonc=
e =3D self-&gt;devNonce;<br>
<br>
unsigned char t[80];<br>
sprintf(t, &quot;self-&gt;handler=3D%p\r\n&quot;, self-&gt;handler);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;handler(self-&gt;app, LD=
L_MAC_DEV_NONCE_UPDATED, &amp;arg);<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;tx.power =3D 0;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;op =3D LDL_OP_JOINING;<b=
r>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 if(self-&gt;state =3D=3D LDL_STAT=
E_IDLE){<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;state =3D =
LDL_STATE_WAIT_OTAA;<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LDL_MAC_timerSet(se=
lf, LDL_TIMER_WAITA, 0);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_OK;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LDL_DEBUG(&quot;OTAA is pending&q=
uot;)<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 else{<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 /* need to re-init with a differe=
nt JoinEUI */<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_DEVNONCE;<b=
r>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 else{<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_BUSY;<br>
=C2=A0 =C2=A0 }<br>
<br>
=C2=A0 =C2=A0 return retval;<br>
}<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 If I comment out sprintf(), it crashes. If I de=
place this debug trace<br>
before or _after_ self-&gt;handler call, firmware runs as expected. I don&#=
39;t<br>
understand. If there is a memory corruption somewhere, I could<br>
understand that a debug trace _before_ the line that triggers the bug<br>
can change something. But I don&#39;t understand why the following function=
<br>
runs as expected :<br>
<br>
enum ldl_mac_status LDL_MAC_otaa(struct ldl_mac *self)<br>
{<br>
=C2=A0 =C2=A0 enum ldl_mac_status retval;<br>
=C2=A0 =C2=A0 union ldl_mac_response_arg arg;<br>
<br>
=C2=A0 =C2=A0 LDL_PEDANTIC(self !=3D NULL)<br>
<br>
=C2=A0 =C2=A0 if(self-&gt;ctx.joined){<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_JOINED;<br>
=C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 else if(self-&gt;op =3D=3D LDL_OP_NONE){<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 if(self-&gt;devNonce &lt;=3D U32(UINT16_MAX)){<=
br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 forgetNetwork(self);<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;trials =3D 0;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;day =3D U32(60) * U32(60=
) * U32(24) * timeTPS;<br>
<br>
#if defined(LDL_ENABLE_L2_1_1)<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LDL_OPS_deriveJoinKeys(self);<br>
#endif<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 fillJoinBuffer(self, U16(self-&gt=
;devNonce));<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;devNonce++;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 arg.dev_nonce_updated.nextDevNonc=
e =3D self-&gt;devNonce;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;handler(self-&gt;app, LD=
L_MAC_DEV_NONCE_UPDATED, &amp;arg);<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;tx.power =3D 0;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;op =3D LDL_OP_JOINING;<b=
r>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 if(self-&gt;state =3D=3D LDL_STAT=
E_IDLE){<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 self-&gt;state =3D =
LDL_STATE_WAIT_OTAA;<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LDL_MAC_timerSet(se=
lf, LDL_TIMER_WAITA, 0);<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_OK;<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 LDL_DEBUG(&quot;OTAA is pending&q=
uot;)<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 else{<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 /* need to re-init with a differe=
nt JoinEUI */<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_DEVNONCE;<b=
r>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 }<br>
=C2=A0 =C2=A0 else{<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 retval =3D LDL_STATUS_BUSY;<br>
=C2=A0 =C2=A0 }<br>
<br>
unsigned char t[80];<br>
sprintf(t, &quot;self-&gt;handler=3D%p\r\n&quot;, self-&gt;handler);<br>
=C2=A0 =C2=A0 return retval;<br>
}<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 Of course, if I comment out :<br>
<br>
unsigned char t[80];<br>
sprintf(t, &quot;self-&gt;handler=3D%p\r\n&quot;, self-&gt;handler);<br>
<br>
it crashes again :<br>
<br>
hilbert:[~/cvs/firmware-antivol] &gt; simavr -t -vvv -m atmega1284 -f<br>
16000000 firmware.elf<br>
Loaded 95670 .text at address 0x0<br>
Loaded 5654 .data<br>
Loaded 2276 .eeprom<br>
01..<br>
..<br>
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D..<br>
=C2=A0Systella L100-A..<br>
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D..<br>
..<br>
Booting firmware 2021062218..<br>
SPI initialized..<br>
Reset LORA..<br>
Reset LORA done..<br>
LoRaWAN 1.1..<br>
Initialization SX1262..<br>
Initialization SX1262 done..<br>
0000000000000000..<br>
MAC initialization..<br>
LDL_MAC_addChannel:790&gt;chIndex=3D0 freq=3D868100000 minRate=3D0 maxRate=
=3D5..<br>
LDL_MAC_addChannel:790&gt;chIndex=3D1 freq=3D868300000 minRate=3D0 maxRate=
=3D5..<br>
LDL_MAC_addChannel:790&gt;chIndex=3D2 freq=3D868500000 minRate=3D0 maxRate=
=3D5..<br>
cb type=3D11..<br>
processInit:994&gt;set radio reset: ticks=3D151..<br>
processRadioReset:1009&gt;clear radio reset: ticks=3D151..<br>
MAC initialization done..<br>
lora_send..<br>
processStartRadioForEntropy:1061&gt;listen for entropy: ticks=3D152..<br>
processEntropy:1078&gt;read entropy: ticks=3D152 entropy=3D0..<br>
cb type=3D0..<br>
LDL_MAC_ready..<br>
LDL_MAC_otaa..<br>
LDL_MAC_addChannel:790&gt;chIndex=3D0 freq=3D868100000 minRate=3D0 maxRate=
=3D5..<br>
LDL_MAC_addChannel:790&gt;chIndex=3D1 freq=3D868300000 minRate=3D0 maxRate=
=3D5..<br>
LDL_MAC_addChannel:790&gt;chIndex=3D2 freq=3D868500000 minRate=3D0 maxRate=
=3D5..<br>
avr_gdb_init listening on port 1234<br>
<br>
<br>
</blockquote></div>
</blockquote></div>

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