ZeroPain in SharedCLibrary from MakeModes

MakeModes has just appeared on PackMan, but is unusable as it triggers a Page Zero write in CLib when you click the Generate button:

*memoryi fc182b40+20
FC182B40 : 1AFFFFFB : BNE     &FC182B34
FC182B44 : E8BD8040 : LDMIA   R13!,{R6,PC}
FC182B48 : E4D13001 : LDRB    R3,[R1],#1
FC182B4C : E4C23001 : STRB    R3,[R2],#1
FC182B50 : E3530000 : CMP     R3,#0
FC182B54 < 1AFFFFFB : BNE     &FC182B48
FC182B58 : E8BD8040 : LDMIA   R13!,{R6,PC}
FC182B5C : 01010101 : Undefined instruction
*where fc182b54
Address &FC182B54 is at offset &00012EC8 in module 'SharedCLibrary'
*showregs
Register dump (stored at &200098D0) is:
R0  = 00000000 R1  = 0001E45C R2  = 00000000 R3  = 00000034
R4  = 00018DA8 R5  = 00018DA8 R6  = 00019994 R7  = 00000000
R8  = 000261A0 R9  = 00000000 R10 = 0001AADC R11 = 0001B534
R12 = 00000000 R13 = 0001B408 R14 = 0000B838 R15 = FC182B54
Mode USR32 flags set: nzcvqjggggeAift        PSR = 00000110

The code appears to be strcpy() when called with a non-word-aligned address; thus:

while ((*p++ = *b++) != 0);

What’s at R14 (&B838 in your dump)? That ought to shed some light on which part of MakeModes is causing the problem. At any rate, copying from &1E45C to &0 is not going to work – so there’s an strcpy() on an uninitialised string pointer happening here.

Here you go..

B800 : EB000A2B : BL      &0000E0B4
B804 : EB00341A : BL      &00018874
B808 : E58404C0 : STR     R0,[R4,#1216]
B80C : E3A01006 : MOV     R1,#6
B810 : E5940010 : LDR     R0,[R4,#16]
B814 : EB000A26 : BL      &0000E0B4
B818 : EB003415 : BL      &00018874
B81C : E58404C4 : STR     R0,[R4,#1220]
B820 : E3A01003 : MOV     R1,#3
B824 : E5940010 : LDR     R0,[R4,#16]
B828 : EB000A21 : BL      &0000E0B4
B82C : E1A01000 : MOV     R1,R0
B830 : E59404C8 : LDR     R0,[R4,#1224]
B834 : EB0033FB : BL      &00018828
B838 : E3A0100D : MOV     R1,#&0D            ; =13
B83C : E5940010 : LDR     R0,[R4,#16]
B840 : EB000A1B : BL      &0000E0B4
B844 : EB00340A : BL      &00018874
B848 : E3590000 : CMP     R9,#0
B84C : E58404CC : STR     R0,[R4,#1228]
B850 : 0A000034 : BEQ     &0000B928
B854 : E28D1F41 : ADD     R1,R13,#&0104      ; =260
B858 : E28F2F63 : ADR     R2,&0000B9EC
B85C : E28F0F63 : ADR     R0,&0000B9F0
B860 : EBFFF3B4 : BL      &00008738

MakeModes has just appeared on PackMan, but is unusable as it triggers a Page Zero write in CLib when you click the Generate button

Version 0.31 working here using a zpp enabled pandaboard, clicking on generate with no monitor chosen, and with eizo f780 chosen at random from the popup menu

MakeModes 0.31 crashes within CLib as described above on attempting to make a new MDF, it is OK with an pre-existing MDF.

MakeModes […] is unusable […] when you click the Generate button

Unfortunately my long distance mind reading powers can’t make much of this, as there’s no mention of the version, a vague description of how to recreate (nothing happens if you just click the generate button). More words, less register dump, please.

Version 0.31 working here using a zpp enabled pandaboard, clicking on generate with no monitor chosen, and with eizo f780 chosen at random from the popup menu

and

MakeModes 0.31 crashes within CLib as described above on attempting to make a new MDF, it is OK with an pre-existing MDF.

Ah ha – Mike/David have the gems of information needed. I never knew MakeModes could make a new MDF from scratch (I always start out picking one from the menu then editing it into shape) otherwise I think I’d have tripped up on the bug when fixing the ZeroPain just before it appeared with the Bonus Binaries.

The oldest MakeModes I could dig out on my Risc PC was 0.26 from 1994, and if you create a new MDF from scratch there – BANG! a type 5 error and it quits.

Please try again tomorrow with MakeModes 0.32, hopefully it’s not unusable any longer.

Please try again tomorrow with MakeModes 0.32, hopefully it’s not unusable any longer.

MakeModes 0.32 can generate a new MDF.

The oldest MakeModes I could dig out on my Risc PC was 0.26 from 1994, and if you create a new MDF from scratch there – BANG! a type 5 error and it quits.

21 years old bug fixed, bonus indeed!

Many Thanks.

Unfortunately my long distance mind reading powers can’t make much of this, as there’s no mention of the version, a vague description of how to recreate (nothing happens if you just click the generate button). More words, less register dump, please.

Apologies Sprow – I thought I’d provided enough information…download MakeModes from PackMan, click Generate. I’ll ensure I provide specific Repro steps next time – I usually do, not sure why I didn’t in this case. Although you don’t want the dumps, I’ll continue to provide them as more information is never a bad thing and in this case, if did quickly confirm the issue being in MakeModes itself.