Re: Someone using COMPAT_SVR4(_32) ?

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

Eduardo Horvath <eeh%NetBSD.org@localhost> wrote:
>On Wed, 13 Sep 2017, Jerome Ibanes wrote:
>
>> 6.0.6 sparc64, 6.1.5 sparc64, 7.1 sparc64 (all GENERIC), fail with the same
>> behavior (meaning, same ktrace ouput) given the same payload (sparc
>> solaris 2.6), ktrace shows:
>> 
>> [...]
>>   1119      1 k        CALL  mmap(0x2000,0x80000002,0,0x45f,2,0)
>>   1119      1 k        RET   mmap 1074167808/0x40068000
>>   1119      1 k        PSIG  SIGSEGV SIG_DFL: code=SEGV_MAPERR,
>> addr=0x0, trap=48)
>
>Hm.  What binary is this?  Solaris 2.6, so that's 32-bits, right?  
>That's a really old version.  I should know, I got the tee shirt.  
>
>Is that on a 32-bit or 64-bit NetBSD kernel?
>
>Compat svr4_32 mmap should be this:
>
>115     STD             { netbsd32_voidp|svr4_32_sys||mmap(netbsd32_voidp addr, 
>                            svr4_32_size_t len, int prot, int flags, int fd, 
>                            svr4_32_off_t pos); }
>
>So according to ktrace, it's requesting some huuuuuuge mapping be added at 
>address 0x2000 from FD 2.  

Does the emulated mmap() restrict segment sizes to be less than one of
the resource limits, it looks to me as if it does.

Several Lisp systems have to chop up big allocations into smaller chunks
when running on NetBSD.