Re: kern/55038: compat_netbsd32 module gives SIGSEGV when executing a.out image

[Dan Plassche <dplassche%gmail.com@localhost>]

The following reply was made to PR kern/55038; it has been noted by GNATS.

From: Dan Plassche <dplassche%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/55038: compat_netbsd32 module gives SIGSEGV when executing
 a.out image
Date: Tue, 3 Mar 2020 19:05:07 -0500

 NetBSD 0.9 binaries execute for me on amd64 if I set "sysctl -w
 vm.user_va0_disable=0" after building a kernel with COMPAT_NOMID and
 EXEC_AOUT set on current.
 
 However, the binaries have errors loading some of the compat43
 libraries that were not previously implemented for compat_netbsd32 (eg
 ogetpagesize on ls as shown below).  They were implemented on native
 i386 compat.
 
 # uname -a
 NetBSD nbsd90vmw 9.99.48 NetBSD 9.99.48 (UNIX) #0: Tue Mar  3 00:04:47
 UTC 2020  dp@nbsd90:/usr/src/sys/arch/amd64/compile/UNIX amd64
 # sysctl -w vm.user_va0_disable=0
 vm.user_va0_disable: 1 -> 0
 # ktrace /emul/nbsd-09/bin/ls; kdump | less
 [1]   Bad system call (core dumped) ktrace /emul/nbsd-09/bin/ls
 
    878      1 ktrace   EMUL  "netbsd"
    878      1 ktrace   CALL
 execve(0x7f7fffcbad37,0x7f7fffcba7a0,0x7f7fffcba7b0)
    878      1 ktrace   NAMI  "/emul/nbsd-09/bin/ls"
    878      1 ls       NAMI  "/emul/netbsd32"
    878      1 ls       EMUL  "netbsd32"
    878      1 ls       RET   execve JUSTRETURN
    878      1 ls       CALL  netbsd32_ioctl(1,TIOCGETA,0xffffed54)
    878      1 ls       GIO   fd 1 read 44 bytes
        "\^B+\0\0\a\0\0\0\0K\0\0\M-K\^E\0 \^D\M^?\M^?\^?\^W\^U\^R\M^?\^C\^\\^Z\
         \^Y\^Q\^S\^V\^O\^A\0\^T\M^?\0\M^V\0\0\0\M^V\0\0"
    878      1 ls       RET   netbsd32_ioctl 0
    878      1 ls       CALL  netbsd32_ioctl(1,TIOCGWINSZ,0xffffed98)
    878      1 ls       GIO   fd 1 read 8 bytes
        "0\0P\0\0\0\0\0"
    878      1 ls       RET   netbsd32_ioctl 0
    878      1 ls       CALL  getuid
    878      1 ls       RET   getuid 0
    878      1 ls       CALL  compat_43_netbsd32_stat43(0xffffed96,0xffffed3c)
    878      1 ls       NAMI  "."
    878      1 ls       RET   compat_43_netbsd32_stat43 0
    878      1 ls       CALL  compat_43_ogetpagesize
    878      1 ls       RET   compat_43_ogetpagesize -1 errno 78
 Function not implemented
    878      1 ls       PSIG  SIGSYS SIG_DFL: code=SI_NOINFO
    878      1 ls       NAMI  "ls.core"