Sure ... and think outside the box of just calling a DIAG. What problem are you tryig to solve? If you want to interrogate CP for users and groups and authorizations then think about how to tie that in with PAM.
Not meaning to complicate things for you, but you'll be pleased with a result that "fits" more generally. You'll get better traction and maybe net some volunteers to help with the coding. -- R; <>< On Sat, Nov 10, 2018, 11:31 Alan Altmark <alan_altm...@us.ibm.com wrote: > > A0? Please make sure that your usage is not outdated. The most common > usages of A0 were replaced long ago by DIAG 88. > > Regards, > Alan Altmark > IBM > > > On Nov 10, 2018, at 10:32 AM, Donald Russell <russell....@gmail.com> > wrote: > > > > Thanks Neale! > > > > In my case I’m using diag a0. Though I may want to do this for other diag > > instructions too. > > > > Getting in/out of supervisor state is my next hurdle. :-) > > > > I was going to use stidp to make sure I was actually on VM but that got > > “Illegal Instruction” when it ran. > > Maybe there’s a function I can call, or I can read /proc/cpuinfo to > verify > > A-it’s IBM/S390 and B-VM is running. I don’t like the idea of reading a > > whole “file” to provide what a single instruction can give me. > > > > I still have to figure out how to get in and out of supervisor state for > > the diag though. > > > > Thanks for tip on generating the machine code. That’s great! :-) > > > > Cheers, > > Don > > > > > > > > > >> On Sat, Nov 10, 2018 at 03:31 Neale Ferguson <ne...@sinenomine.net> > wrote: > >> > >> .byte 0x83, 0x12, 0x00, 0x08 > >> > >> == diag 1,2,8 (CP command) > >> > >> You can either load r1/r2 in the _asm_ section or tell gcc to bind the > >> variables to the registers. > >> > >> Remember, though, that diag is a privileged instruction and won't work > in > >> a userland program. > >> > >> In what particular diag are you interested? > >> > >> > >> -------- Original message -------- > >> From: Donald Russell <russell....@gmail.com> > >> Date: 11/10/18 06:00 (GMT-05:00) > >> To: LINUX-390@VM.MARIST.EDU > >> Subject: [LINUX-390] Using diagnose instruction from C on RHEL 7 > >> > >> Hello, > >> > >> I want to write a program in C and use a diagnose instruction. > >> > >> I thought I could do > >> > >> __asm___( “ diag ... “ ...); > >> > >> but that fails because diag is not a real instruction mnemonic. When I > use > >> gcc to compile and link I get an error: > >> > >> Program.c(.text+0x578): undefined reference to ‘x480a032’ > >> collect2: error: ld returned 1 exit status > >> > >> I thought I could code dc x’8312....’ and force the use of registers 1 > and > >> 2 but it complains that dc is not valid. (The doc says instructions > >> including directives are ok. But obviously not dc directives. :-) I > also > >> tried upper case just to be thorough) > >> > >> How can I coerce C into generating a diagnose instruction? > >> > >> Thanks, > >> Don > >> > >> ---------------------------------------------------------------------- > >> For LINUX-390 subscribe / signoff / archive access instructions, > >> send email to lists...@vm.marist.edu with the message: INFO LINUX-390 > or > >> visit > >> > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > >> ---------------------------------------------------------------------- > >> For more information on Linux on System z, visit > >> > http://wiki.linuxvm.org/ > > >> > >> ---------------------------------------------------------------------- > >> For LINUX-390 subscribe / signoff / archive access instructions, > >> send email to lists...@vm.marist.edu with the message: INFO LINUX-390 > or > >> visit > >> > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > >> ---------------------------------------------------------------------- > >> For more information on Linux on System z, visit > >> > http://wiki.linuxvm.org/ > > >> > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > > > http://wiki.linuxvm.org/ > > > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
