Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: IOPL emulation breaks hpasmd (hp-health) needed by HP DL380 G4 servers | Date | Thu, 16 Sep 2021 19:09:31 +0200 |
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Ondrej,
On Wed, Sep 15 2021 at 14:23, Ondrej Zary wrote: > after upgrading Debian from 10 (kernel 4.19.194) to 11 (kernel 5.10.46) on HP > DL380 G4 servers, hpasmd segfaults. Booting the 4.19.194 kernel allows hpasmd > to work. > > Noticed the iopl(3) call. Checked out a kernel before "x86/iopl: Remove legacy IOPL option" > (a24ca9976843156eabbc5f2d798954b5674d1b61) and built with CONFIG_X86_IOPL_LEGACY. > It works!. > > I even disassembled /opt/hp/hp-health/bin/IrqRouteTbl (it's only 5952 bytes > and does not use any hp libs). There's no CLI, only a couple of INs and OUTs: > ... > 8048f75: 66 ba 84 00 mov dx,0x84 > 8048f79: 66 b8 00 00 mov ax,0x0 > 8048f7d: ee out dx,al > 8048f7e: 66 ba 85 00 mov dx,0x85 > 8048f82: ee out dx,al > > But I still don't know what's going on.
That's weird. Let me think about a way to debug that. I just ran a trivial test program which issues iopl(3) and reads all ports from 0-65535. That works like a charm.
#include <stdio.h> #include <sys/io.h>
int main(void) { unsigned int i; int ret;
ret = iopl(3); if (ret) return ret;
for (i = 0; i < 65536; i++) printf("%5u: %02x\n", i, inb(i));
return 0; }
Which CPU is in that machine?
Can you please run that failing program with GDB and figure out which instruction causes #GP and what the register content is.
Thanks,
tglx
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