Re: [patch] kprobes: dont steal interrupts from vm86

[Stas Sergeev <stsp@aknet.ru>]

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Hi Prasanna.

I've found yet another bug in this
very same piece of code. Now I can
reproduce the interrupt theft without
using either vm86() or modify_ldt().
Test-case is attached. It gets
ocasionally fixed by the patch I've
sent in my previous mail, but it is
really another bug that requires a
separate fix.

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#include <stdlib.h>
#include <signal.h>

void my_trap(int sig)
{
  printf("Test passed, all OK\n");
  exit(0);
}

int main()
{
  signal(SIGTRAP, my_trap);
  asm volatile (".byte 0xcd,3");
  printf("Stolen interrupt, very bad!\n");
}