cvs commit: src/sys/amd64/amd64 machdep.c src/sys/i386/i386 machdep.c src/sys/pc98/pc98 machdep.c

[John Baldwin]

jhb         2006-03-14 16:13:55 UTC

  FreeBSD src repository

  Modified files:
    sys/amd64/amd64      machdep.c 
    sys/i386/i386        machdep.c 
    sys/pc98/pc98        machdep.c 
  Log:
  Don't allow userland to set hardware watch points on kernel memory at all.
  Previously, we tried to allow this only for root.  However, we were calling
  suser() on the *target* process rather than the current process.  This
  means that if you can ptrace() a process running as root you can set a
  hardware watch point in the kernel.  In practice I think you probably have
  to be root in order to pass the p_candebug() checks in ptrace() to attach
  to a process running as root anyway.  Rather than fix the suser(), I just
  axed the entire idea, as I can't think of any good reason _at all_ for
  userland to set hardware watch points for KVM.
  
  MFC after:      3 days
  Also thinks hardware watch points on KVM from userland are bad: bde, rwatson
  
  Revision  Changes    Path
  1.648     +20 -23    src/sys/amd64/amd64/machdep.c
  1.624     +20 -23    src/sys/i386/i386/machdep.c
  1.372     +20 -23    src/sys/pc98/pc98/machdep.c