On Fri, 22 Sep 2000, Andi Kleen wrote:
>
> Also unless I'm missing another thing ptrace allows you to put any addresses
> including kernel address into the debug registers, so you could certainly
> get debug traps everywhere, making my original objection valid.
See:
if(addr < (long) &dummy->u_debugreg[4] &&
((unsigned long) data) >= TASK_SIZE-3) break;
> How does this patch look ?
Horrible. It WILL NOT WORK.
It does a access_ok() that uses the debugger address space to determine if
the debuggee is ok.
Also, debugreg6 is not a linear address at all. Only 0-3 are, so only they
should be tested.
Which is exactly what the test that already exists does.
No, it may not be obvious, but it's all there.
Linus
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This archive was generated by hypermail 2b29 : Sat Sep 23 2000 - 21:00:27 EST