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* ptrace question
@ 2001-10-17 16:23 Rajeev Bector
  0 siblings, 0 replies; 3+ messages in thread
From: Rajeev Bector @ 2001-10-17 16:23 UTC (permalink / raw)
  To: Linux-Kernel

I have a question on the ptrace system call
implementation:

In kernel/ptrace.c in the function access_one_page(),
why is read access denied to pages which are
marked PG_reserved ?

I have some pages in my driver which are reserved
and memory mapped to user applications which I'd
like to access in gdb.

Any clues to what is the risk if I were to enable
accessing of pages which are marked "reserved"

Thanks in advance !
Rajeev


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^ permalink raw reply	[flat|nested] 3+ messages in thread
* ptrace question
@ 2008-07-14 11:02 Harald Krapfenbauer
  2008-07-14 11:43 ` Ralf Baechle
  0 siblings, 1 reply; 3+ messages in thread
From: Harald Krapfenbauer @ 2008-07-14 11:02 UTC (permalink / raw)
  To: linux-mips@linux-mips.org

Hello,

If I write memory (maybe with instructions) of a traced application with
the ptrace() call, are the caches invalidated automatically, i.e. can I
assume that the processor uses the newly written values after continuing?

Thanks + best regards,
Harald

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: ptrace question
  2008-07-14 11:02 ptrace question Harald Krapfenbauer
@ 2008-07-14 11:43 ` Ralf Baechle
  0 siblings, 0 replies; 3+ messages in thread
From: Ralf Baechle @ 2008-07-14 11:43 UTC (permalink / raw)
  To: Harald Krapfenbauer; +Cc: linux-mips@linux-mips.org

On Mon, Jul 14, 2008 at 01:02:26PM +0200, Harald Krapfenbauer wrote:

> Hello,
> 
> If I write memory (maybe with instructions) of a traced application with
> the ptrace() call, are the caches invalidated automatically, i.e. can I
> assume that the processor uses the newly written values after continuing?

ptrace semantics requires PTRACE_POKETEXT to ensure I-cache coherency and
consistency.

  Ralf

^ permalink raw reply	[flat|nested] 3+ messages in thread
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2008-07-14 11:02 ptrace question Harald Krapfenbauer
2008-07-14 11:43 ` Ralf Baechle
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2001-10-17 16:23 Rajeev Bector

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