Messages in this thread | | | Date | Sun, 14 Apr 2013 21:30:21 +0200 | From | Jan Kratochvil <> | Subject | Re: [PATCH 0/2] ptrace/x86: simplify ptrace_write_dr7() |
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On Sun, 14 Apr 2013 21:12:05 +0200, Oleg Nesterov wrote: > Jan, Frederic, et all. What do you think we should do? > > 1. Change ptrace_write_dr7() to do register_user_hw_breakpoint() > if necessary. > > This is what I was going to do, but I am no longer sure > we want this. For what? Unlikely it is very useful to use > the "default" addr == 0 for debugging.
I do not understand how these functions map to the PTRACE_* syscall.
But this was a regression from the application point of view as some application did/do: * waitpid - get the process to: t (tracing stop) * PTRACE_POKEUSER DR7, enableDR0 * PTRACE_POKEUSER DR0, address * PTRACE_CONT
This was perfectly valid before, there is no "default" addr == 0 used for any debugging. Just the applications did not care about PTRACE_POKEUSER ordering. This is also how the bug was found.
Thanks, Jan
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