Re: [PATCH 1/2] kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace

2015-02-20 Thread Petr Mladek
On Fri 2015-02-20 13:52:23, Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > (2015/02/20 19:26), Ingo Molnar wrote: > > > > > > * Petr Mladek wrote: > > > > > >> can_probe() checks if the given address points to the > > >> beginning of an instruction. It analyzes all the > > >> instru

Re: [PATCH 1/2] kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace

2015-02-20 Thread Masami Hiramatsu
(2015/02/20 21:52), Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > >> (2015/02/20 19:26), Ingo Molnar wrote: >>> >>> * Petr Mladek wrote: >>> can_probe() checks if the given address points to the beginning of an instruction. It analyzes all the instructions from the beginni

Re: [PATCH 1/2] kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace

2015-02-20 Thread Ingo Molnar
* Masami Hiramatsu wrote: > (2015/02/20 19:26), Ingo Molnar wrote: > > > > * Petr Mladek wrote: > > > >> can_probe() checks if the given address points to the > >> beginning of an instruction. It analyzes all the > >> instructions from the beginning of the function until the > >> given add

Re: [PATCH 1/2] kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace

2015-02-20 Thread Masami Hiramatsu
(2015/02/20 19:26), Ingo Molnar wrote: > > * Petr Mladek wrote: > >> can_probe() checks if the given address points to the >> beginning of an instruction. It analyzes all the >> instructions from the beginning of the function until the >> given address. The code might be modified by another

Re: [PATCH 1/2] kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace

2015-02-20 Thread Ingo Molnar
* Petr Mladek wrote: > can_probe() checks if the given address points to the > beginning of an instruction. It analyzes all the > instructions from the beginning of the function until the > given address. The code might be modified by another > Kprobe. In this case, the current code is read

[PATCH 1/2] kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace

2015-02-20 Thread Petr Mladek
can_probe() checks if the given address points to the beginning of an instruction. It analyzes all the instructions from the beginning of the function until the given address. The code might be modified by another Kprobe. In this case, the current code is read into a buffer, int3 breakpoint is repl