From mboxrd@z Thu Jan 1 00:00:00 1970 From: rostedt@goodmis.org (Steven Rostedt) Date: Tue, 7 May 2019 08:27:16 -0400 Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions In-Reply-To: <20190507092731.GH2650@hirez.programming.kicks-ass.net> References: <20190502202146.GZ2623@hirez.programming.kicks-ass.net> <20190502185225.0cdfc8bc@gandalf.local.home> <20190502193129.664c5b2e@gandalf.local.home> <20190502195052.0af473cf@gandalf.local.home> <20190503092959.GB2623@hirez.programming.kicks-ass.net> <20190503092247.20cc1ff0@gandalf.local.home> <2045370D-38D8-406C-9E94-C1D483E232C9@amacapital.net> <20190506081951.GJ2606@hirez.programming.kicks-ass.net> <20190507085753.GO2606@hirez.programming.kicks-ass.net> <20190507092731.GH2650@hirez.programming.kicks-ass.net> Message-ID: <20190507082716.73cd5a01@gandalf.local.home> Content-Type: text/plain; charset="UTF-8" Message-ID: <20190507122716.ng4e5PrXxrSxiq-w1bpGGkoW-1RxrvTkuNBQtYSx6mM@z> On Tue, 7 May 2019 11:27:31 +0200 Peter Zijlstra wrote: > FWIW, both these trampolines assume a kprobe will not > int3_emulate_{push/call}(), for both bitnesses. > > But then; I'm thinking kprobes should be inspection only and not modify > things. So that might just be good enough. I believe there are kprobe calls that do modify things. Note, they can modify regs->ip. Kprobes sets the FTRACE_OPS_FL_IPMODIFY flag, thus they can never be put at the same location that is being live patched. -- Steve