Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-15 Thread Steven Rostedt
On Thu, 15 Jan 2015 20:57:29 +0900 Masami Hiramatsu wrote: > > > If the function tracer traces the jprobe handler, the hook function > > for that handler will not be called, and its saved return address > > will be used for the next function. This will result in a kernel > > crash. > >

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-15 Thread Masami Hiramatsu
Hi Steven, Thank you for fixing this bug! (2015/01/15 0:40), Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > If the function graph tracer traces a jprobe callback, the system will > crash. This can easily be demonstrated by compiling the jprobe > sample module that is in the

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-15 Thread Masami Hiramatsu
Hi Steven, Thank you for fixing this bug! (2015/01/15 0:40), Steven Rostedt wrote: From: Steven Rostedt (Red Hat) rost...@goodmis.org If the function graph tracer traces a jprobe callback, the system will crash. This can easily be demonstrated by compiling the jprobe sample module that is

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-15 Thread Steven Rostedt
On Thu, 15 Jan 2015 20:57:29 +0900 Masami Hiramatsu masami.hiramatsu...@hitachi.com wrote: If the function tracer traces the jprobe handler, the hook function for that handler will not be called, and its saved return address will be used for the next function. This will result in a kernel

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-14 Thread Steven Rostedt
On Wed, 14 Jan 2015 17:55:37 +0100 Borislav Petkov wrote: > Err, stupid question: marking the jprobe handler "notrace" doesn't help? > A few reasons. One, that would require all users to make their handler as "notrace". That's not very reliable. Not to mention, I still work at Red Hat and

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-14 Thread Borislav Petkov
On Wed, Jan 14, 2015 at 10:40:01AM -0500, Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > If the function graph tracer traces a jprobe callback, the system will > crash. This can easily be demonstrated by compiling the jprobe > sample module that is in the kernel tree, loading it

[PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-14 Thread Steven Rostedt
From: "Steven Rostedt (Red Hat)" If the function graph tracer traces a jprobe callback, the system will crash. This can easily be demonstrated by compiling the jprobe sample module that is in the kernel tree, loading it and running the function graph tracer. # modprobe jprobe_example.ko #

[PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-14 Thread Steven Rostedt
From: Steven Rostedt (Red Hat) rost...@goodmis.org If the function graph tracer traces a jprobe callback, the system will crash. This can easily be demonstrated by compiling the jprobe sample module that is in the kernel tree, loading it and running the function graph tracer. # modprobe

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-14 Thread Steven Rostedt
On Wed, 14 Jan 2015 17:55:37 +0100 Borislav Petkov b...@alien8.de wrote: Err, stupid question: marking the jprobe handler notrace doesn't help? A few reasons. One, that would require all users to make their handler as notrace. That's not very reliable. Not to mention, I still work at Red

Re: [PATCH 3/3] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing

2015-01-14 Thread Borislav Petkov
On Wed, Jan 14, 2015 at 10:40:01AM -0500, Steven Rostedt wrote: From: Steven Rostedt (Red Hat) rost...@goodmis.org If the function graph tracer traces a jprobe callback, the system will crash. This can easily be demonstrated by compiling the jprobe sample module that is in the kernel tree,