On Mon, 15 Oct 2018 23:56:46 +0900 Masami Hiramatsu <mhira...@kernel.org> wrote:
> On Fri, 12 Oct 2018 15:54:39 -0400 > Steven Rostedt <rost...@goodmis.org> wrote: > > > On Fri, 12 Oct 2018 11:21:28 -0700 > > Andy Lutomirski <l...@amacapital.net> wrote: > > > > > On Fri, Oct 12, 2018 at 9:26 AM Steven Rostedt <rost...@goodmis.org> > > > wrote: > > > > > > > > > > > > Anyone have any issues with this patch? > > > > > > > > > > I'm conceptually okay with it. That being said, > > > regs_within_kernel_stack(), which you're indirectly using, is > > > off-by-a-few. And updating it to use probe_kernel_read() might be > > > nice for robustness. > > > > > > > Something like this? > > > > -- Steve > > > > From: "Steven Rostedt (VMware)" <rost...@goodmis.org> > > Date: Fri, 12 Oct 2018 15:44:20 -0400 > > Subject: [PATCH] x86: ptrace.h: Add regs_get_kernel_stack_nth_safe() > > function > > > > Andy had some concerns about using regs_get_kernel_stack_nth() in a new > > function regs_get_kernel_argument() as if there's any error in the stack > > code, it could cause a bad memory access. Instead, add a new function called > > regs_get_kernel_stack_nth_safe() that does a probe_kernel_read() on the > > stack address to be extra careful in accessing the memory. To share the > > code, regs_get_kernel_stack_nth_addr() was added to just return the stack > > address (or NULL if not on the stack), that both regs_get_kernel_stack_nth() > > and the _safe() version can use. > > This patch looks good to me. > But if the concern is real, all regs_get_kernel_stack_nth() user must move > onto _safe() version, at least all tracers code. > > Reviewed-by: Masami Hiramatsu <mhira...@kernel.org> > Hi Masami, Can you review my v2 version which implements what you suggest. Thanks, -- Steve
