Re: [PATCH 16/17] Plug in new special vfree flag

From: Edgecombe, Rick P
Date: Thu Feb 07 2019 - 12:33:51 EST


On Wed, 2019-02-06 at 11:23 -0500, Steven Rostedt wrote:
> On Wed, 16 Jan 2019 16:32:58 -0800
> Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> wrote:
>
> > Add new flag for handling freeing of special permissioned memory in vmalloc
> > and remove places where memory was set RW before freeing which is no longer
> > needed.
> >
> > In kprobes, bpf and ftrace this just adds the flag, and removes the now
> > unneeded set_memory_ calls before calling vfree.
> >
> > In modules, the freeing of init sections is moved to a work queue, since
> > freeing of RO memory is not supported in an interrupt by vmalloc.
> > Instead of call_rcu, it now uses synchronize_rcu() in the work queue.
> >
> > Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> > Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> > Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> > Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Cc: Jessica Yu <jeyu@xxxxxxxxxx>
> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> > Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
> > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> > ---
> > arch/x86/kernel/ftrace.c | 6 +--
>
> For the ftrace code.
>
> Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
>
> -- Steve
>
Thanks!

Rick
> > arch/x86/kernel/kprobes/core.c | 7 +---
> > include/linux/filter.h | 16 ++-----
> > kernel/bpf/core.c | 1 -
> > kernel/module.c | 77 +++++++++++++++++-----------------
> > 5 files changed, 45 insertions(+), 62 deletions(-)
> >