On 11/22, Oleg Nesterov wrote: > On 11/22, Andrea Parri wrote: > > > > Commit 142b18ddc8143 ("uprobes: Fix handle_swbp() vs unregister() + > > register() race") added the UPROBE_COPY_INSN flag, and corresponding > > smp_wmb() and smp_rmb() memory barriers, to ensure that handle_swbp() > > uses fully-initialized uprobes only. > > > > However, the smp_rmb() is mis-placed: this barrier should be placed > > after handle_swbp() has tested for the flag, thus guaranteeing that > > (program-order) subsequent loads from the uprobe can see the initial > > stores performed by prepare_uprobe(). > > > > Move the smp_rmb() accordingly. Also amend the comments associated > > to the two memory barriers to indicate their actual locations. > > > > Signed-off-by: Andrea Parri <andrea.pa...@amarulasolutions.com> > > Cc: Peter Zijlstra <pet...@infradead.org> > > Cc: Ingo Molnar <mi...@redhat.com> > > Cc: Arnaldo Carvalho de Melo <a...@kernel.org> > > Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> > > Cc: Jiri Olsa <jo...@redhat.com> > > Cc: Namhyung Kim <namhy...@kernel.org> > > Cc: Oleg Nesterov <o...@redhat.com> > > Cc: sta...@kernel.org > > Fixes: 142b18ddc8143 ("uprobes: Fix handle_swbp() vs unregister() + > > register() race") > > Thanks, > > Acked-by: Oleg Nesterov <o...@redhat.com>
Yes, but I am not sure this is the -stable material... Oleg.