On 08/06, Jiri Olsa wrote: > > Once the breakpoint was succesfully modified, the attr->disabled > value is in bp->attr.disabled. So there's no reason to set it > again, removing that. > > Link: http://lkml.kernel.org/n/tip-v5oaellzsmyszv3rfucux...@git.kernel.org > Signed-off-by: Jiri Olsa <jo...@kernel.org> > --- > kernel/events/hw_breakpoint.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c > index fb229d9c7f3c..3e560d7609fd 100644 > --- a/kernel/events/hw_breakpoint.c > +++ b/kernel/events/hw_breakpoint.c > @@ -526,10 +526,9 @@ int modify_user_hw_breakpoint(struct perf_event *bp, > struct perf_event_attr *att > if (err) > return err; > > - if (!attr->disabled) { > + if (!attr->disabled) > perf_event_enable(bp); > - bp->attr.disabled = 0; > - } > +
Yes, but again, this still looks confusing. IMO, we should either remove "bp->attr.disabled = attr->disabled" in modify_user_hw_breakpoint_check() because bp->attr.disabled is not really used, or we should set bp->attr.disabled = 1 on failure just for consistency. Hmm... actually ptrace_get_dr7() checks ->attr.disabled, so we can hit WARN_ON(second_pass) in ptrace_write_dr7() in case when attr.disabled is falsely 0 because modify_user_hw_breakpoint_check() failed before? It seems I am totally confused and need to sleep ;) Oleg.
