On Mon, Feb 19, 2018 at 11:01:40AM +0100, Jiri Olsa wrote:
> On Mon, Feb 19, 2018 at 11:20:36AM +0900, Namhyung Kim wrote:
>
> SNIP
>
> > > +static void machine__set_kernel_mmap(struct machine *machine,
> > > + u64 start, u64 end)
> > > +{
> > > + int i;
> > > +
> > > + for (i = 0; i < MAP__NR_TYPES; i++) {
> > > + machine->vmlinux_maps[i]->start = start;
> > > + machine->vmlinux_maps[i]->end = end;
> > > +
> > > + /*
> > > + * Be a bit paranoid here, some perf.data file came with
> > > + * a zero sized synthesized MMAP event for the kernel.
> > > + */
> > > + if (machine->vmlinux_maps[i]->end == 0)
> > > + machine->vmlinux_maps[i]->end = ~0ULL;
> >
> > Hmm.. this will make map_groups__fixup_end() below not working since
> > it only updates if the end address of a map is zero.
> >
> > And about the paranoid check, AFAIK the only case it cares is the
> > machine__process_kernel_mmap_event() which calls it with
> > event->mmap.start and event->mmap.start + event->mmap.len. Thus, in
> > order for the end to be zero, both start and len should be zero. Then
> > I think this condition can be changed like below:
> >
> > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> > index fe27ef55cbb9..c8acb603c359 100644
> > --- a/tools/perf/util/machine.c
> > +++ b/tools/perf/util/machine.c
> > @@ -1226,7 +1226,7 @@ static void machine__set_kernel_mmap(struct machine
> > *machine,
> > * Be a bit paranoid here, some perf.data file came with
> > * a zero sized synthesized MMAP event for the kernel.
> > */
> > - if (machine->vmlinux_maps[i]->end == 0)
> > + if (start == 0 && end == 0)
> > machine->vmlinux_maps[i]->end = ~0ULL;
> > }
>
> right, the call from machine__create_kernel_maps will have always
> the start != 0 and there will be subsequent map_groups__fixup_end
> call..
>
> seems ok to me.. will you send the patch?
Sure. :)
>From b736729e83b62f97d716a011ccf4e430b614fecd Mon Sep 17 00:00:00 2001
From: Namhyung Kim <namhy...@kernel.org>
Date: Mon, 19 Feb 2018 19:00:46 +0900
Subject: [PATCH] perf tools: Fix paranoid check in machine__set_kernel_mmap()
The machine__set_kernel_mmap() is to setup addresses of the kernel map
using external info. But it has a check when the address is given
from an incorrect input which should have the start and end address of
0 (i.e. machine__process_kernel_mmap_event).
But we also use the end address of 0 for a valid input so change it to
check both start and end addresses.
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/util/machine.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index fe27ef55cbb9..12b7427444a3 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1226,7 +1226,7 @@ static void machine__set_kernel_mmap(struct machine
*machine,
* Be a bit paranoid here, some perf.data file came with
* a zero sized synthesized MMAP event for the kernel.
*/
- if (machine->vmlinux_maps[i]->end == 0)
+ if (start == 0 && end == 0)
machine->vmlinux_maps[i]->end = ~0ULL;
}
}
--
2.16.1
