Messages in this thread Patch in this message | | | Date | Wed, 9 May 2018 14:08:09 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH RFC 06/19] perf tools: Fix kernel_start for KPTI on x86_64 |
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Em Wed, May 09, 2018 at 02:43:35PM +0300, Adrian Hunter escreveu: > On x86_64, KPTI entry trampolines are less than the start of kernel text, > but still above 2^63. So leave kernel_start = 1ULL << 63 for x86_64. > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/util/machine.c | 16 +++++++++++++++- > tools/perf/util/machine.h | 2 ++ > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 72a351613d85..22047ff3cf2a 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -2296,6 +2296,15 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid, > return 0; > } > > +/* > + * Compares the raw arch string. N.B. see instead perf_env__arch() if a > + * normalized arch is needed. > + */ > +bool machine__is(struct machine *machine, const char *arch) > +{ > + return machine->env && !strcmp(machine->env->arch, arch); > +} > +
Please make machine__is(NULL) return false, to reduce boilerplate in callers:
bool machine__is(struct machine *machine, const char *arch) { return machine && machine->env && !strcmp(machine->env->arch, arch); }
> int machine__get_kernel_start(struct machine *machine) > { > struct map *map = machine__kernel_map(machine); > @@ -2312,7 +2321,12 @@ int machine__get_kernel_start(struct machine *machine) > machine->kernel_start = 1ULL << 63; > if (map) { > err = map__load(map); > - if (!err) > + /* > + * On x86_64, KPTI entry trampolines are less than the > + * start of kernel text, but still above 2^63. So leave > + * kernel_start = 1ULL << 63 for x86_64. > + */ > + if (!err && !machine__is(machine, "x86_64")) > machine->kernel_start = map->start; > } > return err; > diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h > index 388fb4741c54..b31d33b5aa2a 100644 > --- a/tools/perf/util/machine.h > +++ b/tools/perf/util/machine.h > @@ -188,6 +188,8 @@ static inline bool machine__is_host(struct machine *machine) > return machine ? machine->pid == HOST_KERNEL_ID : false; > } > > +bool machine__is(struct machine *machine, const char *arch); > + > struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid); > struct thread *machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid); > > -- > 1.9.1
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