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| author |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-05-17 11:56:24 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-05-20 11:43:54 -0300 |
| commit | caf8a0d0499792ac1b3f5b0b84e5890df0039cb6 (patch) | |
| tree | 3c45e30c29ada6d50f6a779f50dc65bc2760d47e /tools/perf/builtin-trace.c | |
| parent | perf machine: Do not bail out if not managing to read ref reloc symbol (diff) | |
| download | linux-dev-caf8a0d0499792ac1b3f5b0b84e5890df0039cb6.tar.xz linux-dev-caf8a0d0499792ac1b3f5b0b84e5890df0039cb6.zip | |
perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1
Hook into the libtraceevent plugin kernel symbol resolver to warn the
user that that can't happen with kptr_restrict=1.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9gc412xx1gl0lvqj1d1xwlyb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/builtin-trace.c')
| -rw-r--r-- | tools/perf/builtin-trace.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 6e5c325148e4..e488ac756f39 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1160,6 +1160,24 @@ static int trace__tool_process(struct perf_tool *tool, return trace__process_event(trace, machine, event, sample); } +static char *trace__machine__resolve_kernel_addr(void *vmachine, unsigned long long *addrp, char **modp) +{ + struct machine *machine = vmachine; + + if (machine->kptr_restrict_warned) + return NULL; + + if (symbol_conf.kptr_restrict) { + pr_warning("Kernel address maps (/proc/{kallsyms,modules}) are restricted.\n\n" + "Check /proc/sys/kernel/kptr_restrict.\n\n" + "Kernel samples will not be resolved.\n"); + machine->kptr_restrict_warned = true; + return NULL; + } + + return machine__resolve_kernel_addr(vmachine, addrp, modp); +} + static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist) { int err = symbol__init(NULL); @@ -1171,7 +1189,7 @@ static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist) if (trace->host == NULL) return -ENOMEM; - if (trace_event__register_resolver(trace->host, machine__resolve_kernel_addr) < 0) + if (trace_event__register_resolver(trace->host, trace__machine__resolve_kernel_addr) < 0) return -errno; err = __machine__synthesize_threads(trace->host, &trace->tool, &trace->opts.target, |