From: Arnaldo Carvalho de Melo <[email protected]>
So perf_config() uses:
int ret = 0;
perf_config_set__for_each_entry(config_set, section, item) {
...
ret = fn();
if (ret < 0)
break;
}
return ret;
Expecting that that break will imediatelly go to function exit to return
that error value (ret).
The problem is that perf_config_set__for_each_entry() expands into two
nested for() loops, one traversing the sections in a config and the
second the items in each of those sections, so we have to change that
'break' to a goto label right before that final 'return ret'.
With that, for instance 'perf trace' now correctly bails out when a
event that is requested to be added via its 'trace.add_events'
~/.perfconfig entry gets rejected by the kernel BPF verifier:
# perf trace ls
event syntax error:
'/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o'
\___ Kernel verifier blocks program loading
(add -v to see detail)
Run 'perf list' for a list of valid events
Error: wrong config key-value pair
trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
#
While before it would continue and explode later, when trying to find
maps that would have been in place had that augmented_raw_syscalls.o
precompiled BPF proggie been accepted by the, humm, bast... rigorous
kernel BPF verifier 8-)
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Taeung Song <[email protected]>
Cc: Yonghong Song <[email protected]>
Fixes: 8a0a9c7e9146 ("perf config: Introduce new init() and exit()")
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/util/config.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 7e3c1b60120c..e7d2c08d263a 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -739,11 +739,15 @@ int perf_config(config_fn_t fn, void *data)
if (ret < 0) {
pr_err("Error: wrong config key-value pair
%s=%s\n",
key, value);
- break;
+ /*
+ * Can't be just a 'break', as
perf_config_set__for_each_entry()
+ * expands to two nested for() loops.
+ */
+ goto out;
}
}
}
-
+out:
return ret;
}
--
2.20.1
