On 2015/10/22 6:58, Alexei Starovoitov wrote:
Fix safety checks for bpf_perf_event_read(): - only non-inherited events can be added to perf_event_array map (do this check statically at map insertion time) - dynamically check that event is local and !pmu->count Otherwise buggy bpf program can cause kernel splat. Fixes: 35578d798400 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter") Signed-off-by: Alexei Starovoitov <[email protected]> --- v1->v2: fix compile in case of !CONFIG_PERF_EVENTS This patch is on top of http://patchwork.ozlabs.org/patch/533585/ to avoid conflicts. Even in the worst case the crash is not possible. Only warn_on_once, so imo net-next is ok. kernel/bpf/arraymap.c | 9 +++++---- kernel/events/core.c | 16 ++++++++++------ 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index e3cfe46b074f..75529cc94304 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -294,10 +294,11 @@ static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd) if (IS_ERR(attr)) return (void *)attr;- if (attr->type != PERF_TYPE_RAW &&- !(attr->type == PERF_TYPE_SOFTWARE && - attr->config == PERF_COUNT_SW_BPF_OUTPUT) && - attr->type != PERF_TYPE_HARDWARE) { + if ((attr->type != PERF_TYPE_RAW && + !(attr->type == PERF_TYPE_SOFTWARE && + attr->config == PERF_COUNT_SW_BPF_OUTPUT) && + attr->type != PERF_TYPE_HARDWARE) || + attr->inherit) {
This 'if' statement is so complex. What about using a inline function instead?
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