perf/x86: Fix possible Spectre-v1 indexing for hw_perf_event cache_*

[mirror_ubuntu-bionic-kernel.git] / arch / x86 / events / core.c

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 140d33288e78e8ef72138a3ec247520f66b158a2..7a2d0bdb9aeb78f4700528b68ebcd8c2b021c253 100644 (file)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -304,17 +304,20 @@ set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
 
        config = attr->config;
 
-       cache_type = (config >>  0) & 0xff;
+       cache_type = (config >> 0) & 0xff;
        if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
                return -EINVAL;
+       cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX);
 
        cache_op = (config >>  8) & 0xff;
        if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
                return -EINVAL;
+       cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX);
 
        cache_result = (config >> 16) & 0xff;
        if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
                return -EINVAL;
+       cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX);
 
        val = hw_cache_event_ids[cache_type][cache_op][cache_result];