Mirrors/opensbi
3
0
Fork 1
mirror of https://github.com/riscv-software-src/opensbi.git synced 2026-09-08 18:21:29 +01:00
Code Issues Packages Projects Releases Wiki Activity

lib: sbi_pmu: Match raw event selector only against raw event map entries

Browse Source 
sbi_pmu_event_get_info() walks hw_event_map[] to decide whether a
requested event is supported. For SBI_PMU_EVENT_RAW_IDX and
SBI_PMU_EVENT_RAW_V2_IDX it compares the requested event_data against
temp->select / temp->select_mask without first checking that the map
entry being examined is itself a raw event entry.

Non-raw hardware event entries are added via sbi_pmu_add_hw_event_counter_map(),
leave select and select_mask at zero, hence they satisfy:

	temp->select == (event_data & temp->select_mask)

so the first non-raw entry visited will always match.
The issue's observability depends purely on the ordering of hw_event_map[]:
if the platform registers its raw events last, every raw event query, including
unsupported ones, will be reported as supported.

Fix it by checking event_idx against temp->start_idx and temp->end_idx before
comparing select/select_mask.

Fixes: e434584216 ("lib: sbi_pmu: Implement SBI PMU event info function")
Signed-off-by: David E. Garcia Porras <david.garcia@aheadcomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260818210023.466462-3-david.garcia@aheadcomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
David E. Garcia Porras
2026-09-03 13:37:34 +05:30
committed by Anup Patel
parent d97cfb33ae
commit d34a39df77
1 changed files with 9 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/sbi/sbi_pmu.c
+9
View File
@@ -1110,6 +1110,15 @@ int sbi_pmu_event_get_info(unsigned long shmem_phys_lo, unsigned long shmem_phys
/* For raw events, event data is used as the select value */ /* For raw events, event data is used as the select value */
if (event_idx == SBI_PMU_EVENT_RAW_IDX || if (event_idx == SBI_PMU_EVENT_RAW_IDX ||
event_idx == SBI_PMU_EVENT_RAW_V2_IDX) { event_idx == SBI_PMU_EVENT_RAW_V2_IDX) {
/*
* Only a raw event map entry carries a
* meaningful select/select_mask pair, so
* skip any entry which does not cover the
* raw event index.
*/
if (temp->start_idx > event_idx ||
event_idx > temp->end_idx)
continue;
/* just match the selector */ /* just match the selector */
if (temp->select == (einfo[i].event_data & if (temp->select == (einfo[i].event_data &
temp->select_mask)) { temp->select_mask)) {