perf, x86: P4 PMU -- do a real check for ESCR address being in hash
To prevent from clashes in future code modifications
do a real check for ESCR address being in hash. At
moment the callers are known to pass sane values but
better to be on a safe side.
And comment fix.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100518212439.004503600@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index 87e1803..5f8e36d 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -670,7 +670,7 @@
/*
* ESCR address hashing is tricky, ESCRs are not sequential
- * in memory but all starts from MSR_P4_BSU_ESCR0 (0x03e0) and
+ * in memory but all starts from MSR_P4_BSU_ESCR0 (0x03a0) and
* the metric between any ESCRs is laid in range [0xa0,0xe1]
*
* so we make ~70% filled hashtable
@@ -735,8 +735,9 @@
{
unsigned int idx = P4_ESCR_MSR_IDX(addr);
- if (unlikely(idx >= P4_ESCR_MSR_TABLE_SIZE ||
- !p4_escr_table[idx])) {
+ if (unlikely(idx >= P4_ESCR_MSR_TABLE_SIZE ||
+ !p4_escr_table[idx] ||
+ p4_escr_table[idx] != addr)) {
WARN_ONCE(1, "P4 PMU: Wrong address passed: %x\n", addr);
return -1;
}