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authorRadim Krčmář <rkrcmar@redhat.com>2017-09-08 14:40:43 +0200
committerRadim Krčmář <rkrcmar@redhat.com>2017-09-08 14:40:43 +0200
commit5f54c8b2d4fad95d1f8ecbe023ebe6038e6d3760 (patch)
treedaca83ea5f9af1bd158504bd0b5af89c5a99b7fa /drivers/cpuidle/cpuidle-powernv.c
parent78809a68490d84eb632a215be2121d4b44c86954 (diff)
parentedd03602d97236e8fea13cd76886c576186aa307 (diff)
Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
This fix was intended for 4.13, but didn't get in because both maintainers were on vacation. Paul Mackerras: "It adds mutual exclusion between list_add_rcu and list_del_rcu calls on the kvm->arch.spapr_tce_tables list. Without this, userspace could potentially trigger corruption of the list and cause a host crash or worse."
Diffstat (limited to 'drivers/cpuidle/cpuidle-powernv.c')
-rw-r--r--drivers/cpuidle/cpuidle-powernv.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 37b0698b7193..42896a67aeae 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -235,6 +235,7 @@ static inline int validate_dt_prop_sizes(const char *prop1, int prop1_len,
return -1;
}
+extern u32 pnv_get_supported_cpuidle_states(void);
static int powernv_add_idle_states(void)
{
struct device_node *power_mgt;
@@ -248,6 +249,8 @@ static int powernv_add_idle_states(void)
const char *names[CPUIDLE_STATE_MAX];
u32 has_stop_states = 0;
int i, rc;
+ u32 supported_flags = pnv_get_supported_cpuidle_states();
+
/* Currently we have snooze statically defined */
@@ -362,6 +365,13 @@ static int powernv_add_idle_states(void)
for (i = 0; i < dt_idle_states; i++) {
unsigned int exit_latency, target_residency;
bool stops_timebase = false;
+
+ /*
+ * Skip the platform idle state whose flag isn't in
+ * the supported_cpuidle_states flag mask.
+ */
+ if ((flags[i] & supported_flags) != flags[i])
+ continue;
/*
* If an idle state has exit latency beyond
* POWERNV_THRESHOLD_LATENCY_NS then don't use it