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authorNeal Liu <neal.liu@mediatek.com>2020-07-27 06:25:46 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-07-29 19:38:30 +0300
commitefe9711214e6138a5a2a46ca4068bfce50c03444 (patch)
tree73343cbdd485268e6e4186b2c947a865895d0b00 /drivers/idle
parent81f94ddfeceddb3b8ffa6cfe5ddd3b896711d9ad (diff)
downloadlinux-efe9711214e6138a5a2a46ca4068bfce50c03444.tar.xz
cpuidle: change enter_s2idle() prototype
Control Flow Integrity(CFI) is a security mechanism that disallows changes to the original control flow graph of a compiled binary, making it significantly harder to perform such attacks. init_state_node() assign same function callback to different function pointer declarations. static int init_state_node(struct cpuidle_state *idle_state, const struct of_device_id *matches, struct device_node *state_node) { ... idle_state->enter = match_id->data; ... idle_state->enter_s2idle = match_id->data; } Function declarations: struct cpuidle_state { ... int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); void (*enter_s2idle) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); }; In this case, either enter() or enter_s2idle() would cause CFI check failed since they use same callee. Align function prototype of enter() since it needs return value for some use cases. The return value of enter_s2idle() is no need currently. Signed-off-by: Neal Liu <neal.liu@mediatek.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/idle')
-rw-r--r--drivers/idle/intel_idle.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index fa23a7ea01ac..3f86f36dab2b 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -173,13 +173,15 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
* Invoked as a suspend-to-idle callback routine with frozen user space, frozen
* scheduler tick and suspended scheduler clock on the target CPU.
*/
-static __cpuidle void intel_idle_s2idle(struct cpuidle_device *dev,
- struct cpuidle_driver *drv, int index)
+static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
{
unsigned long eax = flg2MWAIT(drv->states[index].flags);
unsigned long ecx = 1; /* break on interrupt flag */
mwait_idle_with_hints(eax, ecx);
+
+ return 0;
}
/*