Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Ensure context synchronisation after a write to APIAKey.

 - Fix bullet list formatting in Documentation/arm64/amu.rst to
   eliminate doc warnings.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  Documentation: arm64: fix amu.rst doc warnings
  arm64: sync kernel APIAKey when installing

Author: torvalds

Documentation/arm64/amu.rst

@@ -23,13 +23,14 @@ optional external memory-mapped interface.
 
 Version 1 of the Activity Monitors architecture implements a counter group
 of four fixed and architecturally defined 64-bit event counters.
-  - CPU cycle counter: increments at the frequency of the CPU.
-  - Constant counter: increments at the fixed frequency of the system
-    clock.
-  - Instructions retired: increments with every architecturally executed
-    instruction.
-  - Memory stall cycles: counts instruction dispatch stall cycles caused by
-    misses in the last level cache within the clock domain.
+
+- CPU cycle counter: increments at the frequency of the CPU.
+- Constant counter: increments at the fixed frequency of the system
+  clock.
+- Instructions retired: increments with every architecturally executed
+  instruction.
+- Memory stall cycles: counts instruction dispatch stall cycles caused by
+  misses in the last level cache within the clock domain.
 
 When in WFI or WFE these counters do not increment.
 
@@ -57,11 +58,12 @@ counters, only the presence of the extension.
 
 Firmware (code running at higher exception levels, e.g. arm-tf) support is
 needed to:
- - Enable access for lower exception levels (EL2 and EL1) to the AMU
-   registers.
- - Enable the counters. If not enabled these will read as 0.
- - Save/restore the counters before/after the CPU is being put/brought up
-   from the 'off' power state.
+
+- Enable access for lower exception levels (EL2 and EL1) to the AMU
+  registers.
+- Enable the counters. If not enabled these will read as 0.
+- Save/restore the counters before/after the CPU is being put/brought up
+  from the 'off' power state.
 
 When using kernels that have this feature enabled but boot with broken
 firmware the user may experience panics or lockups when accessing the
@@ -78,10 +80,11 @@ are not trapped in EL2/EL3.
 
 The fixed counters of AMUv1 are accessible though the following system
 register definitions:
- - SYS_AMEVCNTR0_CORE_EL0
- - SYS_AMEVCNTR0_CONST_EL0
- - SYS_AMEVCNTR0_INST_RET_EL0
- - SYS_AMEVCNTR0_MEM_STALL_EL0
+
+- SYS_AMEVCNTR0_CORE_EL0
+- SYS_AMEVCNTR0_CONST_EL0
+- SYS_AMEVCNTR0_INST_RET_EL0
+- SYS_AMEVCNTR0_MEM_STALL_EL0
 
 Auxiliary platform specific counters can be accessed using
 SYS_AMEVCNTR1_EL0(n), where n is a value between 0 and 15.
@@ -93,9 +96,10 @@ Userspace access
 ----------------
 
 Currently, access from userspace to the AMU registers is disabled due to:
- - Security reasons: they might expose information about code executed in
-   secure mode.
- - Purpose: AMU counters are intended for system management use.
+
+- Security reasons: they might expose information about code executed in
+  secure mode.
+- Purpose: AMU counters are intended for system management use.
 
 Also, the presence of the feature is not visible to userspace.
 
@@ -105,8 +109,9 @@ Virtualization
 
 Currently, access from userspace (EL0) and kernelspace (EL1) on the KVM
 guest side is disabled due to:
- - Security reasons: they might expose information about code executed
-   by other guests or the host.
+
+- Security reasons: they might expose information about code executed
+  by other guests or the host.
 
 Any attempt to access the AMU registers will result in an UNDEFINED
 exception being injected into the guest.

arch/arm64/include/asm/pointer_auth.h

@@ -47,7 +47,7 @@ static inline void ptrauth_keys_init_user(struct ptrauth_keys_user *keys)
 		get_random_bytes(&keys->apga, sizeof(keys->apga));
 }
 
-#define __ptrauth_key_install(k, v)				\
+#define __ptrauth_key_install_nosync(k, v)			\
 do {								\
 	struct ptrauth_key __pki_v = (v);			\
 	write_sysreg_s(__pki_v.lo, SYS_ ## k ## KEYLO_EL1);	\
@@ -62,8 +62,11 @@ static __always_inline void ptrauth_keys_init_kernel(struct ptrauth_keys_kernel
 
 static __always_inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kernel *keys)
 {
-	if (system_supports_address_auth())
-		__ptrauth_key_install(APIA, keys->apia);
+	if (!system_supports_address_auth())
+		return;
+
+	__ptrauth_key_install_nosync(APIA, keys->apia);
+	isb();
 }
 
 extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg);