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

Pull more arm64 updates from Catalin Marinas:
 "As I mentioned in the last pull request, there's a second batch of
  security updates for arm64 with mitigations for Spectre/v1 and an
  improved one for Spectre/v2 (via a newly defined firmware interface
  API).

  Spectre v1 mitigation:

   - back-end version of array_index_mask_nospec()

   - masking of the syscall number to restrict speculation through the
     syscall table

   - masking of __user pointers prior to deference in uaccess routines

  Spectre v2 mitigation update:

   - using the new firmware SMC calling convention specification update

   - removing the current PSCI GET_VERSION firmware call mitigation as
     vendors are deploying new SMCCC-capable firmware

   - additional branch predictor hardening for synchronous exceptions
     and interrupts while in user mode

  Meltdown v3 mitigation update:

    - Cavium Thunder X is unaffected but a hardware erratum gets in the
      way. The kernel now starts with the page tables mapped as global
      and switches to non-global if kpti needs to be enabled.

  Other:

   - Theoretical trylock bug fixed"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (38 commits)
  arm64: Kill PSCI_GET_VERSION as a variant-2 workaround
  arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support
  arm/arm64: smccc: Implement SMCCC v1.1 inline primitive
  arm/arm64: smccc: Make function identifiers an unsigned quantity
  firmware/psci: Expose SMCCC version through psci_ops
  firmware/psci: Expose PSCI conduit
  arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
  arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
  arm/arm64: KVM: Turn kvm_psci_version into a static inline
  arm/arm64: KVM: Advertise SMCCC v1.1
  arm/arm64: KVM: Implement PSCI 1.0 support
  arm/arm64: KVM: Add smccc accessors to PSCI code
  arm/arm64: KVM: Add PSCI_VERSION helper
  arm/arm64: KVM: Consolidate the PSCI include files
  arm64: KVM: Increment PC after handling an SMC trap
  arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  arm64: entry: Apply BP hardening for suspicious interrupts from EL0
  arm64: entry: Apply BP hardening for high-priority synchronous exceptions
  arm64: futex: Mask __user pointers prior to dereference
  ...

1 files changed, 16 insertions, 13 deletions

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index cccd2788e631..ec2ee720e33e 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -167,10 +167,10 @@ alternative_else_nop_endif
 	.else
 	add	x21, sp, #S_FRAME_SIZE
 	get_thread_info tsk
-	/* Save the task's original addr_limit and set USER_DS (TASK_SIZE_64) */
+	/* Save the task's original addr_limit and set USER_DS */
 	ldr	x20, [tsk, #TSK_TI_ADDR_LIMIT]
 	str	x20, [sp, #S_ORIG_ADDR_LIMIT]
-	mov	x20, #TASK_SIZE_64
+	mov	x20, #USER_DS
 	str	x20, [tsk, #TSK_TI_ADDR_LIMIT]
 	/* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */
 	.endif /* \el == 0 */
@@ -382,6 +382,7 @@ alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0
  * x7 is reserved for the system call number in 32-bit mode.
  */
 wsc_nr	.req	w25		// number of system calls
+xsc_nr	.req	x25		// number of system calls (zero-extended)
 wscno	.req	w26		// syscall number
 xscno	.req	x26		// syscall number (zero-extended)
 stbl	.req	x27		// syscall table pointer
@@ -770,7 +771,10 @@ el0_sp_pc:
 	 * Stack or PC alignment exception handling
 	 */
 	mrs	x26, far_el1
-	enable_daif
+	enable_da_f
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_off
+#endif
 	ct_user_exit
 	mov	x0, x26
 	mov	x1, x25
@@ -828,6 +832,11 @@ el0_irq_naked:
 #endif
 
 	ct_user_exit
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	tbz	x22, #55, 1f
+	bl	do_el0_irq_bp_hardening
+1:
+#endif
 	irq_handler
 
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -939,6 +948,7 @@ el0_svc_naked:					// compat entry point
 	b.ne	__sys_trace
 	cmp     wscno, wsc_nr			// check upper syscall limit
 	b.hs	ni_sys
+	mask_nospec64 xscno, xsc_nr, x19	// enforce bounds for syscall number
 	ldr	x16, [stbl, xscno, lsl #3]	// address in the syscall table
 	blr	x16				// call sys_* routine
 	b	ret_fast_syscall
@@ -1017,16 +1027,9 @@ alternative_else_nop_endif
 	orr	\tmp, \tmp, #USER_ASID_FLAG
 	msr	ttbr1_el1, \tmp
 	/*
-	 * We avoid running the post_ttbr_update_workaround here because the
-	 * user and kernel ASIDs don't have conflicting mappings, so any
-	 * "blessing" as described in:
-	 *
-	 *   http://lkml.kernel.org/r/56BB848A.6060603@caviumnetworks.com
-	 *
-	 * will not hurt correctness. Whilst this may partially defeat the
-	 * point of using split ASIDs in the first place, it avoids
-	 * the hit of invalidating the entire I-cache on every return to
-	 * userspace.
+	 * We avoid running the post_ttbr_update_workaround here because
+	 * it's only needed by Cavium ThunderX, which requires KPTI to be
+	 * disabled.
 	 */
 	.endm