Merge remote-tracking branch 'stable/linux-6.8.y' into v6.8+

Author: xdevs23

Documentation/admin-guide/hw-vuln/spectre.rst

@@ -138,11 +138,10 @@ associated with the source address of the indirect branch. Specifically,
 the BHB might be shared across privilege levels even in the presence of
 Enhanced IBRS.
 
-Currently the only known real-world BHB attack vector is via
-unprivileged eBPF. Therefore, it's highly recommended to not enable
-unprivileged eBPF, especially when eIBRS is used (without retpolines).
-For a full mitigation against BHB attacks, it's recommended to use
-retpolines (or eIBRS combined with retpolines).
+Previously the only known real-world BHB attack vector was via unprivileged
+eBPF. Further research has found attacks that don't require unprivileged eBPF.
+For a full mitigation against BHB attacks it is recommended to set BHI_DIS_S or
+use the BHB clearing sequence.
 
 Attack scenarios
 ----------------
@@ -430,6 +429,23 @@ The possible values in this file are:
   'PBRSB-eIBRS: Not affected'  CPU is not affected by PBRSB
   ===========================  =======================================================
 
+  - Branch History Injection (BHI) protection status:
+
+.. list-table::
+
+ * - BHI: Not affected
+   - System is not affected
+ * - BHI: Retpoline
+   - System is protected by retpoline
+ * - BHI: BHI_DIS_S
+   - System is protected by BHI_DIS_S
+ * - BHI: SW loop; KVM SW loop
+   - System is protected by software clearing sequence
+ * - BHI: Syscall hardening
+   - Syscalls are hardened against BHI
+ * - BHI: Syscall hardening; KVM: SW loop
+   - System is protected from userspace attacks by syscall hardening; KVM is protected by software clearing sequence
+
 Full mitigation might require a microcode update from the CPU
 vendor. When the necessary microcode is not available, the kernel will
 report vulnerability.
@@ -484,7 +500,11 @@ Spectre variant 2
 
    Systems which support enhanced IBRS (eIBRS) enable IBRS protection once at
    boot, by setting the IBRS bit, and they're automatically protected against
-   Spectre v2 variant attacks.
+   some Spectre v2 variant attacks. The BHB can still influence the choice of
+   indirect branch predictor entry, and although branch predictor entries are
+   isolated between modes when eIBRS is enabled, the BHB itself is not isolated
+   between modes. Systems which support BHI_DIS_S will set it to protect against
+   BHI attacks.
 
    On Intel's enhanced IBRS systems, this includes cross-thread branch target
    injections on SMT systems (STIBP). In other words, Intel eIBRS enables
@@ -638,6 +658,22 @@ kernel command line.
 		spectre_v2=off. Spectre variant 1 mitigations
 		cannot be disabled.
 
+	spectre_bhi=
+
+		[X86] Control mitigation of Branch History Injection
+		(BHI) vulnerability. Syscalls are hardened against BHI
+		regardless of this setting. This setting affects the deployment
+		of the HW BHI control and the SW BHB clearing sequence.
+
+		on
+			unconditionally enable.
+		off
+			unconditionally disable.
+		auto
+			enable if hardware mitigation
+			control(BHI_DIS_S) is available, otherwise
+			enable alternate mitigation in KVM.
+
 For spectre_v2_user see Documentation/admin-guide/kernel-parameters.txt
 
 Mitigation selection guide

Documentation/admin-guide/kernel-parameters.txt

@@ -6043,6 +6043,18 @@
 	sonypi.*=	[HW] Sony Programmable I/O Control Device driver
 			See Documentation/admin-guide/laptops/sonypi.rst
 
+	spectre_bhi=	[X86] Control mitigation of Branch History Injection
+			(BHI) vulnerability. Syscalls are hardened against BHI
+			reglardless of this setting. This setting affects the
+			deployment of the HW BHI control and the SW BHB
+			clearing sequence.
+
+			on   - unconditionally enable.
+			off  - unconditionally disable.
+			auto - (default) enable hardware mitigation
+			       (BHI_DIS_S) if available, otherwise enable
+			       alternate mitigation in KVM.
+
 	spectre_v2=	[X86] Control mitigation of Spectre variant 2
 			(indirect branch speculation) vulnerability.
 			The default operation protects the kernel from

Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 6
 PATCHLEVEL = 8
-SUBLEVEL = 4
+SUBLEVEL = 5
 EXTRAVERSION =
 NAME = Hurr durr I'ma ninja sloth
 

arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi

@@ -943,6 +943,8 @@ ap_spi_fp: &spi10 {
 		vddrf-supply = <&pp1300_l2c>;
 		vddch0-supply = <&pp3300_l10c>;
 		max-speed = <3200000>;
+
+		qcom,local-bd-address-broken;
 	};
 };
 

arch/arm64/kernel/ptrace.c

@@ -729,7 +729,6 @@ static void sve_init_header_from_task(struct user_sve_header *header,
 {
 	unsigned int vq;
 	bool active;
-	bool fpsimd_only;
 	enum vec_type task_type;
 
 	memset(header, 0, sizeof(*header));
@@ -745,20 +744,18 @@ static void sve_init_header_from_task(struct user_sve_header *header,
 	case ARM64_VEC_SVE:
 		if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
 			header->flags |= SVE_PT_VL_INHERIT;
-		fpsimd_only = !test_tsk_thread_flag(target, TIF_SVE);
 		break;
 	case ARM64_VEC_SME:
 		if (test_tsk_thread_flag(target, TIF_SME_VL_INHERIT))
 			header->flags |= SVE_PT_VL_INHERIT;
-		fpsimd_only = false;
 		break;
 	default:
 		WARN_ON_ONCE(1);
 		return;
 	}
 
 	if (active) {
-		if (fpsimd_only) {
+		if (target->thread.fp_type == FP_STATE_FPSIMD) {
 			header->flags |= SVE_PT_REGS_FPSIMD;
 		} else {
 			header->flags |= SVE_PT_REGS_SVE;

arch/arm64/kvm/hyp/nvhe/tlb.c

@@ -154,7 +154,8 @@ void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
 	/* Switch to requested VMID */
 	__tlb_switch_to_guest(mmu, &cxt, false);
 
-	__flush_s2_tlb_range_op(ipas2e1is, start, pages, stride, 0);
+	__flush_s2_tlb_range_op(ipas2e1is, start, pages, stride,
+				TLBI_TTL_UNKNOWN);
 
 	dsb(ish);
 	__tlbi(vmalle1is);

arch/arm64/kvm/hyp/pgtable.c

@@ -829,12 +829,15 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx,
 		 * Perform the appropriate TLB invalidation based on the
 		 * evicted pte value (if any).
 		 */
-		if (kvm_pte_table(ctx->old, ctx->level))
-			kvm_tlb_flush_vmid_range(mmu, ctx->addr,
-						kvm_granule_size(ctx->level));
-		else if (kvm_pte_valid(ctx->old))
+		if (kvm_pte_table(ctx->old, ctx->level)) {
+			u64 size = kvm_granule_size(ctx->level);
+			u64 addr = ALIGN_DOWN(ctx->addr, size);
+
+			kvm_tlb_flush_vmid_range(mmu, addr, size);
+		} else if (kvm_pte_valid(ctx->old)) {
 			kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu,
 				     ctx->addr, ctx->level);
+		}
 	}
 
 	if (stage2_pte_is_counted(ctx->old))

arch/arm64/kvm/hyp/vhe/tlb.c

@@ -171,7 +171,8 @@ void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
 	/* Switch to requested VMID */
 	__tlb_switch_to_guest(mmu, &cxt);
 
-	__flush_s2_tlb_range_op(ipas2e1is, start, pages, stride, 0);
+	__flush_s2_tlb_range_op(ipas2e1is, start, pages, stride,
+				TLBI_TTL_UNKNOWN);
 
 	dsb(ish);
 	__tlbi(vmalle1is);

arch/arm64/kvm/mmu.c

@@ -1631,7 +1631,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
 	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
 
-	if (esr_fsc_is_permission_fault(esr)) {
+	if (esr_fsc_is_translation_fault(esr)) {
 		/* Beyond sanitised PARange (which is the IPA limit) */
 		if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) {
 			kvm_inject_size_fault(vcpu);

arch/arm64/net/bpf_jit_comp.c

@@ -876,7 +876,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
 			emit(A64_UXTH(is64, dst, dst), ctx);
 			break;
 		case 32:
-			emit(A64_REV32(is64, dst, dst), ctx);
+			emit(A64_REV32(0, dst, dst), ctx);
 			/* upper 32 bits already cleared */
 			break;
 		case 64:
@@ -1189,7 +1189,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
 			} else {
 				emit_a64_mov_i(1, tmp, off, ctx);
 				if (sign_extend)
-					emit(A64_LDRSW(dst, src_adj, off_adj), ctx);
+					emit(A64_LDRSW(dst, src, tmp), ctx);
 				else
 					emit(A64_LDR32(dst, src, tmp), ctx);
 			}