From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BD45C433EF for ; Thu, 24 Feb 2022 15:19:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236049AbiBXPUI (ORCPT ); Thu, 24 Feb 2022 10:20:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235986AbiBXPSc (ORCPT ); Thu, 24 Feb 2022 10:18:32 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C54914A222 for ; Thu, 24 Feb 2022 07:17:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=wPLl25fpeIQLW8L8xKToiko4ArI0LSp6NU8/QNuYuJ0=; b=ENbQjLoLz+m7A1scSH3yNztEZL z675SOv02DHkEGshocpql8uExc13E+6TihVJFhXy7yCkR1EXHjdSnTujsp0oPxGwM98wESovuy2Yh tcT8NFyUWM1E973Fbcyf0a6liKxpKcEcBukIno2jUpcfhiLmO7dk0i2MHnF80mZBflmo3dOgaZCGs /C+p7e6GFD9zVqwwLk3/dWDIVmY36cpxs81hM9LT5fpDJNebE5UV1VTJ5yOCzqUWf20xdhV6wmF/9 xfioMEef9KToCbf989addXIZr1nIilbebKXcqAZlrE4egh4SVxzIPqwuB+rWutgW0zzcnQM4Pwxqo OQxE+8HQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nNFs3-00CeM3-Ve; Thu, 24 Feb 2022 15:17:32 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 48455302A1E; Thu, 24 Feb 2022 16:17:29 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 8D1842B35479F; Thu, 24 Feb 2022 16:17:28 +0100 (CET) Message-ID: <20220224151323.661210297@infradead.org> User-Agent: quilt/0.66 Date: Thu, 24 Feb 2022 15:52:06 +0100 From: Peter Zijlstra To: x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com, jpoimboe@redhat.com, andrew.cooper3@citrix.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, ndesaulniers@google.com, keescook@chromium.org, samitolvanen@google.com, mark.rutland@arm.com, alyssa.milburn@intel.com, mbenes@suse.cz, rostedt@goodmis.org, mhiramat@kernel.org, alexei.starovoitov@gmail.com Subject: [PATCH v2 28/39] x86/ibt,xen: Sprinkle the ENDBR References: <20220224145138.952963315@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Even though Xen currently doesn't advertise IBT, prepare for when it will eventually do so and sprinkle the ENDBR dust accordingly. Even though most of the entry points are IRET like, the CPL0 Hypervisor can set WAIT-FOR-ENDBR and demand ENDBR at these sites. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/entry/entry_64.S | 1 + arch/x86/include/asm/segment.h | 2 +- arch/x86/kernel/head_64.S | 1 + arch/x86/xen/enlighten_pv.c | 3 +++ arch/x86/xen/xen-asm.S | 10 ++++++++++ arch/x86/xen/xen-head.S | 8 ++++++-- 6 files changed, 22 insertions(+), 3 deletions(-) --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -822,6 +822,7 @@ SYM_CODE_END(exc_xen_hypervisor_callback */ SYM_CODE_START(xen_failsafe_callback) UNWIND_HINT_EMPTY + ENDBR movl %ds, %ecx cmpw %cx, 0x10(%rsp) jne 1f --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -283,7 +283,7 @@ static inline void vdso_read_cpunode(uns * pop %rcx; pop %r11; jmp early_idt_handler_array[i]; summing up to * max 8 bytes. */ -#define XEN_EARLY_IDT_HANDLER_SIZE 8 +#define XEN_EARLY_IDT_HANDLER_SIZE (8 + 4*HAS_KERNEL_IBT) #ifndef __ASSEMBLY__ --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -389,6 +389,7 @@ SYM_CODE_START(early_idt_handler_array) .fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc .endr SYM_CODE_END(early_idt_handler_array) + ANNOTATE_NOENDBR // early_idt_handler_array[NUM_EXCEPTION_VECTORS] SYM_CODE_START_LOCAL(early_idt_handler_common) UNWIND_HINT_IRET_REGS offset=16 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -624,6 +624,9 @@ static struct trap_array_entry trap_arra TRAP_ENTRY(exc_coprocessor_error, false ), TRAP_ENTRY(exc_alignment_check, false ), TRAP_ENTRY(exc_simd_coprocessor_error, false ), +#ifdef CONFIG_X86_KERNEL_IBT + TRAP_ENTRY(exc_control_protection, false ), +#endif }; static bool __ref get_trap_addr(void **addr, unsigned int ist) --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -122,6 +122,7 @@ SYM_FUNC_END(xen_read_cr2_direct); .macro xen_pv_trap name SYM_CODE_START(xen_\name) UNWIND_HINT_EMPTY + ENDBR pop %rcx pop %r11 jmp \name @@ -147,6 +148,9 @@ xen_pv_trap asm_exc_page_fault xen_pv_trap asm_exc_spurious_interrupt_bug xen_pv_trap asm_exc_coprocessor_error xen_pv_trap asm_exc_alignment_check +#ifdef CONFIG_X86_KERNEL_IBT +xen_pv_trap asm_exc_control_protection +#endif #ifdef CONFIG_X86_MCE xen_pv_trap asm_xenpv_exc_machine_check #endif /* CONFIG_X86_MCE */ @@ -162,6 +166,7 @@ SYM_CODE_START(xen_early_idt_handler_arr i = 0 .rept NUM_EXCEPTION_VECTORS UNWIND_HINT_EMPTY + ENDBR pop %rcx pop %r11 jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE @@ -169,6 +174,7 @@ SYM_CODE_START(xen_early_idt_handler_arr .fill xen_early_idt_handler_array + i*XEN_EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc .endr SYM_CODE_END(xen_early_idt_handler_array) + ANNOTATE_NOENDBR __FINIT hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32 @@ -231,6 +237,7 @@ SYM_CODE_END(xenpv_restore_regs_and_retu /* Normal 64-bit system call target */ SYM_CODE_START(xen_syscall_target) UNWIND_HINT_EMPTY + ENDBR popq %rcx popq %r11 @@ -250,6 +257,7 @@ SYM_CODE_END(xen_syscall_target) /* 32-bit compat syscall target */ SYM_CODE_START(xen_syscall32_target) UNWIND_HINT_EMPTY + ENDBR popq %rcx popq %r11 @@ -267,6 +275,7 @@ SYM_CODE_END(xen_syscall32_target) /* 32-bit compat sysenter target */ SYM_CODE_START(xen_sysenter_target) UNWIND_HINT_EMPTY + ENDBR /* * NB: Xen is polite and clears TF from EFLAGS for us. This means * that we don't need to guard against single step exceptions here. @@ -290,6 +299,7 @@ SYM_CODE_END(xen_sysenter_target) SYM_CODE_START(xen_syscall32_target) SYM_CODE_START(xen_sysenter_target) UNWIND_HINT_EMPTY + ENDBR lea 16(%rsp), %rsp /* strip %rcx, %r11 */ mov $-ENOSYS, %rax pushq $0 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -25,8 +25,11 @@ SYM_CODE_START(hypercall_page) .rept (PAGE_SIZE / 32) UNWIND_HINT_FUNC - .skip 31, 0x90 - RET + ANNOTATE_NOENDBR + /* + * Xen will write the hypercall page, and sort out ENDBR. + */ + .skip 32, 0xcc .endr #define HYPERCALL(n) \ @@ -74,6 +77,7 @@ SYM_CODE_END(startup_xen) .pushsection .text SYM_CODE_START(asm_cpu_bringup_and_idle) UNWIND_HINT_EMPTY + ENDBR call cpu_bringup_and_idle SYM_CODE_END(asm_cpu_bringup_and_idle)