From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 921AC7D40E; Wed, 21 Feb 2024 13:31:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708522314; cv=none; b=uLsbon6Mx1s1Pi+Bj5FyaLM2tMnawOQ++ENgpmN1cPN5SJTdExjeXRqEmmZ7aBxjQvj+pFYUpBW8Trs1kGDAMOiioArGpY1CTNZulZh0BEvmkKf9CUvvvYBJrwG/hNJ+ZG5n3xIlvDk8H1QciTY8Jz+/WMWc2iQZPfcNON8QcaI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708522314; c=relaxed/simple; bh=uNonjg08Ncj20R1LhY2ZUp/OKI2HcXHA+cp5MFKeLUw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UGb3tPx+LKql+vZpuiJr2+SHq4Y8uesooa5BduqDyb56NEE2IACCiDTceYWEEOmUQvzN2F51B8lv8hCO27BZMnt7H3TwJ/ZBGVKrcHn7E81eCWScWaI/15P7hjKEiHDI/qXPFdAhKVNrxj4a4rPLaSFNbFOuFolTGThDe9VY+JI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=i9O6ctSq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="i9O6ctSq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93519C433F1; Wed, 21 Feb 2024 13:31:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708522314; bh=uNonjg08Ncj20R1LhY2ZUp/OKI2HcXHA+cp5MFKeLUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i9O6ctSq1qlL1bY+/lAn2K/9BGyuvxPKOlGQx9YcuFsCpRzLCaZkL8iRB6V6QcFY7 HH4CATAgaR4q9kO9mbF5n10doLotoajbYOYqzMgUuLBhquDqa06gZfNjvLoPGquIJV PsFp2gUMx+9UUGsqHlQubDr3yt4cdPf9Lr+Cicfc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Junichi Nomura , Derek Barbosa , Ingo Molnar , Kees Cook , Linus Torvalds , "Paul E. McKenney" , Andy Lutomirski , "H. Peter Anvin" , Peter Zijlstra , Sasha Levin Subject: [PATCH 5.15 131/476] x86/boot: Ignore NMIs during very early boot Date: Wed, 21 Feb 2024 14:03:02 +0100 Message-ID: <20240221130012.804863415@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240221130007.738356493@linuxfoundation.org> References: <20240221130007.738356493@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jun'ichi Nomura [ Upstream commit 78a509fba9c9b1fcb77f95b7c6be30da3d24823a ] When there are two racing NMIs on x86, the first NMI invokes NMI handler and the 2nd NMI is latched until IRET is executed. If panic on NMI and panic kexec are enabled, the first NMI triggers panic and starts booting the next kernel via kexec. Note that the 2nd NMI is still latched. During the early boot of the next kernel, once an IRET is executed as a result of a page fault, then the 2nd NMI is unlatched and invokes the NMI handler. However, NMI handler is not set up at the early stage of boot, which results in a boot failure. Avoid such problems by setting up a NOP handler for early NMIs. [ mingo: Refined the changelog. ] Signed-off-by: Jun'ichi Nomura Signed-off-by: Derek Barbosa Signed-off-by: Ingo Molnar Cc: Kees Cook Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Andy Lutomirski Cc: "H. Peter Anvin" Cc: Peter Zijlstra Signed-off-by: Sasha Levin --- arch/x86/boot/compressed/ident_map_64.c | 5 +++++ arch/x86/boot/compressed/idt_64.c | 1 + arch/x86/boot/compressed/idt_handlers_64.S | 1 + arch/x86/boot/compressed/misc.h | 1 + 4 files changed, 8 insertions(+) diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index 575d881ff86e..b72dea92cd96 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -357,3 +357,8 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code) */ add_identity_map(address, end); } + +void do_boot_nmi_trap(struct pt_regs *regs, unsigned long error_code) +{ + /* Empty handler to ignore NMI during early boot */ +} diff --git a/arch/x86/boot/compressed/idt_64.c b/arch/x86/boot/compressed/idt_64.c index 9b93567d663a..9620883485ac 100644 --- a/arch/x86/boot/compressed/idt_64.c +++ b/arch/x86/boot/compressed/idt_64.c @@ -45,6 +45,7 @@ void load_stage2_idt(void) boot_idt_desc.address = (unsigned long)boot_idt; set_idt_entry(X86_TRAP_PF, boot_page_fault); + set_idt_entry(X86_TRAP_NMI, boot_nmi_trap); #ifdef CONFIG_AMD_MEM_ENCRYPT set_idt_entry(X86_TRAP_VC, boot_stage2_vc); diff --git a/arch/x86/boot/compressed/idt_handlers_64.S b/arch/x86/boot/compressed/idt_handlers_64.S index 22890e199f5b..4d03c8562f63 100644 --- a/arch/x86/boot/compressed/idt_handlers_64.S +++ b/arch/x86/boot/compressed/idt_handlers_64.S @@ -70,6 +70,7 @@ SYM_FUNC_END(\name) .code64 EXCEPTION_HANDLER boot_page_fault do_boot_page_fault error_code=1 +EXCEPTION_HANDLER boot_nmi_trap do_boot_nmi_trap error_code=0 #ifdef CONFIG_AMD_MEM_ENCRYPT EXCEPTION_HANDLER boot_stage1_vc do_vc_no_ghcb error_code=1 diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 31139256859f..cea1b96c48b2 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -163,6 +163,7 @@ static inline void cleanup_exception_handling(void) { } /* IDT Entry Points */ void boot_page_fault(void); +void boot_nmi_trap(void); void boot_stage1_vc(void); void boot_stage2_vc(void); -- 2.43.0