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From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com,
	andrew.cooper3@citrix.com, linux-kernel@vger.kernel.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: Re: [PATCH v3 22/39] x86/ibt: Add IBT feature, MSR and #CP handling
Date: Fri, 4 Mar 2022 10:07:20 -0800	[thread overview]
Message-ID: <20220304180720.qkvvjtsbbnfugxxy@treble> (raw)
In-Reply-To: <20220303112826.299051388@infradead.org>

On Thu, Mar 03, 2022 at 12:23:43PM +0100, Peter Zijlstra wrote:
> @@ -310,6 +311,7 @@ void machine_kexec(struct kimage *image)
>  	/* Interrupts aren't acceptable while we reboot */
>  	local_irq_disable();
>  	hw_breakpoint_disable();
> +	cet_disable();
>  
>  	if (image->preserve_context) {
>  #ifdef CONFIG_X86_IO_APIC
> --- a/arch/x86/kernel/relocate_kernel_64.S
> +++ b/arch/x86/kernel/relocate_kernel_64.S
> @@ -115,6 +115,14 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_ma
>  	pushq   %rdx
>  
>  	/*
> +	 * Clear X86_CR4_CET (if it was set) such that we can clear CR0_WP
> +	 * below.
> +	 */
> +	movq	%cr4, %rax
> +	andq	$~(X86_CR4_CET), %rax
> +	movq	%rax, %cr4
> +
> +	/*
>  	 * Set cr0 to a known state:
>  	 *  - Paging enabled
>  	 *  - Alignment check disabled

This probably belongs in a separate patch...

-- 
Josh


  parent reply	other threads:[~2022-03-04 18:07 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-03 11:23 [PATCH v3 00/39] x86: Kernel IBT Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 01/39] static_call: Avoid building empty .static_call_sites Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 02/39] x86/module: Fix the paravirt vs alternative order Peter Zijlstra
2022-03-08 13:58   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 03/39] objtool: Add --dry-run Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 04/39] x86/ibt: Base IBT bits Peter Zijlstra
2022-03-07 11:17   ` Peter Zijlstra
2022-03-07 12:25     ` Joao Moreira
2022-03-07 18:19       ` Nick Desaulniers
2022-03-03 11:23 ` [PATCH v3 05/39] x86/ibt: Add ANNOTATE_NOENDBR Peter Zijlstra
2022-03-04 18:59   ` Josh Poimboeuf
2022-03-04 20:22     ` Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 06/39] x86/text-patching: Make text_gen_insn() play nice with ANNOTATE_NOENDBR Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 07/39] x86/ibt,paravirt: Use text_gen_insn() for paravirt_patch() Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 08/39] x86/entry: Cleanup PARAVIRT Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 09/39] x86/entry,xen: Early rewrite of restore_regs_and_return_to_kernel() Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 10/39] x86/ibt,xen: Sprinkle the ENDBR Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 11/39] x86/ibt,entry: Sprinkle ENDBR dust Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 12/39] x86/linkage: Add ENDBR to SYM_FUNC_START*() Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 13/39] x86/ibt,paravirt: Sprinkle ENDBR Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 14/39] x86/ibt,crypto: Add ENDBR for the jump-table entries Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 15/39] x86/ibt,kvm: Add ENDBR to fastops Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 16/39] x86/ibt,ftrace: Search for __fentry__ location Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 17/39] x86/livepatch: Validate " Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 18/39] x86/ibt,ftrace: Make function-graph play nice Peter Zijlstra
2022-03-04 17:51   ` Josh Poimboeuf
2022-03-04 19:48     ` Peter Zijlstra
2022-03-04 21:03       ` Josh Poimboeuf
2022-03-04 21:44         ` Peter Zijlstra
2022-03-04 22:05           ` Josh Poimboeuf
2022-03-04 23:08       ` David Laight
2022-03-03 11:23 ` [PATCH v3 19/39] x86/ibt,kprobes: Cure sym+0 equals fentry woes Peter Zijlstra
2022-03-07  9:44   ` Masami Hiramatsu
2022-03-03 11:23 ` [PATCH v3 20/39] x86/ibt,bpf: Add ENDBR instructions to prologue and trampoline Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 21/39] x86/ibt,ftrace: Add ENDBR to samples/ftrace Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 22/39] x86/ibt: Add IBT feature, MSR and #CP handling Peter Zijlstra
2022-03-04 17:57   ` Josh Poimboeuf
2022-03-04 20:38     ` Peter Zijlstra
2022-03-04 18:07   ` Josh Poimboeuf [this message]
2022-03-04 20:39     ` Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 23/39] x86/alternative: Simplify int3_selftest_ip Peter Zijlstra
2022-03-04 18:02   ` Josh Poimboeuf
2022-03-04 18:09     ` Josh Poimboeuf
2022-03-03 11:23 ` [PATCH v3 24/39] x86/ibt: Disable IBT around firmware Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 25/39] x86/bugs: Disable Retpoline when IBT Peter Zijlstra
2022-03-04 17:39   ` Josh Poimboeuf
2022-03-03 11:23 ` [PATCH v3 26/39] x86/ibt: Annotate text references Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 27/39] x86/ibt,ftrace: Annotate ftrace code patching Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 28/39] x86/ibt,sev: Annotations Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 29/39] x86/ibt: Dont generate ENDBR in .discard.text Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 30/39] x86/ibt: Ensure module init/exit points have references Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 31/39] objtool: Rename --duplicate to --lto Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 32/39] Kbuild: Allow whole module objtool runs Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 33/39] objtool: Read the NOENDBR annotation Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 34/39] objtool: Have WARN_FUNC fall back to sym+off Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 35/39] objtool: Add IBT/ENDBR decoding Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 36/39] objtool: Validate IBT assumptions Peter Zijlstra
2022-03-03 11:23 ` [PATCH v3 37/39] objtool: Optionally WARN about unused ANNOTATE_NOENDBR Peter Zijlstra
2022-03-04 18:27   ` Josh Poimboeuf
2022-03-03 11:23 ` [PATCH v3 38/39] objtool: Find unused ENDBR instructions Peter Zijlstra
2022-03-03 11:24 ` [PATCH v3 39/39] x86/alternative: Use .ibt_endbr_seal to seal indirect calls Peter Zijlstra
2022-03-04 19:09 ` [PATCH v3 00/39] x86: Kernel IBT Josh Poimboeuf
2022-03-04 20:22   ` Peter Zijlstra
2022-03-04 21:39   ` Peter Zijlstra

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