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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 23/39] x86/alternative: Simplify int3_selftest_ip
Date: Fri, 4 Mar 2022 10:09:33 -0800	[thread overview]
Message-ID: <20220304180933.4byakmv7snrai7lh@treble> (raw)
In-Reply-To: <20220304180219.hiyg2e6e6z76mfjz@treble>

On Fri, Mar 04, 2022 at 10:02:23AM -0800, Josh Poimboeuf wrote:
> On Thu, Mar 03, 2022 at 12:23:44PM +0100, Peter Zijlstra wrote:
> > @@ -733,7 +733,7 @@ int3_exception_notify(struct notifier_bl
> >  	if (val != DIE_INT3)
> >  		return NOTIFY_DONE;
> >  
> > -	if (regs->ip - INT3_INSN_SIZE != int3_selftest_ip)
> > +	if (regs->ip - INT3_INSN_SIZE != (unsigned long)&int3_selftest_ip)
> >  		return NOTIFY_DONE;
> >  
> >  	int3_emulate_call(regs, (unsigned long)&int3_magic);
> > @@ -757,14 +757,7 @@ static void __init int3_selftest(void)
> >  	 * then trigger the INT3, padded with NOPs to match a CALL instruction
> >  	 * length.
> >  	 */
> > -	asm volatile ("1: int3; nop; nop; nop; nop\n\t"
> > -		      ".pushsection .init.data,\"aw\"\n\t"
> > -		      ".align " __ASM_SEL(4, 8) "\n\t"
> > -		      ".type int3_selftest_ip, @object\n\t"
> > -		      ".size int3_selftest_ip, " __ASM_SEL(4, 8) "\n\t"
> > -		      "int3_selftest_ip:\n\t"
> > -		      __ASM_SEL(.long, .quad) " 1b\n\t"
> > -		      ".popsection\n\t"
> > +	asm volatile ("int3_selftest_ip: int3; nop; nop; nop; nop\n\t"
> >  		      : ASM_CALL_CONSTRAINT
> >  		      : __ASM_SEL_RAW(a, D) (&val)
> >  		      : "memory");
> 
> Hm, why doesn't this need ANNOTATE_NOENDBR?

Never mind, I see it's added later... though I still have the same
comment about the ANNOTATE_ENDBR coming after the label.

-- 
Josh


  reply	other threads:[~2022-03-04 18:09 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
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 [this message]
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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