All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	rick.p.edgecombe@intel.com, jpoimboe@redhat.com
Subject: [PATCH 4/4] x86,objtool: Explicitly mark idtentry_body()s tail REACHABLE
Date: Fri, 08 Apr 2022 11:45:56 +0200	[thread overview]
Message-ID: <20220408094718.441854969@infradead.org> (raw)
In-Reply-To: 20220408094552.432447640@infradead.org

Objtool can figure out that some \cfunc()s are noreturn and then
complains about certain instances having unreachable tails:

  vmlinux.o: warning: objtool: asm_exc_xen_unknown_trap()+0x16: unreachable instruction

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/entry/entry_64.S |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -337,6 +337,9 @@ SYM_CODE_END(ret_from_fork)
 
 	call	\cfunc
 
+	/* For some configurations \cfunc ends up being a noreturn. */
+	REACHABLE
+
 	jmp	error_return
 .endm
 



  parent reply	other threads:[~2022-04-08  9:48 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-08  9:45 [PATCH 0/4] objtool: Fixes Peter Zijlstra
2022-04-08  9:45 ` [PATCH 1/4] lib/strn*,objtool: Enforce user_access_begin() rules Peter Zijlstra
2022-04-08 14:09   ` Josh Poimboeuf
2022-04-19 20:08   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2022-04-08  9:45 ` [PATCH 2/4] x86,xen,objtool: Add UNWIND hint Peter Zijlstra
2022-04-19 20:08   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2022-04-08  9:45 ` [PATCH 3/4] x86,objtool: Mark cpu_startup_entry() __noreturn Peter Zijlstra
2022-04-11 20:32   ` Josh Poimboeuf
2022-04-12 15:13   ` Josh Poimboeuf
2022-04-19 20:08   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2022-04-08  9:45 ` Peter Zijlstra [this message]
2022-04-19 20:08   ` [tip: x86/urgent] x86,objtool: Explicitly mark idtentry_body()s tail REACHABLE tip-bot2 for Peter Zijlstra
2022-04-08 14:10 ` [PATCH 0/4] objtool: Fixes Josh Poimboeuf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220408094718.441854969@infradead.org \
    --to=peterz@infradead.org \
    --cc=jpoimboe@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rick.p.edgecombe@intel.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.