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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, jpoimboe@redhat.com, jgross@suse.com, mbenes@suse.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org
Subject: [PATCH v2 13/14] objtool: Skip magical retpoline .altinstr_replacement
Date: Thu, 18 Mar 2021 18:11:16 +0100	[thread overview]
Message-ID: <20210318171920.191767166@infradead.org> (raw)
In-Reply-To: 20210318171103.577093939@infradead.org

When the .altinstr_replacement is a retpoline, skip the alternative.
We already special case retpolines anyway.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 tools/objtool/special.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -106,6 +106,14 @@ static int get_alt_entry(struct elf *elf
 			return -1;
 		}
 
+		/*
+		 * Skip retpoline .altinstr_replacement... we already rewrite the
+		 * instructions for retpolines anyway, see arch_is_retpoline()
+		 * usage in add_{call,jump}_destinations().
+		 */
+		if (arch_is_retpoline(new_reloc->sym))
+			return 1;
+
 		alt->new_sec = new_reloc->sym->sec;
 		alt->new_off = (unsigned int)new_reloc->addend;
 
@@ -154,7 +162,9 @@ int special_get_alts(struct elf *elf, st
 			memset(alt, 0, sizeof(*alt));
 
 			ret = get_alt_entry(elf, entry, sec, idx, alt);
-			if (ret)
+			if (ret > 0)
+				continue;
+			if (ret < 0)
 				return ret;
 
 			list_add_tail(&alt->list, alts);



  parent reply	other threads:[~2021-03-18 17:24 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-18 17:11 [PATCH v2 00/14] x86,objtool: Optimize !RETPOLINE Peter Zijlstra
2021-03-18 17:11 ` [PATCH v2 01/14] x86: Add insn_decode_kernel() Peter Zijlstra
2021-03-19 10:40   ` Borislav Petkov
2021-03-18 17:11 ` [PATCH v2 02/14] x86/alternatives: Optimize optimize_nops() Peter Zijlstra
2021-03-21 12:06   ` Borislav Petkov
2021-03-22  8:17     ` Peter Zijlstra
2021-03-22 11:07       ` Borislav Petkov
2021-03-18 17:11 ` [PATCH v2 03/14] x86/retpoline: Simplify retpolines Peter Zijlstra
2021-03-19 17:18   ` David Laight
2021-03-22  9:32     ` Peter Zijlstra
2021-03-22 15:41       ` David Laight
2021-03-18 17:11 ` [PATCH v2 04/14] objtool: Correctly handle retpoline thunk calls Peter Zijlstra
2021-03-18 17:11 ` [PATCH v2 05/14] objtool: Per arch retpoline naming Peter Zijlstra
2021-03-19  2:38   ` Josh Poimboeuf
2021-03-19  9:07     ` Peter Zijlstra
2021-03-18 17:11 ` [PATCH v2 06/14] objtool: Fix static_call list generation Peter Zijlstra
2021-03-22 12:44   ` Miroslav Benes
2021-03-18 17:11 ` [PATCH v2 07/14] objtool: Rework rebuild_reloc logic Peter Zijlstra
2021-03-18 17:11 ` [PATCH v2 08/14] objtool: Add elf_create_reloc() helper Peter Zijlstra
2021-03-19  1:42   ` Josh Poimboeuf
2021-03-19  9:47     ` Peter Zijlstra
2021-03-19 15:12       ` Josh Poimboeuf
2021-03-19 15:24         ` Peter Zijlstra
2021-03-19 15:37           ` Josh Poimboeuf
2021-03-18 17:11 ` [PATCH v2 09/14] objtool: Extract elf_strtab_concat() Peter Zijlstra
2021-03-19  2:10   ` Josh Poimboeuf
2021-03-19  9:52     ` Peter Zijlstra
2021-03-18 17:11 ` [PATCH v2 10/14] objtool: Extract elf_symbol_add() Peter Zijlstra
2021-03-19  2:14   ` Josh Poimboeuf
2021-03-19  9:54     ` Peter Zijlstra
2021-03-19 15:04       ` Josh Poimboeuf
2021-03-18 17:11 ` [PATCH v2 11/14] objtool: Add elf_create_undef_symbol() Peter Zijlstra
2021-03-19  2:29   ` Josh Poimboeuf
2021-03-19  7:56     ` Peter Zijlstra
2021-03-18 17:11 ` [PATCH v2 12/14] objtool: Allow archs to rewrite retpolines Peter Zijlstra
2021-03-19  2:54   ` Josh Poimboeuf
2021-03-19 11:21     ` Peter Zijlstra
2021-03-19 13:28       ` Peter Zijlstra
2021-03-18 17:11 ` Peter Zijlstra [this message]
2021-03-18 17:11 ` [PATCH v2 14/14] objtool,x86: Rewrite retpoline thunk calls Peter Zijlstra
2021-03-19  3:29   ` Josh Poimboeuf
2021-03-19  8:06     ` Peter Zijlstra
2021-03-19 15:30       ` Josh Poimboeuf
2021-03-19 15:56         ` Peter Zijlstra
2021-03-19 22:52           ` Josh Poimboeuf

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