From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Sasha Levin <sashal@kernel.org>,
jpoimboe@kernel.org, bp@suse.de, fenghua.yu@intel.com,
tony.luck@intel.com
Subject: [PATCH AUTOSEL 5.15 07/21] objtool,x86: Teach decode about LOOP* instructions
Date: Mon, 17 Oct 2022 20:09:26 -0400 [thread overview]
Message-ID: <20221018000940.2731329-7-sashal@kernel.org> (raw)
In-Reply-To: <20221018000940.2731329-1-sashal@kernel.org>
From: Peter Zijlstra <peterz@infradead.org>
[ Upstream commit 7a7621dfa417aa3715d2a3bd1bdd6cf5018274d0 ]
When 'discussing' control flow Masami mentioned the LOOP* instructions
and I realized objtool doesn't decode them properly.
As it turns out, these instructions are somewhat inefficient and as
such unlikely to be emitted by the compiler (a few vmlinux.o checks
can't find a single one) so this isn't critical, but still, best to
decode them properly.
Reported-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yxhd4EMKyoFoH9y4@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/objtool/arch/x86/decode.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index f62db0e006e9..16554496af9d 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -574,6 +574,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
*type = INSN_CONTEXT_SWITCH;
break;
+ case 0xe0: /* loopne */
+ case 0xe1: /* loope */
+ case 0xe2: /* loop */
+ *type = INSN_JUMP_CONDITIONAL;
+ break;
+
case 0xe8:
*type = INSN_CALL;
/*
--
2.35.1
next prev parent reply other threads:[~2022-10-18 0:15 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-18 0:09 [PATCH AUTOSEL 5.15 01/21] crypto: qcom-rng - Fix qcom_rng_of_match unused warning Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 02/21] crypto: ccp - Add a quirk to firmware update Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 03/21] gfs2: Switch from strlcpy to strscpy Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 04/21] powerpc/hw_breakpoint: Avoid relying on caller synchronization Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 05/21] cgroup: Remove data-race around cgrp_dfl_visible Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 06/21] of/fdt: Don't calculate initrd size from DT if start > end Sasha Levin
2022-10-18 0:09 ` Sasha Levin [this message]
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 08/21] locking/rwsem: Disable preemption while trying for rwsem lock Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 09/21] gfs2: Check sb_bsize_shift after reading superblock Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 10/21] powerpc/64: don't refer nr_cpu_ids in asm code when it's undefined Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 11/21] m68knommu: fix non-specific 68328 choice interrupt build failure Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 12/21] m68knommu: fix non-mmu classic 68000 legacy timer tick selection Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 13/21] of: Fix "dma-ranges" handling for bus controllers Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 14/21] x86/hyperv: Replace kmap() with kmap_local_page() Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 15/21] kmsan: disable instrumentation of unsupported common kernel code Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 16/21] kmsan: disable physical page merging in biovec Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 17/21] f2fs: fix to detect corrupted meta ino Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 18/21] 9p: trans_fd/p9_conn_cancel: drop client lock earlier Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 19/21] 9p/trans_fd: always use O_NONBLOCK read/write Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 20/21] net/9p: use a dedicated spinlock for trans_fd Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 21/21] virtio_pci: don't try to use intxif pin is zero Sasha Levin
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