From: Muhammad Usama Anjum <musamaanjum@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
colin.king@canonical.com, dan.carpenter@oracle.com
Cc: musamaanjum@gmail.com, linux-kernel@vger.kernel.org
Subject: [PATCH] x86/kprobes: Remove dead code
Date: Wed, 24 Mar 2021 22:36:41 +0500 [thread overview]
Message-ID: <20210324173641.GA404706@LEGION> (raw)
The condition in switch statement `opcode & 0xf0` cannot evaluate to
0xff. So this case statement will never execute. Remove it.
Fixes: 6256e668b7 ("x86/kprobes: Use int3 instead of debug trap for single-step")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
---
arch/x86/kernel/kprobes/core.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 89d9f26785c7..3b7bcc077020 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -177,9 +177,6 @@ int can_boost(struct insn *insn, void *addr)
case 0xf0:
/* clear and set flags are boostable */
return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe));
- case 0xff:
- /* indirect jmp is boostable */
- return X86_MODRM_REG(insn->modrm.bytes[0]) == 4;
default:
/* CS override prefix and call are not boostable */
return (opcode != 0x2e && opcode != 0x9a);
--
2.25.1
next reply other threads:[~2021-03-24 17:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 17:36 Muhammad Usama Anjum [this message]
2021-03-24 17:50 ` Colin Ian King
2021-03-24 22:56 ` Masami Hiramatsu
2021-03-24 23:50 ` Masami Hiramatsu
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