linux-kernel - [RFC PATCH v0 09/19] x86/mce: Convert to insn

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Date:   Tue, 24 Nov 2020 11:19:42 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Andy Lutomirski <luto@...capital.net>,
        Masami Hiramatsu <mhiramat@...nel.org>
Cc:     X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: [RFC PATCH v0 09/19] x86/mce: Convert to insn_decode()

From: Borislav Petkov <bp@...e.de>

Simplify code, no functional changes.

Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/cpu/mce/severity.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index 83df991314c5..a2136ced9d73 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -218,15 +218,15 @@ static struct severity {
 static bool is_copy_from_user(struct pt_regs *regs)
 {
 	u8 insn_buf[MAX_INSN_SIZE];
-	struct insn insn;
 	unsigned long addr;
+	struct insn insn;
+	int ret;
 
 	if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip, MAX_INSN_SIZE))
 		return false;
 
-	kernel_insn_init(&insn, insn_buf, MAX_INSN_SIZE);
-	insn_get_opcode(&insn);
-	if (!insn.opcode.got)
+	ret = insn_decode(&insn, insn_buf, MAX_INSN_SIZE, INSN_MODE_KERN);
+	if (ret < 0)
 		return false;
 
 	switch (insn.opcode.value) {
@@ -234,10 +234,6 @@ static bool is_copy_from_user(struct pt_regs *regs)
 	case 0x8A: case 0x8B:
 	/* MOVZ mem,reg */
 	case 0xB60F: case 0xB70F:
-		insn_get_modrm(&insn);
-		insn_get_sib(&insn);
-		if (!insn.modrm.got || !insn.sib.got)
-			return false;
 		addr = (unsigned long)insn_get_addr_ref(&insn, regs);
 		break;
 	/* REP MOVS */
-- 
2.21.0