From: Heiko Carstens <hca@linux.ibm.com>
Date: Wed, 26 Feb 2025 10:03:04 +0000 (+0100)
Subject: s390/traps: Cleanup get_user() handling in illegal_op()
X-Git-Tag: v6.15-rc1~113^2~23
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e9df614dad8ebe43ed15bef3b18789319a73e0f6;p=thirdparty%2Fkernel%2Flinux.git

s390/traps: Cleanup get_user() handling in illegal_op()

The usage of get_user() in illegal_op() is quite unusual. Make the code
more readable and get rid of unnecessary casts. The generated code is
identical before/after this change.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index 6db2c14665314..478c5871aefaf 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -154,23 +154,23 @@ static void translation_specification_exception(struct pt_regs *regs)
 
 static void illegal_op(struct pt_regs *regs)
 {
-        __u8 opcode[6];
-	__u16 __user *location;
 	int is_uprobe_insn = 0;
+	u16 __user *location;
 	int signal = 0;
+	u16 opcode;
 
 	location = get_trap_ip(regs);
 
 	if (user_mode(regs)) {
-		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
+		if (get_user(opcode, location))
 			return;
-		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
+		if (opcode == S390_BREAKPOINT_U16) {
 			if (current->ptrace)
 				force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
 			else
 				signal = SIGILL;
 #ifdef CONFIG_UPROBES
-		} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
+		} else if (opcode == UPROBE_SWBP_INSN) {
 			is_uprobe_insn = 1;
 #endif
 		} else