linux-kernel - [PATCH v2 03/20] tools/x86/kcpuid: Simplify usage() handling

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Message-ID: <20250312143738.458507-4-darwi@linutronix.de>
Date: Wed, 12 Mar 2025 15:37:20 +0100
From: "Ahmed S. Darwish" <darwi@...utronix.de>
To: Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Borislav Petkov <bp@...en8.de>
Cc: Thomas Gleixner <tglx@...utronix.de>,
	Andrew Cooper <andrew.cooper3@...rix.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	John Ogness <john.ogness@...utronix.de>,
	x86@...nel.org,
	x86-cpuid@...ts.linux.dev,
	LKML <linux-kernel@...r.kernel.org>,
	"Ahmed S. Darwish" <darwi@...utronix.de>
Subject: [PATCH v2 03/20] tools/x86/kcpuid: Simplify usage() handling

Refactor usage() to accept an exit code parameter and exit the program
after usage output.  This streamlines its callers' code paths.

Remove the "Invalid option" error message since getopt_long(3) already
emits a similar message by default.

Signed-off-by: Ahmed S. Darwish <darwi@...utronix.de>
---
 tools/arch/x86/kcpuid/kcpuid.c | 37 +++++++++++++++-------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c
index 8585c1009c8b..b760c5730c89 100644
--- a/tools/arch/x86/kcpuid/kcpuid.c
+++ b/tools/arch/x86/kcpuid/kcpuid.c
@@ -10,6 +10,7 @@
 
 #define ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
 #define min(a, b)	(((a) < (b)) ? (a) : (b))
+#define __noreturn	__attribute__((__noreturn__))
 
 typedef unsigned int u32;
 typedef unsigned long long u64;
@@ -584,17 +585,17 @@ static void setup_platform_cpuid(void)
 	leafs_ext = setup_cpuid_range(0x80000000);
 }
 
-static void usage(void)
+static void __noreturn usage(int exit_code)
 {
-	warnx("kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
-	      "\t-a|--all             Show both bit flags and complex bit fields info\n"
-	      "\t-b|--bitflags        Show boolean flags only\n"
-	      "\t-d|--detail          Show details of the flag/fields (default)\n"
-	      "\t-f|--flags           Specify the cpuid csv file\n"
-	      "\t-h|--help            Show usage info\n"
-	      "\t-l|--leaf=index      Specify the leaf you want to check\n"
-	      "\t-r|--raw             Show raw cpuid data\n"
-	      "\t-s|--subleaf=sub     Specify the subleaf you want to check"
+	errx(exit_code, "kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
+	     "\t-a|--all             Show both bit flags and complex bit fields info\n"
+	     "\t-b|--bitflags        Show boolean flags only\n"
+	     "\t-d|--detail          Show details of the flag/fields (default)\n"
+	     "\t-f|--flags           Specify the cpuid csv file\n"
+	     "\t-h|--help            Show usage info\n"
+	     "\t-l|--leaf=index      Specify the leaf you want to check\n"
+	     "\t-r|--raw             Show raw cpuid data\n"
+	     "\t-s|--subleaf=sub     Specify the subleaf you want to check"
 	);
 }
 
@@ -610,7 +611,7 @@ static struct option opts[] = {
 	{ NULL, 0, NULL, 0 }
 };
 
-static int parse_options(int argc, char *argv[])
+static void parse_options(int argc, char *argv[])
 {
 	int c;
 
@@ -630,9 +631,7 @@ static int parse_options(int argc, char *argv[])
 			user_csv = optarg;
 			break;
 		case 'h':
-			usage();
-			exit(1);
-			break;
+			usage(EXIT_SUCCESS);
 		case 'l':
 			/* main leaf */
 			user_index = strtoul(optarg, NULL, 0);
@@ -645,11 +644,8 @@ static int parse_options(int argc, char *argv[])
 			user_sub = strtoul(optarg, NULL, 0);
 			break;
 		default:
-			warnx("Invalid option '%c'", optopt);
-			return -1;
-	}
-
-	return 0;
+			usage(EXIT_FAILURE);
+		}
 }
 
 /*
@@ -662,8 +658,7 @@ static int parse_options(int argc, char *argv[])
  */
 int main(int argc, char *argv[])
 {
-	if (parse_options(argc, argv))
-		return -1;
+	parse_options(argc, argv);
 
 	/* Setup the cpuid leafs of current platform */
 	setup_platform_cpuid();
-- 
2.48.1