linux-kernel - [PATCH v2 05/20] tools/x86/kcpuid: Print correct CPUID output register names

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250312143738.458507-6-darwi@linutronix.de>
Date: Wed, 12 Mar 2025 15:37:22 +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 05/20] tools/x86/kcpuid: Print correct CPUID output register names

kcpuid --all --detail claims that all bits belong to ECX, in the form
of the header CPUID_${leaf}_ECX[${subleaf}].

Print the correct register name for all CPUID output.

kcpuid --detail also dumps the raw register value if a leaf/subleaf is
covered in the CSV file, but a certain output register within it is not
covered by any CSV entry.  Since register names are now properly printed,
and since the CSV file has become exhaustive using x86-cpuid-db, remove
that value dump as it pollutes the output.

While at it, rename decode_bits() to show_reg().  This makes it match its
show_range(), show_leaf() and show_reg_header() counterparts.

Signed-off-by: Ahmed S. Darwish <darwi@...utronix.de>
---
 tools/arch/x86/kcpuid/kcpuid.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c
index dfabc0a56507..d518a13e4386 100644
--- a/tools/arch/x86/kcpuid/kcpuid.c
+++ b/tools/arch/x86/kcpuid/kcpuid.c
@@ -436,20 +436,12 @@ static void parse_text(void)
 	fclose(file);
 }
 
-
-/* Decode every eax/ebx/ecx/edx */
-static void decode_bits(u32 value, struct reg_desc *rdesc, enum cpuid_reg reg)
+static void show_reg(const struct reg_desc *rdesc, u32 value)
 {
-	struct bits_desc *bdesc;
+	const struct bits_desc *bdesc;
 	int start, end, i;
 	u32 mask;
 
-	if (!rdesc->nr) {
-		if (show_details)
-			printf("\t %s: 0x%08x\n", reg_names[reg], value);
-		return;
-	}
-
 	for (i = 0; i < rdesc->nr; i++) {
 		bdesc = &rdesc->descs[i];
 
@@ -480,18 +472,21 @@ static void decode_bits(u32 value, struct reg_desc *rdesc, enum cpuid_reg reg)
 	}
 }
 
+static void show_reg_header(bool has_entries, u32 leaf, u32 subleaf, const char *reg_name)
+{
+	if (show_details && has_entries)
+		printf("CPUID_0x%x_%s[0x%x]:\n", leaf, reg_name, subleaf);
+}
+
 static void show_leaf(struct subleaf *leaf)
 {
-	if (show_raw) {
+	if (show_raw)
 		leaf_print_raw(leaf);
-	} else {
-		if (show_details)
-			printf("CPUID_0x%x_ECX[0x%x]:\n",
-				leaf->index, leaf->sub);
-	}
 
-	for (int i = R_EAX; i < NR_REGS; i++)
-		decode_bits(leaf->output[i], &leaf->info[i], i);
+	for (int i = R_EAX; i < NR_REGS; i++) {
+		show_reg_header((leaf->info[i].nr > 0), leaf->index, leaf->sub, reg_names[i]);
+		show_reg(&leaf->info[i], leaf->output[i]);
+	}
 
 	if (!show_raw && show_details)
 		printf("\n");
-- 
2.48.1