[tip: x86/cpu] x86/cpu: Initialize boot CPU cpuinfo defaults early

[tip-bot2 for Ihor Solodrai]

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     7a762b51a149b7bfe431a7571bc7df4beea52e5c
Gitweb:        https://git.kernel.org/tip/7a762b51a149b7bfe431a7571bc7df4beea52e5c
Author:        Ihor Solodrai <ihor.solodrai@xxxxxxxxx>
AuthorDate:    Wed, 16 Sep 2026 12:52:00 -07:00
Committer:     Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Thu, 17 Sep 2026 01:57:26 +02:00

x86/cpu: Initialize boot CPU cpuinfo defaults early

early_identify_cpu() clears the capability array, the CPUID table and
extended_cpuid_level, but the architectural defaults for the rest of struct
cpuinfo_x86 are set only later, in identify_cpu().

Use the same defaults from the start, so that the boot CPU does not
depend on a later reset to end up with the right ones.

Signed-off-by: Ihor Solodrai <ihor.solodrai@xxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://patch.msgid.link/20260916195203.1099646-3-ihor.solodrai@xxxxxxxxx
---
 arch/x86/kernel/cpu/common.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 173748a..d1a949a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1814,16 +1814,15 @@ static void init_cpu_info(struct cpuinfo_x86 *c)
  * Do minimum CPU detection early.
  * Fields really needed: vendor, cpuid_level, family, model, mask,
  * cache alignment.
- * The others are not touched to avoid unwanted side effects.
+ * The others are reset to their defaults here and only filled in later,
+ * by identify_cpu().
  *
  * WARNING: this function is only called on the boot CPU.  Don't add code
  * here that is supposed to run on all CPUs.
  */
 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 {
-	memset(&c->x86_capability, 0, sizeof(c->x86_capability));
-	memset(&c->cpuid, 0, sizeof(c->cpuid));
-	c->extended_cpuid_level = 0;
+	init_cpu_info(c);
 
 	if (!cpuid_feature())
 		identify_cpu_without_cpuid(c);