From cdb4d57c3e497fe99a9ffa54f085b75130b12b5a Mon Sep 17 00:00:00 2001 From: Melody Wang Date: Wed, 8 Jul 2026 01:21:17 +0000 Subject: [PATCH] x86/apic: Ensure ICR register write value is handled as 32 bits The low 32-bit ICR data is prepared by __prepare_ICR(), which returns a 32-bit value. However, when this value is assigned to a new variable, it's easy to mistakenly declare that variable with a different width. To avoid this class of mistakes, use __prepare_ICR() directly as the function argument instead of storing its result in an intermediate variable. This also shaves off a bunch of lines in the code. There should be no functionality change resulting from this. Signed-off-by: Melody Wang Signed-off-by: Borislav Petkov (AMD) Acked-by: Thomas Gleixner Link: https://patch.msgid.link/20260708012117.177959-1-huibo.wang@amd.com --- arch/x86/kernel/apic/local.h | 4 +--- arch/x86/kernel/apic/x2apic_phys.c | 4 +--- arch/x86/kernel/apic/x2apic_savic.c | 5 +---- 3 files changed, 3 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/apic/local.h b/arch/x86/kernel/apic/local.h index 998efd442063..090dd71837aa 100644 --- a/arch/x86/kernel/apic/local.h +++ b/arch/x86/kernel/apic/local.h @@ -44,9 +44,7 @@ static inline unsigned int __prepare_ICR(unsigned int shortcut, int vector, #ifdef CONFIG_X86_X2APIC static inline void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest) { - unsigned long cfg = __prepare_ICR(0, vector, dest); - - native_x2apic_icr_write(cfg, apicid); + native_x2apic_icr_write(__prepare_ICR(0, vector, dest), apicid); } #endif diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c index 10f79026e8e3..090647cc5a78 100644 --- a/arch/x86/kernel/apic/x2apic_phys.c +++ b/arch/x86/kernel/apic/x2apic_phys.c @@ -85,11 +85,9 @@ static void static void __x2apic_send_IPI_shorthand(int vector, u32 which) { - unsigned long cfg = __prepare_ICR(which, vector, 0); - /* x2apic MSRs are special and need a special fence: */ weak_wrmsr_fence(); - native_x2apic_icr_write(cfg, 0); + native_x2apic_icr_write(__prepare_ICR(which, vector, 0), 0); } void x2apic_send_IPI_allbutself(int vector) diff --git a/arch/x86/kernel/apic/x2apic_savic.c b/arch/x86/kernel/apic/x2apic_savic.c index dbc5678bc3b6..4bc6d7e018a5 100644 --- a/arch/x86/kernel/apic/x2apic_savic.c +++ b/arch/x86/kernel/apic/x2apic_savic.c @@ -243,10 +243,7 @@ static void savic_write(u32 reg, u32 data) static void send_ipi(u32 dest, unsigned int vector, unsigned int dsh) { - unsigned int icr_low; - - icr_low = __prepare_ICR(dsh, vector, APIC_DEST_PHYSICAL); - savic_icr_write(icr_low, dest); + savic_icr_write(__prepare_ICR(dsh, vector, APIC_DEST_PHYSICAL), dest); } static void savic_send_ipi(int cpu, int vector)