diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2022-11-25 10:42:14 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2023-02-06 15:48:54 +0100 |
| commit | 717cce3bdcf34705417f641bf2fcdf9b038ec36c (patch) | |
| tree | ce78b376b3e6ddc1e8b151ed5f46acd61750f213 /arch/x86/kernel/cpu/common.c | |
| parent | 4c382d723edce1b3c72b55b1b505cf5526a56afc (diff) | |
x86/cpu: Provide the full setup for getcpu() on x86-32
setup_getcpu() configures two things:
- it writes the current CPU & node information into MSR_TSC_AUX
- it writes the same information as a GDT entry.
By using the "full" setup_getcpu() on i386 it is possible to read the CPU
information in userland via RDTSCP() or via LSL from the GDT.
Provide an GDT_ENTRY_CPUNODE for x86-32 and make the setup function
unconditionally available.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Roland Mainz <roland.mainz@nrubsig.org>
Link: https://lore.kernel.org/r/20221125094216.3663444-2-bigeasy@linutronix.de
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 3a9043ef3d6b..a26ce206f7b0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2124,7 +2124,6 @@ static void wait_for_master_cpu(int cpu) #endif } -#ifdef CONFIG_X86_64 static inline void setup_getcpu(int cpu) { unsigned long cpudata = vdso_encode_cpunode(cpu, early_cpu_to_node(cpu)); @@ -2146,6 +2145,7 @@ static inline void setup_getcpu(int cpu) write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPUNODE, &d, DESCTYPE_S); } +#ifdef CONFIG_X86_64 static inline void ucode_cpu_init(int cpu) { if (cpu) @@ -2165,8 +2165,6 @@ static inline void tss_setup_ist(struct tss_struct *tss) #else /* CONFIG_X86_64 */ -static inline void setup_getcpu(int cpu) { } - static inline void ucode_cpu_init(int cpu) { show_ucode_info_early(); |