diff options
Diffstat (limited to 'arch/x86/vdso/vma.c')
| -rw-r--r-- | arch/x86/vdso/vma.c | 83 |
1 files changed, 65 insertions, 18 deletions
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 970463b566cf..009495b9ab4b 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -1,7 +1,8 @@ /* - * Set up the VMAs to tell the VM about the vDSO. * Copyright 2007 Andi Kleen, SUSE Labs. * Subject to the GPL, v.2 + * + * This contains most of the x86 vDSO kernel-side code. */ #include <linux/mm.h> #include <linux/err.h> @@ -10,17 +11,17 @@ #include <linux/init.h> #include <linux/random.h> #include <linux/elf.h> -#include <asm/vsyscall.h> +#include <linux/cpu.h> #include <asm/vgtod.h> #include <asm/proto.h> #include <asm/vdso.h> +#include <asm/vvar.h> #include <asm/page.h> #include <asm/hpet.h> +#include <asm/desc.h> #if defined(CONFIG_X86_64) unsigned int __read_mostly vdso64_enabled = 1; - -extern unsigned short vdso_sync_cpuid; #endif void __init init_vdso_image(const struct vdso_image *image) @@ -38,20 +39,6 @@ void __init init_vdso_image(const struct vdso_image *image) image->alt_len)); } -#if defined(CONFIG_X86_64) -static int __init init_vdso(void) -{ - init_vdso_image(&vdso_image_64); - -#ifdef CONFIG_X86_X32_ABI - init_vdso_image(&vdso_image_x32); -#endif - - return 0; -} -subsys_initcall(init_vdso); -#endif - struct linux_binprm; /* Put the vdso above the (randomized) stack with another randomized offset. @@ -238,3 +225,63 @@ static __init int vdso_setup(char *s) } __setup("vdso=", vdso_setup); #endif + +#ifdef CONFIG_X86_64 +static void vgetcpu_cpu_init(void *arg) +{ + int cpu = smp_processor_id(); + struct desc_struct d = { }; + unsigned long node = 0; +#ifdef CONFIG_NUMA + node = cpu_to_node(cpu); +#endif + if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP)) + write_rdtscp_aux((node << 12) | cpu); + + /* + * Store cpu number in limit so that it can be loaded + * quickly in user space in vgetcpu. (12 bits for the CPU + * and 8 bits for the node) + */ + d.limit0 = cpu | ((node & 0xf) << 12); + d.limit = node >> 4; + d.type = 5; /* RO data, expand down, accessed */ + d.dpl = 3; /* Visible to user code */ + d.s = 1; /* Not a system segment */ + d.p = 1; /* Present */ + d.d = 1; /* 32-bit */ + + write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S); +} + +static int +vgetcpu_cpu_notifier(struct notifier_block *n, unsigned long action, void *arg) +{ + long cpu = (long)arg; + + if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) + smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1); + + return NOTIFY_DONE; +} + +static int __init init_vdso(void) +{ + init_vdso_image(&vdso_image_64); + +#ifdef CONFIG_X86_X32_ABI + init_vdso_image(&vdso_image_x32); +#endif + + cpu_notifier_register_begin(); + + on_each_cpu(vgetcpu_cpu_init, NULL, 1); + /* notifier priority > KVM */ + __hotcpu_notifier(vgetcpu_cpu_notifier, 30); + + cpu_notifier_register_done(); + + return 0; +} +subsys_initcall(init_vdso); +#endif /* CONFIG_X86_64 */ |