diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index 1e60acbed3c..6c8e483ce9e 100644 --- a/arch/i386/kernel/apm.c +++ b/arch/i386/kernel/apm.c @@ -2317,6 +2317,8 @@ static int __init apm_init(void) for (i = 0; i < NR_CPUS; i++) { struct desc_struct *gdt = get_cpu_gdt_table(i); + if (!gdt) + continue; set_base(gdt[APM_CS >> 3], __va((unsigned long)apm_info.bios.cseg << 4)); set_base(gdt[APM_CS_16 >> 3], diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c index 31e344b26ba..cbc32069683 100644 --- a/arch/i386/kernel/cpu/common.c +++ b/arch/i386/kernel/cpu/common.c @@ -18,9 +18,6 @@ #include "cpu.h" -DEFINE_PER_CPU(struct desc_struct, cpu_gdt_table[GDT_ENTRIES]); -EXPORT_PER_CPU_SYMBOL(cpu_gdt_table); - DEFINE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]); EXPORT_PER_CPU_SYMBOL(cpu_16bit_stack); diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index e437fb36749..870f20bf33c 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -525,3 +525,5 @@ ENTRY(cpu_gdt_table) .quad 0x0000000000000000 /* 0xf0 - unused */ .quad 0x0000000000000000 /* 0xf8 - GDT entry 31: double-fault TSS */ + /* Be sure this is zeroed to avoid false validations in Xen */ + .fill PAGE_SIZE_asm / 8 - GDT_ENTRIES,8,0 diff --git a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c index 180f070d03c..3999bec50c3 100644 --- a/arch/i386/kernel/i386_ksyms.c +++ b/arch/i386/kernel/i386_ksyms.c @@ -3,8 +3,7 @@ #include #include -/* This is definitely a GPL-only symbol */ -EXPORT_SYMBOL_GPL(cpu_gdt_table); +EXPORT_SYMBOL_GPL(cpu_gdt_descr); EXPORT_SYMBOL(__down_failed); EXPORT_SYMBOL(__down_failed_interruptible); diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index 9ed449af8e9..b3c2e2c2674 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c @@ -903,6 +903,12 @@ static int __devinit do_boot_cpu(int apicid, int cpu) unsigned long start_eip; unsigned short nmi_high = 0, nmi_low = 0; + if (!cpu_gdt_descr[cpu].address && + !(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) { + printk("Failed to allocate GDT for CPU %d\n", cpu); + return 1; + } + ++cpucount; /* diff --git a/drivers/pnp/pnpbios/bioscalls.c b/drivers/pnp/pnpbios/bioscalls.c index 6b7583f497d..7cb476ed7f9 100644 --- a/drivers/pnp/pnpbios/bioscalls.c +++ b/drivers/pnp/pnpbios/bioscalls.c @@ -69,14 +69,16 @@ __asm__( #define Q_SET_SEL(cpu, selname, address, size) \ do { \ -set_base(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], __va((u32)(address))); \ -set_limit(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], size); \ +struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \ +set_base(gdt[(selname) >> 3], __va((u32)(address))); \ +set_limit(gdt[(selname) >> 3], size); \ } while(0) #define Q2_SET_SEL(cpu, selname, address, size) \ do { \ -set_base(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], (u32)(address)); \ -set_limit(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], size); \ +struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \ +set_base(gdt[(selname) >> 3], (u32)(address)); \ +set_limit(gdt[(selname) >> 3], size); \ } while(0) static struct desc_struct bad_bios_desc = { 0, 0x00409200 }; @@ -115,8 +117,8 @@ static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3, return PNP_FUNCTION_NOT_SUPPORTED; cpu = get_cpu(); - save_desc_40 = per_cpu(cpu_gdt_table,cpu)[0x40 / 8]; - per_cpu(cpu_gdt_table,cpu)[0x40 / 8] = bad_bios_desc; + save_desc_40 = get_cpu_gdt_table(cpu)[0x40 / 8]; + get_cpu_gdt_table(cpu)[0x40 / 8] = bad_bios_desc; /* On some boxes IRQ's during PnP BIOS calls are deadly. */ spin_lock_irqsave(&pnp_bios_lock, flags); @@ -158,7 +160,7 @@ static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3, ); spin_unlock_irqrestore(&pnp_bios_lock, flags); - per_cpu(cpu_gdt_table,cpu)[0x40 / 8] = save_desc_40; + get_cpu_gdt_table(cpu)[0x40 / 8] = save_desc_40; put_cpu(); /* If we get here and this is set then the PnP BIOS faulted on us. */ @@ -535,8 +537,10 @@ void pnpbios_calls_init(union pnp_bios_install_struct *header) set_base(bad_bios_desc, __va((unsigned long)0x40 << 4)); _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4)); - for(i=0; i < NR_CPUS; i++) - { + for (i = 0; i < NR_CPUS; i++) { + struct desc_struct *gdt = get_cpu_gdt_table(i); + if (!gdt) + continue; Q2_SET_SEL(i, PNP_CS32, &pnp_bios_callfunc, 64 * 1024); Q_SET_SEL(i, PNP_CS16, header->fields.pm16cseg, 64 * 1024); Q_SET_SEL(i, PNP_DS, header->fields.pm16dseg, 64 * 1024); diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h index 29b851a18c6..494e73bca09 100644 --- a/include/asm-i386/desc.h +++ b/include/asm-i386/desc.h @@ -15,9 +15,6 @@ #include extern struct desc_struct cpu_gdt_table[GDT_ENTRIES]; -DECLARE_PER_CPU(struct desc_struct, cpu_gdt_table[GDT_ENTRIES]); - -#define get_cpu_gdt_table(_cpu) (per_cpu(cpu_gdt_table,_cpu)) DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]); @@ -29,6 +26,11 @@ struct Xgt_desc_struct { extern struct Xgt_desc_struct idt_descr, cpu_gdt_descr[NR_CPUS]; +static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu) +{ + return ((struct desc_struct *)cpu_gdt_descr[cpu].address); +} + #define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8)) #define load_LDT_desc() __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8))