/* * IA32 helper functions * * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com> * Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com> * Copyright (C) 2001-2002 Hewlett-Packard Co * David Mosberger-Tang <davidm@hpl.hp.com> * * 06/16/00 A. Mallick added csd/ssd/tssd for ia32 thread context * 02/19/01 D. Mosberger dropped tssd; it's not needed * 09/14/01 D. Mosberger fixed memory management for gdt/tss page * 09/29/01 D. Mosberger added ia32_load_segment_descriptors() */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/personality.h> #include <linux/sched.h> #include <asm/intrinsics.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/system.h> #include <asm/processor.h> #include <asm/uaccess.h> #include "ia32priv.h" extern void die_if_kernel (char *str, struct pt_regs *regs, long err); struct exec_domain ia32_exec_domain; struct page *ia32_shared_page[NR_CPUS]; unsigned long *ia32_boot_gdt; unsigned long *cpu_gdt_table[NR_CPUS]; struct page *ia32_gate_page; static unsigned long load_desc (u16 selector) { unsigned long *table, limit, index; if (!selector) return 0; if (selector & IA32_SEGSEL_TI) { table = (unsigned long *) IA32_LDT_OFFSET; limit = IA32_LDT_ENTRIES; } else { table = cpu_gdt_table[smp_processor_id()]; limit = IA32_PAGE_SIZE / sizeof(ia32_boot_gdt[0]); } index = selector >> IA32_SEGSEL_INDEX_SHIFT; if (index >= limit) return 0; return IA32_SEG_UNSCRAMBLE(table[index]); } void ia32_load_segment_descriptors (struct task_struct *task) { struct pt_regs *regs = ia64_task_regs(task); /* Setup the segment descriptors */ regs->r24 = load_desc(regs->r16 >> 16); /* ESD */ regs->r27 = load_desc(regs->r16 >> 0); /* DSD */ regs->r28 = load_desc(regs->r16 >> 32); /* FSD */ regs->r29 = load_desc(regs->r16 >> 48); /* GSD */ regs->ar_csd = load_desc(regs->r17 >> 0); /* CSD */ regs->ar_ssd = load_desc(regs->r17 >> 16); /* SSD */ } int ia32_clone_tls (struct task_struct *child, struct pt_regs *childregs) { struct desc_struct *desc; struct ia32_user_desc info; int idx; if (copy_from_user(&info, (void __user *)(childregs->r14 & 0xffffffff), sizeof(info))) return -EFAULT; if (LDT_empty(&info)) return -EINVAL; idx = info.entry_number; if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) return -EINVAL; desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; desc->a = LDT_entry_a(&info); desc->b = LDT_entry_b(&info); /* XXX: can this be done in a cleaner way ? */ load_TLS(&child->thread, smp_processor_id()); ia32_load_segment_descriptors(child); load_TLS(¤t->thread, smp_processor_id()); return 0; } void ia32_save_state (struct task_struct *t) { t->thread.eflag = ia64_getreg(_IA64_REG_AR_EFLAG); t->thread.fsr = ia64_getreg(_IA64_REG_AR_FSR); t->thread.fcr = ia64_getreg(_IA64_REG_AR_FCR); t->thread.fir = ia64_getreg(_IA64_REG_AR_FIR); t->thread.fdr = ia64_getreg(_IA64_REG_AR_FDR); ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob); ia64_set_kr(IA64_KR_TSSD, t->thread.old_k1); } void ia32_load_state (struct task_struct *t) { unsigned long eflag, fsr, fcr, fir, fdr, tssd; struct pt_regs *regs = ia64_task_regs(t); eflag = t->thread.eflag; fsr = t->thread.fsr; fcr = t->thread.fcr; fir = t->thread.fir; fdr = t->thread.fdr; tssd = load_desc(_TSS); /* TSSD */ ia64_setreg(_IA64_REG_AR_EFLAG, eflag); ia64_setreg(_IA64_REG_AR_FSR, fsr); ia64_setreg(_IA64_REG_AR_FCR, fcr); ia64_setreg(_IA64_REG_AR_FIR, fir); ia64_setreg(_IA64_REG_AR_FDR, fdr); current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE); current->thread.old_k1 = ia64_get_kr(IA64_KR_TSSD); ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE); ia64_set_kr(IA64_KR_TSSD, tssd); regs->r17 = (_TSS << 48) | (_LDT << 32) | (__u32) regs->r17; regs->r30 = load_desc(_LDT); /* LDTD */ load_TLS(&t->thread, smp_processor_id()); } /* * Setup IA32 GDT and TSS */ void ia32_gdt_init (void) { int cpu = smp_processor_id(); ia32_shared_page[cpu] = alloc_page(GFP_KERNEL); if (!ia32_shared_page[cpu]) panic("failed to allocate ia32_shared_page[%d]\n", cpu); cpu_gdt_table[cpu] = page_address(ia32_shared_page[cpu]); /* Copy from the boot cpu's GDT */ memcpy(cpu_gdt_table[cpu], ia32_boot_gdt, PAGE_SIZE); } /* * Setup IA32 GDT and TSS */ static void ia32_boot_gdt_init (void) { unsigned long ldt_size; ia32_shared_page[0] = alloc_page(GFP_KERNEL); if (!ia32_shared_page[0]) panic("failed to allocate ia32_shared_page[0]\n"); ia32_boot_gdt = page_address(ia32_shared_page[0]); cpu_gdt_table[0] = ia32_boot_gdt; /* CS descriptor in IA-32 (scrambled) format */ ia32_boot_gdt[__USER_CS >> 3] = IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT, 0xb, 1, 3, 1, 1, 1, 1); /* DS descriptor in IA-32 (scrambled) format */ ia32_boot_gdt[__USER_DS >> 3] = IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT, 0x3, 1, 3, 1, 1, 1, 1); ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE); ia32_boot_gdt[TSS_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235, 0xb, 0, 3, 1, 1, 1, 0); ia32_boot_gdt[LDT_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1, 0x2, 0, 3, 1, 1, 1, 0); } static void ia32_gate_page_init(void) { unsigned long *sr; ia32_gate_page = alloc_page(GFP_KERNEL); sr = page_address(ia32_gate_page); /* This is popl %eax ; movl $,%eax ; int $0x80 */ *sr++ = 0xb858 | (__IA32_NR_sigreturn << 16) | (0x80cdUL << 48); /* This is movl $,%eax ; int $0x80 */ *sr = 0xb8 | (__IA32_NR_rt_sigreturn << 8) | (0x80cdUL << 40); } void ia32_mem_init(void) { ia32_boot_gdt_init(); ia32_gate_page_init(); } /* * Handle bad IA32 interrupt via syscall */ void ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs) { siginfo_t siginfo; die_if_kernel("Bad IA-32 interrupt", regs, int_num); siginfo.si_signo = SIGTRAP; siginfo.si_errno = int_num; /* XXX is it OK to abuse si_errno like this? */ siginfo.si_flags = 0; siginfo.si_isr = 0; siginfo.si_addr = NULL; siginfo.si_imm = 0; siginfo.si_code = TRAP_BRKPT; force_sig_info(SIGTRAP, &siginfo, current); } void ia32_cpu_init (void) { /* initialize global ia32 state - CR0 and CR4 */ ia64_setreg(_IA64_REG_AR_CFLAG, (((ulong) IA32_CR4 << 32) | IA32_CR0)); } static int __init ia32_init (void) { ia32_exec_domain.name = "Linux/x86"; ia32_exec_domain.handler = NULL; ia32_exec_domain.pers_low = PER_LINUX32; ia32_exec_domain.pers_high = PER_LINUX32; ia32_exec_domain.signal_map = default_exec_domain.signal_map; ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap; register_exec_domain(&ia32_exec_domain); #if PAGE_SHIFT > IA32_PAGE_SHIFT { extern kmem_cache_t *partial_page_cachep; partial_page_cachep = kmem_cache_create("partial_page_cache", sizeof(struct partial_page), 0, 0, NULL, NULL); if (!partial_page_cachep) panic("Cannot create partial page SLAB cache"); } #endif return 0; } __initcall(ia32_init);