diff options
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 862 |
1 files changed, 249 insertions, 613 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 3baf9b9f4c8..ca5b02d405c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -14,8 +14,6 @@ * This file handles the architecture-dependent parts of process handling.. */ -#include <stdarg.h> - #include <linux/cpu.h> #include <linux/errno.h> #include <linux/sched.h> @@ -27,434 +25,108 @@ #include <linux/slab.h> #include <linux/user.h> #include <linux/interrupt.h> -#include <linux/utsname.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/ptrace.h> -#include <linux/random.h> #include <linux/notifier.h> #include <linux/kprobes.h> #include <linux/kdebug.h> -#include <linux/tick.h> +#include <linux/prctl.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/ftrace.h> -#include <asm/uaccess.h> #include <asm/pgtable.h> -#include <asm/system.h> -#include <asm/io.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mmu_context.h> -#include <asm/pda.h> #include <asm/prctl.h> #include <asm/desc.h> #include <asm/proto.h> #include <asm/ia32.h> #include <asm/idle.h> +#include <asm/syscalls.h> +#include <asm/debugreg.h> +#include <asm/switch_to.h> asmlinkage extern void ret_from_fork(void); -unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED; - -unsigned long boot_option_idle_override = 0; -EXPORT_SYMBOL(boot_option_idle_override); - -/* - * Powermanagement idle function, if any.. - */ -void (*pm_idle)(void); -EXPORT_SYMBOL(pm_idle); -static DEFINE_PER_CPU(unsigned int, cpu_idle_state); - -static ATOMIC_NOTIFIER_HEAD(idle_notifier); - -void idle_notifier_register(struct notifier_block *n) -{ - atomic_notifier_chain_register(&idle_notifier, n); -} - -void enter_idle(void) -{ - write_pda(isidle, 1); - atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL); -} - -static void __exit_idle(void) -{ - if (test_and_clear_bit_pda(0, isidle) == 0) - return; - atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL); -} - -/* Called from interrupts to signify idle end */ -void exit_idle(void) -{ - /* idle loop has pid 0 */ - if (current->pid) - return; - __exit_idle(); -} - -/* - * We use this if we don't have any better - * idle routine.. - */ -void default_idle(void) -{ - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); - local_irq_disable(); - if (!need_resched()) { - ktime_t t0, t1; - u64 t0n, t1n; - - t0 = ktime_get(); - t0n = ktime_to_ns(t0); - safe_halt(); /* enables interrupts racelessly */ - local_irq_disable(); - t1 = ktime_get(); - t1n = ktime_to_ns(t1); - sched_clock_idle_wakeup_event(t1n - t0n); - } - local_irq_enable(); - current_thread_info()->status |= TS_POLLING; -} - -/* - * On SMP it's slightly faster (but much more power-consuming!) - * to poll the ->need_resched flag instead of waiting for the - * cross-CPU IPI to arrive. Use this option with caution. - */ -static void poll_idle(void) -{ - local_irq_enable(); - cpu_relax(); -} - -#ifdef CONFIG_HOTPLUG_CPU -DECLARE_PER_CPU(int, cpu_state); - -#include <asm/nmi.h> -/* We halt the CPU with physical CPU hotplug */ -static inline void play_dead(void) -{ - idle_task_exit(); - wbinvd(); - mb(); - /* Ack it */ - __get_cpu_var(cpu_state) = CPU_DEAD; - - local_irq_disable(); - while (1) - halt(); -} -#else -static inline void play_dead(void) -{ - BUG(); -} -#endif /* CONFIG_HOTPLUG_CPU */ - -/* - * The idle thread. There's no useful work to be - * done, so just try to conserve power and have a - * low exit latency (ie sit in a loop waiting for - * somebody to say that they'd like to reschedule) - */ -void cpu_idle(void) -{ - current_thread_info()->status |= TS_POLLING; - /* endless idle loop with no priority at all */ - while (1) { - tick_nohz_stop_sched_tick(); - while (!need_resched()) { - void (*idle)(void); - - if (__get_cpu_var(cpu_idle_state)) - __get_cpu_var(cpu_idle_state) = 0; - - rmb(); - idle = pm_idle; - if (!idle) - idle = default_idle; - if (cpu_is_offline(smp_processor_id())) - play_dead(); - /* - * Idle routines should keep interrupts disabled - * from here on, until they go to idle. - * Otherwise, idle callbacks can misfire. - */ - local_irq_disable(); - enter_idle(); - idle(); - /* In many cases the interrupt that ended idle - has already called exit_idle. But some idle - loops can be woken up without interrupt. */ - __exit_idle(); - } - - tick_nohz_restart_sched_tick(); - preempt_enable_no_resched(); - schedule(); - preempt_disable(); - } -} - -static void do_nothing(void *unused) -{ -} - -void cpu_idle_wait(void) -{ - unsigned int cpu, this_cpu = get_cpu(); - cpumask_t map, tmp = current->cpus_allowed; - - set_cpus_allowed(current, cpumask_of_cpu(this_cpu)); - put_cpu(); - - cpus_clear(map); - for_each_online_cpu(cpu) { - per_cpu(cpu_idle_state, cpu) = 1; - cpu_set(cpu, map); - } - - __get_cpu_var(cpu_idle_state) = 0; - - wmb(); - do { - ssleep(1); - for_each_online_cpu(cpu) { - if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu)) - cpu_clear(cpu, map); - } - cpus_and(map, map, cpu_online_map); - /* - * We waited 1 sec, if a CPU still did not call idle - * it may be because it is in idle and not waking up - * because it has nothing to do. - * Give all the remaining CPUS a kick. - */ - smp_call_function_mask(map, do_nothing, 0, 0); - } while (!cpus_empty(map)); - - set_cpus_allowed(current, tmp); -} -EXPORT_SYMBOL_GPL(cpu_idle_wait); - -/* - * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, - * which can obviate IPI to trigger checking of need_resched. - * We execute MONITOR against need_resched and enter optimized wait state - * through MWAIT. Whenever someone changes need_resched, we would be woken - * up from MWAIT (without an IPI). - * - * New with Core Duo processors, MWAIT can take some hints based on CPU - * capability. - */ -void mwait_idle_with_hints(unsigned long ax, unsigned long cx) -{ - if (!need_resched()) { - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __mwait(ax, cx); - } -} - -/* Default MONITOR/MWAIT with no hints, used for default C1 state */ -static void mwait_idle(void) -{ - if (!need_resched()) { - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __sti_mwait(0, 0); - else - local_irq_enable(); - } else { - local_irq_enable(); - } -} - - -static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) -{ - if (force_mwait) - return 1; - /* Any C1 states supported? */ - return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0; -} - -void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) -{ - static int selected; - - if (selected) - return; -#ifdef CONFIG_X86_SMP - if (pm_idle == poll_idle && smp_num_siblings > 1) { - printk(KERN_WARNING "WARNING: polling idle and HT enabled," - " performance may degrade.\n"); - } -#endif - if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { - /* - * Skip, if setup has overridden idle. - * One CPU supports mwait => All CPUs supports mwait - */ - if (!pm_idle) { - printk(KERN_INFO "using mwait in idle threads.\n"); - pm_idle = mwait_idle; - } - } - selected = 1; -} - -static int __init idle_setup(char *str) -{ - if (!strcmp(str, "poll")) { - printk("using polling idle threads.\n"); - pm_idle = poll_idle; - } else if (!strcmp(str, "mwait")) - force_mwait = 1; - else - return -1; - - boot_option_idle_override = 1; - return 0; -} -early_param("idle", idle_setup); +__visible DEFINE_PER_CPU(unsigned long, old_rsp); /* Prints also some state that isn't saved in the pt_regs */ -void __show_regs(struct pt_regs * regs) +void __show_regs(struct pt_regs *regs, int all) { unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs; unsigned long d0, d1, d2, d3, d6, d7; unsigned int fsindex, gsindex; unsigned int ds, cs, es; - printk("\n"); - print_modules(); - printk("Pid: %d, comm: %.20s %s %s %.*s\n", - current->pid, current->comm, print_tainted(), - init_utsname()->release, - (int)strcspn(init_utsname()->version, " "), - init_utsname()->version); - printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip); - printk_address(regs->ip, 1); - printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->sp, - regs->flags); - printk("RAX: %016lx RBX: %016lx RCX: %016lx\n", + printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip); + printk_address(regs->ip); + printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, + regs->sp, regs->flags); + printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n", regs->ax, regs->bx, regs->cx); - printk("RDX: %016lx RSI: %016lx RDI: %016lx\n", + printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n", regs->dx, regs->si, regs->di); - printk("RBP: %016lx R08: %016lx R09: %016lx\n", + printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n", regs->bp, regs->r8, regs->r9); - printk("R10: %016lx R11: %016lx R12: %016lx\n", - regs->r10, regs->r11, regs->r12); - printk("R13: %016lx R14: %016lx R15: %016lx\n", - regs->r13, regs->r14, regs->r15); - - asm("movl %%ds,%0" : "=r" (ds)); - asm("movl %%cs,%0" : "=r" (cs)); - asm("movl %%es,%0" : "=r" (es)); + printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n", + regs->r10, regs->r11, regs->r12); + printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n", + regs->r13, regs->r14, regs->r15); + + asm("movl %%ds,%0" : "=r" (ds)); + asm("movl %%cs,%0" : "=r" (cs)); + asm("movl %%es,%0" : "=r" (es)); asm("movl %%fs,%0" : "=r" (fsindex)); asm("movl %%gs,%0" : "=r" (gsindex)); rdmsrl(MSR_FS_BASE, fs); - rdmsrl(MSR_GS_BASE, gs); - rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); + rdmsrl(MSR_GS_BASE, gs); + rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); + + if (!all) + return; cr0 = read_cr0(); cr2 = read_cr2(); cr3 = read_cr3(); cr4 = read_cr4(); - printk("FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", - fs,fsindex,gs,gsindex,shadowgs); - printk("CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, es, cr0); - printk("CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, cr4); + printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", + fs, fsindex, gs, gsindex, shadowgs); + printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, + es, cr0); + printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, + cr4); get_debugreg(d0, 0); get_debugreg(d1, 1); get_debugreg(d2, 2); - printk("DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); get_debugreg(d3, 3); get_debugreg(d6, 6); get_debugreg(d7, 7); - printk("DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); -} - -void show_regs(struct pt_regs *regs) -{ - printk("CPU %d:", smp_processor_id()); - __show_regs(regs); - show_trace(NULL, regs, (void *)(regs + 1), regs->bp); -} - -/* - * Free current thread data structures etc.. - */ -void exit_thread(void) -{ - struct task_struct *me = current; - struct thread_struct *t = &me->thread; - - if (me->thread.io_bitmap_ptr) { - struct tss_struct *tss = &per_cpu(init_tss, get_cpu()); - kfree(t->io_bitmap_ptr); - t->io_bitmap_ptr = NULL; - clear_thread_flag(TIF_IO_BITMAP); - /* - * Careful, clear this in the TSS too: - */ - memset(tss->io_bitmap, 0xff, t->io_bitmap_max); - t->io_bitmap_max = 0; - put_cpu(); - } -} + /* Only print out debug registers if they are in their non-default state. */ + if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) && + (d6 == DR6_RESERVED) && (d7 == 0x400)) + return; -void flush_thread(void) -{ - struct task_struct *tsk = current; + printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); + printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); - if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) { - clear_tsk_thread_flag(tsk, TIF_ABI_PENDING); - if (test_tsk_thread_flag(tsk, TIF_IA32)) { - clear_tsk_thread_flag(tsk, TIF_IA32); - } else { - set_tsk_thread_flag(tsk, TIF_IA32); - current_thread_info()->status |= TS_COMPAT; - } - } - clear_tsk_thread_flag(tsk, TIF_DEBUG); - - tsk->thread.debugreg0 = 0; - tsk->thread.debugreg1 = 0; - tsk->thread.debugreg2 = 0; - tsk->thread.debugreg3 = 0; - tsk->thread.debugreg6 = 0; - tsk->thread.debugreg7 = 0; - memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); - /* - * Forget coprocessor state.. - */ - clear_fpu(tsk); - clear_used_math(); } void release_thread(struct task_struct *dead_task) { if (dead_task->mm) { if (dead_task->mm->context.size) { - printk("WARNING: dead process %8s still has LDT? <%p/%d>\n", - dead_task->comm, - dead_task->mm->context.ldt, - dead_task->mm->context.size); + pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n", + dead_task->comm, + dead_task->mm->context.ldt, + dead_task->mm->context.size); BUG(); } } @@ -479,54 +151,57 @@ static inline u32 read_32bit_tls(struct task_struct *t, int tls) return get_desc_base(&t->thread.tls_array[tls]); } -/* - * This gets called before we allocate a new thread and copy - * the current task into it. - */ -void prepare_to_copy(struct task_struct *tsk) -{ - unlazy_fpu(tsk); -} - -int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, - unsigned long unused, - struct task_struct * p, struct pt_regs * regs) +int copy_thread(unsigned long clone_flags, unsigned long sp, + unsigned long arg, struct task_struct *p) { int err; - struct pt_regs * childregs; + struct pt_regs *childregs; struct task_struct *me = current; - childregs = ((struct pt_regs *) - (THREAD_SIZE + task_stack_page(p))) - 1; - *childregs = *regs; - - childregs->ax = 0; - childregs->sp = sp; - if (sp == ~0UL) - childregs->sp = (unsigned long)childregs; - + p->thread.sp0 = (unsigned long)task_stack_page(p) + THREAD_SIZE; + childregs = task_pt_regs(p); p->thread.sp = (unsigned long) childregs; - p->thread.sp0 = (unsigned long) (childregs+1); p->thread.usersp = me->thread.usersp; - set_tsk_thread_flag(p, TIF_FORK); + p->thread.fpu_counter = 0; + p->thread.io_bitmap_ptr = NULL; + + savesegment(gs, p->thread.gsindex); + p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs; + savesegment(fs, p->thread.fsindex); + p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs; + savesegment(es, p->thread.es); + savesegment(ds, p->thread.ds); + memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); + + if (unlikely(p->flags & PF_KTHREAD)) { + /* kernel thread */ + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->sp = (unsigned long)childregs; + childregs->ss = __KERNEL_DS; + childregs->bx = sp; /* function */ + childregs->bp = arg; + childregs->orig_ax = -1; + childregs->cs = __KERNEL_CS | get_kernel_rpl(); + childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED; + return 0; + } + *childregs = *current_pt_regs(); - p->thread.fs = me->thread.fs; - p->thread.gs = me->thread.gs; + childregs->ax = 0; + if (sp) + childregs->sp = sp; - asm("mov %%gs,%0" : "=m" (p->thread.gsindex)); - asm("mov %%fs,%0" : "=m" (p->thread.fsindex)); - asm("mov %%es,%0" : "=m" (p->thread.es)); - asm("mov %%ds,%0" : "=m" (p->thread.ds)); + err = -ENOMEM; + memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) { - p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); + p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr, + IO_BITMAP_BYTES, GFP_KERNEL); if (!p->thread.io_bitmap_ptr) { p->thread.io_bitmap_max = 0; return -ENOMEM; } - memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, - IO_BITMAP_BYTES); set_tsk_thread_flag(p, TIF_IO_BITMAP); } @@ -538,10 +213,10 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, if (test_thread_flag(TIF_IA32)) err = do_set_thread_area(p, -1, (struct user_desc __user *)childregs->si, 0); - else -#endif - err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); - if (err) + else +#endif + err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); + if (err) goto out; } err = 0; @@ -550,68 +225,44 @@ out: kfree(p->thread.io_bitmap_ptr); p->thread.io_bitmap_max = 0; } + return err; } -/* - * This special macro can be used to load a debugging register - */ -#define loaddebug(thread, r) set_debugreg(thread->debugreg ## r, r) - -static inline void __switch_to_xtra(struct task_struct *prev_p, - struct task_struct *next_p, - struct tss_struct *tss) +static void +start_thread_common(struct pt_regs *regs, unsigned long new_ip, + unsigned long new_sp, + unsigned int _cs, unsigned int _ss, unsigned int _ds) { - struct thread_struct *prev, *next; - unsigned long debugctl; - - prev = &prev_p->thread, - next = &next_p->thread; - - debugctl = prev->debugctlmsr; - if (next->ds_area_msr != prev->ds_area_msr) { - /* we clear debugctl to make sure DS - * is not in use when we change it */ - debugctl = 0; - wrmsrl(MSR_IA32_DEBUGCTLMSR, 0); - wrmsrl(MSR_IA32_DS_AREA, next->ds_area_msr); - } - - if (next->debugctlmsr != debugctl) - wrmsrl(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr); - - if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { - loaddebug(next, 0); - loaddebug(next, 1); - loaddebug(next, 2); - loaddebug(next, 3); - /* no 4 and 5 */ - loaddebug(next, 6); - loaddebug(next, 7); - } - - if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) { - /* - * Copy the relevant range of the IO bitmap. - * Normally this is 128 bytes or less: - */ - memcpy(tss->io_bitmap, next->io_bitmap_ptr, - max(prev->io_bitmap_max, next->io_bitmap_max)); - } else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) { - /* - * Clear any possible leftover bits: - */ - memset(tss->io_bitmap, 0xff, prev->io_bitmap_max); - } + loadsegment(fs, 0); + loadsegment(es, _ds); + loadsegment(ds, _ds); + load_gs_index(0); + current->thread.usersp = new_sp; + regs->ip = new_ip; + regs->sp = new_sp; + this_cpu_write(old_rsp, new_sp); + regs->cs = _cs; + regs->ss = _ss; + regs->flags = X86_EFLAGS_IF; +} -#ifdef X86_BTS - if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS)) - ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS); +void +start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) +{ + start_thread_common(regs, new_ip, new_sp, + __USER_CS, __USER_DS, 0); +} - if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS)) - ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES); -#endif +#ifdef CONFIG_IA32_EMULATION +void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp) +{ + start_thread_common(regs, new_ip, new_sp, + test_thread_flag(TIF_X32) + ? __USER_CS : __USER32_CS, + __USER_DS, __USER_DS); } +#endif /* * switch_to(x,y) should switch tasks from x to y. @@ -621,95 +272,108 @@ static inline void __switch_to_xtra(struct task_struct *prev_p, * - could test fs/gs bitsliced * * Kprobes not supported here. Set the probe on schedule instead. + * Function graph tracer not supported too. */ -struct task_struct * +__visible __notrace_funcgraph struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct *next_p) { - struct thread_struct *prev = &prev_p->thread, - *next = &next_p->thread; + struct thread_struct *prev = &prev_p->thread; + struct thread_struct *next = &next_p->thread; int cpu = smp_processor_id(); struct tss_struct *tss = &per_cpu(init_tss, cpu); + unsigned fsindex, gsindex; + fpu_switch_t fpu; - /* we're going to use this soon, after a few expensive things */ - if (next_p->fpu_counter>5) - prefetch(&next->i387.fxsave); + fpu = switch_fpu_prepare(prev_p, next_p, cpu); /* * Reload esp0, LDT and the page table pointer: */ load_sp0(tss, next); - /* + /* * Switch DS and ES. * This won't pick up thread selector changes, but I guess that is ok. */ - asm volatile("mov %%es,%0" : "=m" (prev->es)); + savesegment(es, prev->es); if (unlikely(next->es | prev->es)) - loadsegment(es, next->es); - - asm volatile ("mov %%ds,%0" : "=m" (prev->ds)); + loadsegment(es, next->es); + + savesegment(ds, prev->ds); if (unlikely(next->ds | prev->ds)) loadsegment(ds, next->ds); + + /* We must save %fs and %gs before load_TLS() because + * %fs and %gs may be cleared by load_TLS(). + * + * (e.g. xen_load_tls()) + */ + savesegment(fs, fsindex); + savesegment(gs, gsindex); + load_TLS(next, cpu); - /* + /* + * Leave lazy mode, flushing any hypercalls made here. + * This must be done before restoring TLS segments so + * the GDT and LDT are properly updated, and must be + * done before math_state_restore, so the TS bit is up + * to date. + */ + arch_end_context_switch(next_p); + + /* * Switch FS and GS. + * + * Segment register != 0 always requires a reload. Also + * reload when it has changed. When prev process used 64bit + * base always reload to avoid an information leak. */ - { - unsigned fsindex; - asm volatile("movl %%fs,%0" : "=r" (fsindex)); - /* segment register != 0 always requires a reload. - also reload when it has changed. - when prev process used 64bit base always reload - to avoid an information leak. */ - if (unlikely(fsindex | next->fsindex | prev->fs)) { - loadsegment(fs, next->fsindex); - /* check if the user used a selector != 0 - * if yes clear 64bit base, since overloaded base - * is always mapped to the Null selector - */ - if (fsindex) - prev->fs = 0; - } - /* when next process has a 64bit base use it */ - if (next->fs) - wrmsrl(MSR_FS_BASE, next->fs); - prev->fsindex = fsindex; + if (unlikely(fsindex | next->fsindex | prev->fs)) { + loadsegment(fs, next->fsindex); + /* + * Check if the user used a selector != 0; if yes + * clear 64bit base, since overloaded base is always + * mapped to the Null selector + */ + if (fsindex) + prev->fs = 0; } - { - unsigned gsindex; - asm volatile("movl %%gs,%0" : "=r" (gsindex)); - if (unlikely(gsindex | next->gsindex | prev->gs)) { - load_gs_index(next->gsindex); - if (gsindex) - prev->gs = 0; - } - if (next->gs) - wrmsrl(MSR_KERNEL_GS_BASE, next->gs); - prev->gsindex = gsindex; + /* when next process has a 64bit base use it */ + if (next->fs) + wrmsrl(MSR_FS_BASE, next->fs); + prev->fsindex = fsindex; + + if (unlikely(gsindex | next->gsindex | prev->gs)) { + load_gs_index(next->gsindex); + if (gsindex) + prev->gs = 0; } + if (next->gs) + wrmsrl(MSR_KERNEL_GS_BASE, next->gs); + prev->gsindex = gsindex; - /* Must be after DS reload */ - unlazy_fpu(prev_p); + switch_fpu_finish(next_p, fpu); - /* + /* * Switch the PDA and FPU contexts. */ - prev->usersp = read_pda(oldrsp); - write_pda(oldrsp, next->usersp); - write_pda(pcurrent, next_p); - - write_pda(kernelstack, - (unsigned long)task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET); -#ifdef CONFIG_CC_STACKPROTECTOR - write_pda(stack_canary, next_p->stack_canary); + prev->usersp = this_cpu_read(old_rsp); + this_cpu_write(old_rsp, next->usersp); + this_cpu_write(current_task, next_p); + /* - * Build time only check to make sure the stack_canary is at - * offset 40 in the pda; this is a gcc ABI requirement + * If it were not for PREEMPT_ACTIVE we could guarantee that the + * preempt_count of all tasks was equal here and this would not be + * needed. */ - BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40); -#endif + task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count); + this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count); + + this_cpu_write(kernel_stack, + (unsigned long)task_stack_page(next_p) + + THREAD_SIZE - KERNEL_STACK_OFFSET); /* * Now maybe reload the debug registers and handle I/O bitmaps @@ -718,40 +382,21 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) __switch_to_xtra(prev_p, next_p, tss); - /* If the task has used fpu the last 5 timeslices, just do a full - * restore of the math state immediately to avoid the trap; the - * chances of needing FPU soon are obviously high now - */ - if (next_p->fpu_counter>5) - math_state_restore(); return prev_p; } -/* - * sys_execve() executes a new program. - */ -asmlinkage -long sys_execve(char __user *name, char __user * __user *argv, - char __user * __user *envp, struct pt_regs *regs) -{ - long error; - char * filename; - - filename = getname(name); - error = PTR_ERR(filename); - if (IS_ERR(filename)) - return error; - error = do_execve(filename, argv, envp, regs); - putname(filename); - return error; -} - void set_personality_64bit(void) { /* inherit personality from parent */ /* Make sure to be in 64bit mode */ clear_thread_flag(TIF_IA32); + clear_thread_flag(TIF_ADDR32); + clear_thread_flag(TIF_X32); + + /* Ensure the corresponding mm is not marked. */ + if (current->mm) + current->mm->context.ia32_compat = 0; /* TBD: overwrites user setup. Should have two bits. But 64bit processes have always behaved this way, @@ -760,88 +405,87 @@ void set_personality_64bit(void) current->personality &= ~READ_IMPLIES_EXEC; } -asmlinkage long sys_fork(struct pt_regs *regs) +void set_personality_ia32(bool x32) { - return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); -} - -asmlinkage long -sys_clone(unsigned long clone_flags, unsigned long newsp, - void __user *parent_tid, void __user *child_tid, struct pt_regs *regs) -{ - if (!newsp) - newsp = regs->sp; - return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid); -} + /* inherit personality from parent */ -/* - * This is trivial, and on the face of it looks like it - * could equally well be done in user mode. - * - * Not so, for quite unobvious reasons - register pressure. - * In user mode vfork() cannot have a stack frame, and if - * done by calling the "clone()" system call directly, you - * do not have enough call-clobbered registers to hold all - * the information you need. - */ -asmlinkage long sys_vfork(struct pt_regs *regs) -{ - return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, - NULL, NULL); + /* Make sure to be in 32bit mode */ + set_thread_flag(TIF_ADDR32); + + /* Mark the associated mm as containing 32-bit tasks. */ + if (x32) { + clear_thread_flag(TIF_IA32); + set_thread_flag(TIF_X32); + if (current->mm) + current->mm->context.ia32_compat = TIF_X32; + current->personality &= ~READ_IMPLIES_EXEC; + /* is_compat_task() uses the presence of the x32 + syscall bit flag to determine compat status */ + current_thread_info()->status &= ~TS_COMPAT; + } else { + set_thread_flag(TIF_IA32); + clear_thread_flag(TIF_X32); + if (current->mm) + current->mm->context.ia32_compat = TIF_IA32; + current->personality |= force_personality32; + /* Prepare the first "return" to user space */ + current_thread_info()->status |= TS_COMPAT; + } } +EXPORT_SYMBOL_GPL(set_personality_ia32); unsigned long get_wchan(struct task_struct *p) { unsigned long stack; - u64 fp,ip; + u64 fp, ip; int count = 0; - if (!p || p == current || p->state==TASK_RUNNING) - return 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; stack = (unsigned long)task_stack_page(p); - if (p->thread.sp < stack || p->thread.sp > stack+THREAD_SIZE) + if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE) return 0; fp = *(u64 *)(p->thread.sp); - do { + do { if (fp < (unsigned long)stack || - fp > (unsigned long)stack+THREAD_SIZE) - return 0; + fp >= (unsigned long)stack+THREAD_SIZE) + return 0; ip = *(u64 *)(fp+8); if (!in_sched_functions(ip)) return ip; - fp = *(u64 *)fp; - } while (count++ < 16); + fp = *(u64 *)fp; + } while (count++ < 16); return 0; } long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) -{ - int ret = 0; +{ + int ret = 0; int doit = task == current; int cpu; - switch (code) { + switch (code) { case ARCH_SET_GS: if (addr >= TASK_SIZE_OF(task)) - return -EPERM; + return -EPERM; cpu = get_cpu(); - /* handle small bases via the GDT because that's faster to + /* handle small bases via the GDT because that's faster to switch. */ - if (addr <= 0xffffffff) { - set_32bit_tls(task, GS_TLS, addr); - if (doit) { + if (addr <= 0xffffffff) { + set_32bit_tls(task, GS_TLS, addr); + if (doit) { load_TLS(&task->thread, cpu); - load_gs_index(GS_TLS_SEL); + load_gs_index(GS_TLS_SEL); } - task->thread.gsindex = GS_TLS_SEL; + task->thread.gsindex = GS_TLS_SEL; task->thread.gs = 0; - } else { + } else { task->thread.gsindex = 0; task->thread.gs = addr; if (doit) { load_gs_index(0); - ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr); - } + ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr); + } } put_cpu(); break; @@ -857,7 +501,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) set_32bit_tls(task, FS_TLS, addr); if (doit) { load_TLS(&task->thread, cpu); - asm volatile("movl %0,%%fs" :: "r"(FS_TLS_SEL)); + loadsegment(fs, FS_TLS_SEL); } task->thread.fsindex = FS_TLS_SEL; task->thread.fs = 0; @@ -867,8 +511,8 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) if (doit) { /* set the selector to 0 to not confuse __switch_to */ - asm volatile("movl %0,%%fs" :: "r" (0)); - ret = checking_wrmsrl(MSR_FS_BASE, addr); + loadsegment(fs, 0); + ret = wrmsrl_safe(MSR_FS_BASE, addr); } } put_cpu(); @@ -890,13 +534,12 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) if (task->thread.gsindex == GS_TLS_SEL) base = read_32bit_tls(task, GS_TLS); else if (doit) { - asm("movl %%gs,%0" : "=r" (gsindex)); + savesegment(gs, gsindex); if (gsindex) rdmsrl(MSR_KERNEL_GS_BASE, base); else base = task->thread.gs; - } - else + } else base = task->thread.gs; ret = put_user(base, (unsigned long __user *)addr); break; @@ -915,15 +558,8 @@ long sys_arch_prctl(int code, unsigned long addr) return do_arch_prctl(current, code, addr); } -unsigned long arch_align_stack(unsigned long sp) -{ - if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) - sp -= get_random_int() % 8192; - return sp & ~0xf; -} - -unsigned long arch_randomize_brk(struct mm_struct *mm) +unsigned long KSTK_ESP(struct task_struct *task) { - unsigned long range_end = mm->brk + 0x02000000; - return randomize_range(mm->brk, range_end, 0) ? : mm->brk; + return (test_tsk_thread_flag(task, TIF_IA32)) ? + (task_pt_regs(task)->sp) : ((task)->thread.usersp); } |