diff options
Diffstat (limited to 'arch/i386/kernel/process.c')
| -rw-r--r-- | arch/i386/kernel/process.c | 114 |
1 files changed, 103 insertions, 11 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index 96e3ea6b17c7..e3f362e8af5b 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -13,6 +13,7 @@ #include <stdarg.h> +#include <linux/cpu.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/fs.h> @@ -37,6 +38,7 @@ #include <linux/kallsyms.h> #include <linux/ptrace.h> #include <linux/random.h> +#include <linux/kprobes.h> #include <asm/uaccess.h> #include <asm/pgtable.h> @@ -54,6 +56,9 @@ #include <linux/irq.h> #include <linux/err.h> +#include <asm/tlbflush.h> +#include <asm/cpu.h> + asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); static int hlt_counter; @@ -73,6 +78,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk) * Powermanagement idle function, if any.. */ void (*pm_idle)(void); +EXPORT_SYMBOL(pm_idle); static DEFINE_PER_CPU(unsigned int, cpu_idle_state); void disable_hlt(void) @@ -105,6 +111,9 @@ void default_idle(void) cpu_relax(); } } +#ifdef CONFIG_APM_MODULE +EXPORT_SYMBOL(default_idle); +#endif /* * On SMP it's slightly faster (but much more power-consuming!) @@ -138,14 +147,42 @@ static void poll_idle (void) } } +#ifdef CONFIG_HOTPLUG_CPU +#include <asm/nmi.h> +/* We don't actually take CPU down, just spin without interrupts. */ +static inline void play_dead(void) +{ + /* This must be done before dead CPU ack */ + cpu_exit_clear(); + wbinvd(); + mb(); + /* Ack it */ + __get_cpu_var(cpu_state) = CPU_DEAD; + + /* + * With physical CPU hotplug, we should halt the cpu + */ + local_irq_disable(); + while (1) + __asm__ __volatile__("hlt":::"memory"); +} +#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) +void cpu_idle(void) { + int cpu = raw_smp_processor_id(); + /* endless idle loop with no priority at all */ while (1) { while (!need_resched()) { @@ -160,6 +197,9 @@ void cpu_idle (void) if (!idle) idle = default_idle; + if (cpu_is_offline(cpu)) + play_dead(); + __get_cpu_var(irq_stat).idle_timestamp = jiffies; idle(); } @@ -218,7 +258,7 @@ static void mwait_idle(void) } } -void __init select_idle_routine(const struct cpuinfo_x86 *c) +void __devinit select_idle_routine(const struct cpuinfo_x86 *c) { if (cpu_has(c, X86_FEATURE_MWAIT)) { printk("monitor/mwait feature present.\n"); @@ -262,7 +302,7 @@ void show_regs(struct pt_regs * regs) printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id()); print_symbol("EIP is at %s\n", regs->eip); - if (regs->xcs & 3) + if (user_mode(regs)) printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp); printk(" EFLAGS: %08lx %s (%s)\n", regs->eflags, print_tainted(), system_utsname.release); @@ -325,6 +365,7 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) /* Ok, create the new process.. */ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } +EXPORT_SYMBOL(kernel_thread); /* * Free current thread data structures etc.. @@ -334,6 +375,13 @@ void exit_thread(void) struct task_struct *tsk = current; struct thread_struct *t = &tsk->thread; + /* + * Remove function-return probe instances associated with this task + * and put them back on the free list. Do not insert an exit probe for + * this function, it will be disabled by kprobe_flush_task if you do. + */ + kprobe_flush_task(tsk); + /* The process may have allocated an io port bitmap... nuke it. */ if (unlikely(NULL != t->io_bitmap_ptr)) { int cpu = get_cpu(); @@ -357,6 +405,13 @@ void flush_thread(void) { struct task_struct *tsk = current; + /* + * Remove function-return probe instances associated with this task + * and put them back on the free list. Do not insert an exit probe for + * this function, it will be disabled by kprobe_flush_task if you do. + */ + kprobe_flush_task(tsk); + memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8); memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); /* @@ -508,6 +563,7 @@ void dump_thread(struct pt_regs * regs, struct user * dump) dump->u_fpvalid = dump_fpu (regs, &dump->i387); } +EXPORT_SYMBOL(dump_thread); /* * Capture the user space registers if the task is not running (in user space) @@ -561,6 +617,33 @@ handle_io_bitmap(struct thread_struct *next, struct tss_struct *tss) } /* + * This function selects if the context switch from prev to next + * has to tweak the TSC disable bit in the cr4. + */ +static inline void disable_tsc(struct task_struct *prev_p, + struct task_struct *next_p) +{ + struct thread_info *prev, *next; + + /* + * gcc should eliminate the ->thread_info dereference if + * has_secure_computing returns 0 at compile time (SECCOMP=n). + */ + prev = prev_p->thread_info; + next = next_p->thread_info; + + if (has_secure_computing(prev) || has_secure_computing(next)) { + /* slow path here */ + if (has_secure_computing(prev) && + !has_secure_computing(next)) { + write_cr4(read_cr4() & ~X86_CR4_TSD); + } else if (!has_secure_computing(prev) && + has_secure_computing(next)) + write_cr4(read_cr4() | X86_CR4_TSD); + } +} + +/* * switch_to(x,yn) should switch tasks from x to y. * * We fsave/fwait so that an exception goes off at the right time @@ -617,28 +700,34 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas /* * Restore %fs and %gs if needed. + * + * Glibc normally makes %fs be zero, and %gs is one of + * the TLS segments. */ - if (unlikely(prev->fs | prev->gs | next->fs | next->gs)) { + if (unlikely(prev->fs | next->fs)) loadsegment(fs, next->fs); + + if (prev->gs | next->gs) loadsegment(gs, next->gs); - } /* * Now maybe reload the debug registers */ if (unlikely(next->debugreg[7])) { - loaddebug(next, 0); - loaddebug(next, 1); - loaddebug(next, 2); - loaddebug(next, 3); + set_debugreg(next->debugreg[0], 0); + set_debugreg(next->debugreg[1], 1); + set_debugreg(next->debugreg[2], 2); + set_debugreg(next->debugreg[3], 3); /* no 4 and 5 */ - loaddebug(next, 6); - loaddebug(next, 7); + set_debugreg(next->debugreg[6], 6); + set_debugreg(next->debugreg[7], 7); } if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr)) handle_io_bitmap(next, tss); + disable_tsc(prev_p, next_p); + return prev_p; } @@ -731,6 +820,7 @@ unsigned long get_wchan(struct task_struct *p) } while (count++ < 16); return 0; } +EXPORT_SYMBOL(get_wchan); /* * sys_alloc_thread_area: get a yet unused TLS descriptor index. @@ -827,6 +917,8 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info) if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) return -EINVAL; + memset(&info, 0, sizeof(info)); + desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; info.entry_number = idx; |