Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1995 Linus Torvalds |
3 | * | |
4 | * Pentium III FXSR, SSE support | |
5 | * Gareth Hughes <gareth@valinux.com>, May 2000 | |
6612538c | 6 | * |
1da177e4 LT |
7 | * X86-64 port |
8 | * Andi Kleen. | |
76e4f660 AR |
9 | * |
10 | * CPU hotplug support - ashok.raj@intel.com | |
1da177e4 LT |
11 | */ |
12 | ||
13 | /* | |
14 | * This file handles the architecture-dependent parts of process handling.. | |
15 | */ | |
16 | ||
17 | #include <stdarg.h> | |
18 | ||
76e4f660 | 19 | #include <linux/cpu.h> |
1da177e4 LT |
20 | #include <linux/errno.h> |
21 | #include <linux/sched.h> | |
6612538c | 22 | #include <linux/fs.h> |
1da177e4 LT |
23 | #include <linux/kernel.h> |
24 | #include <linux/mm.h> | |
25 | #include <linux/elfcore.h> | |
26 | #include <linux/smp.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/user.h> | |
1da177e4 | 29 | #include <linux/interrupt.h> |
6612538c | 30 | #include <linux/utsname.h> |
1da177e4 | 31 | #include <linux/delay.h> |
6612538c | 32 | #include <linux/module.h> |
1da177e4 | 33 | #include <linux/ptrace.h> |
1da177e4 | 34 | #include <linux/random.h> |
95833c83 | 35 | #include <linux/notifier.h> |
c6fd91f0 | 36 | #include <linux/kprobes.h> |
1eeb66a1 | 37 | #include <linux/kdebug.h> |
02290683 | 38 | #include <linux/tick.h> |
529e25f6 | 39 | #include <linux/prctl.h> |
1da177e4 LT |
40 | |
41 | #include <asm/uaccess.h> | |
42 | #include <asm/pgtable.h> | |
43 | #include <asm/system.h> | |
44 | #include <asm/io.h> | |
45 | #include <asm/processor.h> | |
46 | #include <asm/i387.h> | |
47 | #include <asm/mmu_context.h> | |
48 | #include <asm/pda.h> | |
49 | #include <asm/prctl.h> | |
1da177e4 LT |
50 | #include <asm/desc.h> |
51 | #include <asm/proto.h> | |
52 | #include <asm/ia32.h> | |
95833c83 | 53 | #include <asm/idle.h> |
1da177e4 LT |
54 | |
55 | asmlinkage extern void ret_from_fork(void); | |
56 | ||
57 | unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED; | |
58 | ||
1da177e4 LT |
59 | unsigned long boot_option_idle_override = 0; |
60 | EXPORT_SYMBOL(boot_option_idle_override); | |
61 | ||
62 | /* | |
63 | * Powermanagement idle function, if any.. | |
64 | */ | |
65 | void (*pm_idle)(void); | |
2ee60e17 | 66 | EXPORT_SYMBOL(pm_idle); |
1da177e4 | 67 | |
e041c683 | 68 | static ATOMIC_NOTIFIER_HEAD(idle_notifier); |
95833c83 AK |
69 | |
70 | void idle_notifier_register(struct notifier_block *n) | |
71 | { | |
e041c683 | 72 | atomic_notifier_chain_register(&idle_notifier, n); |
95833c83 | 73 | } |
95833c83 | 74 | |
95833c83 AK |
75 | void enter_idle(void) |
76 | { | |
a15da49d | 77 | write_pda(isidle, 1); |
e041c683 | 78 | atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL); |
95833c83 AK |
79 | } |
80 | ||
81 | static void __exit_idle(void) | |
82 | { | |
9446868b | 83 | if (test_and_clear_bit_pda(0, isidle) == 0) |
a15da49d | 84 | return; |
e041c683 | 85 | atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL); |
95833c83 AK |
86 | } |
87 | ||
88 | /* Called from interrupts to signify idle end */ | |
89 | void exit_idle(void) | |
90 | { | |
a15da49d AK |
91 | /* idle loop has pid 0 */ |
92 | if (current->pid) | |
95833c83 AK |
93 | return; |
94 | __exit_idle(); | |
95 | } | |
96 | ||
1da177e4 LT |
97 | /* |
98 | * We use this if we don't have any better | |
99 | * idle routine.. | |
100 | */ | |
d8954222 | 101 | void default_idle(void) |
1da177e4 | 102 | { |
495ab9c0 | 103 | current_thread_info()->status &= ~TS_POLLING; |
0888f06a IM |
104 | /* |
105 | * TS_POLLING-cleared state must be visible before we | |
106 | * test NEED_RESCHED: | |
107 | */ | |
108 | smp_mb(); | |
7f424a8b | 109 | if (!need_resched()) |
5ee613b6 | 110 | safe_halt(); /* enables interrupts racelessly */ |
7f424a8b PZ |
111 | else |
112 | local_irq_enable(); | |
495ab9c0 | 113 | current_thread_info()->status |= TS_POLLING; |
1da177e4 LT |
114 | } |
115 | ||
76e4f660 AR |
116 | #ifdef CONFIG_HOTPLUG_CPU |
117 | DECLARE_PER_CPU(int, cpu_state); | |
118 | ||
119 | #include <asm/nmi.h> | |
1fa744e6 | 120 | /* We halt the CPU with physical CPU hotplug */ |
76e4f660 AR |
121 | static inline void play_dead(void) |
122 | { | |
123 | idle_task_exit(); | |
124 | wbinvd(); | |
125 | mb(); | |
126 | /* Ack it */ | |
127 | __get_cpu_var(cpu_state) = CPU_DEAD; | |
128 | ||
1fa744e6 | 129 | local_irq_disable(); |
76e4f660 | 130 | while (1) |
1fa744e6 | 131 | halt(); |
76e4f660 AR |
132 | } |
133 | #else | |
134 | static inline void play_dead(void) | |
135 | { | |
136 | BUG(); | |
137 | } | |
138 | #endif /* CONFIG_HOTPLUG_CPU */ | |
139 | ||
1da177e4 LT |
140 | /* |
141 | * The idle thread. There's no useful work to be | |
142 | * done, so just try to conserve power and have a | |
143 | * low exit latency (ie sit in a loop waiting for | |
144 | * somebody to say that they'd like to reschedule) | |
145 | */ | |
b10db7f0 | 146 | void cpu_idle(void) |
1da177e4 | 147 | { |
495ab9c0 | 148 | current_thread_info()->status |= TS_POLLING; |
1da177e4 LT |
149 | /* endless idle loop with no priority at all */ |
150 | while (1) { | |
3d97775a | 151 | tick_nohz_stop_sched_tick(); |
1da177e4 LT |
152 | while (!need_resched()) { |
153 | void (*idle)(void); | |
154 | ||
1da177e4 LT |
155 | rmb(); |
156 | idle = pm_idle; | |
157 | if (!idle) | |
158 | idle = default_idle; | |
76e4f660 AR |
159 | if (cpu_is_offline(smp_processor_id())) |
160 | play_dead(); | |
d331e739 VP |
161 | /* |
162 | * Idle routines should keep interrupts disabled | |
163 | * from here on, until they go to idle. | |
164 | * Otherwise, idle callbacks can misfire. | |
165 | */ | |
166 | local_irq_disable(); | |
95833c83 | 167 | enter_idle(); |
1da177e4 | 168 | idle(); |
a15da49d AK |
169 | /* In many cases the interrupt that ended idle |
170 | has already called exit_idle. But some idle | |
171 | loops can be woken up without interrupt. */ | |
95833c83 | 172 | __exit_idle(); |
1da177e4 LT |
173 | } |
174 | ||
02290683 | 175 | tick_nohz_restart_sched_tick(); |
5bfb5d69 | 176 | preempt_enable_no_resched(); |
1da177e4 | 177 | schedule(); |
5bfb5d69 | 178 | preempt_disable(); |
1da177e4 LT |
179 | } |
180 | } | |
181 | ||
6612538c | 182 | /* Prints also some state that isn't saved in the pt_regs */ |
1da177e4 LT |
183 | void __show_regs(struct pt_regs * regs) |
184 | { | |
185 | unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs; | |
bb1995d5 | 186 | unsigned long d0, d1, d2, d3, d6, d7; |
6612538c HS |
187 | unsigned int fsindex, gsindex; |
188 | unsigned int ds, cs, es; | |
1da177e4 LT |
189 | |
190 | printk("\n"); | |
191 | print_modules(); | |
9acf23c4 AK |
192 | printk("Pid: %d, comm: %.20s %s %s %.*s\n", |
193 | current->pid, current->comm, print_tainted(), | |
96b644bd SH |
194 | init_utsname()->release, |
195 | (int)strcspn(init_utsname()->version, " "), | |
196 | init_utsname()->version); | |
65ea5b03 | 197 | printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip); |
aafbd7eb | 198 | printk_address(regs->ip, 1); |
65ea5b03 PA |
199 | printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->sp, |
200 | regs->flags); | |
1da177e4 | 201 | printk("RAX: %016lx RBX: %016lx RCX: %016lx\n", |
65ea5b03 | 202 | regs->ax, regs->bx, regs->cx); |
1da177e4 | 203 | printk("RDX: %016lx RSI: %016lx RDI: %016lx\n", |
65ea5b03 | 204 | regs->dx, regs->si, regs->di); |
1da177e4 | 205 | printk("RBP: %016lx R08: %016lx R09: %016lx\n", |
65ea5b03 | 206 | regs->bp, regs->r8, regs->r9); |
1da177e4 LT |
207 | printk("R10: %016lx R11: %016lx R12: %016lx\n", |
208 | regs->r10, regs->r11, regs->r12); | |
209 | printk("R13: %016lx R14: %016lx R15: %016lx\n", | |
210 | regs->r13, regs->r14, regs->r15); | |
211 | ||
212 | asm("movl %%ds,%0" : "=r" (ds)); | |
213 | asm("movl %%cs,%0" : "=r" (cs)); | |
214 | asm("movl %%es,%0" : "=r" (es)); | |
215 | asm("movl %%fs,%0" : "=r" (fsindex)); | |
216 | asm("movl %%gs,%0" : "=r" (gsindex)); | |
217 | ||
218 | rdmsrl(MSR_FS_BASE, fs); | |
219 | rdmsrl(MSR_GS_BASE, gs); | |
220 | rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); | |
221 | ||
f51c9452 GOC |
222 | cr0 = read_cr0(); |
223 | cr2 = read_cr2(); | |
224 | cr3 = read_cr3(); | |
225 | cr4 = read_cr4(); | |
1da177e4 LT |
226 | |
227 | printk("FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", | |
228 | fs,fsindex,gs,gsindex,shadowgs); | |
229 | printk("CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, es, cr0); | |
230 | printk("CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, cr4); | |
bb1995d5 AS |
231 | |
232 | get_debugreg(d0, 0); | |
233 | get_debugreg(d1, 1); | |
234 | get_debugreg(d2, 2); | |
235 | printk("DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); | |
236 | get_debugreg(d3, 3); | |
237 | get_debugreg(d6, 6); | |
238 | get_debugreg(d7, 7); | |
239 | printk("DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); | |
1da177e4 LT |
240 | } |
241 | ||
242 | void show_regs(struct pt_regs *regs) | |
243 | { | |
c078d326 | 244 | printk("CPU %d:", smp_processor_id()); |
1da177e4 | 245 | __show_regs(regs); |
bc850d6b | 246 | show_trace(NULL, regs, (void *)(regs + 1), regs->bp); |
1da177e4 LT |
247 | } |
248 | ||
249 | /* | |
250 | * Free current thread data structures etc.. | |
251 | */ | |
252 | void exit_thread(void) | |
253 | { | |
254 | struct task_struct *me = current; | |
255 | struct thread_struct *t = &me->thread; | |
73649dab | 256 | |
6612538c | 257 | if (me->thread.io_bitmap_ptr) { |
1da177e4 LT |
258 | struct tss_struct *tss = &per_cpu(init_tss, get_cpu()); |
259 | ||
260 | kfree(t->io_bitmap_ptr); | |
261 | t->io_bitmap_ptr = NULL; | |
d3a4f48d | 262 | clear_thread_flag(TIF_IO_BITMAP); |
1da177e4 LT |
263 | /* |
264 | * Careful, clear this in the TSS too: | |
265 | */ | |
266 | memset(tss->io_bitmap, 0xff, t->io_bitmap_max); | |
267 | t->io_bitmap_max = 0; | |
268 | put_cpu(); | |
269 | } | |
270 | } | |
271 | ||
272 | void flush_thread(void) | |
273 | { | |
274 | struct task_struct *tsk = current; | |
1da177e4 | 275 | |
303cd153 MD |
276 | if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) { |
277 | clear_tsk_thread_flag(tsk, TIF_ABI_PENDING); | |
278 | if (test_tsk_thread_flag(tsk, TIF_IA32)) { | |
279 | clear_tsk_thread_flag(tsk, TIF_IA32); | |
280 | } else { | |
281 | set_tsk_thread_flag(tsk, TIF_IA32); | |
4d9bc79c | 282 | current_thread_info()->status |= TS_COMPAT; |
303cd153 | 283 | } |
4d9bc79c | 284 | } |
303cd153 | 285 | clear_tsk_thread_flag(tsk, TIF_DEBUG); |
1da177e4 LT |
286 | |
287 | tsk->thread.debugreg0 = 0; | |
288 | tsk->thread.debugreg1 = 0; | |
289 | tsk->thread.debugreg2 = 0; | |
290 | tsk->thread.debugreg3 = 0; | |
291 | tsk->thread.debugreg6 = 0; | |
292 | tsk->thread.debugreg7 = 0; | |
6612538c | 293 | memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); |
1da177e4 LT |
294 | /* |
295 | * Forget coprocessor state.. | |
296 | */ | |
297 | clear_fpu(tsk); | |
298 | clear_used_math(); | |
299 | } | |
300 | ||
301 | void release_thread(struct task_struct *dead_task) | |
302 | { | |
303 | if (dead_task->mm) { | |
304 | if (dead_task->mm->context.size) { | |
305 | printk("WARNING: dead process %8s still has LDT? <%p/%d>\n", | |
306 | dead_task->comm, | |
307 | dead_task->mm->context.ldt, | |
308 | dead_task->mm->context.size); | |
309 | BUG(); | |
310 | } | |
311 | } | |
312 | } | |
313 | ||
314 | static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) | |
315 | { | |
6612538c | 316 | struct user_desc ud = { |
1da177e4 LT |
317 | .base_addr = addr, |
318 | .limit = 0xfffff, | |
319 | .seg_32bit = 1, | |
320 | .limit_in_pages = 1, | |
321 | .useable = 1, | |
322 | }; | |
ade1af77 | 323 | struct desc_struct *desc = t->thread.tls_array; |
1da177e4 | 324 | desc += tls; |
80fbb69a | 325 | fill_ldt(desc, &ud); |
1da177e4 LT |
326 | } |
327 | ||
328 | static inline u32 read_32bit_tls(struct task_struct *t, int tls) | |
329 | { | |
91394eb0 | 330 | return get_desc_base(&t->thread.tls_array[tls]); |
1da177e4 LT |
331 | } |
332 | ||
333 | /* | |
334 | * This gets called before we allocate a new thread and copy | |
335 | * the current task into it. | |
336 | */ | |
337 | void prepare_to_copy(struct task_struct *tsk) | |
338 | { | |
339 | unlazy_fpu(tsk); | |
340 | } | |
341 | ||
65ea5b03 | 342 | int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, |
1da177e4 LT |
343 | unsigned long unused, |
344 | struct task_struct * p, struct pt_regs * regs) | |
345 | { | |
346 | int err; | |
347 | struct pt_regs * childregs; | |
348 | struct task_struct *me = current; | |
349 | ||
a88cde13 | 350 | childregs = ((struct pt_regs *) |
57eafdc2 | 351 | (THREAD_SIZE + task_stack_page(p))) - 1; |
1da177e4 LT |
352 | *childregs = *regs; |
353 | ||
65ea5b03 PA |
354 | childregs->ax = 0; |
355 | childregs->sp = sp; | |
356 | if (sp == ~0UL) | |
357 | childregs->sp = (unsigned long)childregs; | |
1da177e4 | 358 | |
faca6227 PA |
359 | p->thread.sp = (unsigned long) childregs; |
360 | p->thread.sp0 = (unsigned long) (childregs+1); | |
361 | p->thread.usersp = me->thread.usersp; | |
1da177e4 | 362 | |
e4f17c43 | 363 | set_tsk_thread_flag(p, TIF_FORK); |
1da177e4 LT |
364 | |
365 | p->thread.fs = me->thread.fs; | |
366 | p->thread.gs = me->thread.gs; | |
367 | ||
fd51f666 L |
368 | asm("mov %%gs,%0" : "=m" (p->thread.gsindex)); |
369 | asm("mov %%fs,%0" : "=m" (p->thread.fsindex)); | |
370 | asm("mov %%es,%0" : "=m" (p->thread.es)); | |
371 | asm("mov %%ds,%0" : "=m" (p->thread.ds)); | |
1da177e4 | 372 | |
d3a4f48d | 373 | if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) { |
1da177e4 LT |
374 | p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); |
375 | if (!p->thread.io_bitmap_ptr) { | |
376 | p->thread.io_bitmap_max = 0; | |
377 | return -ENOMEM; | |
378 | } | |
a88cde13 AK |
379 | memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, |
380 | IO_BITMAP_BYTES); | |
d3a4f48d | 381 | set_tsk_thread_flag(p, TIF_IO_BITMAP); |
6612538c | 382 | } |
1da177e4 LT |
383 | |
384 | /* | |
385 | * Set a new TLS for the child thread? | |
386 | */ | |
387 | if (clone_flags & CLONE_SETTLS) { | |
388 | #ifdef CONFIG_IA32_EMULATION | |
389 | if (test_thread_flag(TIF_IA32)) | |
efd1ca52 | 390 | err = do_set_thread_area(p, -1, |
65ea5b03 | 391 | (struct user_desc __user *)childregs->si, 0); |
1da177e4 LT |
392 | else |
393 | #endif | |
394 | err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); | |
395 | if (err) | |
396 | goto out; | |
397 | } | |
398 | err = 0; | |
399 | out: | |
400 | if (err && p->thread.io_bitmap_ptr) { | |
401 | kfree(p->thread.io_bitmap_ptr); | |
402 | p->thread.io_bitmap_max = 0; | |
403 | } | |
404 | return err; | |
405 | } | |
406 | ||
513ad84b IM |
407 | void |
408 | start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) | |
409 | { | |
410 | asm volatile("movl %0, %%fs; movl %0, %%es; movl %0, %%ds" :: "r"(0)); | |
411 | load_gs_index(0); | |
412 | regs->ip = new_ip; | |
413 | regs->sp = new_sp; | |
414 | write_pda(oldrsp, new_sp); | |
415 | regs->cs = __USER_CS; | |
416 | regs->ss = __USER_DS; | |
417 | regs->flags = 0x200; | |
418 | set_fs(USER_DS); | |
aa283f49 SS |
419 | /* |
420 | * Free the old FP and other extended state | |
421 | */ | |
422 | free_thread_xstate(current); | |
513ad84b IM |
423 | } |
424 | EXPORT_SYMBOL_GPL(start_thread); | |
425 | ||
529e25f6 EB |
426 | static void hard_disable_TSC(void) |
427 | { | |
428 | write_cr4(read_cr4() | X86_CR4_TSD); | |
429 | } | |
430 | ||
431 | void disable_TSC(void) | |
432 | { | |
433 | preempt_disable(); | |
434 | if (!test_and_set_thread_flag(TIF_NOTSC)) | |
435 | /* | |
436 | * Must flip the CPU state synchronously with | |
437 | * TIF_NOTSC in the current running context. | |
438 | */ | |
439 | hard_disable_TSC(); | |
440 | preempt_enable(); | |
441 | } | |
442 | ||
443 | static void hard_enable_TSC(void) | |
444 | { | |
445 | write_cr4(read_cr4() & ~X86_CR4_TSD); | |
446 | } | |
447 | ||
a4928cff | 448 | static void enable_TSC(void) |
529e25f6 EB |
449 | { |
450 | preempt_disable(); | |
451 | if (test_and_clear_thread_flag(TIF_NOTSC)) | |
452 | /* | |
453 | * Must flip the CPU state synchronously with | |
454 | * TIF_NOTSC in the current running context. | |
455 | */ | |
456 | hard_enable_TSC(); | |
457 | preempt_enable(); | |
458 | } | |
459 | ||
460 | int get_tsc_mode(unsigned long adr) | |
461 | { | |
462 | unsigned int val; | |
463 | ||
464 | if (test_thread_flag(TIF_NOTSC)) | |
465 | val = PR_TSC_SIGSEGV; | |
466 | else | |
467 | val = PR_TSC_ENABLE; | |
468 | ||
469 | return put_user(val, (unsigned int __user *)adr); | |
470 | } | |
471 | ||
472 | int set_tsc_mode(unsigned int val) | |
473 | { | |
474 | if (val == PR_TSC_SIGSEGV) | |
475 | disable_TSC(); | |
476 | else if (val == PR_TSC_ENABLE) | |
477 | enable_TSC(); | |
478 | else | |
479 | return -EINVAL; | |
480 | ||
481 | return 0; | |
482 | } | |
483 | ||
1da177e4 LT |
484 | /* |
485 | * This special macro can be used to load a debugging register | |
486 | */ | |
6612538c HS |
487 | #define loaddebug(thread, r) set_debugreg(thread->debugreg ## r, r) |
488 | ||
d3a4f48d | 489 | static inline void __switch_to_xtra(struct task_struct *prev_p, |
6612538c HS |
490 | struct task_struct *next_p, |
491 | struct tss_struct *tss) | |
d3a4f48d SE |
492 | { |
493 | struct thread_struct *prev, *next; | |
eee3af4a | 494 | unsigned long debugctl; |
d3a4f48d SE |
495 | |
496 | prev = &prev_p->thread, | |
497 | next = &next_p->thread; | |
498 | ||
eee3af4a MM |
499 | debugctl = prev->debugctlmsr; |
500 | if (next->ds_area_msr != prev->ds_area_msr) { | |
501 | /* we clear debugctl to make sure DS | |
502 | * is not in use when we change it */ | |
503 | debugctl = 0; | |
5b0e5084 | 504 | update_debugctlmsr(0); |
eee3af4a MM |
505 | wrmsrl(MSR_IA32_DS_AREA, next->ds_area_msr); |
506 | } | |
507 | ||
508 | if (next->debugctlmsr != debugctl) | |
5b0e5084 | 509 | update_debugctlmsr(next->debugctlmsr); |
7e991604 | 510 | |
d3a4f48d SE |
511 | if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { |
512 | loaddebug(next, 0); | |
513 | loaddebug(next, 1); | |
514 | loaddebug(next, 2); | |
515 | loaddebug(next, 3); | |
516 | /* no 4 and 5 */ | |
517 | loaddebug(next, 6); | |
518 | loaddebug(next, 7); | |
519 | } | |
520 | ||
529e25f6 EB |
521 | if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^ |
522 | test_tsk_thread_flag(next_p, TIF_NOTSC)) { | |
523 | /* prev and next are different */ | |
524 | if (test_tsk_thread_flag(next_p, TIF_NOTSC)) | |
525 | hard_disable_TSC(); | |
526 | else | |
527 | hard_enable_TSC(); | |
528 | } | |
529 | ||
d3a4f48d SE |
530 | if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) { |
531 | /* | |
532 | * Copy the relevant range of the IO bitmap. | |
533 | * Normally this is 128 bytes or less: | |
534 | */ | |
535 | memcpy(tss->io_bitmap, next->io_bitmap_ptr, | |
536 | max(prev->io_bitmap_max, next->io_bitmap_max)); | |
537 | } else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) { | |
538 | /* | |
539 | * Clear any possible leftover bits: | |
540 | */ | |
541 | memset(tss->io_bitmap, 0xff, prev->io_bitmap_max); | |
542 | } | |
eee3af4a | 543 | |
b4ef95de | 544 | #ifdef X86_BTS |
eee3af4a MM |
545 | if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS)) |
546 | ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS); | |
547 | ||
548 | if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS)) | |
549 | ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES); | |
b4ef95de | 550 | #endif |
d3a4f48d SE |
551 | } |
552 | ||
1da177e4 LT |
553 | /* |
554 | * switch_to(x,y) should switch tasks from x to y. | |
555 | * | |
6612538c | 556 | * This could still be optimized: |
1da177e4 LT |
557 | * - fold all the options into a flag word and test it with a single test. |
558 | * - could test fs/gs bitsliced | |
099f318b AK |
559 | * |
560 | * Kprobes not supported here. Set the probe on schedule instead. | |
1da177e4 | 561 | */ |
f438d914 | 562 | struct task_struct * |
a88cde13 | 563 | __switch_to(struct task_struct *prev_p, struct task_struct *next_p) |
1da177e4 LT |
564 | { |
565 | struct thread_struct *prev = &prev_p->thread, | |
566 | *next = &next_p->thread; | |
6612538c | 567 | int cpu = smp_processor_id(); |
1da177e4 LT |
568 | struct tss_struct *tss = &per_cpu(init_tss, cpu); |
569 | ||
e07e23e1 AV |
570 | /* we're going to use this soon, after a few expensive things */ |
571 | if (next_p->fpu_counter>5) | |
61c4628b | 572 | prefetch(next->xstate); |
e07e23e1 | 573 | |
1da177e4 LT |
574 | /* |
575 | * Reload esp0, LDT and the page table pointer: | |
576 | */ | |
7818a1e0 | 577 | load_sp0(tss, next); |
1da177e4 LT |
578 | |
579 | /* | |
580 | * Switch DS and ES. | |
581 | * This won't pick up thread selector changes, but I guess that is ok. | |
582 | */ | |
fd51f666 | 583 | asm volatile("mov %%es,%0" : "=m" (prev->es)); |
1da177e4 LT |
584 | if (unlikely(next->es | prev->es)) |
585 | loadsegment(es, next->es); | |
586 | ||
fd51f666 | 587 | asm volatile ("mov %%ds,%0" : "=m" (prev->ds)); |
1da177e4 LT |
588 | if (unlikely(next->ds | prev->ds)) |
589 | loadsegment(ds, next->ds); | |
590 | ||
591 | load_TLS(next, cpu); | |
592 | ||
593 | /* | |
594 | * Switch FS and GS. | |
595 | */ | |
596 | { | |
597 | unsigned fsindex; | |
598 | asm volatile("movl %%fs,%0" : "=r" (fsindex)); | |
599 | /* segment register != 0 always requires a reload. | |
600 | also reload when it has changed. | |
601 | when prev process used 64bit base always reload | |
602 | to avoid an information leak. */ | |
603 | if (unlikely(fsindex | next->fsindex | prev->fs)) { | |
604 | loadsegment(fs, next->fsindex); | |
605 | /* check if the user used a selector != 0 | |
606 | * if yes clear 64bit base, since overloaded base | |
607 | * is always mapped to the Null selector | |
608 | */ | |
609 | if (fsindex) | |
610 | prev->fs = 0; | |
611 | } | |
612 | /* when next process has a 64bit base use it */ | |
613 | if (next->fs) | |
614 | wrmsrl(MSR_FS_BASE, next->fs); | |
615 | prev->fsindex = fsindex; | |
616 | } | |
617 | { | |
618 | unsigned gsindex; | |
619 | asm volatile("movl %%gs,%0" : "=r" (gsindex)); | |
620 | if (unlikely(gsindex | next->gsindex | prev->gs)) { | |
621 | load_gs_index(next->gsindex); | |
622 | if (gsindex) | |
623 | prev->gs = 0; | |
624 | } | |
625 | if (next->gs) | |
626 | wrmsrl(MSR_KERNEL_GS_BASE, next->gs); | |
627 | prev->gsindex = gsindex; | |
628 | } | |
629 | ||
0a5ace2a AK |
630 | /* Must be after DS reload */ |
631 | unlazy_fpu(prev_p); | |
632 | ||
1da177e4 | 633 | /* |
45948d77 | 634 | * Switch the PDA and FPU contexts. |
1da177e4 | 635 | */ |
faca6227 PA |
636 | prev->usersp = read_pda(oldrsp); |
637 | write_pda(oldrsp, next->usersp); | |
1da177e4 | 638 | write_pda(pcurrent, next_p); |
18bd057b | 639 | |
a88cde13 | 640 | write_pda(kernelstack, |
7b0bda74 | 641 | (unsigned long)task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET); |
0a425405 AV |
642 | #ifdef CONFIG_CC_STACKPROTECTOR |
643 | write_pda(stack_canary, next_p->stack_canary); | |
644 | /* | |
645 | * Build time only check to make sure the stack_canary is at | |
646 | * offset 40 in the pda; this is a gcc ABI requirement | |
647 | */ | |
648 | BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40); | |
649 | #endif | |
1da177e4 LT |
650 | |
651 | /* | |
d3a4f48d | 652 | * Now maybe reload the debug registers and handle I/O bitmaps |
1da177e4 | 653 | */ |
eee3af4a MM |
654 | if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT || |
655 | task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) | |
d3a4f48d | 656 | __switch_to_xtra(prev_p, next_p, tss); |
1da177e4 | 657 | |
e07e23e1 AV |
658 | /* If the task has used fpu the last 5 timeslices, just do a full |
659 | * restore of the math state immediately to avoid the trap; the | |
660 | * chances of needing FPU soon are obviously high now | |
661 | */ | |
662 | if (next_p->fpu_counter>5) | |
663 | math_state_restore(); | |
1da177e4 LT |
664 | return prev_p; |
665 | } | |
666 | ||
667 | /* | |
668 | * sys_execve() executes a new program. | |
669 | */ | |
6612538c | 670 | asmlinkage |
1da177e4 | 671 | long sys_execve(char __user *name, char __user * __user *argv, |
5d119b2c | 672 | char __user * __user *envp, struct pt_regs *regs) |
1da177e4 LT |
673 | { |
674 | long error; | |
675 | char * filename; | |
676 | ||
677 | filename = getname(name); | |
678 | error = PTR_ERR(filename); | |
5d119b2c | 679 | if (IS_ERR(filename)) |
1da177e4 | 680 | return error; |
5d119b2c | 681 | error = do_execve(filename, argv, envp, regs); |
1da177e4 LT |
682 | putname(filename); |
683 | return error; | |
684 | } | |
685 | ||
686 | void set_personality_64bit(void) | |
687 | { | |
688 | /* inherit personality from parent */ | |
689 | ||
690 | /* Make sure to be in 64bit mode */ | |
6612538c | 691 | clear_thread_flag(TIF_IA32); |
1da177e4 LT |
692 | |
693 | /* TBD: overwrites user setup. Should have two bits. | |
694 | But 64bit processes have always behaved this way, | |
695 | so it's not too bad. The main problem is just that | |
6612538c | 696 | 32bit childs are affected again. */ |
1da177e4 LT |
697 | current->personality &= ~READ_IMPLIES_EXEC; |
698 | } | |
699 | ||
700 | asmlinkage long sys_fork(struct pt_regs *regs) | |
701 | { | |
65ea5b03 | 702 | return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); |
1da177e4 LT |
703 | } |
704 | ||
a88cde13 AK |
705 | asmlinkage long |
706 | sys_clone(unsigned long clone_flags, unsigned long newsp, | |
707 | void __user *parent_tid, void __user *child_tid, struct pt_regs *regs) | |
1da177e4 LT |
708 | { |
709 | if (!newsp) | |
65ea5b03 | 710 | newsp = regs->sp; |
1da177e4 LT |
711 | return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid); |
712 | } | |
713 | ||
714 | /* | |
715 | * This is trivial, and on the face of it looks like it | |
716 | * could equally well be done in user mode. | |
717 | * | |
718 | * Not so, for quite unobvious reasons - register pressure. | |
719 | * In user mode vfork() cannot have a stack frame, and if | |
720 | * done by calling the "clone()" system call directly, you | |
721 | * do not have enough call-clobbered registers to hold all | |
722 | * the information you need. | |
723 | */ | |
724 | asmlinkage long sys_vfork(struct pt_regs *regs) | |
725 | { | |
65ea5b03 | 726 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, |
1da177e4 LT |
727 | NULL, NULL); |
728 | } | |
729 | ||
730 | unsigned long get_wchan(struct task_struct *p) | |
731 | { | |
732 | unsigned long stack; | |
65ea5b03 | 733 | u64 fp,ip; |
1da177e4 LT |
734 | int count = 0; |
735 | ||
736 | if (!p || p == current || p->state==TASK_RUNNING) | |
737 | return 0; | |
57eafdc2 | 738 | stack = (unsigned long)task_stack_page(p); |
faca6227 | 739 | if (p->thread.sp < stack || p->thread.sp > stack+THREAD_SIZE) |
1da177e4 | 740 | return 0; |
faca6227 | 741 | fp = *(u64 *)(p->thread.sp); |
1da177e4 | 742 | do { |
a88cde13 AK |
743 | if (fp < (unsigned long)stack || |
744 | fp > (unsigned long)stack+THREAD_SIZE) | |
1da177e4 | 745 | return 0; |
65ea5b03 PA |
746 | ip = *(u64 *)(fp+8); |
747 | if (!in_sched_functions(ip)) | |
748 | return ip; | |
1da177e4 LT |
749 | fp = *(u64 *)fp; |
750 | } while (count++ < 16); | |
751 | return 0; | |
752 | } | |
753 | ||
754 | long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) | |
755 | { | |
756 | int ret = 0; | |
757 | int doit = task == current; | |
758 | int cpu; | |
759 | ||
760 | switch (code) { | |
761 | case ARCH_SET_GS: | |
84929801 | 762 | if (addr >= TASK_SIZE_OF(task)) |
1da177e4 LT |
763 | return -EPERM; |
764 | cpu = get_cpu(); | |
765 | /* handle small bases via the GDT because that's faster to | |
766 | switch. */ | |
767 | if (addr <= 0xffffffff) { | |
768 | set_32bit_tls(task, GS_TLS, addr); | |
769 | if (doit) { | |
770 | load_TLS(&task->thread, cpu); | |
771 | load_gs_index(GS_TLS_SEL); | |
772 | } | |
773 | task->thread.gsindex = GS_TLS_SEL; | |
774 | task->thread.gs = 0; | |
775 | } else { | |
776 | task->thread.gsindex = 0; | |
777 | task->thread.gs = addr; | |
778 | if (doit) { | |
a88cde13 AK |
779 | load_gs_index(0); |
780 | ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr); | |
1da177e4 LT |
781 | } |
782 | } | |
783 | put_cpu(); | |
784 | break; | |
785 | case ARCH_SET_FS: | |
786 | /* Not strictly needed for fs, but do it for symmetry | |
787 | with gs */ | |
84929801 | 788 | if (addr >= TASK_SIZE_OF(task)) |
6612538c | 789 | return -EPERM; |
1da177e4 | 790 | cpu = get_cpu(); |
6612538c | 791 | /* handle small bases via the GDT because that's faster to |
1da177e4 | 792 | switch. */ |
6612538c | 793 | if (addr <= 0xffffffff) { |
1da177e4 | 794 | set_32bit_tls(task, FS_TLS, addr); |
6612538c HS |
795 | if (doit) { |
796 | load_TLS(&task->thread, cpu); | |
a88cde13 | 797 | asm volatile("movl %0,%%fs" :: "r"(FS_TLS_SEL)); |
1da177e4 LT |
798 | } |
799 | task->thread.fsindex = FS_TLS_SEL; | |
800 | task->thread.fs = 0; | |
6612538c | 801 | } else { |
1da177e4 LT |
802 | task->thread.fsindex = 0; |
803 | task->thread.fs = addr; | |
804 | if (doit) { | |
805 | /* set the selector to 0 to not confuse | |
806 | __switch_to */ | |
a88cde13 AK |
807 | asm volatile("movl %0,%%fs" :: "r" (0)); |
808 | ret = checking_wrmsrl(MSR_FS_BASE, addr); | |
1da177e4 LT |
809 | } |
810 | } | |
811 | put_cpu(); | |
812 | break; | |
6612538c HS |
813 | case ARCH_GET_FS: { |
814 | unsigned long base; | |
1da177e4 LT |
815 | if (task->thread.fsindex == FS_TLS_SEL) |
816 | base = read_32bit_tls(task, FS_TLS); | |
a88cde13 | 817 | else if (doit) |
1da177e4 | 818 | rdmsrl(MSR_FS_BASE, base); |
a88cde13 | 819 | else |
1da177e4 | 820 | base = task->thread.fs; |
6612538c HS |
821 | ret = put_user(base, (unsigned long __user *)addr); |
822 | break; | |
1da177e4 | 823 | } |
6612538c | 824 | case ARCH_GET_GS: { |
1da177e4 | 825 | unsigned long base; |
97c2803c | 826 | unsigned gsindex; |
1da177e4 LT |
827 | if (task->thread.gsindex == GS_TLS_SEL) |
828 | base = read_32bit_tls(task, GS_TLS); | |
97c2803c | 829 | else if (doit) { |
6612538c | 830 | asm("movl %%gs,%0" : "=r" (gsindex)); |
97c2803c JB |
831 | if (gsindex) |
832 | rdmsrl(MSR_KERNEL_GS_BASE, base); | |
833 | else | |
834 | base = task->thread.gs; | |
835 | } | |
a88cde13 | 836 | else |
1da177e4 | 837 | base = task->thread.gs; |
6612538c | 838 | ret = put_user(base, (unsigned long __user *)addr); |
1da177e4 LT |
839 | break; |
840 | } | |
841 | ||
842 | default: | |
843 | ret = -EINVAL; | |
844 | break; | |
6612538c | 845 | } |
1da177e4 | 846 | |
6612538c HS |
847 | return ret; |
848 | } | |
1da177e4 LT |
849 | |
850 | long sys_arch_prctl(int code, unsigned long addr) | |
851 | { | |
852 | return do_arch_prctl(current, code, addr); | |
1da177e4 LT |
853 | } |
854 | ||
855 | unsigned long arch_align_stack(unsigned long sp) | |
856 | { | |
c16b63e0 | 857 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
1da177e4 LT |
858 | sp -= get_random_int() % 8192; |
859 | return sp & ~0xf; | |
860 | } | |
c1d171a0 JK |
861 | |
862 | unsigned long arch_randomize_brk(struct mm_struct *mm) | |
863 | { | |
864 | unsigned long range_end = mm->brk + 0x02000000; | |
865 | return randomize_range(mm->brk, range_end, 0) ? : mm->brk; | |
866 | } |