| 1 | /* |
| 2 | * Copyright (C) 1995 Linus Torvalds |
| 3 | * |
| 4 | * Pentium III FXSR, SSE support |
| 5 | * Gareth Hughes <gareth@valinux.com>, May 2000 |
| 6 | * |
| 7 | * X86-64 port |
| 8 | * Andi Kleen. |
| 9 | * |
| 10 | * CPU hotplug support - ashok.raj@intel.com |
| 11 | */ |
| 12 | |
| 13 | /* |
| 14 | * This file handles the architecture-dependent parts of process handling.. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/cpu.h> |
| 18 | #include <linux/errno.h> |
| 19 | #include <linux/sched.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/elfcore.h> |
| 24 | #include <linux/smp.h> |
| 25 | #include <linux/slab.h> |
| 26 | #include <linux/user.h> |
| 27 | #include <linux/interrupt.h> |
| 28 | #include <linux/delay.h> |
| 29 | #include <linux/module.h> |
| 30 | #include <linux/ptrace.h> |
| 31 | #include <linux/notifier.h> |
| 32 | #include <linux/kprobes.h> |
| 33 | #include <linux/kdebug.h> |
| 34 | #include <linux/prctl.h> |
| 35 | #include <linux/uaccess.h> |
| 36 | #include <linux/io.h> |
| 37 | #include <linux/ftrace.h> |
| 38 | |
| 39 | #include <asm/pgtable.h> |
| 40 | #include <asm/processor.h> |
| 41 | #include <asm/i387.h> |
| 42 | #include <asm/fpu-internal.h> |
| 43 | #include <asm/mmu_context.h> |
| 44 | #include <asm/prctl.h> |
| 45 | #include <asm/desc.h> |
| 46 | #include <asm/proto.h> |
| 47 | #include <asm/ia32.h> |
| 48 | #include <asm/idle.h> |
| 49 | #include <asm/syscalls.h> |
| 50 | #include <asm/debugreg.h> |
| 51 | #include <asm/switch_to.h> |
| 52 | |
| 53 | asmlinkage extern void ret_from_fork(void); |
| 54 | |
| 55 | DEFINE_PER_CPU(unsigned long, old_rsp); |
| 56 | |
| 57 | /* Prints also some state that isn't saved in the pt_regs */ |
| 58 | void __show_regs(struct pt_regs *regs, int all) |
| 59 | { |
| 60 | unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs; |
| 61 | unsigned long d0, d1, d2, d3, d6, d7; |
| 62 | unsigned int fsindex, gsindex; |
| 63 | unsigned int ds, cs, es; |
| 64 | |
| 65 | show_regs_common(); |
| 66 | printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip); |
| 67 | printk_address(regs->ip, 1); |
| 68 | printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, |
| 69 | regs->sp, regs->flags); |
| 70 | printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n", |
| 71 | regs->ax, regs->bx, regs->cx); |
| 72 | printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n", |
| 73 | regs->dx, regs->si, regs->di); |
| 74 | printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n", |
| 75 | regs->bp, regs->r8, regs->r9); |
| 76 | printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n", |
| 77 | regs->r10, regs->r11, regs->r12); |
| 78 | printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n", |
| 79 | regs->r13, regs->r14, regs->r15); |
| 80 | |
| 81 | asm("movl %%ds,%0" : "=r" (ds)); |
| 82 | asm("movl %%cs,%0" : "=r" (cs)); |
| 83 | asm("movl %%es,%0" : "=r" (es)); |
| 84 | asm("movl %%fs,%0" : "=r" (fsindex)); |
| 85 | asm("movl %%gs,%0" : "=r" (gsindex)); |
| 86 | |
| 87 | rdmsrl(MSR_FS_BASE, fs); |
| 88 | rdmsrl(MSR_GS_BASE, gs); |
| 89 | rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); |
| 90 | |
| 91 | if (!all) |
| 92 | return; |
| 93 | |
| 94 | cr0 = read_cr0(); |
| 95 | cr2 = read_cr2(); |
| 96 | cr3 = read_cr3(); |
| 97 | cr4 = read_cr4(); |
| 98 | |
| 99 | printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", |
| 100 | fs, fsindex, gs, gsindex, shadowgs); |
| 101 | printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, |
| 102 | es, cr0); |
| 103 | printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, |
| 104 | cr4); |
| 105 | |
| 106 | get_debugreg(d0, 0); |
| 107 | get_debugreg(d1, 1); |
| 108 | get_debugreg(d2, 2); |
| 109 | printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); |
| 110 | get_debugreg(d3, 3); |
| 111 | get_debugreg(d6, 6); |
| 112 | get_debugreg(d7, 7); |
| 113 | printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); |
| 114 | } |
| 115 | |
| 116 | void release_thread(struct task_struct *dead_task) |
| 117 | { |
| 118 | if (dead_task->mm) { |
| 119 | if (dead_task->mm->context.size) { |
| 120 | pr_warn("WARNING: dead process %8s still has LDT? <%p/%d>\n", |
| 121 | dead_task->comm, |
| 122 | dead_task->mm->context.ldt, |
| 123 | dead_task->mm->context.size); |
| 124 | BUG(); |
| 125 | } |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) |
| 130 | { |
| 131 | struct user_desc ud = { |
| 132 | .base_addr = addr, |
| 133 | .limit = 0xfffff, |
| 134 | .seg_32bit = 1, |
| 135 | .limit_in_pages = 1, |
| 136 | .useable = 1, |
| 137 | }; |
| 138 | struct desc_struct *desc = t->thread.tls_array; |
| 139 | desc += tls; |
| 140 | fill_ldt(desc, &ud); |
| 141 | } |
| 142 | |
| 143 | static inline u32 read_32bit_tls(struct task_struct *t, int tls) |
| 144 | { |
| 145 | return get_desc_base(&t->thread.tls_array[tls]); |
| 146 | } |
| 147 | |
| 148 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
| 149 | unsigned long unused, |
| 150 | struct task_struct *p, struct pt_regs *regs) |
| 151 | { |
| 152 | int err; |
| 153 | struct pt_regs *childregs; |
| 154 | struct task_struct *me = current; |
| 155 | |
| 156 | childregs = ((struct pt_regs *) |
| 157 | (THREAD_SIZE + task_stack_page(p))) - 1; |
| 158 | *childregs = *regs; |
| 159 | |
| 160 | childregs->ax = 0; |
| 161 | if (user_mode(regs)) |
| 162 | childregs->sp = sp; |
| 163 | else |
| 164 | childregs->sp = (unsigned long)childregs; |
| 165 | |
| 166 | p->thread.sp = (unsigned long) childregs; |
| 167 | p->thread.sp0 = (unsigned long) (childregs+1); |
| 168 | p->thread.usersp = me->thread.usersp; |
| 169 | |
| 170 | set_tsk_thread_flag(p, TIF_FORK); |
| 171 | |
| 172 | p->fpu_counter = 0; |
| 173 | p->thread.io_bitmap_ptr = NULL; |
| 174 | |
| 175 | savesegment(gs, p->thread.gsindex); |
| 176 | p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs; |
| 177 | savesegment(fs, p->thread.fsindex); |
| 178 | p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs; |
| 179 | savesegment(es, p->thread.es); |
| 180 | savesegment(ds, p->thread.ds); |
| 181 | |
| 182 | err = -ENOMEM; |
| 183 | memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); |
| 184 | |
| 185 | if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) { |
| 186 | p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr, |
| 187 | IO_BITMAP_BYTES, GFP_KERNEL); |
| 188 | if (!p->thread.io_bitmap_ptr) { |
| 189 | p->thread.io_bitmap_max = 0; |
| 190 | return -ENOMEM; |
| 191 | } |
| 192 | set_tsk_thread_flag(p, TIF_IO_BITMAP); |
| 193 | } |
| 194 | |
| 195 | /* |
| 196 | * Set a new TLS for the child thread? |
| 197 | */ |
| 198 | if (clone_flags & CLONE_SETTLS) { |
| 199 | #ifdef CONFIG_IA32_EMULATION |
| 200 | if (test_thread_flag(TIF_IA32)) |
| 201 | err = do_set_thread_area(p, -1, |
| 202 | (struct user_desc __user *)childregs->si, 0); |
| 203 | else |
| 204 | #endif |
| 205 | err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); |
| 206 | if (err) |
| 207 | goto out; |
| 208 | } |
| 209 | err = 0; |
| 210 | out: |
| 211 | if (err && p->thread.io_bitmap_ptr) { |
| 212 | kfree(p->thread.io_bitmap_ptr); |
| 213 | p->thread.io_bitmap_max = 0; |
| 214 | } |
| 215 | |
| 216 | return err; |
| 217 | } |
| 218 | |
| 219 | static void |
| 220 | start_thread_common(struct pt_regs *regs, unsigned long new_ip, |
| 221 | unsigned long new_sp, |
| 222 | unsigned int _cs, unsigned int _ss, unsigned int _ds) |
| 223 | { |
| 224 | loadsegment(fs, 0); |
| 225 | loadsegment(es, _ds); |
| 226 | loadsegment(ds, _ds); |
| 227 | load_gs_index(0); |
| 228 | current->thread.usersp = new_sp; |
| 229 | regs->ip = new_ip; |
| 230 | regs->sp = new_sp; |
| 231 | this_cpu_write(old_rsp, new_sp); |
| 232 | regs->cs = _cs; |
| 233 | regs->ss = _ss; |
| 234 | regs->flags = X86_EFLAGS_IF; |
| 235 | /* |
| 236 | * Free the old FP and other extended state |
| 237 | */ |
| 238 | free_thread_xstate(current); |
| 239 | } |
| 240 | |
| 241 | void |
| 242 | start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) |
| 243 | { |
| 244 | start_thread_common(regs, new_ip, new_sp, |
| 245 | __USER_CS, __USER_DS, 0); |
| 246 | } |
| 247 | |
| 248 | #ifdef CONFIG_IA32_EMULATION |
| 249 | void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp) |
| 250 | { |
| 251 | start_thread_common(regs, new_ip, new_sp, |
| 252 | test_thread_flag(TIF_X32) |
| 253 | ? __USER_CS : __USER32_CS, |
| 254 | __USER_DS, __USER_DS); |
| 255 | } |
| 256 | #endif |
| 257 | |
| 258 | /* |
| 259 | * switch_to(x,y) should switch tasks from x to y. |
| 260 | * |
| 261 | * This could still be optimized: |
| 262 | * - fold all the options into a flag word and test it with a single test. |
| 263 | * - could test fs/gs bitsliced |
| 264 | * |
| 265 | * Kprobes not supported here. Set the probe on schedule instead. |
| 266 | * Function graph tracer not supported too. |
| 267 | */ |
| 268 | __notrace_funcgraph struct task_struct * |
| 269 | __switch_to(struct task_struct *prev_p, struct task_struct *next_p) |
| 270 | { |
| 271 | struct thread_struct *prev = &prev_p->thread; |
| 272 | struct thread_struct *next = &next_p->thread; |
| 273 | int cpu = smp_processor_id(); |
| 274 | struct tss_struct *tss = &per_cpu(init_tss, cpu); |
| 275 | unsigned fsindex, gsindex; |
| 276 | fpu_switch_t fpu; |
| 277 | |
| 278 | fpu = switch_fpu_prepare(prev_p, next_p, cpu); |
| 279 | |
| 280 | /* |
| 281 | * Reload esp0, LDT and the page table pointer: |
| 282 | */ |
| 283 | load_sp0(tss, next); |
| 284 | |
| 285 | /* |
| 286 | * Switch DS and ES. |
| 287 | * This won't pick up thread selector changes, but I guess that is ok. |
| 288 | */ |
| 289 | savesegment(es, prev->es); |
| 290 | if (unlikely(next->es | prev->es)) |
| 291 | loadsegment(es, next->es); |
| 292 | |
| 293 | savesegment(ds, prev->ds); |
| 294 | if (unlikely(next->ds | prev->ds)) |
| 295 | loadsegment(ds, next->ds); |
| 296 | |
| 297 | |
| 298 | /* We must save %fs and %gs before load_TLS() because |
| 299 | * %fs and %gs may be cleared by load_TLS(). |
| 300 | * |
| 301 | * (e.g. xen_load_tls()) |
| 302 | */ |
| 303 | savesegment(fs, fsindex); |
| 304 | savesegment(gs, gsindex); |
| 305 | |
| 306 | load_TLS(next, cpu); |
| 307 | |
| 308 | /* |
| 309 | * Leave lazy mode, flushing any hypercalls made here. |
| 310 | * This must be done before restoring TLS segments so |
| 311 | * the GDT and LDT are properly updated, and must be |
| 312 | * done before math_state_restore, so the TS bit is up |
| 313 | * to date. |
| 314 | */ |
| 315 | arch_end_context_switch(next_p); |
| 316 | |
| 317 | /* |
| 318 | * Switch FS and GS. |
| 319 | * |
| 320 | * Segment register != 0 always requires a reload. Also |
| 321 | * reload when it has changed. When prev process used 64bit |
| 322 | * base always reload to avoid an information leak. |
| 323 | */ |
| 324 | if (unlikely(fsindex | next->fsindex | prev->fs)) { |
| 325 | loadsegment(fs, next->fsindex); |
| 326 | /* |
| 327 | * Check if the user used a selector != 0; if yes |
| 328 | * clear 64bit base, since overloaded base is always |
| 329 | * mapped to the Null selector |
| 330 | */ |
| 331 | if (fsindex) |
| 332 | prev->fs = 0; |
| 333 | } |
| 334 | /* when next process has a 64bit base use it */ |
| 335 | if (next->fs) |
| 336 | wrmsrl(MSR_FS_BASE, next->fs); |
| 337 | prev->fsindex = fsindex; |
| 338 | |
| 339 | if (unlikely(gsindex | next->gsindex | prev->gs)) { |
| 340 | load_gs_index(next->gsindex); |
| 341 | if (gsindex) |
| 342 | prev->gs = 0; |
| 343 | } |
| 344 | if (next->gs) |
| 345 | wrmsrl(MSR_KERNEL_GS_BASE, next->gs); |
| 346 | prev->gsindex = gsindex; |
| 347 | |
| 348 | switch_fpu_finish(next_p, fpu); |
| 349 | |
| 350 | /* |
| 351 | * Switch the PDA and FPU contexts. |
| 352 | */ |
| 353 | prev->usersp = this_cpu_read(old_rsp); |
| 354 | this_cpu_write(old_rsp, next->usersp); |
| 355 | this_cpu_write(current_task, next_p); |
| 356 | |
| 357 | this_cpu_write(kernel_stack, |
| 358 | (unsigned long)task_stack_page(next_p) + |
| 359 | THREAD_SIZE - KERNEL_STACK_OFFSET); |
| 360 | |
| 361 | /* |
| 362 | * Now maybe reload the debug registers and handle I/O bitmaps |
| 363 | */ |
| 364 | if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT || |
| 365 | task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) |
| 366 | __switch_to_xtra(prev_p, next_p, tss); |
| 367 | |
| 368 | return prev_p; |
| 369 | } |
| 370 | |
| 371 | void set_personality_64bit(void) |
| 372 | { |
| 373 | /* inherit personality from parent */ |
| 374 | |
| 375 | /* Make sure to be in 64bit mode */ |
| 376 | clear_thread_flag(TIF_IA32); |
| 377 | clear_thread_flag(TIF_ADDR32); |
| 378 | clear_thread_flag(TIF_X32); |
| 379 | |
| 380 | /* Ensure the corresponding mm is not marked. */ |
| 381 | if (current->mm) |
| 382 | current->mm->context.ia32_compat = 0; |
| 383 | |
| 384 | /* TBD: overwrites user setup. Should have two bits. |
| 385 | But 64bit processes have always behaved this way, |
| 386 | so it's not too bad. The main problem is just that |
| 387 | 32bit childs are affected again. */ |
| 388 | current->personality &= ~READ_IMPLIES_EXEC; |
| 389 | } |
| 390 | |
| 391 | void set_personality_ia32(bool x32) |
| 392 | { |
| 393 | /* inherit personality from parent */ |
| 394 | |
| 395 | /* Make sure to be in 32bit mode */ |
| 396 | set_thread_flag(TIF_ADDR32); |
| 397 | |
| 398 | /* Mark the associated mm as containing 32-bit tasks. */ |
| 399 | if (current->mm) |
| 400 | current->mm->context.ia32_compat = 1; |
| 401 | |
| 402 | if (x32) { |
| 403 | clear_thread_flag(TIF_IA32); |
| 404 | set_thread_flag(TIF_X32); |
| 405 | current->personality &= ~READ_IMPLIES_EXEC; |
| 406 | /* is_compat_task() uses the presence of the x32 |
| 407 | syscall bit flag to determine compat status */ |
| 408 | current_thread_info()->status &= ~TS_COMPAT; |
| 409 | } else { |
| 410 | set_thread_flag(TIF_IA32); |
| 411 | clear_thread_flag(TIF_X32); |
| 412 | current->personality |= force_personality32; |
| 413 | /* Prepare the first "return" to user space */ |
| 414 | current_thread_info()->status |= TS_COMPAT; |
| 415 | } |
| 416 | } |
| 417 | EXPORT_SYMBOL_GPL(set_personality_ia32); |
| 418 | |
| 419 | unsigned long get_wchan(struct task_struct *p) |
| 420 | { |
| 421 | unsigned long stack; |
| 422 | u64 fp, ip; |
| 423 | int count = 0; |
| 424 | |
| 425 | if (!p || p == current || p->state == TASK_RUNNING) |
| 426 | return 0; |
| 427 | stack = (unsigned long)task_stack_page(p); |
| 428 | if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE) |
| 429 | return 0; |
| 430 | fp = *(u64 *)(p->thread.sp); |
| 431 | do { |
| 432 | if (fp < (unsigned long)stack || |
| 433 | fp >= (unsigned long)stack+THREAD_SIZE) |
| 434 | return 0; |
| 435 | ip = *(u64 *)(fp+8); |
| 436 | if (!in_sched_functions(ip)) |
| 437 | return ip; |
| 438 | fp = *(u64 *)fp; |
| 439 | } while (count++ < 16); |
| 440 | return 0; |
| 441 | } |
| 442 | |
| 443 | long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) |
| 444 | { |
| 445 | int ret = 0; |
| 446 | int doit = task == current; |
| 447 | int cpu; |
| 448 | |
| 449 | switch (code) { |
| 450 | case ARCH_SET_GS: |
| 451 | if (addr >= TASK_SIZE_OF(task)) |
| 452 | return -EPERM; |
| 453 | cpu = get_cpu(); |
| 454 | /* handle small bases via the GDT because that's faster to |
| 455 | switch. */ |
| 456 | if (addr <= 0xffffffff) { |
| 457 | set_32bit_tls(task, GS_TLS, addr); |
| 458 | if (doit) { |
| 459 | load_TLS(&task->thread, cpu); |
| 460 | load_gs_index(GS_TLS_SEL); |
| 461 | } |
| 462 | task->thread.gsindex = GS_TLS_SEL; |
| 463 | task->thread.gs = 0; |
| 464 | } else { |
| 465 | task->thread.gsindex = 0; |
| 466 | task->thread.gs = addr; |
| 467 | if (doit) { |
| 468 | load_gs_index(0); |
| 469 | ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr); |
| 470 | } |
| 471 | } |
| 472 | put_cpu(); |
| 473 | break; |
| 474 | case ARCH_SET_FS: |
| 475 | /* Not strictly needed for fs, but do it for symmetry |
| 476 | with gs */ |
| 477 | if (addr >= TASK_SIZE_OF(task)) |
| 478 | return -EPERM; |
| 479 | cpu = get_cpu(); |
| 480 | /* handle small bases via the GDT because that's faster to |
| 481 | switch. */ |
| 482 | if (addr <= 0xffffffff) { |
| 483 | set_32bit_tls(task, FS_TLS, addr); |
| 484 | if (doit) { |
| 485 | load_TLS(&task->thread, cpu); |
| 486 | loadsegment(fs, FS_TLS_SEL); |
| 487 | } |
| 488 | task->thread.fsindex = FS_TLS_SEL; |
| 489 | task->thread.fs = 0; |
| 490 | } else { |
| 491 | task->thread.fsindex = 0; |
| 492 | task->thread.fs = addr; |
| 493 | if (doit) { |
| 494 | /* set the selector to 0 to not confuse |
| 495 | __switch_to */ |
| 496 | loadsegment(fs, 0); |
| 497 | ret = checking_wrmsrl(MSR_FS_BASE, addr); |
| 498 | } |
| 499 | } |
| 500 | put_cpu(); |
| 501 | break; |
| 502 | case ARCH_GET_FS: { |
| 503 | unsigned long base; |
| 504 | if (task->thread.fsindex == FS_TLS_SEL) |
| 505 | base = read_32bit_tls(task, FS_TLS); |
| 506 | else if (doit) |
| 507 | rdmsrl(MSR_FS_BASE, base); |
| 508 | else |
| 509 | base = task->thread.fs; |
| 510 | ret = put_user(base, (unsigned long __user *)addr); |
| 511 | break; |
| 512 | } |
| 513 | case ARCH_GET_GS: { |
| 514 | unsigned long base; |
| 515 | unsigned gsindex; |
| 516 | if (task->thread.gsindex == GS_TLS_SEL) |
| 517 | base = read_32bit_tls(task, GS_TLS); |
| 518 | else if (doit) { |
| 519 | savesegment(gs, gsindex); |
| 520 | if (gsindex) |
| 521 | rdmsrl(MSR_KERNEL_GS_BASE, base); |
| 522 | else |
| 523 | base = task->thread.gs; |
| 524 | } else |
| 525 | base = task->thread.gs; |
| 526 | ret = put_user(base, (unsigned long __user *)addr); |
| 527 | break; |
| 528 | } |
| 529 | |
| 530 | default: |
| 531 | ret = -EINVAL; |
| 532 | break; |
| 533 | } |
| 534 | |
| 535 | return ret; |
| 536 | } |
| 537 | |
| 538 | long sys_arch_prctl(int code, unsigned long addr) |
| 539 | { |
| 540 | return do_arch_prctl(current, code, addr); |
| 541 | } |
| 542 | |
| 543 | unsigned long KSTK_ESP(struct task_struct *task) |
| 544 | { |
| 545 | return (test_tsk_thread_flag(task, TIF_IA32)) ? |
| 546 | (task_pt_regs(task)->sp) : ((task)->thread.usersp); |
| 547 | } |