Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/process.c | |
3 | * | |
4 | * Copyright (C) 1996-2000 Russell King - Converted to ARM. | |
5 | * Original Copyright (C) 1995 Linus Torvalds | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #include <stdarg.h> | |
12 | ||
ecea4ab6 | 13 | #include <linux/export.h> |
1da177e4 LT |
14 | #include <linux/sched.h> |
15 | #include <linux/kernel.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/stddef.h> | |
18 | #include <linux/unistd.h> | |
1da177e4 | 19 | #include <linux/user.h> |
1da177e4 LT |
20 | #include <linux/delay.h> |
21 | #include <linux/reboot.h> | |
22 | #include <linux/interrupt.h> | |
23 | #include <linux/kallsyms.h> | |
24 | #include <linux/init.h> | |
a054a811 | 25 | #include <linux/cpu.h> |
84dff1a7 | 26 | #include <linux/elfcore.h> |
74617fb6 | 27 | #include <linux/pm.h> |
9e4559dd | 28 | #include <linux/tick.h> |
154c772e | 29 | #include <linux/utsname.h> |
33fa9b13 | 30 | #include <linux/uaccess.h> |
990cb8ac | 31 | #include <linux/random.h> |
864232fa | 32 | #include <linux/hw_breakpoint.h> |
fa8bbb13 | 33 | #include <linux/leds.h> |
7b6d864b | 34 | #include <linux/reboot.h> |
1da177e4 | 35 | |
9ca03a21 | 36 | #include <asm/cacheflush.h> |
9ecb47de | 37 | #include <asm/idmap.h> |
1da177e4 | 38 | #include <asm/processor.h> |
d6551e88 | 39 | #include <asm/thread_notify.h> |
2d7c11bf | 40 | #include <asm/stacktrace.h> |
779dd959 | 41 | #include <asm/system_misc.h> |
2ea83398 | 42 | #include <asm/mach/time.h> |
a4780ade | 43 | #include <asm/tls.h> |
1da177e4 | 44 | |
c743f380 NP |
45 | #ifdef CONFIG_CC_STACKPROTECTOR |
46 | #include <linux/stackprotector.h> | |
47 | unsigned long __stack_chk_guard __read_mostly; | |
48 | EXPORT_SYMBOL(__stack_chk_guard); | |
49 | #endif | |
50 | ||
e2e55fde | 51 | static const char *processor_modes[] __maybe_unused = { |
ae0a846e RK |
52 | "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , |
53 | "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", | |
54 | "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , | |
55 | "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" | |
56 | }; | |
57 | ||
e2e55fde | 58 | static const char *isa_modes[] __maybe_unused = { |
909d6c6c GD |
59 | "ARM" , "Thumb" , "Jazelle", "ThumbEE" |
60 | }; | |
61 | ||
290130a1 WD |
62 | extern void call_with_stack(void (*fn)(void *), void *arg, void *sp); |
63 | typedef void (*phys_reset_t)(unsigned long); | |
64 | ||
65 | /* | |
66 | * A temporary stack to use for CPU reset. This is static so that we | |
67 | * don't clobber it with the identity mapping. When running with this | |
68 | * stack, any references to the current task *will not work* so you | |
69 | * should really do as little as possible before jumping to your reset | |
70 | * code. | |
71 | */ | |
72 | static u64 soft_restart_stack[16]; | |
73 | ||
74 | static void __soft_restart(void *addr) | |
74617fb6 | 75 | { |
290130a1 | 76 | phys_reset_t phys_reset; |
74617fb6 | 77 | |
290130a1 | 78 | /* Take out a flat memory mapping. */ |
5aafec15 | 79 | setup_mm_for_reboot(); |
74617fb6 | 80 | |
9ca03a21 RK |
81 | /* Clean and invalidate caches */ |
82 | flush_cache_all(); | |
83 | ||
84 | /* Turn off caching */ | |
85 | cpu_proc_fin(); | |
86 | ||
87 | /* Push out any further dirty data, and ensure cache is empty */ | |
88 | flush_cache_all(); | |
89 | ||
290130a1 WD |
90 | /* Switch to the identity mapping. */ |
91 | phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset); | |
92 | phys_reset((unsigned long)addr); | |
74617fb6 | 93 | |
290130a1 WD |
94 | /* Should never get here. */ |
95 | BUG(); | |
96 | } | |
97 | ||
98 | void soft_restart(unsigned long addr) | |
99 | { | |
100 | u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack); | |
101 | ||
102 | /* Disable interrupts first */ | |
c7d442f4 | 103 | raw_local_irq_disable(); |
290130a1 WD |
104 | local_fiq_disable(); |
105 | ||
106 | /* Disable the L2 if we're the last man standing. */ | |
107 | if (num_online_cpus() == 1) | |
108 | outer_disable(); | |
109 | ||
110 | /* Change to the new stack and continue with the reset. */ | |
111 | call_with_stack(__soft_restart, (void *)addr, (void *)stack); | |
112 | ||
113 | /* Should never get here. */ | |
114 | BUG(); | |
e879c862 RK |
115 | } |
116 | ||
7b6d864b | 117 | static void null_restart(enum reboot_mode reboot_mode, const char *cmd) |
e879c862 | 118 | { |
74617fb6 RP |
119 | } |
120 | ||
1da177e4 | 121 | /* |
74617fb6 | 122 | * Function pointers to optional machine specific functions |
1da177e4 | 123 | */ |
1da177e4 LT |
124 | void (*pm_power_off)(void); |
125 | EXPORT_SYMBOL(pm_power_off); | |
126 | ||
7b6d864b | 127 | void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart; |
74617fb6 RP |
128 | EXPORT_SYMBOL_GPL(arm_pm_restart); |
129 | ||
1da177e4 | 130 | /* |
4fa20439 | 131 | * This is our default idle handler. |
1da177e4 | 132 | */ |
4fa20439 NP |
133 | |
134 | void (*arm_pm_idle)(void); | |
135 | ||
ad68cc7a NP |
136 | /* |
137 | * Called from the core idle loop. | |
138 | */ | |
139 | ||
140 | void arch_cpu_idle(void) | |
1da177e4 | 141 | { |
4fa20439 NP |
142 | if (arm_pm_idle) |
143 | arm_pm_idle(); | |
144 | else | |
ae940913 | 145 | cpu_do_idle(); |
9ccdac36 | 146 | local_irq_enable(); |
1da177e4 LT |
147 | } |
148 | ||
f7b861b7 | 149 | void arch_cpu_idle_prepare(void) |
1da177e4 LT |
150 | { |
151 | local_fiq_enable(); | |
f7b861b7 | 152 | } |
1da177e4 | 153 | |
f7b861b7 TG |
154 | void arch_cpu_idle_enter(void) |
155 | { | |
156 | ledtrig_cpu(CPU_LED_IDLE_START); | |
157 | #ifdef CONFIG_PL310_ERRATA_769419 | |
158 | wmb(); | |
a054a811 | 159 | #endif |
f7b861b7 | 160 | } |
a054a811 | 161 | |
f7b861b7 TG |
162 | void arch_cpu_idle_exit(void) |
163 | { | |
164 | ledtrig_cpu(CPU_LED_IDLE_END); | |
165 | } | |
166 | ||
167 | #ifdef CONFIG_HOTPLUG_CPU | |
168 | void arch_cpu_idle_dead(void) | |
169 | { | |
170 | cpu_die(); | |
171 | } | |
11ed0ba1 | 172 | #endif |
f7b861b7 | 173 | |
19ab428f SW |
174 | /* |
175 | * Called by kexec, immediately prior to machine_kexec(). | |
176 | * | |
177 | * This must completely disable all secondary CPUs; simply causing those CPUs | |
178 | * to execute e.g. a RAM-based pin loop is not sufficient. This allows the | |
179 | * kexec'd kernel to use any and all RAM as it sees fit, without having to | |
180 | * avoid any code or data used by any SW CPU pin loop. The CPU hotplug | |
181 | * functionality embodied in disable_nonboot_cpus() to achieve this. | |
182 | */ | |
3d3f78d7 | 183 | void machine_shutdown(void) |
1da177e4 | 184 | { |
19ab428f | 185 | disable_nonboot_cpus(); |
1da177e4 LT |
186 | } |
187 | ||
19ab428f SW |
188 | /* |
189 | * Halting simply requires that the secondary CPUs stop performing any | |
190 | * activity (executing tasks, handling interrupts). smp_send_stop() | |
191 | * achieves this. | |
192 | */ | |
3d3f78d7 RK |
193 | void machine_halt(void) |
194 | { | |
44424c34 | 195 | local_irq_disable(); |
19ab428f SW |
196 | smp_send_stop(); |
197 | ||
98bd8b96 | 198 | local_irq_disable(); |
3d3f78d7 RK |
199 | while (1); |
200 | } | |
1da177e4 | 201 | |
19ab428f SW |
202 | /* |
203 | * Power-off simply requires that the secondary CPUs stop performing any | |
204 | * activity (executing tasks, handling interrupts). smp_send_stop() | |
205 | * achieves this. When the system power is turned off, it will take all CPUs | |
206 | * with it. | |
207 | */ | |
1da177e4 LT |
208 | void machine_power_off(void) |
209 | { | |
44424c34 | 210 | local_irq_disable(); |
19ab428f SW |
211 | smp_send_stop(); |
212 | ||
1da177e4 LT |
213 | if (pm_power_off) |
214 | pm_power_off(); | |
215 | } | |
216 | ||
19ab428f SW |
217 | /* |
218 | * Restart requires that the secondary CPUs stop performing any activity | |
219 | * while the primary CPU resets the system. Systems with a single CPU can | |
220 | * use soft_restart() as their machine descriptor's .restart hook, since that | |
221 | * will cause the only available CPU to reset. Systems with multiple CPUs must | |
222 | * provide a HW restart implementation, to ensure that all CPUs reset at once. | |
223 | * This is required so that any code running after reset on the primary CPU | |
224 | * doesn't have to co-ordinate with other CPUs to ensure they aren't still | |
225 | * executing pre-reset code, and using RAM that the primary CPU's code wishes | |
226 | * to use. Implementing such co-ordination would be essentially impossible. | |
227 | */ | |
be093beb | 228 | void machine_restart(char *cmd) |
1da177e4 | 229 | { |
44424c34 | 230 | local_irq_disable(); |
19ab428f | 231 | smp_send_stop(); |
ac15e00b | 232 | |
be093beb | 233 | arm_pm_restart(reboot_mode, cmd); |
ac15e00b RK |
234 | |
235 | /* Give a grace period for failure to restart of 1s */ | |
236 | mdelay(1000); | |
237 | ||
238 | /* Whoops - the platform was unable to reboot. Tell the user! */ | |
239 | printk("Reboot failed -- System halted\n"); | |
98bd8b96 | 240 | local_irq_disable(); |
ac15e00b | 241 | while (1); |
1da177e4 LT |
242 | } |
243 | ||
652a12ef | 244 | void __show_regs(struct pt_regs *regs) |
1da177e4 | 245 | { |
154c772e RK |
246 | unsigned long flags; |
247 | char buf[64]; | |
1da177e4 | 248 | |
a43cb95d TH |
249 | show_regs_print_info(KERN_DEFAULT); |
250 | ||
1da177e4 LT |
251 | print_symbol("PC is at %s\n", instruction_pointer(regs)); |
252 | print_symbol("LR is at %s\n", regs->ARM_lr); | |
154c772e | 253 | printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" |
1da177e4 | 254 | "sp : %08lx ip : %08lx fp : %08lx\n", |
154c772e RK |
255 | regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, |
256 | regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); | |
1da177e4 LT |
257 | printk("r10: %08lx r9 : %08lx r8 : %08lx\n", |
258 | regs->ARM_r10, regs->ARM_r9, | |
259 | regs->ARM_r8); | |
260 | printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", | |
261 | regs->ARM_r7, regs->ARM_r6, | |
262 | regs->ARM_r5, regs->ARM_r4); | |
263 | printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", | |
264 | regs->ARM_r3, regs->ARM_r2, | |
265 | regs->ARM_r1, regs->ARM_r0); | |
154c772e RK |
266 | |
267 | flags = regs->ARM_cpsr; | |
268 | buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; | |
269 | buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; | |
270 | buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; | |
271 | buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; | |
272 | buf[4] = '\0'; | |
273 | ||
e2e55fde | 274 | #ifndef CONFIG_CPU_V7M |
909d6c6c | 275 | printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", |
154c772e | 276 | buf, interrupts_enabled(regs) ? "n" : "ff", |
1da177e4 LT |
277 | fast_interrupts_enabled(regs) ? "n" : "ff", |
278 | processor_modes[processor_mode(regs)], | |
909d6c6c | 279 | isa_modes[isa_mode(regs)], |
1da177e4 | 280 | get_fs() == get_ds() ? "kernel" : "user"); |
e2e55fde UKK |
281 | #else |
282 | printk("xPSR: %08lx\n", regs->ARM_cpsr); | |
283 | #endif | |
284 | ||
154c772e | 285 | #ifdef CONFIG_CPU_CP15 |
1da177e4 | 286 | { |
f12d0d7c | 287 | unsigned int ctrl; |
154c772e RK |
288 | |
289 | buf[0] = '\0'; | |
f12d0d7c | 290 | #ifdef CONFIG_CPU_CP15_MMU |
154c772e RK |
291 | { |
292 | unsigned int transbase, dac; | |
293 | asm("mrc p15, 0, %0, c2, c0\n\t" | |
294 | "mrc p15, 0, %1, c3, c0\n" | |
295 | : "=r" (transbase), "=r" (dac)); | |
296 | snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", | |
297 | transbase, dac); | |
298 | } | |
f12d0d7c | 299 | #endif |
154c772e RK |
300 | asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); |
301 | ||
302 | printk("Control: %08x%s\n", ctrl, buf); | |
303 | } | |
f12d0d7c | 304 | #endif |
1da177e4 LT |
305 | } |
306 | ||
652a12ef RK |
307 | void show_regs(struct pt_regs * regs) |
308 | { | |
309 | printk("\n"); | |
652a12ef | 310 | __show_regs(regs); |
b380ab4f | 311 | dump_stack(); |
652a12ef RK |
312 | } |
313 | ||
797245f5 RK |
314 | ATOMIC_NOTIFIER_HEAD(thread_notify_head); |
315 | ||
316 | EXPORT_SYMBOL_GPL(thread_notify_head); | |
317 | ||
1da177e4 LT |
318 | /* |
319 | * Free current thread data structures etc.. | |
320 | */ | |
321 | void exit_thread(void) | |
322 | { | |
797245f5 | 323 | thread_notify(THREAD_NOTIFY_EXIT, current_thread_info()); |
1da177e4 LT |
324 | } |
325 | ||
1da177e4 LT |
326 | void flush_thread(void) |
327 | { | |
328 | struct thread_info *thread = current_thread_info(); | |
329 | struct task_struct *tsk = current; | |
330 | ||
864232fa WD |
331 | flush_ptrace_hw_breakpoint(tsk); |
332 | ||
1da177e4 LT |
333 | memset(thread->used_cp, 0, sizeof(thread->used_cp)); |
334 | memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); | |
d6551e88 RK |
335 | memset(&thread->fpstate, 0, sizeof(union fp_state)); |
336 | ||
fbfb872f NL |
337 | flush_tls(); |
338 | ||
d6551e88 | 339 | thread_notify(THREAD_NOTIFY_FLUSH, thread); |
1da177e4 LT |
340 | } |
341 | ||
342 | void release_thread(struct task_struct *dead_task) | |
343 | { | |
1da177e4 LT |
344 | } |
345 | ||
346 | asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); | |
347 | ||
348 | int | |
6f2c55b8 | 349 | copy_thread(unsigned long clone_flags, unsigned long stack_start, |
afa86fc4 | 350 | unsigned long stk_sz, struct task_struct *p) |
1da177e4 | 351 | { |
815d5ec8 AV |
352 | struct thread_info *thread = task_thread_info(p); |
353 | struct pt_regs *childregs = task_pt_regs(p); | |
1da177e4 | 354 | |
1da177e4 | 355 | memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); |
9e14f828 | 356 | |
38a61b6b AV |
357 | if (likely(!(p->flags & PF_KTHREAD))) { |
358 | *childregs = *current_pt_regs(); | |
9e14f828 | 359 | childregs->ARM_r0 = 0; |
38a61b6b AV |
360 | if (stack_start) |
361 | childregs->ARM_sp = stack_start; | |
9e14f828 | 362 | } else { |
9fff2fa0 | 363 | memset(childregs, 0, sizeof(struct pt_regs)); |
9e14f828 AV |
364 | thread->cpu_context.r4 = stk_sz; |
365 | thread->cpu_context.r5 = stack_start; | |
9e14f828 AV |
366 | childregs->ARM_cpsr = SVC_MODE; |
367 | } | |
9fff2fa0 | 368 | thread->cpu_context.pc = (unsigned long)ret_from_fork; |
1da177e4 | 369 | thread->cpu_context.sp = (unsigned long)childregs; |
1da177e4 | 370 | |
864232fa WD |
371 | clear_ptrace_hw_breakpoint(p); |
372 | ||
1da177e4 | 373 | if (clone_flags & CLONE_SETTLS) |
a4780ade AH |
374 | thread->tp_value[0] = childregs->ARM_r3; |
375 | thread->tp_value[1] = get_tpuser(); | |
1da177e4 | 376 | |
2e82669a CM |
377 | thread_notify(THREAD_NOTIFY_COPY, thread); |
378 | ||
1da177e4 LT |
379 | return 0; |
380 | } | |
381 | ||
cde3f860 AB |
382 | /* |
383 | * Fill in the task's elfregs structure for a core dump. | |
384 | */ | |
385 | int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) | |
386 | { | |
387 | elf_core_copy_regs(elfregs, task_pt_regs(t)); | |
388 | return 1; | |
389 | } | |
390 | ||
1da177e4 LT |
391 | /* |
392 | * fill in the fpe structure for a core dump... | |
393 | */ | |
394 | int dump_fpu (struct pt_regs *regs, struct user_fp *fp) | |
395 | { | |
396 | struct thread_info *thread = current_thread_info(); | |
397 | int used_math = thread->used_cp[1] | thread->used_cp[2]; | |
398 | ||
399 | if (used_math) | |
400 | memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); | |
401 | ||
402 | return used_math != 0; | |
403 | } | |
404 | EXPORT_SYMBOL(dump_fpu); | |
405 | ||
1da177e4 LT |
406 | unsigned long get_wchan(struct task_struct *p) |
407 | { | |
2d7c11bf | 408 | struct stackframe frame; |
1b15ec7a | 409 | unsigned long stack_page; |
1da177e4 LT |
410 | int count = 0; |
411 | if (!p || p == current || p->state == TASK_RUNNING) | |
412 | return 0; | |
413 | ||
2d7c11bf CM |
414 | frame.fp = thread_saved_fp(p); |
415 | frame.sp = thread_saved_sp(p); | |
416 | frame.lr = 0; /* recovered from the stack */ | |
417 | frame.pc = thread_saved_pc(p); | |
1b15ec7a | 418 | stack_page = (unsigned long)task_stack_page(p); |
1da177e4 | 419 | do { |
1b15ec7a KK |
420 | if (frame.sp < stack_page || |
421 | frame.sp >= stack_page + THREAD_SIZE || | |
422 | unwind_frame(&frame) < 0) | |
1da177e4 | 423 | return 0; |
2d7c11bf CM |
424 | if (!in_sched_functions(frame.pc)) |
425 | return frame.pc; | |
1da177e4 LT |
426 | } while (count ++ < 16); |
427 | return 0; | |
428 | } | |
990cb8ac NP |
429 | |
430 | unsigned long arch_randomize_brk(struct mm_struct *mm) | |
431 | { | |
432 | unsigned long range_end = mm->brk + 0x02000000; | |
433 | return randomize_range(mm->brk, range_end, 0) ? : mm->brk; | |
434 | } | |
ec706dab | 435 | |
6cde6d42 | 436 | #ifdef CONFIG_MMU |
a5463cd3 | 437 | #ifdef CONFIG_KUSER_HELPERS |
ec706dab NP |
438 | /* |
439 | * The vectors page is always readable from user space for the | |
48be69a0 RK |
440 | * atomic helpers. Insert it into the gate_vma so that it is visible |
441 | * through ptrace and /proc/<pid>/mem. | |
ec706dab | 442 | */ |
f6604efe RK |
443 | static struct vm_area_struct gate_vma = { |
444 | .vm_start = 0xffff0000, | |
445 | .vm_end = 0xffff0000 + PAGE_SIZE, | |
446 | .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC, | |
f6604efe | 447 | }; |
ec706dab | 448 | |
f9d4861f | 449 | static int __init gate_vma_init(void) |
ec706dab | 450 | { |
f6604efe | 451 | gate_vma.vm_page_prot = PAGE_READONLY_EXEC; |
f9d4861f WD |
452 | return 0; |
453 | } | |
454 | arch_initcall(gate_vma_init); | |
455 | ||
456 | struct vm_area_struct *get_gate_vma(struct mm_struct *mm) | |
457 | { | |
458 | return &gate_vma; | |
459 | } | |
460 | ||
461 | int in_gate_area(struct mm_struct *mm, unsigned long addr) | |
462 | { | |
463 | return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end); | |
464 | } | |
465 | ||
466 | int in_gate_area_no_mm(unsigned long addr) | |
467 | { | |
468 | return in_gate_area(NULL, addr); | |
ec706dab | 469 | } |
1d0bbf42 | 470 | #define is_gate_vma(vma) ((vma) == &gate_vma) |
a5463cd3 RK |
471 | #else |
472 | #define is_gate_vma(vma) 0 | |
473 | #endif | |
ec706dab NP |
474 | |
475 | const char *arch_vma_name(struct vm_area_struct *vma) | |
476 | { | |
a5463cd3 | 477 | return is_gate_vma(vma) ? "[vectors]" : |
48be69a0 RK |
478 | (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ? |
479 | "[sigpage]" : NULL; | |
480 | } | |
481 | ||
e0d40756 | 482 | static struct page *signal_page; |
48be69a0 RK |
483 | extern struct page *get_signal_page(void); |
484 | ||
485 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) | |
486 | { | |
487 | struct mm_struct *mm = current->mm; | |
48be69a0 RK |
488 | unsigned long addr; |
489 | int ret; | |
490 | ||
e0d40756 RK |
491 | if (!signal_page) |
492 | signal_page = get_signal_page(); | |
493 | if (!signal_page) | |
48be69a0 RK |
494 | return -ENOMEM; |
495 | ||
496 | down_write(&mm->mmap_sem); | |
497 | addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); | |
498 | if (IS_ERR_VALUE(addr)) { | |
499 | ret = addr; | |
500 | goto up_fail; | |
501 | } | |
502 | ||
503 | ret = install_special_mapping(mm, addr, PAGE_SIZE, | |
504 | VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, | |
e0d40756 | 505 | &signal_page); |
48be69a0 RK |
506 | |
507 | if (ret == 0) | |
508 | mm->context.sigpage = addr; | |
509 | ||
510 | up_fail: | |
511 | up_write(&mm->mmap_sem); | |
512 | return ret; | |
ec706dab | 513 | } |
6cde6d42 | 514 | #endif |