Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/s390/mm/fault.c |
| 3 | * |
| 4 | * S390 version |
| 5 | * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 6 | * Author(s): Hartmut Penner (hp@de.ibm.com) |
| 7 | * Ulrich Weigand (uweigand@de.ibm.com) |
| 8 | * |
| 9 | * Derived from "arch/i386/mm/fault.c" |
| 10 | * Copyright (C) 1995 Linus Torvalds |
| 11 | */ |
| 12 | |
Heiko Carstens | 052ff46 | 2011-01-05 12:47:28 +0100 | [diff] [blame] | 13 | #include <linux/kernel_stat.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 14 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/signal.h> |
| 16 | #include <linux/sched.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/errno.h> |
| 19 | #include <linux/string.h> |
| 20 | #include <linux/types.h> |
| 21 | #include <linux/ptrace.h> |
| 22 | #include <linux/mman.h> |
| 23 | #include <linux/mm.h> |
Heiko Carstens | 7757591 | 2009-06-12 10:26:25 +0200 | [diff] [blame] | 24 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/smp.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 26 | #include <linux/kdebug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/init.h> |
| 28 | #include <linux/console.h> |
| 29 | #include <linux/module.h> |
| 30 | #include <linux/hardirq.h> |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 31 | #include <linux/kprobes.h> |
Martin Schwidefsky | be5ec36 | 2007-04-27 16:01:44 +0200 | [diff] [blame] | 32 | #include <linux/uaccess.h> |
Gerald Schaefer | 53492b1 | 2008-04-30 13:38:46 +0200 | [diff] [blame] | 33 | #include <linux/hugetlb.h> |
Heiko Carstens | cbb870c | 2010-02-26 22:37:43 +0100 | [diff] [blame] | 34 | #include <asm/asm-offsets.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <asm/system.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <asm/pgtable.h> |
Heiko Carstens | d7b250e | 2011-05-26 09:48:24 +0200 | [diff] [blame] | 37 | #include <asm/irq.h> |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 38 | #include <asm/mmu_context.h> |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 39 | #include <asm/compat.h> |
Heiko Carstens | a806170 | 2008-04-17 07:46:26 +0200 | [diff] [blame] | 40 | #include "../kernel/entry.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 42 | #ifndef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #define __FAIL_ADDR_MASK 0x7ffff000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #define __SUBCODE_MASK 0x0200 |
| 45 | #define __PF_RES_FIELD 0ULL |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 46 | #else /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | #define __FAIL_ADDR_MASK -4096L |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | #define __SUBCODE_MASK 0x0600 |
| 49 | #define __PF_RES_FIELD 0x8000000000000000ULL |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 50 | #endif /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 52 | #define VM_FAULT_BADCONTEXT 0x010000 |
| 53 | #define VM_FAULT_BADMAP 0x020000 |
| 54 | #define VM_FAULT_BADACCESS 0x040000 |
| 55 | |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 56 | static unsigned long store_indication; |
| 57 | |
| 58 | void fault_init(void) |
| 59 | { |
Martin Schwidefsky | 14375bc | 2010-10-25 16:10:51 +0200 | [diff] [blame] | 60 | if (test_facility(2) && test_facility(75)) |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 61 | store_indication = 0xc00; |
| 62 | } |
| 63 | |
Martin Schwidefsky | 7ecb344 | 2009-12-07 12:51:44 +0100 | [diff] [blame] | 64 | static inline int notify_page_fault(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 65 | { |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 66 | int ret = 0; |
| 67 | |
| 68 | /* kprobe_running() needs smp_processor_id() */ |
Heiko Carstens | 22e0a04 | 2010-02-26 22:37:45 +0100 | [diff] [blame] | 69 | if (kprobes_built_in() && !user_mode(regs)) { |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 70 | preempt_disable(); |
| 71 | if (kprobe_running() && kprobe_fault_handler(regs, 14)) |
| 72 | ret = 1; |
| 73 | preempt_enable(); |
| 74 | } |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 75 | return ret; |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 76 | } |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 77 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
| 79 | /* |
| 80 | * Unlock any spinlocks which will prevent us from getting the |
Kirill Korotaev | cefc8be | 2007-02-10 01:46:18 -0800 | [diff] [blame] | 81 | * message out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | */ |
| 83 | void bust_spinlocks(int yes) |
| 84 | { |
| 85 | if (yes) { |
| 86 | oops_in_progress = 1; |
| 87 | } else { |
| 88 | int loglevel_save = console_loglevel; |
| 89 | console_unblank(); |
| 90 | oops_in_progress = 0; |
| 91 | /* |
| 92 | * OK, the message is on the console. Now we call printk() |
| 93 | * without oops_in_progress set so that printk will give klogd |
| 94 | * a poke. Hold onto your hats... |
| 95 | */ |
| 96 | console_loglevel = 15; |
| 97 | printk(" "); |
| 98 | console_loglevel = loglevel_save; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | /* |
Gerald Schaefer | 482b05d | 2007-03-05 23:35:54 +0100 | [diff] [blame] | 103 | * Returns the address space associated with the fault. |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 104 | * Returns 0 for kernel space and 1 for user space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 106 | static inline int user_space_fault(unsigned long trans_exc_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
| 108 | /* |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 109 | * The lowest two bits of the translation exception |
| 110 | * identification indicate which paging table was used. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 112 | trans_exc_code &= 3; |
| 113 | if (trans_exc_code == 2) |
| 114 | /* Access via secondary space, set_fs setting decides */ |
| 115 | return current->thread.mm_segment.ar4; |
Martin Schwidefsky | b11b533 | 2009-12-07 12:51:43 +0100 | [diff] [blame] | 116 | if (user_mode == HOME_SPACE_MODE) |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 117 | /* User space if the access has been done via home space. */ |
| 118 | return trans_exc_code == 3; |
| 119 | /* |
| 120 | * If the user space is not the home space the kernel runs in home |
| 121 | * space. Access via secondary space has already been covered, |
| 122 | * access via primary space or access register is from user space |
| 123 | * and access via home space is from the kernel. |
| 124 | */ |
| 125 | return trans_exc_code != 3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | } |
| 127 | |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 128 | static inline void report_user_fault(struct pt_regs *regs, long int_code, |
| 129 | int signr, unsigned long address) |
| 130 | { |
| 131 | if ((task_pid_nr(current) > 1) && !show_unhandled_signals) |
| 132 | return; |
| 133 | if (!unhandled_signal(current, signr)) |
| 134 | return; |
| 135 | if (!printk_ratelimit()) |
| 136 | return; |
| 137 | printk("User process fault: interruption code 0x%lX ", int_code); |
| 138 | print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN); |
| 139 | printk("\n"); |
| 140 | printk("failing address: %lX\n", address); |
| 141 | show_regs(regs); |
| 142 | } |
| 143 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | /* |
| 145 | * Send SIGSEGV to task. This is an external routine |
| 146 | * to keep the stack usage of do_page_fault small. |
| 147 | */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 148 | static noinline void do_sigsegv(struct pt_regs *regs, long int_code, |
| 149 | int si_code, unsigned long trans_exc_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | { |
| 151 | struct siginfo si; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 152 | unsigned long address; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 154 | address = trans_exc_code & __FAIL_ADDR_MASK; |
| 155 | current->thread.prot_addr = address; |
| 156 | current->thread.trap_no = int_code; |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 157 | report_user_fault(regs, int_code, SIGSEGV, address); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | si.si_signo = SIGSEGV; |
| 159 | si.si_code = si_code; |
Heiko Carstens | d2c993d | 2006-07-12 16:41:55 +0200 | [diff] [blame] | 160 | si.si_addr = (void __user *) address; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | force_sig_info(SIGSEGV, &si, current); |
| 162 | } |
| 163 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 164 | static noinline void do_no_context(struct pt_regs *regs, long int_code, |
| 165 | unsigned long trans_exc_code) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 166 | { |
| 167 | const struct exception_table_entry *fixup; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 168 | unsigned long address; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 169 | |
| 170 | /* Are we prepared to handle this kernel fault? */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 171 | fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 172 | if (fixup) { |
| 173 | regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE; |
| 174 | return; |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Oops. The kernel tried to access some bad page. We'll have to |
| 179 | * terminate things with extreme prejudice. |
| 180 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 181 | address = trans_exc_code & __FAIL_ADDR_MASK; |
Martin Schwidefsky | b11b533 | 2009-12-07 12:51:43 +0100 | [diff] [blame] | 182 | if (!user_space_fault(trans_exc_code)) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 183 | printk(KERN_ALERT "Unable to handle kernel pointer dereference" |
| 184 | " at virtual kernel address %p\n", (void *)address); |
| 185 | else |
| 186 | printk(KERN_ALERT "Unable to handle kernel paging request" |
| 187 | " at virtual user address %p\n", (void *)address); |
| 188 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 189 | die("Oops", regs, int_code); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 190 | do_exit(SIGKILL); |
| 191 | } |
| 192 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 193 | static noinline void do_low_address(struct pt_regs *regs, long int_code, |
| 194 | unsigned long trans_exc_code) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 195 | { |
| 196 | /* Low-address protection hit in kernel mode means |
| 197 | NULL pointer write access in kernel mode. */ |
| 198 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 199 | /* Low-address protection hit in user mode 'cannot happen'. */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 200 | die ("Low-address protection", regs, int_code); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 201 | do_exit(SIGKILL); |
| 202 | } |
| 203 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 204 | do_no_context(regs, int_code, trans_exc_code); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 205 | } |
| 206 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 207 | static noinline void do_sigbus(struct pt_regs *regs, long int_code, |
| 208 | unsigned long trans_exc_code) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 209 | { |
| 210 | struct task_struct *tsk = current; |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 211 | unsigned long address; |
| 212 | struct siginfo si; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 213 | |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 214 | /* |
| 215 | * Send a sigbus, regardless of whether we were in kernel |
| 216 | * or user mode. |
| 217 | */ |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 218 | address = trans_exc_code & __FAIL_ADDR_MASK; |
| 219 | tsk->thread.prot_addr = address; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 220 | tsk->thread.trap_no = int_code; |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 221 | si.si_signo = SIGBUS; |
| 222 | si.si_errno = 0; |
| 223 | si.si_code = BUS_ADRERR; |
| 224 | si.si_addr = (void __user *) address; |
| 225 | force_sig_info(SIGBUS, &si, tsk); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 226 | } |
| 227 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 228 | static noinline void do_fault_error(struct pt_regs *regs, long int_code, |
| 229 | unsigned long trans_exc_code, int fault) |
| 230 | { |
| 231 | int si_code; |
| 232 | |
| 233 | switch (fault) { |
| 234 | case VM_FAULT_BADACCESS: |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 235 | case VM_FAULT_BADMAP: |
| 236 | /* Bad memory access. Check if it is kernel or user space. */ |
| 237 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 238 | /* User mode accesses just cause a SIGSEGV */ |
| 239 | si_code = (fault == VM_FAULT_BADMAP) ? |
| 240 | SEGV_MAPERR : SEGV_ACCERR; |
| 241 | do_sigsegv(regs, int_code, si_code, trans_exc_code); |
| 242 | return; |
| 243 | } |
| 244 | case VM_FAULT_BADCONTEXT: |
| 245 | do_no_context(regs, int_code, trans_exc_code); |
| 246 | break; |
| 247 | default: /* fault & VM_FAULT_ERROR */ |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 248 | if (fault & VM_FAULT_OOM) { |
| 249 | if (!(regs->psw.mask & PSW_MASK_PSTATE)) |
| 250 | do_no_context(regs, int_code, trans_exc_code); |
| 251 | else |
| 252 | pagefault_out_of_memory(); |
| 253 | } else if (fault & VM_FAULT_SIGBUS) { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 254 | /* Kernel mode? Handle exceptions or die */ |
| 255 | if (!(regs->psw.mask & PSW_MASK_PSTATE)) |
| 256 | do_no_context(regs, int_code, trans_exc_code); |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 257 | else |
| 258 | do_sigbus(regs, int_code, trans_exc_code); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 259 | } else |
| 260 | BUG(); |
| 261 | break; |
| 262 | } |
| 263 | } |
| 264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | /* |
| 266 | * This routine handles page faults. It determines the address, |
| 267 | * and the problem, and then passes it off to one of the appropriate |
| 268 | * routines. |
| 269 | * |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 270 | * interruption code (int_code): |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | * 04 Protection -> Write-Protection (suprression) |
| 272 | * 10 Segment translation -> Not present (nullification) |
| 273 | * 11 Page translation -> Not present (nullification) |
| 274 | * 3b Region third trans. -> Not present (nullification) |
| 275 | */ |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 276 | static inline int do_exception(struct pt_regs *regs, int access, |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 277 | unsigned long trans_exc_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | { |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 279 | struct task_struct *tsk; |
| 280 | struct mm_struct *mm; |
| 281 | struct vm_area_struct *vma; |
| 282 | unsigned long address; |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 283 | unsigned int flags; |
| 284 | int fault; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | |
Martin Schwidefsky | 7ecb344 | 2009-12-07 12:51:44 +0100 | [diff] [blame] | 286 | if (notify_page_fault(regs)) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 287 | return 0; |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 288 | |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 289 | tsk = current; |
| 290 | mm = tsk->mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | /* |
| 293 | * Verify that the fault happened in user space, that |
| 294 | * we are not in an interrupt and that there is a |
| 295 | * user context. |
| 296 | */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 297 | fault = VM_FAULT_BADCONTEXT; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 298 | if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm)) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 299 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 301 | address = trans_exc_code & __FAIL_ADDR_MASK; |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 302 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address); |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 303 | flags = FAULT_FLAG_ALLOW_RETRY; |
| 304 | if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) |
| 305 | flags |= FAULT_FLAG_WRITE; |
| 306 | retry: |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 307 | down_read(&mm->mmap_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 309 | fault = VM_FAULT_BADMAP; |
Gerald Schaefer | 482b05d | 2007-03-05 23:35:54 +0100 | [diff] [blame] | 310 | vma = find_vma(mm, address); |
| 311 | if (!vma) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 312 | goto out_up; |
Gerald Schaefer | c1821c2 | 2007-02-05 21:18:17 +0100 | [diff] [blame] | 313 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 314 | if (unlikely(vma->vm_start > address)) { |
| 315 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 316 | goto out_up; |
| 317 | if (expand_stack(vma, address)) |
| 318 | goto out_up; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * Ok, we have a good vm_area for this memory access, so |
| 323 | * we can handle it.. |
| 324 | */ |
| 325 | fault = VM_FAULT_BADACCESS; |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 326 | if (unlikely(!(vma->vm_flags & access))) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 327 | goto out_up; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | |
Gerald Schaefer | 53492b1 | 2008-04-30 13:38:46 +0200 | [diff] [blame] | 329 | if (is_vm_hugetlb_page(vma)) |
| 330 | address &= HPAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | /* |
| 332 | * If for any reason at all we couldn't handle the fault, |
| 333 | * make sure we exit gracefully rather than endlessly redo |
| 334 | * the fault. |
| 335 | */ |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 336 | fault = handle_mm_fault(mm, vma, address, flags); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 337 | if (unlikely(fault & VM_FAULT_ERROR)) |
| 338 | goto out_up; |
| 339 | |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 340 | /* |
| 341 | * Major/minor page fault accounting is only done on the |
| 342 | * initial attempt. If we go through a retry, it is extremely |
| 343 | * likely that the page will be found in page cache at that point. |
| 344 | */ |
| 345 | if (flags & FAULT_FLAG_ALLOW_RETRY) { |
| 346 | if (fault & VM_FAULT_MAJOR) { |
| 347 | tsk->maj_flt++; |
| 348 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0, |
| 349 | regs, address); |
| 350 | } else { |
| 351 | tsk->min_flt++; |
| 352 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0, |
| 353 | regs, address); |
| 354 | } |
| 355 | if (fault & VM_FAULT_RETRY) { |
| 356 | /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk |
| 357 | * of starvation. */ |
| 358 | flags &= ~FAULT_FLAG_ALLOW_RETRY; |
| 359 | goto retry; |
| 360 | } |
Heiko Carstens | bde69af | 2009-09-11 10:29:06 +0200 | [diff] [blame] | 361 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | /* |
| 363 | * The instruction that caused the program check will |
| 364 | * be repeated. Don't signal single step via SIGTRAP. |
| 365 | */ |
Martin Schwidefsky | 5e9a269 | 2011-01-05 12:48:10 +0100 | [diff] [blame] | 366 | clear_tsk_thread_flag(tsk, TIF_PER_TRAP); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 367 | fault = 0; |
| 368 | out_up: |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 369 | up_read(&mm->mmap_sem); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 370 | out: |
| 371 | return fault; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | } |
| 373 | |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 374 | void __kprobes do_protection_exception(struct pt_regs *regs, long pgm_int_code, |
| 375 | unsigned long trans_exc_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 377 | int fault; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 378 | |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 379 | /* Protection exception is suppressing, decrement psw address. */ |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 380 | regs->psw.addr -= (pgm_int_code >> 16); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 381 | /* |
| 382 | * Check for low-address protection. This needs to be treated |
| 383 | * as a special case because the translation exception code |
| 384 | * field is not guaranteed to contain valid data in this case. |
| 385 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 386 | if (unlikely(!(trans_exc_code & 4))) { |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 387 | do_low_address(regs, pgm_int_code, trans_exc_code); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 388 | return; |
| 389 | } |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 390 | fault = do_exception(regs, VM_WRITE, trans_exc_code); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 391 | if (unlikely(fault)) |
| 392 | do_fault_error(regs, 4, trans_exc_code, fault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | } |
| 394 | |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 395 | void __kprobes do_dat_exception(struct pt_regs *regs, long pgm_int_code, |
| 396 | unsigned long trans_exc_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | { |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 398 | int access, fault; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 399 | |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 400 | access = VM_READ | VM_EXEC | VM_WRITE; |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 401 | fault = do_exception(regs, access, trans_exc_code); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 402 | if (unlikely(fault)) |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 403 | do_fault_error(regs, pgm_int_code & 255, trans_exc_code, fault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | } |
| 405 | |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 406 | #ifdef CONFIG_64BIT |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 407 | void __kprobes do_asce_exception(struct pt_regs *regs, long pgm_int_code, |
| 408 | unsigned long trans_exc_code) |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 409 | { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 410 | struct mm_struct *mm = current->mm; |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 411 | struct vm_area_struct *vma; |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 412 | |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 413 | if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm)) |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 414 | goto no_context; |
| 415 | |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 416 | down_read(&mm->mmap_sem); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 417 | vma = find_vma(mm, trans_exc_code & __FAIL_ADDR_MASK); |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 418 | up_read(&mm->mmap_sem); |
| 419 | |
| 420 | if (vma) { |
| 421 | update_mm(mm, current); |
| 422 | return; |
| 423 | } |
| 424 | |
| 425 | /* User mode accesses just cause a SIGSEGV */ |
| 426 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 427 | do_sigsegv(regs, pgm_int_code, SEGV_MAPERR, trans_exc_code); |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 428 | return; |
| 429 | } |
| 430 | |
| 431 | no_context: |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 432 | do_no_context(regs, pgm_int_code, trans_exc_code); |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 433 | } |
| 434 | #endif |
| 435 | |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 436 | int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write) |
Gerald Schaefer | 6c1e3e7 | 2009-12-07 12:51:47 +0100 | [diff] [blame] | 437 | { |
| 438 | struct pt_regs regs; |
| 439 | int access, fault; |
| 440 | |
| 441 | regs.psw.mask = psw_kernel_bits; |
| 442 | if (!irqs_disabled()) |
| 443 | regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT; |
| 444 | regs.psw.addr = (unsigned long) __builtin_return_address(0); |
| 445 | regs.psw.addr |= PSW_ADDR_AMODE; |
| 446 | uaddr &= PAGE_MASK; |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 447 | access = write ? VM_WRITE : VM_READ; |
Gerald Schaefer | 6c1e3e7 | 2009-12-07 12:51:47 +0100 | [diff] [blame] | 448 | fault = do_exception(®s, access, uaddr | 2); |
| 449 | if (unlikely(fault)) { |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 450 | if (fault & VM_FAULT_OOM) |
| 451 | return -EFAULT; |
| 452 | else if (fault & VM_FAULT_SIGBUS) |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 453 | do_sigbus(®s, pgm_int_code, uaddr); |
Gerald Schaefer | 6c1e3e7 | 2009-12-07 12:51:47 +0100 | [diff] [blame] | 454 | } |
| 455 | return fault ? -EFAULT : 0; |
| 456 | } |
| 457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | #ifdef CONFIG_PFAULT |
| 459 | /* |
| 460 | * 'pfault' pseudo page faults routines. |
| 461 | */ |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 462 | static int pfault_disable; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | |
| 464 | static int __init nopfault(char *str) |
| 465 | { |
| 466 | pfault_disable = 1; |
| 467 | return 1; |
| 468 | } |
| 469 | |
| 470 | __setup("nopfault", nopfault); |
| 471 | |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 472 | struct pfault_refbk { |
| 473 | u16 refdiagc; |
| 474 | u16 reffcode; |
| 475 | u16 refdwlen; |
| 476 | u16 refversn; |
| 477 | u64 refgaddr; |
| 478 | u64 refselmk; |
| 479 | u64 refcmpmk; |
| 480 | u64 reserved; |
| 481 | } __attribute__ ((packed, aligned(8))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | |
| 483 | int pfault_init(void) |
| 484 | { |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 485 | struct pfault_refbk refbk = { |
| 486 | .refdiagc = 0x258, |
| 487 | .reffcode = 0, |
| 488 | .refdwlen = 5, |
| 489 | .refversn = 2, |
| 490 | .refgaddr = __LC_CURRENT_PID, |
| 491 | .refselmk = 1ULL << 48, |
| 492 | .refcmpmk = 1ULL << 48, |
| 493 | .reserved = __PF_RES_FIELD }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | int rc; |
| 495 | |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 496 | if (!MACHINE_IS_VM || pfault_disable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | return -1; |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 498 | asm volatile( |
| 499 | " diag %1,%0,0x258\n" |
| 500 | "0: j 2f\n" |
| 501 | "1: la %0,8\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | "2:\n" |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 503 | EX_TABLE(0b,1b) |
| 504 | : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | return rc; |
| 506 | } |
| 507 | |
| 508 | void pfault_fini(void) |
| 509 | { |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 510 | struct pfault_refbk refbk = { |
| 511 | .refdiagc = 0x258, |
| 512 | .reffcode = 1, |
| 513 | .refdwlen = 5, |
| 514 | .refversn = 2, |
| 515 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 517 | if (!MACHINE_IS_VM || pfault_disable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | return; |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 519 | asm volatile( |
| 520 | " diag %0,0,0x258\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | "0:\n" |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 522 | EX_TABLE(0b,0b) |
| 523 | : : "a" (&refbk), "m" (refbk) : "cc"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | } |
| 525 | |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 526 | static DEFINE_SPINLOCK(pfault_lock); |
| 527 | static LIST_HEAD(pfault_list); |
| 528 | |
Martin Schwidefsky | f6649a7 | 2010-10-25 16:10:38 +0200 | [diff] [blame] | 529 | static void pfault_interrupt(unsigned int ext_int_code, |
| 530 | unsigned int param32, unsigned long param64) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | { |
| 532 | struct task_struct *tsk; |
| 533 | __u16 subcode; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 534 | pid_t pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | |
| 536 | /* |
| 537 | * Get the external interruption subcode & pfault |
| 538 | * initial/completion signal bit. VM stores this |
| 539 | * in the 'cpu address' field associated with the |
| 540 | * external interrupt. |
| 541 | */ |
Martin Schwidefsky | f6649a7 | 2010-10-25 16:10:38 +0200 | [diff] [blame] | 542 | subcode = ext_int_code >> 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | if ((subcode & 0xff00) != __SUBCODE_MASK) |
| 544 | return; |
Heiko Carstens | a985183 | 2011-04-29 10:42:19 +0200 | [diff] [blame] | 545 | kstat_cpu(smp_processor_id()).irqs[EXTINT_PFL]++; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 546 | if (subcode & 0x0080) { |
| 547 | /* Get the token (= pid of the affected task). */ |
| 548 | pid = sizeof(void *) == 4 ? param32 : param64; |
| 549 | rcu_read_lock(); |
| 550 | tsk = find_task_by_pid_ns(pid, &init_pid_ns); |
| 551 | if (tsk) |
| 552 | get_task_struct(tsk); |
| 553 | rcu_read_unlock(); |
| 554 | if (!tsk) |
| 555 | return; |
| 556 | } else { |
| 557 | tsk = current; |
| 558 | } |
| 559 | spin_lock(&pfault_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 560 | if (subcode & 0x0080) { |
| 561 | /* signal bit is set -> a page has been swapped in by VM */ |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 562 | if (tsk->thread.pfault_wait == 1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | /* Initial interrupt was faster than the completion |
| 564 | * interrupt. pfault_wait is valid. Set pfault_wait |
| 565 | * back to zero and wake up the process. This can |
| 566 | * safely be done because the task is still sleeping |
Martin Schwidefsky | b6d0944 | 2005-09-03 15:58:02 -0700 | [diff] [blame] | 567 | * and can't produce new pfaults. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | tsk->thread.pfault_wait = 0; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 569 | list_del(&tsk->thread.list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | wake_up_process(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 571 | } else { |
| 572 | /* Completion interrupt was faster than initial |
| 573 | * interrupt. Set pfault_wait to -1 so the initial |
| 574 | * interrupt doesn't put the task to sleep. */ |
| 575 | tsk->thread.pfault_wait = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | } |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 577 | put_task_struct(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | } else { |
| 579 | /* signal bit not set -> a real page is missing. */ |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 580 | if (tsk->thread.pfault_wait == -1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | /* Completion interrupt was faster than the initial |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 582 | * interrupt (pfault_wait == -1). Set pfault_wait |
| 583 | * back to zero and exit. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | tsk->thread.pfault_wait = 0; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 585 | } else { |
| 586 | /* Initial interrupt arrived before completion |
| 587 | * interrupt. Let the task sleep. */ |
| 588 | tsk->thread.pfault_wait = 1; |
| 589 | list_add(&tsk->thread.list, &pfault_list); |
| 590 | set_task_state(tsk, TASK_UNINTERRUPTIBLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | set_tsk_need_resched(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 592 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | } |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 594 | spin_unlock(&pfault_lock); |
| 595 | } |
| 596 | |
| 597 | static int __cpuinit pfault_cpu_notify(struct notifier_block *self, |
| 598 | unsigned long action, void *hcpu) |
| 599 | { |
| 600 | struct thread_struct *thread, *next; |
| 601 | struct task_struct *tsk; |
| 602 | |
| 603 | switch (action) { |
| 604 | case CPU_DEAD: |
| 605 | case CPU_DEAD_FROZEN: |
| 606 | spin_lock_irq(&pfault_lock); |
| 607 | list_for_each_entry_safe(thread, next, &pfault_list, list) { |
| 608 | thread->pfault_wait = 0; |
| 609 | list_del(&thread->list); |
| 610 | tsk = container_of(thread, struct task_struct, thread); |
| 611 | wake_up_process(tsk); |
| 612 | } |
| 613 | spin_unlock_irq(&pfault_lock); |
| 614 | break; |
| 615 | default: |
| 616 | break; |
| 617 | } |
| 618 | return NOTIFY_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 621 | static int __init pfault_irq_init(void) |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 622 | { |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 623 | int rc; |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 624 | |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 625 | if (!MACHINE_IS_VM) |
| 626 | return 0; |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 627 | rc = register_external_interrupt(0x2603, pfault_interrupt); |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 628 | if (rc) |
| 629 | goto out_extint; |
| 630 | rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP; |
| 631 | if (rc) |
| 632 | goto out_pfault; |
Heiko Carstens | df7997a | 2011-05-26 09:48:23 +0200 | [diff] [blame] | 633 | service_subclass_irq_register(); |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 634 | hotcpu_notifier(pfault_cpu_notify, 0); |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 635 | return 0; |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 636 | |
| 637 | out_pfault: |
| 638 | unregister_external_interrupt(0x2603, pfault_interrupt); |
| 639 | out_extint: |
| 640 | pfault_disable = 1; |
| 641 | return rc; |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 642 | } |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 643 | early_initcall(pfault_irq_init); |
| 644 | |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 645 | #endif /* CONFIG_PFAULT */ |