Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * S390 version |
Heiko Carstens | a53c8fa | 2012-07-20 11:15:04 +0200 | [diff] [blame] | 3 | * Copyright IBM Corp. 1999 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * Author(s): Hartmut Penner (hp@de.ibm.com) |
| 5 | * Ulrich Weigand (uweigand@de.ibm.com) |
| 6 | * |
| 7 | * Derived from "arch/i386/mm/fault.c" |
| 8 | * Copyright (C) 1995 Linus Torvalds |
| 9 | */ |
| 10 | |
Heiko Carstens | 052ff46 | 2011-01-05 12:47:28 +0100 | [diff] [blame] | 11 | #include <linux/kernel_stat.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 12 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/signal.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/ptrace.h> |
| 20 | #include <linux/mman.h> |
| 21 | #include <linux/mm.h> |
Heiko Carstens | 7757591 | 2009-06-12 10:26:25 +0200 | [diff] [blame] | 22 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/smp.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 24 | #include <linux/kdebug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/init.h> |
| 26 | #include <linux/console.h> |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/hardirq.h> |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 29 | #include <linux/kprobes.h> |
Martin Schwidefsky | be5ec36 | 2007-04-27 16:01:44 +0200 | [diff] [blame] | 30 | #include <linux/uaccess.h> |
Gerald Schaefer | 53492b1 | 2008-04-30 13:38:46 +0200 | [diff] [blame] | 31 | #include <linux/hugetlb.h> |
Heiko Carstens | cbb870c | 2010-02-26 22:37:43 +0100 | [diff] [blame] | 32 | #include <asm/asm-offsets.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #include <asm/pgtable.h> |
Heiko Carstens | d7b250e | 2011-05-26 09:48:24 +0200 | [diff] [blame] | 34 | #include <asm/irq.h> |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 35 | #include <asm/mmu_context.h> |
David Howells | a0616cd | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 36 | #include <asm/facility.h> |
Heiko Carstens | a806170 | 2008-04-17 07:46:26 +0200 | [diff] [blame] | 37 | #include "../kernel/entry.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 39 | #ifndef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | #define __FAIL_ADDR_MASK 0x7ffff000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #define __SUBCODE_MASK 0x0200 |
| 42 | #define __PF_RES_FIELD 0ULL |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 43 | #else /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #define __FAIL_ADDR_MASK -4096L |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #define __SUBCODE_MASK 0x0600 |
| 46 | #define __PF_RES_FIELD 0x8000000000000000ULL |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 47 | #endif /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 49 | #define VM_FAULT_BADCONTEXT 0x010000 |
| 50 | #define VM_FAULT_BADMAP 0x020000 |
| 51 | #define VM_FAULT_BADACCESS 0x040000 |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 52 | #define VM_FAULT_SIGNAL 0x080000 |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 53 | #define VM_FAULT_PFAULT 0x100000 |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 54 | |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 55 | static unsigned long store_indication __read_mostly; |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 56 | |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 57 | #ifdef CONFIG_64BIT |
| 58 | static int __init fault_init(void) |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 59 | { |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 60 | if (test_facility(75)) |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 61 | store_indication = 0xc00; |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 62 | return 0; |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 63 | } |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 64 | early_initcall(fault_init); |
| 65 | #endif |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 66 | |
Martin Schwidefsky | 7ecb344 | 2009-12-07 12:51:44 +0100 | [diff] [blame] | 67 | static inline int notify_page_fault(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 68 | { |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 69 | int ret = 0; |
| 70 | |
| 71 | /* kprobe_running() needs smp_processor_id() */ |
Heiko Carstens | 22e0a04 | 2010-02-26 22:37:45 +0100 | [diff] [blame] | 72 | if (kprobes_built_in() && !user_mode(regs)) { |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 73 | preempt_disable(); |
| 74 | if (kprobe_running() && kprobe_fault_handler(regs, 14)) |
| 75 | ret = 1; |
| 76 | preempt_enable(); |
| 77 | } |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 78 | return ret; |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 79 | } |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 80 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | |
| 82 | /* |
| 83 | * Unlock any spinlocks which will prevent us from getting the |
Kirill Korotaev | cefc8be | 2007-02-10 01:46:18 -0800 | [diff] [blame] | 84 | * message out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | */ |
| 86 | void bust_spinlocks(int yes) |
| 87 | { |
| 88 | if (yes) { |
| 89 | oops_in_progress = 1; |
| 90 | } else { |
| 91 | int loglevel_save = console_loglevel; |
| 92 | console_unblank(); |
| 93 | oops_in_progress = 0; |
| 94 | /* |
| 95 | * OK, the message is on the console. Now we call printk() |
| 96 | * without oops_in_progress set so that printk will give klogd |
| 97 | * a poke. Hold onto your hats... |
| 98 | */ |
| 99 | console_loglevel = 15; |
| 100 | printk(" "); |
| 101 | console_loglevel = loglevel_save; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | /* |
Gerald Schaefer | 482b05d | 2007-03-05 23:35:54 +0100 | [diff] [blame] | 106 | * Returns the address space associated with the fault. |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 107 | * Returns 0 for kernel space and 1 for user space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 109 | static inline int user_space_fault(unsigned long trans_exc_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | { |
| 111 | /* |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 112 | * The lowest two bits of the translation exception |
| 113 | * identification indicate which paging table was used. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 115 | trans_exc_code &= 3; |
| 116 | if (trans_exc_code == 2) |
| 117 | /* Access via secondary space, set_fs setting decides */ |
| 118 | return current->thread.mm_segment.ar4; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 119 | /* |
Martin Schwidefsky | e258d71 | 2013-09-24 09:14:56 +0200 | [diff] [blame] | 120 | * Access via primary space or access register is from user space |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 121 | * and access via home space is from the kernel. |
| 122 | */ |
| 123 | return trans_exc_code != 3; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | } |
| 125 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 126 | static inline void report_user_fault(struct pt_regs *regs, long signr) |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 127 | { |
| 128 | if ((task_pid_nr(current) > 1) && !show_unhandled_signals) |
| 129 | return; |
| 130 | if (!unhandled_signal(current, signr)) |
| 131 | return; |
| 132 | if (!printk_ratelimit()) |
| 133 | return; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 134 | printk(KERN_ALERT "User process fault: interruption code 0x%X ", |
| 135 | regs->int_code); |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 136 | print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN); |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 137 | printk(KERN_CONT "\n"); |
| 138 | printk(KERN_ALERT "failing address: %lX\n", |
| 139 | regs->int_parm_long & __FAIL_ADDR_MASK); |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 140 | show_regs(regs); |
| 141 | } |
| 142 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | /* |
| 144 | * Send SIGSEGV to task. This is an external routine |
| 145 | * to keep the stack usage of do_page_fault small. |
| 146 | */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 147 | static noinline void do_sigsegv(struct pt_regs *regs, int si_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | { |
| 149 | struct siginfo si; |
| 150 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 151 | report_user_fault(regs, SIGSEGV); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | si.si_signo = SIGSEGV; |
| 153 | si.si_code = si_code; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 154 | si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | force_sig_info(SIGSEGV, &si, current); |
| 156 | } |
| 157 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 158 | static noinline void do_no_context(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 159 | { |
| 160 | const struct exception_table_entry *fixup; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 161 | unsigned long address; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 162 | |
| 163 | /* Are we prepared to handle this kernel fault? */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 164 | fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 165 | if (fixup) { |
Heiko Carstens | eb608fb | 2012-09-05 13:26:11 +0200 | [diff] [blame] | 166 | regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 167 | return; |
| 168 | } |
| 169 | |
| 170 | /* |
| 171 | * Oops. The kernel tried to access some bad page. We'll have to |
| 172 | * terminate things with extreme prejudice. |
| 173 | */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 174 | address = regs->int_parm_long & __FAIL_ADDR_MASK; |
| 175 | if (!user_space_fault(regs->int_parm_long)) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 176 | printk(KERN_ALERT "Unable to handle kernel pointer dereference" |
| 177 | " at virtual kernel address %p\n", (void *)address); |
| 178 | else |
| 179 | printk(KERN_ALERT "Unable to handle kernel paging request" |
| 180 | " at virtual user address %p\n", (void *)address); |
| 181 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 182 | die(regs, "Oops"); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 183 | do_exit(SIGKILL); |
| 184 | } |
| 185 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 186 | static noinline void do_low_address(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 187 | { |
| 188 | /* Low-address protection hit in kernel mode means |
| 189 | NULL pointer write access in kernel mode. */ |
| 190 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 191 | /* Low-address protection hit in user mode 'cannot happen'. */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 192 | die (regs, "Low-address protection"); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 193 | do_exit(SIGKILL); |
| 194 | } |
| 195 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 196 | do_no_context(regs); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 197 | } |
| 198 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 199 | static noinline void do_sigbus(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 200 | { |
| 201 | struct task_struct *tsk = current; |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 202 | struct siginfo si; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 203 | |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 204 | /* |
| 205 | * Send a sigbus, regardless of whether we were in kernel |
| 206 | * or user mode. |
| 207 | */ |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 208 | si.si_signo = SIGBUS; |
| 209 | si.si_errno = 0; |
| 210 | si.si_code = BUS_ADRERR; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 211 | si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 212 | force_sig_info(SIGBUS, &si, tsk); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 213 | } |
| 214 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 215 | static noinline void do_fault_error(struct pt_regs *regs, int fault) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 216 | { |
| 217 | int si_code; |
| 218 | |
| 219 | switch (fault) { |
| 220 | case VM_FAULT_BADACCESS: |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 221 | case VM_FAULT_BADMAP: |
| 222 | /* Bad memory access. Check if it is kernel or user space. */ |
Heiko Carstens | 7d25617 | 2012-07-27 10:31:12 +0200 | [diff] [blame] | 223 | if (user_mode(regs)) { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 224 | /* User mode accesses just cause a SIGSEGV */ |
| 225 | si_code = (fault == VM_FAULT_BADMAP) ? |
| 226 | SEGV_MAPERR : SEGV_ACCERR; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 227 | do_sigsegv(regs, si_code); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 228 | return; |
| 229 | } |
| 230 | case VM_FAULT_BADCONTEXT: |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 231 | case VM_FAULT_PFAULT: |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 232 | do_no_context(regs); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 233 | break; |
Heiko Carstens | f2c76e3 | 2012-07-27 08:54:20 +0200 | [diff] [blame] | 234 | case VM_FAULT_SIGNAL: |
| 235 | if (!user_mode(regs)) |
| 236 | do_no_context(regs); |
| 237 | break; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 238 | default: /* fault & VM_FAULT_ERROR */ |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 239 | if (fault & VM_FAULT_OOM) { |
Heiko Carstens | 7d25617 | 2012-07-27 10:31:12 +0200 | [diff] [blame] | 240 | if (!user_mode(regs)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 241 | do_no_context(regs); |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 242 | else |
| 243 | pagefault_out_of_memory(); |
| 244 | } else if (fault & VM_FAULT_SIGBUS) { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 245 | /* Kernel mode? Handle exceptions or die */ |
Heiko Carstens | 7d25617 | 2012-07-27 10:31:12 +0200 | [diff] [blame] | 246 | if (!user_mode(regs)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 247 | do_no_context(regs); |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 248 | else |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 249 | do_sigbus(regs); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 250 | } else |
| 251 | BUG(); |
| 252 | break; |
| 253 | } |
| 254 | } |
| 255 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | /* |
| 257 | * This routine handles page faults. It determines the address, |
| 258 | * and the problem, and then passes it off to one of the appropriate |
| 259 | * routines. |
| 260 | * |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 261 | * interruption code (int_code): |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | * 04 Protection -> Write-Protection (suprression) |
| 263 | * 10 Segment translation -> Not present (nullification) |
| 264 | * 11 Page translation -> Not present (nullification) |
| 265 | * 3b Region third trans. -> Not present (nullification) |
| 266 | */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 267 | static inline int do_exception(struct pt_regs *regs, int access) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | { |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 269 | #ifdef CONFIG_PGSTE |
| 270 | struct gmap *gmap; |
| 271 | #endif |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 272 | struct task_struct *tsk; |
| 273 | struct mm_struct *mm; |
| 274 | struct vm_area_struct *vma; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 275 | unsigned long trans_exc_code; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 276 | unsigned long address; |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 277 | unsigned int flags; |
| 278 | int fault; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
Martin Schwidefsky | 39efd4e | 2012-11-21 16:36:27 +0100 | [diff] [blame] | 280 | tsk = current; |
| 281 | /* |
| 282 | * The instruction that caused the program check has |
| 283 | * been nullified. Don't signal single step via SIGTRAP. |
| 284 | */ |
| 285 | clear_tsk_thread_flag(tsk, TIF_PER_TRAP); |
| 286 | |
Martin Schwidefsky | 7ecb344 | 2009-12-07 12:51:44 +0100 | [diff] [blame] | 287 | if (notify_page_fault(regs)) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 288 | return 0; |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 289 | |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 290 | mm = tsk->mm; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 291 | trans_exc_code = regs->int_parm_long; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | /* |
| 294 | * Verify that the fault happened in user space, that |
| 295 | * we are not in an interrupt and that there is a |
| 296 | * user context. |
| 297 | */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 298 | fault = VM_FAULT_BADCONTEXT; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 299 | if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm)) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 300 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 302 | address = trans_exc_code & __FAIL_ADDR_MASK; |
Peter Zijlstra | a8b0ca1 | 2011-06-27 14:41:57 +0200 | [diff] [blame] | 303 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); |
Heiko Carstens | f2c76e3 | 2012-07-27 08:54:20 +0200 | [diff] [blame] | 304 | flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
Johannes Weiner | 759496b | 2013-09-12 15:13:39 -0700 | [diff] [blame] | 305 | if (user_mode(regs)) |
| 306 | flags |= FAULT_FLAG_USER; |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 307 | if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) |
| 308 | flags |= FAULT_FLAG_WRITE; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 309 | down_read(&mm->mmap_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 311 | #ifdef CONFIG_PGSTE |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 312 | gmap = (struct gmap *) |
| 313 | ((current->flags & PF_VCPU) ? S390_lowcore.gmap : 0); |
| 314 | if (gmap) { |
| 315 | address = __gmap_fault(address, gmap); |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 316 | if (address == -EFAULT) { |
| 317 | fault = VM_FAULT_BADMAP; |
| 318 | goto out_up; |
| 319 | } |
| 320 | if (address == -ENOMEM) { |
| 321 | fault = VM_FAULT_OOM; |
| 322 | goto out_up; |
| 323 | } |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 324 | if (gmap->pfault_enabled) |
| 325 | flags |= FAULT_FLAG_RETRY_NOWAIT; |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 326 | } |
| 327 | #endif |
| 328 | |
| 329 | retry: |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 330 | fault = VM_FAULT_BADMAP; |
Gerald Schaefer | 482b05d | 2007-03-05 23:35:54 +0100 | [diff] [blame] | 331 | vma = find_vma(mm, address); |
| 332 | if (!vma) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 333 | goto out_up; |
Gerald Schaefer | c1821c2 | 2007-02-05 21:18:17 +0100 | [diff] [blame] | 334 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 335 | if (unlikely(vma->vm_start > address)) { |
| 336 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 337 | goto out_up; |
| 338 | if (expand_stack(vma, address)) |
| 339 | goto out_up; |
| 340 | } |
| 341 | |
| 342 | /* |
| 343 | * Ok, we have a good vm_area for this memory access, so |
| 344 | * we can handle it.. |
| 345 | */ |
| 346 | fault = VM_FAULT_BADACCESS; |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 347 | if (unlikely(!(vma->vm_flags & access))) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 348 | goto out_up; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | |
Gerald Schaefer | 53492b1 | 2008-04-30 13:38:46 +0200 | [diff] [blame] | 350 | if (is_vm_hugetlb_page(vma)) |
| 351 | address &= HPAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | /* |
| 353 | * If for any reason at all we couldn't handle the fault, |
| 354 | * make sure we exit gracefully rather than endlessly redo |
| 355 | * the fault. |
| 356 | */ |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 357 | fault = handle_mm_fault(mm, vma, address, flags); |
Heiko Carstens | f2c76e3 | 2012-07-27 08:54:20 +0200 | [diff] [blame] | 358 | /* No reason to continue if interrupted by SIGKILL. */ |
| 359 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) { |
| 360 | fault = VM_FAULT_SIGNAL; |
| 361 | goto out; |
| 362 | } |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 363 | if (unlikely(fault & VM_FAULT_ERROR)) |
| 364 | goto out_up; |
| 365 | |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 366 | /* |
| 367 | * Major/minor page fault accounting is only done on the |
| 368 | * initial attempt. If we go through a retry, it is extremely |
| 369 | * likely that the page will be found in page cache at that point. |
| 370 | */ |
| 371 | if (flags & FAULT_FLAG_ALLOW_RETRY) { |
| 372 | if (fault & VM_FAULT_MAJOR) { |
| 373 | tsk->maj_flt++; |
Peter Zijlstra | a8b0ca1 | 2011-06-27 14:41:57 +0200 | [diff] [blame] | 374 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 375 | regs, address); |
| 376 | } else { |
| 377 | tsk->min_flt++; |
Peter Zijlstra | a8b0ca1 | 2011-06-27 14:41:57 +0200 | [diff] [blame] | 378 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 379 | regs, address); |
| 380 | } |
| 381 | if (fault & VM_FAULT_RETRY) { |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 382 | #ifdef CONFIG_PGSTE |
| 383 | if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) { |
| 384 | /* FAULT_FLAG_RETRY_NOWAIT has been set, |
| 385 | * mmap_sem has not been released */ |
| 386 | current->thread.gmap_pfault = 1; |
| 387 | fault = VM_FAULT_PFAULT; |
| 388 | goto out_up; |
| 389 | } |
| 390 | #endif |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 391 | /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk |
| 392 | * of starvation. */ |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame^] | 393 | flags &= ~(FAULT_FLAG_ALLOW_RETRY | |
| 394 | FAULT_FLAG_RETRY_NOWAIT); |
Shaohua Li | 45cac65 | 2012-10-08 16:32:19 -0700 | [diff] [blame] | 395 | flags |= FAULT_FLAG_TRIED; |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 396 | down_read(&mm->mmap_sem); |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 397 | goto retry; |
| 398 | } |
Heiko Carstens | bde69af | 2009-09-11 10:29:06 +0200 | [diff] [blame] | 399 | } |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 400 | fault = 0; |
| 401 | out_up: |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 402 | up_read(&mm->mmap_sem); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 403 | out: |
| 404 | return fault; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | } |
| 406 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 407 | void __kprobes do_protection_exception(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | { |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 409 | unsigned long trans_exc_code; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 410 | int fault; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 411 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 412 | trans_exc_code = regs->int_parm_long; |
Martin Schwidefsky | f752ac4 | 2013-04-16 13:25:06 +0200 | [diff] [blame] | 413 | /* |
| 414 | * Protection exceptions are suppressing, decrement psw address. |
| 415 | * The exception to this rule are aborted transactions, for these |
| 416 | * the PSW already points to the correct location. |
| 417 | */ |
| 418 | if (!(regs->int_code & 0x200)) |
| 419 | regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 420 | /* |
| 421 | * Check for low-address protection. This needs to be treated |
| 422 | * as a special case because the translation exception code |
| 423 | * field is not guaranteed to contain valid data in this case. |
| 424 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 425 | if (unlikely(!(trans_exc_code & 4))) { |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 426 | do_low_address(regs); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 427 | return; |
| 428 | } |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 429 | fault = do_exception(regs, VM_WRITE); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 430 | if (unlikely(fault)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 431 | do_fault_error(regs, fault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | } |
| 433 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 434 | void __kprobes do_dat_exception(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | { |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 436 | int access, fault; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 437 | |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 438 | access = VM_READ | VM_EXEC | VM_WRITE; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 439 | fault = do_exception(regs, access); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 440 | if (unlikely(fault)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 441 | do_fault_error(regs, fault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | } |
| 443 | |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 444 | 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] | 445 | { |
| 446 | struct pt_regs regs; |
| 447 | int access, fault; |
| 448 | |
Heiko Carstens | 008c2e8 | 2012-07-27 09:45:39 +0200 | [diff] [blame] | 449 | /* Emulate a uaccess fault from kernel mode. */ |
Martin Schwidefsky | e258d71 | 2013-09-24 09:14:56 +0200 | [diff] [blame] | 450 | regs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT | PSW_MASK_MCHECK; |
Gerald Schaefer | 6c1e3e7 | 2009-12-07 12:51:47 +0100 | [diff] [blame] | 451 | if (!irqs_disabled()) |
| 452 | regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT; |
| 453 | regs.psw.addr = (unsigned long) __builtin_return_address(0); |
| 454 | regs.psw.addr |= PSW_ADDR_AMODE; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 455 | regs.int_code = pgm_int_code; |
| 456 | regs.int_parm_long = (uaddr & PAGE_MASK) | 2; |
Martin Schwidefsky | 1e54622 | 2010-10-25 16:10:37 +0200 | [diff] [blame] | 457 | access = write ? VM_WRITE : VM_READ; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 458 | fault = do_exception(®s, access); |
Heiko Carstens | 008c2e8 | 2012-07-27 09:45:39 +0200 | [diff] [blame] | 459 | /* |
| 460 | * Since the fault happened in kernel mode while performing a uaccess |
| 461 | * all we need to do now is emulating a fixup in case "fault" is not |
| 462 | * zero. |
| 463 | * For the calling uaccess functions this results always in -EFAULT. |
| 464 | */ |
Gerald Schaefer | 6c1e3e7 | 2009-12-07 12:51:47 +0100 | [diff] [blame] | 465 | return fault ? -EFAULT : 0; |
| 466 | } |
| 467 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | #ifdef CONFIG_PFAULT |
| 469 | /* |
| 470 | * 'pfault' pseudo page faults routines. |
| 471 | */ |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 472 | static int pfault_disable; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
| 474 | static int __init nopfault(char *str) |
| 475 | { |
| 476 | pfault_disable = 1; |
| 477 | return 1; |
| 478 | } |
| 479 | |
| 480 | __setup("nopfault", nopfault); |
| 481 | |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 482 | struct pfault_refbk { |
| 483 | u16 refdiagc; |
| 484 | u16 reffcode; |
| 485 | u16 refdwlen; |
| 486 | u16 refversn; |
| 487 | u64 refgaddr; |
| 488 | u64 refselmk; |
| 489 | u64 refcmpmk; |
| 490 | u64 reserved; |
| 491 | } __attribute__ ((packed, aligned(8))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | |
| 493 | int pfault_init(void) |
| 494 | { |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 495 | struct pfault_refbk refbk = { |
| 496 | .refdiagc = 0x258, |
| 497 | .reffcode = 0, |
| 498 | .refdwlen = 5, |
| 499 | .refversn = 2, |
| 500 | .refgaddr = __LC_CURRENT_PID, |
| 501 | .refselmk = 1ULL << 48, |
| 502 | .refcmpmk = 1ULL << 48, |
| 503 | .reserved = __PF_RES_FIELD }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | int rc; |
| 505 | |
Carsten Otte | f32269a | 2011-12-27 11:27:11 +0100 | [diff] [blame] | 506 | if (pfault_disable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | return -1; |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 508 | asm volatile( |
| 509 | " diag %1,%0,0x258\n" |
| 510 | "0: j 2f\n" |
| 511 | "1: la %0,8\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | "2:\n" |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 513 | EX_TABLE(0b,1b) |
| 514 | : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | return rc; |
| 516 | } |
| 517 | |
| 518 | void pfault_fini(void) |
| 519 | { |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 520 | struct pfault_refbk refbk = { |
| 521 | .refdiagc = 0x258, |
| 522 | .reffcode = 1, |
| 523 | .refdwlen = 5, |
| 524 | .refversn = 2, |
| 525 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | |
Carsten Otte | f32269a | 2011-12-27 11:27:11 +0100 | [diff] [blame] | 527 | if (pfault_disable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | return; |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 529 | asm volatile( |
| 530 | " diag %0,0,0x258\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | "0:\n" |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 532 | EX_TABLE(0b,0b) |
| 533 | : : "a" (&refbk), "m" (refbk) : "cc"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | } |
| 535 | |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 536 | static DEFINE_SPINLOCK(pfault_lock); |
| 537 | static LIST_HEAD(pfault_list); |
| 538 | |
Heiko Carstens | fde15c3 | 2012-03-11 11:59:31 -0400 | [diff] [blame] | 539 | static void pfault_interrupt(struct ext_code ext_code, |
Martin Schwidefsky | f6649a7 | 2010-10-25 16:10:38 +0200 | [diff] [blame] | 540 | unsigned int param32, unsigned long param64) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | { |
| 542 | struct task_struct *tsk; |
| 543 | __u16 subcode; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 544 | pid_t pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | |
| 546 | /* |
| 547 | * Get the external interruption subcode & pfault |
| 548 | * initial/completion signal bit. VM stores this |
| 549 | * in the 'cpu address' field associated with the |
| 550 | * external interrupt. |
| 551 | */ |
Heiko Carstens | fde15c3 | 2012-03-11 11:59:31 -0400 | [diff] [blame] | 552 | subcode = ext_code.subcode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | if ((subcode & 0xff00) != __SUBCODE_MASK) |
| 554 | return; |
Heiko Carstens | 420f42e | 2013-01-02 15:18:18 +0100 | [diff] [blame] | 555 | inc_irq_stat(IRQEXT_PFL); |
Heiko Carstens | 54c2779 | 2012-05-10 09:44:35 +0200 | [diff] [blame] | 556 | /* Get the token (= pid of the affected task). */ |
| 557 | pid = sizeof(void *) == 4 ? param32 : param64; |
| 558 | rcu_read_lock(); |
| 559 | tsk = find_task_by_pid_ns(pid, &init_pid_ns); |
| 560 | if (tsk) |
| 561 | get_task_struct(tsk); |
| 562 | rcu_read_unlock(); |
| 563 | if (!tsk) |
| 564 | return; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 565 | spin_lock(&pfault_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | if (subcode & 0x0080) { |
| 567 | /* signal bit is set -> a page has been swapped in by VM */ |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 568 | if (tsk->thread.pfault_wait == 1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | /* Initial interrupt was faster than the completion |
| 570 | * interrupt. pfault_wait is valid. Set pfault_wait |
| 571 | * back to zero and wake up the process. This can |
| 572 | * safely be done because the task is still sleeping |
Martin Schwidefsky | b6d0944 | 2005-09-03 15:58:02 -0700 | [diff] [blame] | 573 | * and can't produce new pfaults. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | tsk->thread.pfault_wait = 0; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 575 | list_del(&tsk->thread.list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | wake_up_process(tsk); |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 577 | put_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 578 | } else { |
| 579 | /* Completion interrupt was faster than initial |
| 580 | * interrupt. Set pfault_wait to -1 so the initial |
Heiko Carstens | fa2fb2f | 2011-11-14 11:19:01 +0100 | [diff] [blame] | 581 | * interrupt doesn't put the task to sleep. |
| 582 | * If the task is not running, ignore the completion |
| 583 | * interrupt since it must be a leftover of a PFAULT |
| 584 | * CANCEL operation which didn't remove all pending |
| 585 | * completion interrupts. */ |
| 586 | if (tsk->state == TASK_RUNNING) |
| 587 | tsk->thread.pfault_wait = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | } |
| 589 | } else { |
| 590 | /* signal bit not set -> a real page is missing. */ |
Heiko Carstens | d49f47f | 2012-05-10 10:47:21 +0200 | [diff] [blame] | 591 | if (WARN_ON_ONCE(tsk != current)) |
| 592 | goto out; |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 593 | if (tsk->thread.pfault_wait == 1) { |
| 594 | /* Already on the list with a reference: put to sleep */ |
Heiko Carstens | 0a16ba7 | 2012-05-10 09:56:34 +0200 | [diff] [blame] | 595 | __set_task_state(tsk, TASK_UNINTERRUPTIBLE); |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 596 | set_tsk_need_resched(tsk); |
| 597 | } else if (tsk->thread.pfault_wait == -1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | /* Completion interrupt was faster than the initial |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 599 | * interrupt (pfault_wait == -1). Set pfault_wait |
| 600 | * back to zero and exit. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | tsk->thread.pfault_wait = 0; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 602 | } else { |
| 603 | /* Initial interrupt arrived before completion |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 604 | * interrupt. Let the task sleep. |
| 605 | * An extra task reference is needed since a different |
| 606 | * cpu may set the task state to TASK_RUNNING again |
| 607 | * before the scheduler is reached. */ |
| 608 | get_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 609 | tsk->thread.pfault_wait = 1; |
| 610 | list_add(&tsk->thread.list, &pfault_list); |
Heiko Carstens | 0a16ba7 | 2012-05-10 09:56:34 +0200 | [diff] [blame] | 611 | __set_task_state(tsk, TASK_UNINTERRUPTIBLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | set_tsk_need_resched(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 613 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | } |
Heiko Carstens | d49f47f | 2012-05-10 10:47:21 +0200 | [diff] [blame] | 615 | out: |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 616 | spin_unlock(&pfault_lock); |
Heiko Carstens | 54c2779 | 2012-05-10 09:44:35 +0200 | [diff] [blame] | 617 | put_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 618 | } |
| 619 | |
Paul Gortmaker | e2741f1 | 2013-06-18 17:04:52 -0400 | [diff] [blame] | 620 | static int pfault_cpu_notify(struct notifier_block *self, unsigned long action, |
| 621 | void *hcpu) |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 622 | { |
| 623 | struct thread_struct *thread, *next; |
| 624 | struct task_struct *tsk; |
| 625 | |
Heiko Carstens | 1c72592 | 2012-08-27 15:43:49 +0200 | [diff] [blame] | 626 | switch (action & ~CPU_TASKS_FROZEN) { |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 627 | case CPU_DEAD: |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 628 | spin_lock_irq(&pfault_lock); |
| 629 | list_for_each_entry_safe(thread, next, &pfault_list, list) { |
| 630 | thread->pfault_wait = 0; |
| 631 | list_del(&thread->list); |
| 632 | tsk = container_of(thread, struct task_struct, thread); |
| 633 | wake_up_process(tsk); |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 634 | put_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 635 | } |
| 636 | spin_unlock_irq(&pfault_lock); |
| 637 | break; |
| 638 | default: |
| 639 | break; |
| 640 | } |
| 641 | return NOTIFY_OK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 644 | static int __init pfault_irq_init(void) |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 645 | { |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 646 | int rc; |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 647 | |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 648 | rc = register_external_interrupt(0x2603, pfault_interrupt); |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 649 | if (rc) |
| 650 | goto out_extint; |
| 651 | rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP; |
| 652 | if (rc) |
| 653 | goto out_pfault; |
Heiko Carstens | 82003c3 | 2013-09-04 13:35:45 +0200 | [diff] [blame] | 654 | irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 655 | hotcpu_notifier(pfault_cpu_notify, 0); |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 656 | return 0; |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 657 | |
| 658 | out_pfault: |
| 659 | unregister_external_interrupt(0x2603, pfault_interrupt); |
| 660 | out_extint: |
| 661 | pfault_disable = 1; |
| 662 | return rc; |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 663 | } |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 664 | early_initcall(pfault_irq_init); |
| 665 | |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 666 | #endif /* CONFIG_PFAULT */ |