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> |
Paul Gortmaker | dcc096c | 2016-09-19 17:54:56 -0400 | [diff] [blame] | 27 | #include <linux/extable.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Martin Schwidefsky | 1ec2772 | 2015-08-20 17:28:44 +0200 | [diff] [blame] | 33 | #include <asm/diag.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <asm/pgtable.h> |
Martin Schwidefsky | 1e133ab | 2016-03-08 11:49:57 +0100 | [diff] [blame] | 35 | #include <asm/gmap.h> |
Heiko Carstens | d7b250e | 2011-05-26 09:48:24 +0200 | [diff] [blame] | 36 | #include <asm/irq.h> |
Martin Schwidefsky | 6252d70 | 2008-02-09 18:24:37 +0100 | [diff] [blame] | 37 | #include <asm/mmu_context.h> |
David Howells | a0616cd | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 38 | #include <asm/facility.h> |
Heiko Carstens | a806170 | 2008-04-17 07:46:26 +0200 | [diff] [blame] | 39 | #include "../kernel/entry.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #define __FAIL_ADDR_MASK -4096L |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #define __SUBCODE_MASK 0x0600 |
| 43 | #define __PF_RES_FIELD 0x8000000000000000ULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 45 | #define VM_FAULT_BADCONTEXT 0x010000 |
| 46 | #define VM_FAULT_BADMAP 0x020000 |
| 47 | #define VM_FAULT_BADACCESS 0x040000 |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 48 | #define VM_FAULT_SIGNAL 0x080000 |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 49 | #define VM_FAULT_PFAULT 0x100000 |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 50 | |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 51 | static unsigned long store_indication __read_mostly; |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 52 | |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 53 | static int __init fault_init(void) |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 54 | { |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 55 | if (test_facility(75)) |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 56 | store_indication = 0xc00; |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 57 | return 0; |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 58 | } |
Heiko Carstens | a4f32bd | 2012-10-30 14:49:37 +0100 | [diff] [blame] | 59 | early_initcall(fault_init); |
Martin Schwidefsky | 92f842e | 2010-10-25 16:10:13 +0200 | [diff] [blame] | 60 | |
Martin Schwidefsky | 7ecb344 | 2009-12-07 12:51:44 +0100 | [diff] [blame] | 61 | static inline int notify_page_fault(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 62 | { |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 63 | int ret = 0; |
| 64 | |
| 65 | /* kprobe_running() needs smp_processor_id() */ |
Heiko Carstens | 22e0a04 | 2010-02-26 22:37:45 +0100 | [diff] [blame] | 66 | if (kprobes_built_in() && !user_mode(regs)) { |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 67 | preempt_disable(); |
| 68 | if (kprobe_running() && kprobe_fault_handler(regs, 14)) |
| 69 | ret = 1; |
| 70 | preempt_enable(); |
| 71 | } |
Christoph Hellwig | 33464e3 | 2007-05-04 18:47:46 +0200 | [diff] [blame] | 72 | return ret; |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 73 | } |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
| 76 | /* |
| 77 | * Unlock any spinlocks which will prevent us from getting the |
Kirill Korotaev | cefc8be | 2007-02-10 01:46:18 -0800 | [diff] [blame] | 78 | * message out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | */ |
| 80 | void bust_spinlocks(int yes) |
| 81 | { |
| 82 | if (yes) { |
| 83 | oops_in_progress = 1; |
| 84 | } else { |
| 85 | int loglevel_save = console_loglevel; |
| 86 | console_unblank(); |
| 87 | oops_in_progress = 0; |
| 88 | /* |
| 89 | * OK, the message is on the console. Now we call printk() |
| 90 | * without oops_in_progress set so that printk will give klogd |
| 91 | * a poke. Hold onto your hats... |
| 92 | */ |
| 93 | console_loglevel = 15; |
| 94 | printk(" "); |
| 95 | console_loglevel = loglevel_save; |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | /* |
Gerald Schaefer | 482b05d | 2007-03-05 23:35:54 +0100 | [diff] [blame] | 100 | * Returns the address space associated with the fault. |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 101 | * Returns 0 for kernel space and 1 for user space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | */ |
Heiko Carstens | 457f218 | 2014-03-21 10:42:25 +0100 | [diff] [blame] | 103 | static inline int user_space_fault(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | { |
Heiko Carstens | 457f218 | 2014-03-21 10:42:25 +0100 | [diff] [blame] | 105 | unsigned long trans_exc_code; |
| 106 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | /* |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 108 | * The lowest two bits of the translation exception |
| 109 | * identification indicate which paging table was used. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | */ |
Heiko Carstens | 457f218 | 2014-03-21 10:42:25 +0100 | [diff] [blame] | 111 | trans_exc_code = regs->int_parm_long & 3; |
| 112 | if (trans_exc_code == 3) /* home space -> kernel */ |
| 113 | return 0; |
| 114 | if (user_mode(regs)) |
| 115 | return 1; |
| 116 | if (trans_exc_code == 2) /* secondary space -> set_fs */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 117 | return current->thread.mm_segment.ar4; |
Heiko Carstens | 457f218 | 2014-03-21 10:42:25 +0100 | [diff] [blame] | 118 | if (current->flags & PF_VCPU) |
| 119 | return 1; |
| 120 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | } |
| 122 | |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 123 | static int bad_address(void *p) |
| 124 | { |
| 125 | unsigned long dummy; |
| 126 | |
| 127 | return probe_kernel_address((unsigned long *)p, dummy); |
| 128 | } |
| 129 | |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 130 | static void dump_pagetable(unsigned long asce, unsigned long address) |
| 131 | { |
| 132 | unsigned long *table = __va(asce & PAGE_MASK); |
| 133 | |
| 134 | pr_alert("AS:%016lx ", asce); |
| 135 | switch (asce & _ASCE_TYPE_MASK) { |
| 136 | case _ASCE_TYPE_REGION1: |
| 137 | table = table + ((address >> 53) & 0x7ff); |
| 138 | if (bad_address(table)) |
| 139 | goto bad; |
| 140 | pr_cont("R1:%016lx ", *table); |
| 141 | if (*table & _REGION_ENTRY_INVALID) |
| 142 | goto out; |
| 143 | table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| 144 | /* fallthrough */ |
| 145 | case _ASCE_TYPE_REGION2: |
| 146 | table = table + ((address >> 42) & 0x7ff); |
| 147 | if (bad_address(table)) |
| 148 | goto bad; |
| 149 | pr_cont("R2:%016lx ", *table); |
| 150 | if (*table & _REGION_ENTRY_INVALID) |
| 151 | goto out; |
| 152 | table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| 153 | /* fallthrough */ |
| 154 | case _ASCE_TYPE_REGION3: |
| 155 | table = table + ((address >> 31) & 0x7ff); |
| 156 | if (bad_address(table)) |
| 157 | goto bad; |
| 158 | pr_cont("R3:%016lx ", *table); |
| 159 | if (*table & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE)) |
| 160 | goto out; |
| 161 | table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); |
| 162 | /* fallthrough */ |
| 163 | case _ASCE_TYPE_SEGMENT: |
| 164 | table = table + ((address >> 20) & 0x7ff); |
| 165 | if (bad_address(table)) |
| 166 | goto bad; |
Joe Perches | 91c0837 | 2015-01-05 04:29:18 -0800 | [diff] [blame] | 167 | pr_cont("S:%016lx ", *table); |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 168 | if (*table & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE)) |
| 169 | goto out; |
| 170 | table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN); |
| 171 | } |
| 172 | table = table + ((address >> 12) & 0xff); |
| 173 | if (bad_address(table)) |
| 174 | goto bad; |
| 175 | pr_cont("P:%016lx ", *table); |
| 176 | out: |
| 177 | pr_cont("\n"); |
| 178 | return; |
| 179 | bad: |
| 180 | pr_cont("BAD\n"); |
| 181 | } |
| 182 | |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 183 | static void dump_fault_info(struct pt_regs *regs) |
| 184 | { |
| 185 | unsigned long asce; |
| 186 | |
Heiko Carstens | 5d7ecce | 2016-02-24 14:27:46 +0100 | [diff] [blame] | 187 | pr_alert("Failing address: %016lx TEID: %016lx\n", |
| 188 | regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long); |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 189 | pr_alert("Fault in "); |
| 190 | switch (regs->int_parm_long & 3) { |
| 191 | case 3: |
| 192 | pr_cont("home space "); |
| 193 | break; |
| 194 | case 2: |
| 195 | pr_cont("secondary space "); |
| 196 | break; |
| 197 | case 1: |
| 198 | pr_cont("access register "); |
| 199 | break; |
| 200 | case 0: |
| 201 | pr_cont("primary space "); |
| 202 | break; |
| 203 | } |
| 204 | pr_cont("mode while using "); |
| 205 | if (!user_space_fault(regs)) { |
| 206 | asce = S390_lowcore.kernel_asce; |
| 207 | pr_cont("kernel "); |
| 208 | } |
| 209 | #ifdef CONFIG_PGSTE |
| 210 | else if ((current->flags & PF_VCPU) && S390_lowcore.gmap) { |
| 211 | struct gmap *gmap = (struct gmap *)S390_lowcore.gmap; |
| 212 | asce = gmap->asce; |
| 213 | pr_cont("gmap "); |
| 214 | } |
| 215 | #endif |
| 216 | else { |
| 217 | asce = S390_lowcore.user_asce; |
| 218 | pr_cont("user "); |
| 219 | } |
| 220 | pr_cont("ASCE.\n"); |
| 221 | dump_pagetable(asce, regs->int_parm_long & __FAIL_ADDR_MASK); |
| 222 | } |
| 223 | |
Heiko Carstens | 5d7ecce | 2016-02-24 14:27:46 +0100 | [diff] [blame] | 224 | int show_unhandled_signals = 1; |
| 225 | |
| 226 | void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault) |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 227 | { |
| 228 | if ((task_pid_nr(current) > 1) && !show_unhandled_signals) |
| 229 | return; |
| 230 | if (!unhandled_signal(current, signr)) |
| 231 | return; |
| 232 | if (!printk_ratelimit()) |
| 233 | return; |
Hendrik Brueckner | db1177ee | 2015-01-29 14:38:38 +0100 | [diff] [blame] | 234 | printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ", |
Heiko Carstens | 413d404 | 2014-11-19 13:31:08 +0100 | [diff] [blame] | 235 | regs->int_code & 0xffff, regs->int_code >> 17); |
Heiko Carstens | 9cb1cce | 2016-01-18 13:12:19 +0100 | [diff] [blame] | 236 | print_vma_addr(KERN_CONT "in ", regs->psw.addr); |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 237 | printk(KERN_CONT "\n"); |
Heiko Carstens | 5d7ecce | 2016-02-24 14:27:46 +0100 | [diff] [blame] | 238 | if (is_mm_fault) |
| 239 | dump_fault_info(regs); |
Heiko Carstens | ab3c68e | 2010-05-17 10:00:21 +0200 | [diff] [blame] | 240 | show_regs(regs); |
| 241 | } |
| 242 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | /* |
| 244 | * Send SIGSEGV to task. This is an external routine |
| 245 | * to keep the stack usage of do_page_fault small. |
| 246 | */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 247 | static noinline void do_sigsegv(struct pt_regs *regs, int si_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | { |
| 249 | struct siginfo si; |
| 250 | |
Heiko Carstens | 5d7ecce | 2016-02-24 14:27:46 +0100 | [diff] [blame] | 251 | report_user_fault(regs, SIGSEGV, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | si.si_signo = SIGSEGV; |
Michal Hocko | cf0d44d | 2016-05-23 15:35:51 +0200 | [diff] [blame] | 253 | si.si_errno = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | si.si_code = si_code; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 255 | si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | force_sig_info(SIGSEGV, &si, current); |
| 257 | } |
| 258 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 259 | static noinline void do_no_context(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 260 | { |
| 261 | const struct exception_table_entry *fixup; |
| 262 | |
| 263 | /* Are we prepared to handle this kernel fault? */ |
Heiko Carstens | 9cb1cce | 2016-01-18 13:12:19 +0100 | [diff] [blame] | 264 | fixup = search_exception_tables(regs->psw.addr); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 265 | if (fixup) { |
Heiko Carstens | fecc868 | 2016-01-18 12:49:44 +0100 | [diff] [blame] | 266 | regs->psw.addr = extable_fixup(fixup); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 267 | return; |
| 268 | } |
| 269 | |
| 270 | /* |
| 271 | * Oops. The kernel tried to access some bad page. We'll have to |
| 272 | * terminate things with extreme prejudice. |
| 273 | */ |
Heiko Carstens | 457f218 | 2014-03-21 10:42:25 +0100 | [diff] [blame] | 274 | if (!user_space_fault(regs)) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 275 | printk(KERN_ALERT "Unable to handle kernel pointer dereference" |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 276 | " in virtual kernel address space\n"); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 277 | else |
| 278 | printk(KERN_ALERT "Unable to handle kernel paging request" |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 279 | " in virtual user address space\n"); |
Heiko Carstens | 3b7df34 | 2014-04-07 10:20:40 +0200 | [diff] [blame] | 280 | dump_fault_info(regs); |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 281 | die(regs, "Oops"); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 282 | do_exit(SIGKILL); |
| 283 | } |
| 284 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 285 | static noinline void do_low_address(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 286 | { |
| 287 | /* Low-address protection hit in kernel mode means |
| 288 | NULL pointer write access in kernel mode. */ |
| 289 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 290 | /* Low-address protection hit in user mode 'cannot happen'. */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 291 | die (regs, "Low-address protection"); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 292 | do_exit(SIGKILL); |
| 293 | } |
| 294 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 295 | do_no_context(regs); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 296 | } |
| 297 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 298 | static noinline void do_sigbus(struct pt_regs *regs) |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 299 | { |
| 300 | struct task_struct *tsk = current; |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 301 | struct siginfo si; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 302 | |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 303 | /* |
| 304 | * Send a sigbus, regardless of whether we were in kernel |
| 305 | * or user mode. |
| 306 | */ |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 307 | si.si_signo = SIGBUS; |
| 308 | si.si_errno = 0; |
| 309 | si.si_code = BUS_ADRERR; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 310 | si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 311 | force_sig_info(SIGBUS, &si, tsk); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 312 | } |
| 313 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 314 | static noinline void do_fault_error(struct pt_regs *regs, int fault) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 315 | { |
| 316 | int si_code; |
| 317 | |
| 318 | switch (fault) { |
| 319 | case VM_FAULT_BADACCESS: |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 320 | case VM_FAULT_BADMAP: |
| 321 | /* Bad memory access. Check if it is kernel or user space. */ |
Heiko Carstens | 7d25617 | 2012-07-27 10:31:12 +0200 | [diff] [blame] | 322 | if (user_mode(regs)) { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 323 | /* User mode accesses just cause a SIGSEGV */ |
| 324 | si_code = (fault == VM_FAULT_BADMAP) ? |
| 325 | SEGV_MAPERR : SEGV_ACCERR; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 326 | do_sigsegv(regs, si_code); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 327 | return; |
| 328 | } |
| 329 | case VM_FAULT_BADCONTEXT: |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 330 | case VM_FAULT_PFAULT: |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 331 | do_no_context(regs); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 332 | break; |
Heiko Carstens | f2c76e3 | 2012-07-27 08:54:20 +0200 | [diff] [blame] | 333 | case VM_FAULT_SIGNAL: |
| 334 | if (!user_mode(regs)) |
| 335 | do_no_context(regs); |
| 336 | break; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 337 | default: /* fault & VM_FAULT_ERROR */ |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 338 | if (fault & VM_FAULT_OOM) { |
Heiko Carstens | 7d25617 | 2012-07-27 10:31:12 +0200 | [diff] [blame] | 339 | if (!user_mode(regs)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 340 | do_no_context(regs); |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 341 | else |
| 342 | pagefault_out_of_memory(); |
Linus Torvalds | 33692f2 | 2015-01-29 10:51:32 -0800 | [diff] [blame] | 343 | } else if (fault & VM_FAULT_SIGSEGV) { |
| 344 | /* Kernel mode? Handle exceptions or die */ |
| 345 | if (!user_mode(regs)) |
| 346 | do_no_context(regs); |
| 347 | else |
| 348 | do_sigsegv(regs, SEGV_MAPERR); |
Heiko Carstens | 9958318 | 2011-05-26 09:48:29 +0200 | [diff] [blame] | 349 | } else if (fault & VM_FAULT_SIGBUS) { |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 350 | /* Kernel mode? Handle exceptions or die */ |
Heiko Carstens | 7d25617 | 2012-07-27 10:31:12 +0200 | [diff] [blame] | 351 | if (!user_mode(regs)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 352 | do_no_context(regs); |
Martin Schwidefsky | 36bf968 | 2010-10-25 16:10:35 +0200 | [diff] [blame] | 353 | else |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 354 | do_sigbus(regs); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 355 | } else |
| 356 | BUG(); |
| 357 | break; |
| 358 | } |
| 359 | } |
| 360 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | /* |
| 362 | * This routine handles page faults. It determines the address, |
| 363 | * and the problem, and then passes it off to one of the appropriate |
| 364 | * routines. |
| 365 | * |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 366 | * interruption code (int_code): |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | * 04 Protection -> Write-Protection (suprression) |
| 368 | * 10 Segment translation -> Not present (nullification) |
| 369 | * 11 Page translation -> Not present (nullification) |
| 370 | * 3b Region third trans. -> Not present (nullification) |
| 371 | */ |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 372 | static inline int do_exception(struct pt_regs *regs, int access) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | { |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 374 | #ifdef CONFIG_PGSTE |
| 375 | struct gmap *gmap; |
| 376 | #endif |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 377 | struct task_struct *tsk; |
| 378 | struct mm_struct *mm; |
| 379 | struct vm_area_struct *vma; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 380 | unsigned long trans_exc_code; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 381 | unsigned long address; |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 382 | unsigned int flags; |
| 383 | int fault; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
Martin Schwidefsky | 39efd4e | 2012-11-21 16:36:27 +0100 | [diff] [blame] | 385 | tsk = current; |
| 386 | /* |
| 387 | * The instruction that caused the program check has |
| 388 | * been nullified. Don't signal single step via SIGTRAP. |
| 389 | */ |
Martin Schwidefsky | d3a73ac | 2014-04-15 12:55:07 +0200 | [diff] [blame] | 390 | clear_pt_regs_flag(regs, PIF_PER_TRAP); |
Martin Schwidefsky | 39efd4e | 2012-11-21 16:36:27 +0100 | [diff] [blame] | 391 | |
Martin Schwidefsky | 7ecb344 | 2009-12-07 12:51:44 +0100 | [diff] [blame] | 392 | if (notify_page_fault(regs)) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 393 | return 0; |
Michael Grundy | 4ba069b | 2006-09-20 15:58:39 +0200 | [diff] [blame] | 394 | |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 395 | mm = tsk->mm; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 396 | trans_exc_code = regs->int_parm_long; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | /* |
| 399 | * Verify that the fault happened in user space, that |
| 400 | * we are not in an interrupt and that there is a |
| 401 | * user context. |
| 402 | */ |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 403 | fault = VM_FAULT_BADCONTEXT; |
David Hildenbrand | 70ffdb9 | 2015-05-11 17:52:11 +0200 | [diff] [blame] | 404 | if (unlikely(!user_space_fault(regs) || faulthandler_disabled() || !mm)) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 405 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 407 | address = trans_exc_code & __FAIL_ADDR_MASK; |
Peter Zijlstra | a8b0ca1 | 2011-06-27 14:41:57 +0200 | [diff] [blame] | 408 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); |
Heiko Carstens | f2c76e3 | 2012-07-27 08:54:20 +0200 | [diff] [blame] | 409 | flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
Johannes Weiner | 759496b | 2013-09-12 15:13:39 -0700 | [diff] [blame] | 410 | if (user_mode(regs)) |
| 411 | flags |= FAULT_FLAG_USER; |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 412 | if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) |
| 413 | flags |= FAULT_FLAG_WRITE; |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 414 | down_read(&mm->mmap_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 416 | #ifdef CONFIG_PGSTE |
Martin Schwidefsky | 527e30b | 2014-04-30 16:04:25 +0200 | [diff] [blame] | 417 | gmap = (current->flags & PF_VCPU) ? |
| 418 | (struct gmap *) S390_lowcore.gmap : NULL; |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 419 | if (gmap) { |
Martin Schwidefsky | 527e30b | 2014-04-30 16:04:25 +0200 | [diff] [blame] | 420 | current->thread.gmap_addr = address; |
Martin Schwidefsky | 4be130a | 2016-03-08 12:12:18 +0100 | [diff] [blame] | 421 | current->thread.gmap_write_flag = !!(flags & FAULT_FLAG_WRITE); |
David Hildenbrand | 4a49443 | 2016-03-08 12:31:52 +0100 | [diff] [blame] | 422 | current->thread.gmap_int_code = regs->int_code & 0xffff; |
Martin Schwidefsky | 527e30b | 2014-04-30 16:04:25 +0200 | [diff] [blame] | 423 | address = __gmap_translate(gmap, address); |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 424 | if (address == -EFAULT) { |
| 425 | fault = VM_FAULT_BADMAP; |
| 426 | goto out_up; |
| 427 | } |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 428 | if (gmap->pfault_enabled) |
| 429 | flags |= FAULT_FLAG_RETRY_NOWAIT; |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 430 | } |
| 431 | #endif |
| 432 | |
| 433 | retry: |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 434 | fault = VM_FAULT_BADMAP; |
Gerald Schaefer | 482b05d | 2007-03-05 23:35:54 +0100 | [diff] [blame] | 435 | vma = find_vma(mm, address); |
| 436 | if (!vma) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 437 | goto out_up; |
Gerald Schaefer | c1821c2 | 2007-02-05 21:18:17 +0100 | [diff] [blame] | 438 | |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 439 | if (unlikely(vma->vm_start > address)) { |
| 440 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 441 | goto out_up; |
| 442 | if (expand_stack(vma, address)) |
| 443 | goto out_up; |
| 444 | } |
| 445 | |
| 446 | /* |
| 447 | * Ok, we have a good vm_area for this memory access, so |
| 448 | * we can handle it.. |
| 449 | */ |
| 450 | fault = VM_FAULT_BADACCESS; |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 451 | if (unlikely(!(vma->vm_flags & access))) |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 452 | goto out_up; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | |
Gerald Schaefer | 53492b1 | 2008-04-30 13:38:46 +0200 | [diff] [blame] | 454 | if (is_vm_hugetlb_page(vma)) |
| 455 | address &= HPAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | /* |
| 457 | * If for any reason at all we couldn't handle the fault, |
| 458 | * make sure we exit gracefully rather than endlessly redo |
| 459 | * the fault. |
| 460 | */ |
Kirill A. Shutemov | dcddffd | 2016-07-26 15:25:18 -0700 | [diff] [blame] | 461 | fault = handle_mm_fault(vma, address, flags); |
Heiko Carstens | f2c76e3 | 2012-07-27 08:54:20 +0200 | [diff] [blame] | 462 | /* No reason to continue if interrupted by SIGKILL. */ |
| 463 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) { |
| 464 | fault = VM_FAULT_SIGNAL; |
| 465 | goto out; |
| 466 | } |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 467 | if (unlikely(fault & VM_FAULT_ERROR)) |
| 468 | goto out_up; |
| 469 | |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 470 | /* |
| 471 | * Major/minor page fault accounting is only done on the |
| 472 | * initial attempt. If we go through a retry, it is extremely |
| 473 | * likely that the page will be found in page cache at that point. |
| 474 | */ |
| 475 | if (flags & FAULT_FLAG_ALLOW_RETRY) { |
| 476 | if (fault & VM_FAULT_MAJOR) { |
| 477 | tsk->maj_flt++; |
Peter Zijlstra | a8b0ca1 | 2011-06-27 14:41:57 +0200 | [diff] [blame] | 478 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 479 | regs, address); |
| 480 | } else { |
| 481 | tsk->min_flt++; |
Peter Zijlstra | a8b0ca1 | 2011-06-27 14:41:57 +0200 | [diff] [blame] | 482 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 483 | regs, address); |
| 484 | } |
| 485 | if (fault & VM_FAULT_RETRY) { |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 486 | #ifdef CONFIG_PGSTE |
| 487 | if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) { |
| 488 | /* FAULT_FLAG_RETRY_NOWAIT has been set, |
| 489 | * mmap_sem has not been released */ |
| 490 | current->thread.gmap_pfault = 1; |
| 491 | fault = VM_FAULT_PFAULT; |
| 492 | goto out_up; |
| 493 | } |
| 494 | #endif |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 495 | /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk |
| 496 | * of starvation. */ |
Dominik Dingel | 24eb3a8 | 2013-06-17 16:25:18 +0200 | [diff] [blame] | 497 | flags &= ~(FAULT_FLAG_ALLOW_RETRY | |
| 498 | FAULT_FLAG_RETRY_NOWAIT); |
Shaohua Li | 45cac65 | 2012-10-08 16:32:19 -0700 | [diff] [blame] | 499 | flags |= FAULT_FLAG_TRIED; |
Martin Schwidefsky | e5992f2 | 2011-07-24 10:48:20 +0200 | [diff] [blame] | 500 | down_read(&mm->mmap_sem); |
Heiko Carstens | 33ce614 | 2011-05-26 09:48:30 +0200 | [diff] [blame] | 501 | goto retry; |
| 502 | } |
Heiko Carstens | bde69af | 2009-09-11 10:29:06 +0200 | [diff] [blame] | 503 | } |
Martin Schwidefsky | 527e30b | 2014-04-30 16:04:25 +0200 | [diff] [blame] | 504 | #ifdef CONFIG_PGSTE |
| 505 | if (gmap) { |
| 506 | address = __gmap_link(gmap, current->thread.gmap_addr, |
| 507 | address); |
| 508 | if (address == -EFAULT) { |
| 509 | fault = VM_FAULT_BADMAP; |
| 510 | goto out_up; |
| 511 | } |
| 512 | if (address == -ENOMEM) { |
| 513 | fault = VM_FAULT_OOM; |
| 514 | goto out_up; |
| 515 | } |
| 516 | } |
| 517 | #endif |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 518 | fault = 0; |
| 519 | out_up: |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 520 | up_read(&mm->mmap_sem); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 521 | out: |
| 522 | return fault; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | } |
| 524 | |
Heiko Carstens | 7a5388d | 2014-10-22 12:42:38 +0200 | [diff] [blame] | 525 | void do_protection_exception(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | { |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 527 | unsigned long trans_exc_code; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 528 | int fault; |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 529 | |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 530 | trans_exc_code = regs->int_parm_long; |
Martin Schwidefsky | f752ac4 | 2013-04-16 13:25:06 +0200 | [diff] [blame] | 531 | /* |
| 532 | * Protection exceptions are suppressing, decrement psw address. |
| 533 | * The exception to this rule are aborted transactions, for these |
| 534 | * the PSW already points to the correct location. |
| 535 | */ |
| 536 | if (!(regs->int_code & 0x200)) |
| 537 | regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 538 | /* |
| 539 | * Check for low-address protection. This needs to be treated |
| 540 | * as a special case because the translation exception code |
| 541 | * field is not guaranteed to contain valid data in this case. |
| 542 | */ |
Martin Schwidefsky | 61365e1 | 2009-12-07 12:51:42 +0100 | [diff] [blame] | 543 | if (unlikely(!(trans_exc_code & 4))) { |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 544 | do_low_address(regs); |
Martin Schwidefsky | 10c1031 | 2007-04-27 16:01:43 +0200 | [diff] [blame] | 545 | return; |
| 546 | } |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 547 | fault = do_exception(regs, VM_WRITE); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 548 | if (unlikely(fault)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 549 | do_fault_error(regs, fault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | } |
Heiko Carstens | 7a5388d | 2014-10-22 12:42:38 +0200 | [diff] [blame] | 551 | NOKPROBE_SYMBOL(do_protection_exception); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | |
Heiko Carstens | 7a5388d | 2014-10-22 12:42:38 +0200 | [diff] [blame] | 553 | void do_dat_exception(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | { |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 555 | int access, fault; |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 556 | |
Martin Schwidefsky | 1ab947d | 2009-12-07 12:51:46 +0100 | [diff] [blame] | 557 | access = VM_READ | VM_EXEC | VM_WRITE; |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 558 | fault = do_exception(regs, access); |
Martin Schwidefsky | 50d7280 | 2009-12-07 12:51:45 +0100 | [diff] [blame] | 559 | if (unlikely(fault)) |
Martin Schwidefsky | aa33c8c | 2011-12-27 11:27:18 +0100 | [diff] [blame] | 560 | do_fault_error(regs, fault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | } |
Heiko Carstens | 7a5388d | 2014-10-22 12:42:38 +0200 | [diff] [blame] | 562 | NOKPROBE_SYMBOL(do_dat_exception); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | #ifdef CONFIG_PFAULT |
| 565 | /* |
| 566 | * 'pfault' pseudo page faults routines. |
| 567 | */ |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 568 | static int pfault_disable; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | |
| 570 | static int __init nopfault(char *str) |
| 571 | { |
| 572 | pfault_disable = 1; |
| 573 | return 1; |
| 574 | } |
| 575 | |
| 576 | __setup("nopfault", nopfault); |
| 577 | |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 578 | struct pfault_refbk { |
| 579 | u16 refdiagc; |
| 580 | u16 reffcode; |
| 581 | u16 refdwlen; |
| 582 | u16 refversn; |
| 583 | u64 refgaddr; |
| 584 | u64 refselmk; |
| 585 | u64 refcmpmk; |
| 586 | u64 reserved; |
| 587 | } __attribute__ ((packed, aligned(8))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | |
| 589 | int pfault_init(void) |
| 590 | { |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 591 | struct pfault_refbk refbk = { |
| 592 | .refdiagc = 0x258, |
| 593 | .reffcode = 0, |
| 594 | .refdwlen = 5, |
| 595 | .refversn = 2, |
Christian Borntraeger | e22cf8c | 2015-10-06 18:06:15 +0200 | [diff] [blame] | 596 | .refgaddr = __LC_LPP, |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 597 | .refselmk = 1ULL << 48, |
| 598 | .refcmpmk = 1ULL << 48, |
| 599 | .reserved = __PF_RES_FIELD }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | int rc; |
| 601 | |
Carsten Otte | f32269a | 2011-12-27 11:27:11 +0100 | [diff] [blame] | 602 | if (pfault_disable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | return -1; |
Martin Schwidefsky | 1ec2772 | 2015-08-20 17:28:44 +0200 | [diff] [blame] | 604 | diag_stat_inc(DIAG_STAT_X258); |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 605 | asm volatile( |
| 606 | " diag %1,%0,0x258\n" |
| 607 | "0: j 2f\n" |
| 608 | "1: la %0,8\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | "2:\n" |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 610 | EX_TABLE(0b,1b) |
| 611 | : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | return rc; |
| 613 | } |
| 614 | |
| 615 | void pfault_fini(void) |
| 616 | { |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 617 | struct pfault_refbk refbk = { |
| 618 | .refdiagc = 0x258, |
| 619 | .reffcode = 1, |
| 620 | .refdwlen = 5, |
| 621 | .refversn = 2, |
| 622 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | |
Carsten Otte | f32269a | 2011-12-27 11:27:11 +0100 | [diff] [blame] | 624 | if (pfault_disable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | return; |
Martin Schwidefsky | 1ec2772 | 2015-08-20 17:28:44 +0200 | [diff] [blame] | 626 | diag_stat_inc(DIAG_STAT_X258); |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 627 | asm volatile( |
| 628 | " diag %0,0,0x258\n" |
Heiko Carstens | 6c22c98 | 2016-06-10 09:57:05 +0200 | [diff] [blame] | 629 | "0: nopr %%r7\n" |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 630 | EX_TABLE(0b,0b) |
| 631 | : : "a" (&refbk), "m" (refbk) : "cc"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | } |
| 633 | |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 634 | static DEFINE_SPINLOCK(pfault_lock); |
| 635 | static LIST_HEAD(pfault_list); |
| 636 | |
Peter Zijlstra | 0227f7c | 2016-03-22 21:42:53 +0100 | [diff] [blame] | 637 | #define PF_COMPLETE 0x0080 |
| 638 | |
| 639 | /* |
| 640 | * The mechanism of our pfault code: if Linux is running as guest, runs a user |
| 641 | * space process and the user space process accesses a page that the host has |
| 642 | * paged out we get a pfault interrupt. |
| 643 | * |
| 644 | * This allows us, within the guest, to schedule a different process. Without |
| 645 | * this mechanism the host would have to suspend the whole virtual cpu until |
| 646 | * the page has been paged in. |
| 647 | * |
| 648 | * So when we get such an interrupt then we set the state of the current task |
| 649 | * to uninterruptible and also set the need_resched flag. Both happens within |
| 650 | * interrupt context(!). If we later on want to return to user space we |
| 651 | * recognize the need_resched flag and then call schedule(). It's not very |
| 652 | * obvious how this works... |
| 653 | * |
| 654 | * Of course we have a lot of additional fun with the completion interrupt (-> |
| 655 | * host signals that a page of a process has been paged in and the process can |
| 656 | * continue to run). This interrupt can arrive on any cpu and, since we have |
| 657 | * virtual cpus, actually appear before the interrupt that signals that a page |
| 658 | * is missing. |
| 659 | */ |
Heiko Carstens | fde15c3 | 2012-03-11 11:59:31 -0400 | [diff] [blame] | 660 | static void pfault_interrupt(struct ext_code ext_code, |
Martin Schwidefsky | f6649a7 | 2010-10-25 16:10:38 +0200 | [diff] [blame] | 661 | unsigned int param32, unsigned long param64) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | { |
| 663 | struct task_struct *tsk; |
| 664 | __u16 subcode; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 665 | pid_t pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | |
| 667 | /* |
Peter Zijlstra | 0227f7c | 2016-03-22 21:42:53 +0100 | [diff] [blame] | 668 | * Get the external interruption subcode & pfault initial/completion |
| 669 | * signal bit. VM stores this in the 'cpu address' field associated |
| 670 | * with the external interrupt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | */ |
Heiko Carstens | fde15c3 | 2012-03-11 11:59:31 -0400 | [diff] [blame] | 672 | subcode = ext_code.subcode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | if ((subcode & 0xff00) != __SUBCODE_MASK) |
| 674 | return; |
Heiko Carstens | 420f42e | 2013-01-02 15:18:18 +0100 | [diff] [blame] | 675 | inc_irq_stat(IRQEXT_PFL); |
Heiko Carstens | 54c2779 | 2012-05-10 09:44:35 +0200 | [diff] [blame] | 676 | /* Get the token (= pid of the affected task). */ |
Christian Borntraeger | e22cf8c | 2015-10-06 18:06:15 +0200 | [diff] [blame] | 677 | pid = param64 & LPP_PFAULT_PID_MASK; |
Heiko Carstens | 54c2779 | 2012-05-10 09:44:35 +0200 | [diff] [blame] | 678 | rcu_read_lock(); |
| 679 | tsk = find_task_by_pid_ns(pid, &init_pid_ns); |
| 680 | if (tsk) |
| 681 | get_task_struct(tsk); |
| 682 | rcu_read_unlock(); |
| 683 | if (!tsk) |
| 684 | return; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 685 | spin_lock(&pfault_lock); |
Peter Zijlstra | 0227f7c | 2016-03-22 21:42:53 +0100 | [diff] [blame] | 686 | if (subcode & PF_COMPLETE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | /* signal bit is set -> a page has been swapped in by VM */ |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 688 | if (tsk->thread.pfault_wait == 1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | /* Initial interrupt was faster than the completion |
| 690 | * interrupt. pfault_wait is valid. Set pfault_wait |
| 691 | * back to zero and wake up the process. This can |
| 692 | * safely be done because the task is still sleeping |
Martin Schwidefsky | b6d0944 | 2005-09-03 15:58:02 -0700 | [diff] [blame] | 693 | * and can't produce new pfaults. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | tsk->thread.pfault_wait = 0; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 695 | list_del(&tsk->thread.list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | wake_up_process(tsk); |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 697 | put_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 698 | } else { |
| 699 | /* Completion interrupt was faster than initial |
| 700 | * interrupt. Set pfault_wait to -1 so the initial |
Heiko Carstens | fa2fb2f | 2011-11-14 11:19:01 +0100 | [diff] [blame] | 701 | * interrupt doesn't put the task to sleep. |
| 702 | * If the task is not running, ignore the completion |
| 703 | * interrupt since it must be a leftover of a PFAULT |
| 704 | * CANCEL operation which didn't remove all pending |
| 705 | * completion interrupts. */ |
| 706 | if (tsk->state == TASK_RUNNING) |
| 707 | tsk->thread.pfault_wait = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | } |
| 709 | } else { |
| 710 | /* signal bit not set -> a real page is missing. */ |
Heiko Carstens | d49f47f | 2012-05-10 10:47:21 +0200 | [diff] [blame] | 711 | if (WARN_ON_ONCE(tsk != current)) |
| 712 | goto out; |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 713 | if (tsk->thread.pfault_wait == 1) { |
| 714 | /* Already on the list with a reference: put to sleep */ |
Peter Zijlstra | 0227f7c | 2016-03-22 21:42:53 +0100 | [diff] [blame] | 715 | goto block; |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 716 | } else if (tsk->thread.pfault_wait == -1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | /* Completion interrupt was faster than the initial |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 718 | * interrupt (pfault_wait == -1). Set pfault_wait |
| 719 | * back to zero and exit. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | tsk->thread.pfault_wait = 0; |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 721 | } else { |
| 722 | /* Initial interrupt arrived before completion |
Heiko Carstens | d5e50a5 | 2012-05-09 09:37:30 +0200 | [diff] [blame] | 723 | * interrupt. Let the task sleep. |
| 724 | * An extra task reference is needed since a different |
| 725 | * cpu may set the task state to TASK_RUNNING again |
| 726 | * before the scheduler is reached. */ |
| 727 | get_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 728 | tsk->thread.pfault_wait = 1; |
| 729 | list_add(&tsk->thread.list, &pfault_list); |
Peter Zijlstra | 0227f7c | 2016-03-22 21:42:53 +0100 | [diff] [blame] | 730 | block: |
| 731 | /* Since this must be a userspace fault, there |
| 732 | * is no kernel task state to trample. Rely on the |
| 733 | * return to userspace schedule() to block. */ |
| 734 | __set_current_state(TASK_UNINTERRUPTIBLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | set_tsk_need_resched(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 736 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | } |
Heiko Carstens | d49f47f | 2012-05-10 10:47:21 +0200 | [diff] [blame] | 738 | out: |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 739 | spin_unlock(&pfault_lock); |
Heiko Carstens | 54c2779 | 2012-05-10 09:44:35 +0200 | [diff] [blame] | 740 | put_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 741 | } |
| 742 | |
Sebastian Andrzej Siewior | 84c9cee | 2016-09-06 19:04:53 +0200 | [diff] [blame] | 743 | static int pfault_cpu_dead(unsigned int cpu) |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 744 | { |
| 745 | struct thread_struct *thread, *next; |
| 746 | struct task_struct *tsk; |
| 747 | |
Sebastian Andrzej Siewior | 84c9cee | 2016-09-06 19:04:53 +0200 | [diff] [blame] | 748 | spin_lock_irq(&pfault_lock); |
| 749 | list_for_each_entry_safe(thread, next, &pfault_list, list) { |
| 750 | thread->pfault_wait = 0; |
| 751 | list_del(&thread->list); |
| 752 | tsk = container_of(thread, struct task_struct, thread); |
| 753 | wake_up_process(tsk); |
| 754 | put_task_struct(tsk); |
Heiko Carstens | f2db2e6 | 2011-05-23 10:24:34 +0200 | [diff] [blame] | 755 | } |
Sebastian Andrzej Siewior | 84c9cee | 2016-09-06 19:04:53 +0200 | [diff] [blame] | 756 | spin_unlock_irq(&pfault_lock); |
| 757 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 760 | static int __init pfault_irq_init(void) |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 761 | { |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 762 | int rc; |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 763 | |
Thomas Huth | 1dad093 | 2014-03-31 15:24:08 +0200 | [diff] [blame] | 764 | rc = register_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 765 | if (rc) |
| 766 | goto out_extint; |
| 767 | rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP; |
| 768 | if (rc) |
| 769 | goto out_pfault; |
Heiko Carstens | 82003c3 | 2013-09-04 13:35:45 +0200 | [diff] [blame] | 770 | irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); |
Sebastian Andrzej Siewior | 84c9cee | 2016-09-06 19:04:53 +0200 | [diff] [blame] | 771 | cpuhp_setup_state_nocalls(CPUHP_S390_PFAULT_DEAD, "s390/pfault:dead", |
| 772 | NULL, pfault_cpu_dead); |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 773 | return 0; |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 774 | |
| 775 | out_pfault: |
Thomas Huth | 1dad093 | 2014-03-31 15:24:08 +0200 | [diff] [blame] | 776 | unregister_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 777 | out_extint: |
| 778 | pfault_disable = 1; |
| 779 | return rc; |
Heiko Carstens | 29b08d2 | 2006-12-04 15:40:40 +0100 | [diff] [blame] | 780 | } |
Heiko Carstens | fb0a9d7 | 2011-01-05 12:47:39 +0100 | [diff] [blame] | 781 | early_initcall(pfault_irq_init); |
| 782 | |
Heiko Carstens | 7dd8fe1 | 2011-05-23 10:24:35 +0200 | [diff] [blame] | 783 | #endif /* CONFIG_PFAULT */ |