1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * S390 low-level entry points. 4 * 5 * Copyright IBM Corp. 1999, 2012 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 7 * Hartmut Penner (hp@de.ibm.com), 8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 9 * Heiko Carstens <heiko.carstens@de.ibm.com> 10 */ 11 12#include <linux/init.h> 13#include <linux/linkage.h> 14#include <asm/alternative-asm.h> 15#include <asm/processor.h> 16#include <asm/cache.h> 17#include <asm/dwarf.h> 18#include <asm/errno.h> 19#include <asm/ptrace.h> 20#include <asm/thread_info.h> 21#include <asm/asm-offsets.h> 22#include <asm/unistd.h> 23#include <asm/page.h> 24#include <asm/sigp.h> 25#include <asm/irq.h> 26#include <asm/vx-insn.h> 27#include <asm/setup.h> 28#include <asm/nmi.h> 29#include <asm/export.h> 30#include <asm/nospec-insn.h> 31 32__PT_R0 = __PT_GPRS 33__PT_R1 = __PT_GPRS + 8 34__PT_R2 = __PT_GPRS + 16 35__PT_R3 = __PT_GPRS + 24 36__PT_R4 = __PT_GPRS + 32 37__PT_R5 = __PT_GPRS + 40 38__PT_R6 = __PT_GPRS + 48 39__PT_R7 = __PT_GPRS + 56 40__PT_R8 = __PT_GPRS + 64 41__PT_R9 = __PT_GPRS + 72 42__PT_R10 = __PT_GPRS + 80 43__PT_R11 = __PT_GPRS + 88 44__PT_R12 = __PT_GPRS + 96 45__PT_R13 = __PT_GPRS + 104 46__PT_R14 = __PT_GPRS + 112 47__PT_R15 = __PT_GPRS + 120 48 49STACK_SHIFT = PAGE_SHIFT + THREAD_SIZE_ORDER 50STACK_SIZE = 1 << STACK_SHIFT 51STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE 52 53_LPP_OFFSET = __LC_LPP 54 55 .macro CHECK_STACK savearea 56#ifdef CONFIG_CHECK_STACK 57 tml %r15,STACK_SIZE - CONFIG_STACK_GUARD 58 lghi %r14,\savearea 59 jz stack_overflow 60#endif 61 .endm 62 63 .macro CHECK_VMAP_STACK savearea,oklabel 64#ifdef CONFIG_VMAP_STACK 65 lgr %r14,%r15 66 nill %r14,0x10000 - STACK_SIZE 67 oill %r14,STACK_INIT 68 clg %r14,__LC_KERNEL_STACK 69 je \oklabel 70 clg %r14,__LC_ASYNC_STACK 71 je \oklabel 72 clg %r14,__LC_MCCK_STACK 73 je \oklabel 74 clg %r14,__LC_NODAT_STACK 75 je \oklabel 76 clg %r14,__LC_RESTART_STACK 77 je \oklabel 78 lghi %r14,\savearea 79 j stack_overflow 80#else 81 j \oklabel 82#endif 83 .endm 84 85 .macro STCK savearea 86 ALTERNATIVE ".insn s,0xb2050000,\savearea", \ 87 ".insn s,0xb27c0000,\savearea", 25 88 .endm 89 90 /* 91 * The TSTMSK macro generates a test-under-mask instruction by 92 * calculating the memory offset for the specified mask value. 93 * Mask value can be any constant. The macro shifts the mask 94 * value to calculate the memory offset for the test-under-mask 95 * instruction. 96 */ 97 .macro TSTMSK addr, mask, size=8, bytepos=0 98 .if (\bytepos < \size) && (\mask >> 8) 99 .if (\mask & 0xff) 100 .error "Mask exceeds byte boundary" 101 .endif 102 TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)" 103 .exitm 104 .endif 105 .ifeq \mask 106 .error "Mask must not be zero" 107 .endif 108 off = \size - \bytepos - 1 109 tm off+\addr, \mask 110 .endm 111 112 .macro BPOFF 113 ALTERNATIVE "", ".long 0xb2e8c000", 82 114 .endm 115 116 .macro BPON 117 ALTERNATIVE "", ".long 0xb2e8d000", 82 118 .endm 119 120 .macro BPENTER tif_ptr,tif_mask 121 ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .long 0xb2e8d000", \ 122 "", 82 123 .endm 124 125 .macro BPEXIT tif_ptr,tif_mask 126 TSTMSK \tif_ptr,\tif_mask 127 ALTERNATIVE "jz .+8; .long 0xb2e8c000", \ 128 "jnz .+8; .long 0xb2e8d000", 82 129 .endm 130 131 /* 132 * The CHKSTG macro jumps to the provided label in case the 133 * machine check interruption code reports one of unrecoverable 134 * storage errors: 135 * - Storage error uncorrected 136 * - Storage key error uncorrected 137 * - Storage degradation with Failing-storage-address validity 138 */ 139 .macro CHKSTG errlabel 140 TSTMSK __LC_MCCK_CODE,(MCCK_CODE_STG_ERROR|MCCK_CODE_STG_KEY_ERROR) 141 jnz \errlabel 142 TSTMSK __LC_MCCK_CODE,MCCK_CODE_STG_DEGRAD 143 jz oklabel\@ 144 TSTMSK __LC_MCCK_CODE,MCCK_CODE_STG_FAIL_ADDR 145 jnz \errlabel 146oklabel\@: 147 .endm 148 149#if IS_ENABLED(CONFIG_KVM) 150 /* 151 * The OUTSIDE macro jumps to the provided label in case the value 152 * in the provided register is outside of the provided range. The 153 * macro is useful for checking whether a PSW stored in a register 154 * pair points inside or outside of a block of instructions. 155 * @reg: register to check 156 * @start: start of the range 157 * @end: end of the range 158 * @outside_label: jump here if @reg is outside of [@start..@end) 159 */ 160 .macro OUTSIDE reg,start,end,outside_label 161 lgr %r14,\reg 162 larl %r13,\start 163 slgr %r14,%r13 164 lghi %r13,\end - \start 165 clgr %r14,%r13 166 jhe \outside_label 167 .endm 168 169 .macro SIEEXIT 170 lg %r9,__SF_SIE_CONTROL(%r15) # get control block pointer 171 ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE 172 lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce 173 larl %r9,sie_exit # skip forward to sie_exit 174 .endm 175#endif 176 177 GEN_BR_THUNK %r14 178 GEN_BR_THUNK %r14,%r13 179 180 .section .kprobes.text, "ax" 181.Ldummy: 182 /* 183 * This nop exists only in order to avoid that __bpon starts at 184 * the beginning of the kprobes text section. In that case we would 185 * have several symbols at the same address. E.g. objdump would take 186 * an arbitrary symbol name when disassembling this code. 187 * With the added nop in between the __bpon symbol is unique 188 * again. 189 */ 190 nop 0 191 192ENTRY(__bpon) 193 .globl __bpon 194 BPON 195 BR_EX %r14 196ENDPROC(__bpon) 197 198/* 199 * Scheduler resume function, called by switch_to 200 * gpr2 = (task_struct *) prev 201 * gpr3 = (task_struct *) next 202 * Returns: 203 * gpr2 = prev 204 */ 205ENTRY(__switch_to) 206 stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task 207 lghi %r4,__TASK_stack 208 lghi %r1,__TASK_thread 209 llill %r5,STACK_INIT 210 stg %r15,__THREAD_ksp(%r1,%r2) # store kernel stack of prev 211 lg %r15,0(%r4,%r3) # start of kernel stack of next 212 agr %r15,%r5 # end of kernel stack of next 213 stg %r3,__LC_CURRENT # store task struct of next 214 stg %r15,__LC_KERNEL_STACK # store end of kernel stack 215 lg %r15,__THREAD_ksp(%r1,%r3) # load kernel stack of next 216 aghi %r3,__TASK_pid 217 mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next 218 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task 219 ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40 220 BR_EX %r14 221ENDPROC(__switch_to) 222 223#if IS_ENABLED(CONFIG_KVM) 224/* 225 * sie64a calling convention: 226 * %r2 pointer to sie control block 227 * %r3 guest register save area 228 */ 229ENTRY(sie64a) 230 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers 231 lg %r12,__LC_CURRENT 232 stg %r2,__SF_SIE_CONTROL(%r15) # save control block pointer 233 stg %r3,__SF_SIE_SAVEAREA(%r15) # save guest register save area 234 xc __SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0 235 mvc __SF_SIE_FLAGS(8,%r15),__TI_flags(%r12) # copy thread flags 236 lmg %r0,%r13,0(%r3) # load guest gprs 0-13 237 lg %r14,__LC_GMAP # get gmap pointer 238 ltgr %r14,%r14 239 jz .Lsie_gmap 240 lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce 241.Lsie_gmap: 242 lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer 243 oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now 244 tm __SIE_PROG20+3(%r14),3 # last exit... 245 jnz .Lsie_skip 246 TSTMSK __LC_CPU_FLAGS,_CIF_FPU 247 jo .Lsie_skip # exit if fp/vx regs changed 248 BPEXIT __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) 249.Lsie_entry: 250 sie 0(%r14) 251 BPOFF 252 BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) 253.Lsie_skip: 254 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE 255 lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce 256.Lsie_done: 257# some program checks are suppressing. C code (e.g. do_protection_exception) 258# will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There 259# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable. 260# Other instructions between sie64a and .Lsie_done should not cause program 261# interrupts. So lets use 3 nops as a landing pad for all possible rewinds. 262.Lrewind_pad6: 263 nopr 7 264.Lrewind_pad4: 265 nopr 7 266.Lrewind_pad2: 267 nopr 7 268 .globl sie_exit 269sie_exit: 270 lg %r14,__SF_SIE_SAVEAREA(%r15) # load guest register save area 271 stmg %r0,%r13,0(%r14) # save guest gprs 0-13 272 xgr %r0,%r0 # clear guest registers to 273 xgr %r1,%r1 # prevent speculative use 274 xgr %r3,%r3 275 xgr %r4,%r4 276 xgr %r5,%r5 277 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers 278 lg %r2,__SF_SIE_REASON(%r15) # return exit reason code 279 BR_EX %r14 280.Lsie_fault: 281 lghi %r14,-EFAULT 282 stg %r14,__SF_SIE_REASON(%r15) # set exit reason code 283 j sie_exit 284 285 EX_TABLE(.Lrewind_pad6,.Lsie_fault) 286 EX_TABLE(.Lrewind_pad4,.Lsie_fault) 287 EX_TABLE(.Lrewind_pad2,.Lsie_fault) 288 EX_TABLE(sie_exit,.Lsie_fault) 289ENDPROC(sie64a) 290EXPORT_SYMBOL(sie64a) 291EXPORT_SYMBOL(sie_exit) 292#endif 293 294/* 295 * SVC interrupt handler routine. System calls are synchronous events and 296 * are entered with interrupts disabled. 297 */ 298 299ENTRY(system_call) 300 stpt __LC_SYS_ENTER_TIMER 301 stmg %r8,%r15,__LC_SAVE_AREA_SYNC 302 BPOFF 303 lghi %r14,0 304.Lsysc_per: 305 lctlg %c1,%c1,__LC_KERNEL_ASCE 306 lg %r12,__LC_CURRENT 307 lg %r15,__LC_KERNEL_STACK 308 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 309 stmg %r0,%r7,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 310 BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP 311 # clear user controlled register to prevent speculative use 312 xgr %r0,%r0 313 xgr %r1,%r1 314 xgr %r4,%r4 315 xgr %r5,%r5 316 xgr %r6,%r6 317 xgr %r7,%r7 318 xgr %r8,%r8 319 xgr %r9,%r9 320 xgr %r10,%r10 321 xgr %r11,%r11 322 la %r2,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs 323 mvc __PT_R8(64,%r2),__LC_SAVE_AREA_SYNC 324 lgr %r3,%r14 325 brasl %r14,__do_syscall 326 lctlg %c1,%c1,__LC_USER_ASCE 327 mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 328 BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP 329 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 330 stpt __LC_EXIT_TIMER 331 b __LC_RETURN_LPSWE 332ENDPROC(system_call) 333 334# 335# a new process exits the kernel with ret_from_fork 336# 337ENTRY(ret_from_fork) 338 lgr %r3,%r11 339 brasl %r14,__ret_from_fork 340 lctlg %c1,%c1,__LC_USER_ASCE 341 mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 342 BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP 343 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 344 stpt __LC_EXIT_TIMER 345 b __LC_RETURN_LPSWE 346ENDPROC(ret_from_fork) 347 348/* 349 * Program check handler routine 350 */ 351 352ENTRY(pgm_check_handler) 353 stpt __LC_SYS_ENTER_TIMER 354 BPOFF 355 stmg %r8,%r15,__LC_SAVE_AREA_SYNC 356 lg %r12,__LC_CURRENT 357 lghi %r10,0 358 lmg %r8,%r9,__LC_PGM_OLD_PSW 359 tmhh %r8,0x0001 # coming from user space? 360 jno .Lpgm_skip_asce 361 lctlg %c1,%c1,__LC_KERNEL_ASCE 362 j 3f # -> fault in user space 363.Lpgm_skip_asce: 364#if IS_ENABLED(CONFIG_KVM) 365 # cleanup critical section for program checks in sie64a 366 OUTSIDE %r9,.Lsie_gmap,.Lsie_done,1f 367 SIEEXIT 368 lghi %r10,_PIF_GUEST_FAULT 369#endif 3701: tmhh %r8,0x4000 # PER bit set in old PSW ? 371 jnz 2f # -> enabled, can't be a double fault 372 tm __LC_PGM_ILC+3,0x80 # check for per exception 373 jnz .Lpgm_svcper # -> single stepped svc 3742: CHECK_STACK __LC_SAVE_AREA_SYNC 375 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 376 # CHECK_VMAP_STACK branches to stack_overflow or 4f 377 CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,4f 3783: BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP 379 lg %r15,__LC_KERNEL_STACK 3804: la %r11,STACK_FRAME_OVERHEAD(%r15) 381 stg %r10,__PT_FLAGS(%r11) 382 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 383 stmg %r0,%r7,__PT_R0(%r11) 384 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC 385 stmg %r8,%r9,__PT_PSW(%r11) 386 387 # clear user controlled registers to prevent speculative use 388 xgr %r0,%r0 389 xgr %r1,%r1 390 xgr %r3,%r3 391 xgr %r4,%r4 392 xgr %r5,%r5 393 xgr %r6,%r6 394 xgr %r7,%r7 395 lgr %r2,%r11 396 brasl %r14,__do_pgm_check 397 tmhh %r8,0x0001 # returning to user space? 398 jno .Lpgm_exit_kernel 399 lctlg %c1,%c1,__LC_USER_ASCE 400 BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP 401 stpt __LC_EXIT_TIMER 402.Lpgm_exit_kernel: 403 mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 404 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 405 b __LC_RETURN_LPSWE 406 407# 408# single stepped system call 409# 410.Lpgm_svcper: 411 mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW 412 larl %r14,.Lsysc_per 413 stg %r14,__LC_RETURN_PSW+8 414 lghi %r14,1 415 lpswe __LC_RETURN_PSW # branch to .Lsysc_per 416ENDPROC(pgm_check_handler) 417 418/* 419 * Interrupt handler macro used for external and IO interrupts. 420 */ 421.macro INT_HANDLER name,lc_old_psw,handler 422ENTRY(\name) 423 STCK __LC_INT_CLOCK 424 stpt __LC_SYS_ENTER_TIMER 425 BPOFF 426 stmg %r8,%r15,__LC_SAVE_AREA_ASYNC 427 lg %r12,__LC_CURRENT 428 lmg %r8,%r9,\lc_old_psw 429 tmhh %r8,0x0001 # interrupting from user ? 430 jnz 1f 431#if IS_ENABLED(CONFIG_KVM) 432 OUTSIDE %r9,.Lsie_gmap,.Lsie_done,0f 433 BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) 434 SIEEXIT 435#endif 4360: CHECK_STACK __LC_SAVE_AREA_ASYNC 437 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 438 j 2f 4391: BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP 440 lctlg %c1,%c1,__LC_KERNEL_ASCE 441 lg %r15,__LC_KERNEL_STACK 4422: xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 443 la %r11,STACK_FRAME_OVERHEAD(%r15) 444 stmg %r0,%r7,__PT_R0(%r11) 445 # clear user controlled registers to prevent speculative use 446 xgr %r0,%r0 447 xgr %r1,%r1 448 xgr %r3,%r3 449 xgr %r4,%r4 450 xgr %r5,%r5 451 xgr %r6,%r6 452 xgr %r7,%r7 453 xgr %r10,%r10 454 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) 455 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC 456 stmg %r8,%r9,__PT_PSW(%r11) 457 tm %r8,0x0001 # coming from user space? 458 jno 1f 459 lctlg %c1,%c1,__LC_KERNEL_ASCE 4601: lgr %r2,%r11 # pass pointer to pt_regs 461 brasl %r14,\handler 462 mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) 463 tmhh %r8,0x0001 # returning to user ? 464 jno 2f 465 lctlg %c1,%c1,__LC_USER_ASCE 466 BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP 467 stpt __LC_EXIT_TIMER 4682: lmg %r0,%r15,__PT_R0(%r11) 469 b __LC_RETURN_LPSWE 470ENDPROC(\name) 471.endm 472 473INT_HANDLER ext_int_handler,__LC_EXT_OLD_PSW,do_ext_irq 474INT_HANDLER io_int_handler,__LC_IO_OLD_PSW,do_io_irq 475 476/* 477 * Load idle PSW. 478 */ 479ENTRY(psw_idle) 480 stg %r14,(__SF_GPRS+8*8)(%r15) 481 stg %r3,__SF_EMPTY(%r15) 482 larl %r1,psw_idle_exit 483 stg %r1,__SF_EMPTY+8(%r15) 484 larl %r1,smp_cpu_mtid 485 llgf %r1,0(%r1) 486 ltgr %r1,%r1 487 jz .Lpsw_idle_stcctm 488 .insn rsy,0xeb0000000017,%r1,5,__MT_CYCLES_ENTER(%r2) 489.Lpsw_idle_stcctm: 490 oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT 491 BPON 492 STCK __CLOCK_IDLE_ENTER(%r2) 493 stpt __TIMER_IDLE_ENTER(%r2) 494 lpswe __SF_EMPTY(%r15) 495.globl psw_idle_exit 496psw_idle_exit: 497 BR_EX %r14 498ENDPROC(psw_idle) 499 500/* 501 * Machine check handler routines 502 */ 503ENTRY(mcck_int_handler) 504 STCK __LC_MCCK_CLOCK 505 BPOFF 506 la %r1,4095 # validate r1 507 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # validate cpu timer 508 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs 509 lg %r12,__LC_CURRENT 510 lmg %r8,%r9,__LC_MCK_OLD_PSW 511 TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE 512 jo .Lmcck_panic # yes -> rest of mcck code invalid 513 TSTMSK __LC_MCCK_CODE,MCCK_CODE_CR_VALID 514 jno .Lmcck_panic # control registers invalid -> panic 515 la %r14,4095 516 lctlg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r14) # validate ctl regs 517 ptlb 518 lghi %r14,__LC_CPU_TIMER_SAVE_AREA 519 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 520 TSTMSK __LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID 521 jo 3f 522 la %r14,__LC_SYS_ENTER_TIMER 523 clc 0(8,%r14),__LC_EXIT_TIMER 524 jl 1f 525 la %r14,__LC_EXIT_TIMER 5261: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER 527 jl 2f 528 la %r14,__LC_LAST_UPDATE_TIMER 5292: spt 0(%r14) 530 mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 5313: TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID 532 jno .Lmcck_panic 533 tmhh %r8,0x0001 # interrupting from user ? 534 jnz 6f 535 TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID 536 jno .Lmcck_panic 537#if IS_ENABLED(CONFIG_KVM) 538 OUTSIDE %r9,.Lsie_gmap,.Lsie_done,6f 539 OUTSIDE %r9,.Lsie_entry,.Lsie_skip,4f 540 oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST 541 j 5f 5424: CHKSTG .Lmcck_panic 5435: larl %r14,.Lstosm_tmp 544 stosm 0(%r14),0x04 # turn dat on, keep irqs off 545 BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) 546 SIEEXIT 547 j .Lmcck_stack 548#endif 5496: CHKSTG .Lmcck_panic 550 larl %r14,.Lstosm_tmp 551 stosm 0(%r14),0x04 # turn dat on, keep irqs off 552 tmhh %r8,0x0001 # interrupting from user ? 553 jz .Lmcck_stack 554 BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP 555.Lmcck_stack: 556 lg %r15,__LC_MCCK_STACK 557 la %r11,STACK_FRAME_OVERHEAD(%r15) 558 stctg %c1,%c1,__PT_CR1(%r11) 559 lctlg %c1,%c1,__LC_KERNEL_ASCE 560 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 561 lghi %r14,__LC_GPREGS_SAVE_AREA+64 562 stmg %r0,%r7,__PT_R0(%r11) 563 # clear user controlled registers to prevent speculative use 564 xgr %r0,%r0 565 xgr %r1,%r1 566 xgr %r3,%r3 567 xgr %r4,%r4 568 xgr %r5,%r5 569 xgr %r6,%r6 570 xgr %r7,%r7 571 xgr %r10,%r10 572 mvc __PT_R8(64,%r11),0(%r14) 573 stmg %r8,%r9,__PT_PSW(%r11) 574 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) 575 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 576 lgr %r2,%r11 # pass pointer to pt_regs 577 brasl %r14,s390_do_machine_check 578 cghi %r2,0 579 je .Lmcck_return 580 lg %r1,__LC_KERNEL_STACK # switch to kernel stack 581 mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) 582 xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) 583 la %r11,STACK_FRAME_OVERHEAD(%r1) 584 lgr %r15,%r1 585 brasl %r14,s390_handle_mcck 586.Lmcck_return: 587 lctlg %c1,%c1,__PT_CR1(%r11) 588 lmg %r0,%r10,__PT_R0(%r11) 589 mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW 590 tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? 591 jno 0f 592 BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP 593 stpt __LC_EXIT_TIMER 5940: lmg %r11,%r15,__PT_R11(%r11) 595 b __LC_RETURN_MCCK_LPSWE 596 597.Lmcck_panic: 598 /* 599 * Iterate over all possible CPU addresses in the range 0..0xffff 600 * and stop each CPU using signal processor. Use compare and swap 601 * to allow just one CPU-stopper and prevent concurrent CPUs from 602 * stopping each other while leaving the others running. 603 */ 604 lhi %r5,0 605 lhi %r6,1 606 larl %r7,.Lstop_lock 607 cs %r5,%r6,0(%r7) # single CPU-stopper only 608 jnz 4f 609 larl %r7,.Lthis_cpu 610 stap 0(%r7) # this CPU address 611 lh %r4,0(%r7) 612 nilh %r4,0 613 lhi %r0,1 614 sll %r0,16 # CPU counter 615 lhi %r3,0 # next CPU address 6160: cr %r3,%r4 617 je 2f 6181: sigp %r1,%r3,SIGP_STOP # stop next CPU 619 brc SIGP_CC_BUSY,1b 6202: ahi %r3,1 621 brct %r0,0b 6223: sigp %r1,%r4,SIGP_STOP # stop this CPU 623 brc SIGP_CC_BUSY,3b 6244: j 4b 625ENDPROC(mcck_int_handler) 626 627# 628# PSW restart interrupt handler 629# 630ENTRY(restart_int_handler) 631 ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40 632 stg %r15,__LC_SAVE_AREA_RESTART 633 lg %r15,__LC_RESTART_STACK 634 xc STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15) 635 stmg %r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 636 mvc STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART 637 mvc STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW 638 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) 639 lg %r1,__LC_RESTART_FN # load fn, parm & source cpu 640 lg %r2,__LC_RESTART_DATA 641 lg %r3,__LC_RESTART_SOURCE 642 ltgr %r3,%r3 # test source cpu address 643 jm 1f # negative -> skip source stop 6440: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu 645 brc 10,0b # wait for status stored 6461: basr %r14,%r1 # call function 647 stap __SF_EMPTY(%r15) # store cpu address 648 llgh %r3,__SF_EMPTY(%r15) 6492: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu 650 brc 2,2b 6513: j 3b 652ENDPROC(restart_int_handler) 653 654 .section .kprobes.text, "ax" 655 656#if defined(CONFIG_CHECK_STACK) || defined(CONFIG_VMAP_STACK) 657/* 658 * The synchronous or the asynchronous stack overflowed. We are dead. 659 * No need to properly save the registers, we are going to panic anyway. 660 * Setup a pt_regs so that show_trace can provide a good call trace. 661 */ 662ENTRY(stack_overflow) 663 lg %r15,__LC_NODAT_STACK # change to panic stack 664 la %r11,STACK_FRAME_OVERHEAD(%r15) 665 stmg %r0,%r7,__PT_R0(%r11) 666 stmg %r8,%r9,__PT_PSW(%r11) 667 mvc __PT_R8(64,%r11),0(%r14) 668 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2 669 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 670 lgr %r2,%r11 # pass pointer to pt_regs 671 jg kernel_stack_overflow 672ENDPROC(stack_overflow) 673#endif 674 675 .section .data, "aw" 676 .align 4 677.Lstop_lock: .long 0 678.Lthis_cpu: .short 0 679.Lstosm_tmp: .byte 0 680 .section .rodata, "a" 681#define SYSCALL(esame,emu) .quad __s390x_ ## esame 682 .globl sys_call_table 683sys_call_table: 684#include "asm/syscall_table.h" 685#undef SYSCALL 686 687#ifdef CONFIG_COMPAT 688 689#define SYSCALL(esame,emu) .quad __s390_ ## emu 690 .globl sys_call_table_emu 691sys_call_table_emu: 692#include "asm/syscall_table.h" 693#undef SYSCALL 694#endif 695