/* * S390 low-level entry points. * * Copyright IBM Corp. 1999, 2012 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Hartmut Penner (hp@de.ibm.com), * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), * Heiko Carstens */ #include #include #include #include #include #include #include #include #include #include __PT_R0 = __PT_GPRS __PT_R1 = __PT_GPRS + 4 __PT_R2 = __PT_GPRS + 8 __PT_R3 = __PT_GPRS + 12 __PT_R4 = __PT_GPRS + 16 __PT_R5 = __PT_GPRS + 20 __PT_R6 = __PT_GPRS + 24 __PT_R7 = __PT_GPRS + 28 __PT_R8 = __PT_GPRS + 32 __PT_R9 = __PT_GPRS + 36 __PT_R10 = __PT_GPRS + 40 __PT_R11 = __PT_GPRS + 44 __PT_R12 = __PT_GPRS + 48 __PT_R13 = __PT_GPRS + 524 __PT_R14 = __PT_GPRS + 56 __PT_R15 = __PT_GPRS + 60 _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ _TIF_MCCK_PENDING | _TIF_PER_TRAP ) _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ _TIF_MCCK_PENDING) _TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \ _TIF_SYSCALL_TRACEPOINT) STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER STACK_SIZE = 1 << STACK_SHIFT #define BASED(name) name-system_call(%r13) .macro TRACE_IRQS_ON #ifdef CONFIG_TRACE_IRQFLAGS basr %r2,%r0 l %r1,BASED(.Lhardirqs_on) basr %r14,%r1 # call trace_hardirqs_on_caller #endif .endm .macro TRACE_IRQS_OFF #ifdef CONFIG_TRACE_IRQFLAGS basr %r2,%r0 l %r1,BASED(.Lhardirqs_off) basr %r14,%r1 # call trace_hardirqs_off_caller #endif .endm .macro LOCKDEP_SYS_EXIT #ifdef CONFIG_LOCKDEP tm __PT_PSW+1(%r11),0x01 # returning to user ? jz .+10 l %r1,BASED(.Llockdep_sys_exit) basr %r14,%r1 # call lockdep_sys_exit #endif .endm .macro CHECK_STACK stacksize,savearea #ifdef CONFIG_CHECK_STACK tml %r15,\stacksize - CONFIG_STACK_GUARD la %r14,\savearea jz stack_overflow #endif .endm .macro SWITCH_ASYNC savearea,stack,shift tmh %r8,0x0001 # interrupting from user ? jnz 1f lr %r14,%r9 sl %r14,BASED(.Lcritical_start) cl %r14,BASED(.Lcritical_length) jhe 0f la %r11,\savearea # inside critical section, do cleanup bras %r14,cleanup_critical tmh %r8,0x0001 # retest problem state after cleanup jnz 1f 0: l %r14,\stack # are we already on the target stack? slr %r14,%r15 sra %r14,\shift jnz 1f CHECK_STACK 1<<\shift,\savearea j 2f 1: l %r15,\stack # load target stack 2: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) la %r11,STACK_FRAME_OVERHEAD(%r15) .endm .macro ADD64 high,low,timer al \high,\timer al \low,4+\timer brc 12,.+8 ahi \high,1 .endm .macro SUB64 high,low,timer sl \high,\timer sl \low,4+\timer brc 3,.+8 ahi \high,-1 .endm .macro UPDATE_VTIME high,low,enter_timer lm \high,\low,__LC_EXIT_TIMER SUB64 \high,\low,\enter_timer ADD64 \high,\low,__LC_USER_TIMER stm \high,\low,__LC_USER_TIMER lm \high,\low,__LC_LAST_UPDATE_TIMER SUB64 \high,\low,__LC_EXIT_TIMER ADD64 \high,\low,__LC_SYSTEM_TIMER stm \high,\low,__LC_SYSTEM_TIMER mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer .endm .macro REENABLE_IRQS st %r8,__LC_RETURN_PSW ni __LC_RETURN_PSW,0xbf ssm __LC_RETURN_PSW .endm .section .kprobes.text, "ax" /* * Scheduler resume function, called by switch_to * gpr2 = (task_struct *) prev * gpr3 = (task_struct *) next * Returns: * gpr2 = prev */ ENTRY(__switch_to) stm %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task st %r15,__THREAD_ksp(%r2) # store kernel stack of prev l %r4,__THREAD_info(%r2) # get thread_info of prev l %r5,__THREAD_info(%r3) # get thread_info of next lr %r15,%r5 ahi %r15,STACK_SIZE # end of kernel stack of next st %r3,__LC_CURRENT # store task struct of next st %r5,__LC_THREAD_INFO # store thread info of next st %r15,__LC_KERNEL_STACK # store end of kernel stack lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next l %r15,__THREAD_ksp(%r3) # load kernel stack of next tm __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending? jz 0f ni __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev oi __TI_flags+3(%r5),_TIF_MCCK_PENDING # set it in next 0: lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task br %r14 __critical_start: /* * SVC interrupt handler routine. System calls are synchronous events and * are executed with interrupts enabled. */ ENTRY(system_call) stpt __LC_SYNC_ENTER_TIMER sysc_stm: stm %r8,%r15,__LC_SAVE_AREA_SYNC l %r12,__LC_THREAD_INFO l %r13,__LC_SVC_NEW_PSW+4 sysc_per: l %r15,__LC_KERNEL_STACK ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs sysc_vtime: UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER stm %r0,%r7,__PT_R0(%r11) mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC mvc __PT_PSW(8,%r11),__LC_SVC_OLD_PSW mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC sysc_do_svc: oi __TI_flags+3(%r12),_TIF_SYSCALL lh %r8,__PT_INT_CODE+2(%r11) sla %r8,2 # shift and test for svc0 jnz sysc_nr_ok # svc 0: system call number in %r1 cl %r1,BASED(.Lnr_syscalls) jnl sysc_nr_ok sth %r1,__PT_INT_CODE+2(%r11) lr %r8,%r1 sla %r8,2 sysc_nr_ok: l %r10,BASED(.Lsys_call_table) # 31 bit system call table xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) st %r2,__PT_ORIG_GPR2(%r11) st %r7,STACK_FRAME_OVERHEAD(%r15) l %r9,0(%r8,%r10) # get system call addr. tm __TI_flags+2(%r12),_TIF_TRACE >> 8 jnz sysc_tracesys basr %r14,%r9 # call sys_xxxx st %r2,__PT_R2(%r11) # store return value sysc_return: LOCKDEP_SYS_EXIT sysc_tif: tm __PT_PSW+1(%r11),0x01 # returning to user ? jno sysc_restore tm __TI_flags+3(%r12),_TIF_WORK_SVC jnz sysc_work # check for work ni __TI_flags+3(%r12),255-_TIF_SYSCALL sysc_restore: mvc __LC_RETURN_PSW(8),__PT_PSW(%r11) stpt __LC_EXIT_TIMER lm %r0,%r15,__PT_R0(%r11) lpsw __LC_RETURN_PSW sysc_done: # # One of the work bits is on. Find out which one. # sysc_work: tm __TI_flags+3(%r12),_TIF_MCCK_PENDING jo sysc_mcck_pending tm __TI_flags+3(%r12),_TIF_NEED_RESCHED jo sysc_reschedule tm __TI_flags+3(%r12),_TIF_SIGPENDING jo sysc_sigpending tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME jo sysc_notify_resume tm __TI_flags+3(%r12),_TIF_PER_TRAP jo sysc_singlestep j sysc_return # beware of critical section cleanup # # _TIF_NEED_RESCHED is set, call schedule # sysc_reschedule: l %r1,BASED(.Lschedule) la %r14,BASED(sysc_return) br %r1 # call schedule # # _TIF_MCCK_PENDING is set, call handler # sysc_mcck_pending: l %r1,BASED(.Lhandle_mcck) la %r14,BASED(sysc_return) br %r1 # TIF bit will be cleared by handler # # _TIF_SIGPENDING is set, call do_signal # sysc_sigpending: ni __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP lr %r2,%r11 # pass pointer to pt_regs l %r1,BASED(.Ldo_signal) basr %r14,%r1 # call do_signal tm __TI_flags+3(%r12),_TIF_SYSCALL jno sysc_return lm %r2,%r7,__PT_R2(%r11) # load svc arguments xr %r8,%r8 # svc 0 returns -ENOSYS clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2) jnl sysc_nr_ok # invalid svc number -> do svc 0 lh %r8,__PT_INT_CODE+2(%r11) # load new svc number sla %r8,2 j sysc_nr_ok # restart svc # # _TIF_NOTIFY_RESUME is set, call do_notify_resume # sysc_notify_resume: lr %r2,%r11 # pass pointer to pt_regs l %r1,BASED(.Ldo_notify_resume) la %r14,BASED(sysc_return) br %r1 # call do_notify_resume # # _TIF_PER_TRAP is set, call do_per_trap # sysc_singlestep: ni __TI_flags+3(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP) lr %r2,%r11 # pass pointer to pt_regs l %r1,BASED(.Ldo_per_trap) la %r14,BASED(sysc_return) br %r1 # call do_per_trap # # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before # and after the system call # sysc_tracesys: l %r1,BASED(.Ltrace_enter) lr %r2,%r11 # pass pointer to pt_regs la %r3,0 xr %r0,%r0 icm %r0,3,__PT_INT_CODE+2(%r11) st %r0,__PT_R2(%r11) basr %r14,%r1 # call do_syscall_trace_enter cl %r2,BASED(.Lnr_syscalls) jnl sysc_tracenogo lr %r8,%r2 sll %r8,2 l %r9,0(%r8,%r10) sysc_tracego: lm %r3,%r7,__PT_R3(%r11) st %r7,STACK_FRAME_OVERHEAD(%r15) l %r2,__PT_ORIG_GPR2(%r11) basr %r14,%r9 # call sys_xxx st %r2,__PT_R2(%r11) # store return value sysc_tracenogo: tm __TI_flags+2(%r12),_TIF_TRACE >> 8 jz sysc_return l %r1,BASED(.Ltrace_exit) lr %r2,%r11 # pass pointer to pt_regs la %r14,BASED(sysc_return) br %r1 # call do_syscall_trace_exit # # a new process exits the kernel with ret_from_fork # ENTRY(ret_from_fork) la %r11,STACK_FRAME_OVERHEAD(%r15) l %r12,__LC_THREAD_INFO l %r13,__LC_SVC_NEW_PSW+4 tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ? jo 0f st %r15,__PT_R15(%r11) # store stack pointer for new kthread 0: l %r1,BASED(.Lschedule_tail) basr %r14,%r1 # call schedule_tail TRACE_IRQS_ON ssm __LC_SVC_NEW_PSW # reenable interrupts j sysc_tracenogo # # kernel_execve function needs to deal with pt_regs that is not # at the usual place # ENTRY(kernel_execve) stm %r12,%r15,48(%r15) lr %r14,%r15 l %r13,__LC_SVC_NEW_PSW+4 ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) st %r14,__SF_BACKCHAIN(%r15) la %r12,STACK_FRAME_OVERHEAD(%r15) xc 0(__PT_SIZE,%r12),0(%r12) l %r1,BASED(.Ldo_execve) lr %r5,%r12 basr %r14,%r1 # call do_execve ltr %r2,%r2 je 0f ahi %r15,(STACK_FRAME_OVERHEAD + __PT_SIZE) lm %r12,%r15,48(%r15) br %r14 # execve succeeded. 0: ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts l %r15,__LC_KERNEL_STACK # load ksp ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) la %r11,STACK_FRAME_OVERHEAD(%r15) mvc 0(__PT_SIZE,%r11),0(%r12) # copy pt_regs l %r12,__LC_THREAD_INFO xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) ssm __LC_SVC_NEW_PSW # reenable interrupts j sysc_return /* * Program check handler routine */ ENTRY(pgm_check_handler) stpt __LC_SYNC_ENTER_TIMER stm %r8,%r15,__LC_SAVE_AREA_SYNC l %r12,__LC_THREAD_INFO l %r13,__LC_SVC_NEW_PSW+4 lm %r8,%r9,__LC_PGM_OLD_PSW tmh %r8,0x0001 # test problem state bit jnz 1f # -> fault in user space tmh %r8,0x4000 # PER bit set in old PSW ? jnz 0f # -> enabled, can't be a double fault tm __LC_PGM_ILC+3,0x80 # check for per exception jnz pgm_svcper # -> single stepped svc 0: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC j 2f 1: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER l %r15,__LC_KERNEL_STACK 2: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) la %r11,STACK_FRAME_OVERHEAD(%r15) stm %r0,%r7,__PT_R0(%r11) mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC stm %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC mvc __PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE tm __LC_PGM_ILC+3,0x80 # check for per exception jz 0f l %r1,__TI_task(%r12) tmh %r8,0x0001 # kernel per event ? jz pgm_kprobe oi __TI_flags+3(%r12),_TIF_PER_TRAP mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID 0: REENABLE_IRQS xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) l %r1,BASED(.Ljump_table) la %r10,0x7f n %r10,__PT_INT_CODE(%r11) je sysc_return sll %r10,2 l %r1,0(%r10,%r1) # load address of handler routine lr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # branch to interrupt-handler j sysc_return # # PER event in supervisor state, must be kprobes # pgm_kprobe: REENABLE_IRQS xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) l %r1,BASED(.Ldo_per_trap) lr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # call do_per_trap j sysc_return # # single stepped system call # pgm_svcper: oi __TI_flags+3(%r12),_TIF_PER_TRAP mvc __LC_RETURN_PSW(4),__LC_SVC_NEW_PSW mvc __LC_RETURN_PSW+4(4),BASED(.Lsysc_per) lpsw __LC_RETURN_PSW # branch to sysc_per and enable irqs /* * IO interrupt handler routine */ ENTRY(io_int_handler) stck __LC_INT_CLOCK stpt __LC_ASYNC_ENTER_TIMER stm %r8,%r15,__LC_SAVE_AREA_ASYNC l %r12,__LC_THREAD_INFO l %r13,__LC_SVC_NEW_PSW+4 lm %r8,%r9,__LC_IO_OLD_PSW tmh %r8,0x0001 # interrupting from user ? jz io_skip UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER io_skip: SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT stm %r0,%r7,__PT_R0(%r11) mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC stm %r8,%r9,__PT_PSW(%r11) TRACE_IRQS_OFF xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) l %r1,BASED(.Ldo_IRQ) lr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # call do_IRQ io_return: LOCKDEP_SYS_EXIT TRACE_IRQS_ON io_tif: tm __TI_flags+3(%r12),_TIF_WORK_INT jnz io_work # there is work to do (signals etc.) io_restore: mvc __LC_RETURN_PSW(8),__PT_PSW(%r11) stpt __LC_EXIT_TIMER lm %r0,%r15,__PT_R0(%r11) lpsw __LC_RETURN_PSW io_done: # # There is work todo, find out in which context we have been interrupted: # 1) if we return to user space we can do all _TIF_WORK_INT work # 2) if we return to kernel code and preemptive scheduling is enabled check # the preemption counter and if it is zero call preempt_schedule_irq # Before any work can be done, a switch to the kernel stack is required. # io_work: tm __PT_PSW+1(%r11),0x01 # returning to user ? jo io_work_user # yes -> do resched & signal #ifdef CONFIG_PREEMPT # check for preemptive scheduling icm %r0,15,__TI_precount(%r12) jnz io_restore # preemption disabled tm __TI_flags+3(%r12),_TIF_NEED_RESCHED jno io_restore # switch to kernel stack l %r1,__PT_R15(%r11) ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r1) lr %r15,%r1 # TRACE_IRQS_ON already done at io_return, call # TRACE_IRQS_OFF to keep things symmetrical TRACE_IRQS_OFF l %r1,BASED(.Lpreempt_irq) basr %r14,%r1 # call preempt_schedule_irq j io_return #else j io_restore #endif # # Need to do work before returning to userspace, switch to kernel stack # io_work_user: l %r1,__LC_KERNEL_STACK ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r1) lr %r15,%r1 # # One of the work bits is on. Find out which one. # Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED # and _TIF_MCCK_PENDING # io_work_tif: tm __TI_flags+3(%r12),_TIF_MCCK_PENDING jo io_mcck_pending tm __TI_flags+3(%r12),_TIF_NEED_RESCHED jo io_reschedule tm __TI_flags+3(%r12),_TIF_SIGPENDING jo io_sigpending tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME jo io_notify_resume j io_return # beware of critical section cleanup # # _TIF_MCCK_PENDING is set, call handler # io_mcck_pending: # TRACE_IRQS_ON already done at io_return l %r1,BASED(.Lhandle_mcck) basr %r14,%r1 # TIF bit will be cleared by handler TRACE_IRQS_OFF j io_return # # _TIF_NEED_RESCHED is set, call schedule # io_reschedule: # TRACE_IRQS_ON already done at io_return l %r1,BASED(.Lschedule) ssm __LC_SVC_NEW_PSW # reenable interrupts basr %r14,%r1 # call scheduler ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts TRACE_IRQS_OFF j io_return # # _TIF_SIGPENDING is set, call do_signal # io_sigpending: # TRACE_IRQS_ON already done at io_return l %r1,BASED(.Ldo_signal) ssm __LC_SVC_NEW_PSW # reenable interrupts lr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # call do_signal ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts TRACE_IRQS_OFF j io_return # # _TIF_SIGPENDING is set, call do_signal # io_notify_resume: # TRACE_IRQS_ON already done at io_return l %r1,BASED(.Ldo_notify_resume) ssm __LC_SVC_NEW_PSW # reenable interrupts lr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # call do_notify_resume ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts TRACE_IRQS_OFF j io_return /* * External interrupt handler routine */ ENTRY(ext_int_handler) stck __LC_INT_CLOCK stpt __LC_ASYNC_ENTER_TIMER stm %r8,%r15,__LC_SAVE_AREA_ASYNC l %r12,__LC_THREAD_INFO l %r13,__LC_SVC_NEW_PSW+4 lm %r8,%r9,__LC_EXT_OLD_PSW tmh %r8,0x0001 # interrupting from user ? jz ext_skip UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER ext_skip: SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT stm %r0,%r7,__PT_R0(%r11) mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC stm %r8,%r9,__PT_PSW(%r11) TRACE_IRQS_OFF lr %r2,%r11 # pass pointer to pt_regs l %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code l %r4,__LC_EXT_PARAMS # get external parameters l %r1,BASED(.Ldo_extint) basr %r14,%r1 # call do_extint j io_return /* * Load idle PSW. The second "half" of this function is in cleanup_idle. */ ENTRY(psw_idle) st %r3,__SF_EMPTY(%r15) basr %r1,0 la %r1,psw_idle_lpsw+4-.(%r1) st %r1,__SF_EMPTY+4(%r15) oi __SF_EMPTY+4(%r15),0x80 stck __CLOCK_IDLE_ENTER(%r2) stpt __TIMER_IDLE_ENTER(%r2) psw_idle_lpsw: lpsw __SF_EMPTY(%r15) br %r14 psw_idle_end: __critical_end: /* * Machine check handler routines */ ENTRY(mcck_int_handler) stck __LC_MCCK_CLOCK spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs l %r12,__LC_THREAD_INFO l %r13,__LC_SVC_NEW_PSW+4 lm %r8,%r9,__LC_MCK_OLD_PSW tm __LC_MCCK_CODE,0x80 # system damage? jo mcck_panic # yes -> rest of mcck code invalid la %r14,__LC_CPU_TIMER_SAVE_AREA mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid? jo 3f la %r14,__LC_SYNC_ENTER_TIMER clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER jl 0f la %r14,__LC_ASYNC_ENTER_TIMER 0: clc 0(8,%r14),__LC_EXIT_TIMER jl 1f la %r14,__LC_EXIT_TIMER 1: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER jl 2f la %r14,__LC_LAST_UPDATE_TIMER 2: spt 0(%r14) mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 3: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? jno mcck_panic # no -> skip cleanup critical tm %r8,0x0001 # interrupting from user ? jz mcck_skip UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER mcck_skip: SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT mvc __PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA stm %r8,%r9,__PT_PSW(%r11) xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) l %r1,BASED(.Ldo_machine_check) lr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # call s390_do_machine_check tm __PT_PSW+1(%r11),0x01 # returning to user ? jno mcck_return l %r1,__LC_KERNEL_STACK # switch to kernel stack ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r15) lr %r15,%r1 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off tm __TI_flags+3(%r12),_TIF_MCCK_PENDING jno mcck_return TRACE_IRQS_OFF l %r1,BASED(.Lhandle_mcck) basr %r14,%r1 # call s390_handle_mcck TRACE_IRQS_ON mcck_return: mvc __LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? jno 0f lm %r0,%r15,__PT_R0(%r11) stpt __LC_EXIT_TIMER lpsw __LC_RETURN_MCCK_PSW 0: lm %r0,%r15,__PT_R0(%r11) lpsw __LC_RETURN_MCCK_PSW mcck_panic: l %r14,__LC_PANIC_STACK slr %r14,%r15 sra %r14,PAGE_SHIFT jz 0f l %r15,__LC_PANIC_STACK 0: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) j mcck_skip # # PSW restart interrupt handler # ENTRY(restart_int_handler) st %r15,__LC_SAVE_AREA_RESTART l %r15,__LC_RESTART_STACK ahi %r15,-__PT_SIZE # create pt_regs on stack xc 0(__PT_SIZE,%r15),0(%r15) stm %r0,%r14,__PT_R0(%r15) mvc __PT_R15(4,%r15),__LC_SAVE_AREA_RESTART mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) l %r1,__LC_RESTART_FN # load fn, parm & source cpu l %r2,__LC_RESTART_DATA l %r3,__LC_RESTART_SOURCE ltr %r3,%r3 # test source cpu address jm 1f # negative -> skip source stop 0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu brc 10,0b # wait for status stored 1: basr %r14,%r1 # call function stap __SF_EMPTY(%r15) # store cpu address lh %r3,__SF_EMPTY(%r15) 2: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu brc 2,2b 3: j 3b .section .kprobes.text, "ax" #ifdef CONFIG_CHECK_STACK /* * The synchronous or the asynchronous stack overflowed. We are dead. * No need to properly save the registers, we are going to panic anyway. * Setup a pt_regs so that show_trace can provide a good call trace. */ stack_overflow: l %r15,__LC_PANIC_STACK # change to panic stack ahi %r15,-__PT_SIZE # create pt_regs stm %r0,%r7,__PT_R0(%r15) stm %r8,%r9,__PT_PSW(%r15) mvc __PT_R8(32,%r11),0(%r14) lr %r15,%r11 ahi %r15,-STACK_FRAME_OVERHEAD l %r1,BASED(1f) xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) lr %r2,%r11 # pass pointer to pt_regs br %r1 # branch to kernel_stack_overflow 1: .long kernel_stack_overflow #endif cleanup_table: .long system_call + 0x80000000 .long sysc_do_svc + 0x80000000 .long sysc_tif + 0x80000000 .long sysc_restore + 0x80000000 .long sysc_done + 0x80000000 .long io_tif + 0x80000000 .long io_restore + 0x80000000 .long io_done + 0x80000000 .long psw_idle + 0x80000000 .long psw_idle_end + 0x80000000 cleanup_critical: cl %r9,BASED(cleanup_table) # system_call jl 0f cl %r9,BASED(cleanup_table+4) # sysc_do_svc jl cleanup_system_call cl %r9,BASED(cleanup_table+8) # sysc_tif jl 0f cl %r9,BASED(cleanup_table+12) # sysc_restore jl cleanup_sysc_tif cl %r9,BASED(cleanup_table+16) # sysc_done jl cleanup_sysc_restore cl %r9,BASED(cleanup_table+20) # io_tif jl 0f cl %r9,BASED(cleanup_table+24) # io_restore jl cleanup_io_tif cl %r9,BASED(cleanup_table+28) # io_done jl cleanup_io_restore cl %r9,BASED(cleanup_table+32) # psw_idle jl 0f cl %r9,BASED(cleanup_table+36) # psw_idle_end jl cleanup_idle 0: br %r14 cleanup_system_call: # check if stpt has been executed cl %r9,BASED(cleanup_system_call_insn) jh 0f mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER chi %r11,__LC_SAVE_AREA_ASYNC je 0f mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER 0: # check if stm has been executed cl %r9,BASED(cleanup_system_call_insn+4) jh 0f mvc __LC_SAVE_AREA_SYNC(32),0(%r11) 0: # set up saved registers r12, and r13 st %r12,16(%r11) # r12 thread-info pointer st %r13,20(%r11) # r13 literal-pool pointer # check if the user time calculation has been done cl %r9,BASED(cleanup_system_call_insn+8) jh 0f l %r10,__LC_EXIT_TIMER l %r15,__LC_EXIT_TIMER+4 SUB64 %r10,%r15,__LC_SYNC_ENTER_TIMER ADD64 %r10,%r15,__LC_USER_TIMER st %r10,__LC_USER_TIMER st %r15,__LC_USER_TIMER+4 0: # check if the system time calculation has been done cl %r9,BASED(cleanup_system_call_insn+12) jh 0f l %r10,__LC_LAST_UPDATE_TIMER l %r15,__LC_LAST_UPDATE_TIMER+4 SUB64 %r10,%r15,__LC_EXIT_TIMER ADD64 %r10,%r15,__LC_SYSTEM_TIMER st %r10,__LC_SYSTEM_TIMER st %r15,__LC_SYSTEM_TIMER+4 0: # update accounting time stamp mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER # set up saved register 11 l %r15,__LC_KERNEL_STACK ahi %r15,-__PT_SIZE st %r15,12(%r11) # r11 pt_regs pointer # fill pt_regs mvc __PT_R8(32,%r15),__LC_SAVE_AREA_SYNC stm %r0,%r7,__PT_R0(%r15) mvc __PT_PSW(8,%r15),__LC_SVC_OLD_PSW mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC # setup saved register 15 ahi %r15,-STACK_FRAME_OVERHEAD st %r15,28(%r11) # r15 stack pointer # set new psw address and exit l %r9,BASED(cleanup_table+4) # sysc_do_svc + 0x80000000 br %r14 cleanup_system_call_insn: .long system_call + 0x80000000 .long sysc_stm + 0x80000000 .long sysc_vtime + 0x80000000 + 36 .long sysc_vtime + 0x80000000 + 76 cleanup_sysc_tif: l %r9,BASED(cleanup_table+8) # sysc_tif + 0x80000000 br %r14 cleanup_sysc_restore: cl %r9,BASED(cleanup_sysc_restore_insn) jhe 0f l %r9,12(%r11) # get saved pointer to pt_regs mvc __LC_RETURN_PSW(8),__PT_PSW(%r9) mvc 0(32,%r11),__PT_R8(%r9) lm %r0,%r7,__PT_R0(%r9) 0: lm %r8,%r9,__LC_RETURN_PSW br %r14 cleanup_sysc_restore_insn: .long sysc_done - 4 + 0x80000000 cleanup_io_tif: l %r9,BASED(cleanup_table+20) # io_tif + 0x80000000 br %r14 cleanup_io_restore: cl %r9,BASED(cleanup_io_restore_insn) jhe 0f l %r9,12(%r11) # get saved r11 pointer to pt_regs mvc __LC_RETURN_PSW(8),__PT_PSW(%r9) mvc 0(32,%r11),__PT_R8(%r9) lm %r0,%r7,__PT_R0(%r9) 0: lm %r8,%r9,__LC_RETURN_PSW br %r14 cleanup_io_restore_insn: .long io_done - 4 + 0x80000000 cleanup_idle: # copy interrupt clock & cpu timer mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER chi %r11,__LC_SAVE_AREA_ASYNC je 0f mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER 0: # check if stck has been executed cl %r9,BASED(cleanup_idle_insn) jhe 1f mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2) mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3) 1: # account system time going idle lm %r9,%r10,__LC_STEAL_TIMER ADD64 %r9,%r10,__CLOCK_IDLE_ENTER(%r2) SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK stm %r9,%r10,__LC_STEAL_TIMER mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2) lm %r9,%r10,__LC_SYSTEM_TIMER ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER SUB64 %r9,%r10,__TIMER_IDLE_ENTER(%r2) stm %r9,%r10,__LC_SYSTEM_TIMER mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) # prepare return psw n %r8,BASED(cleanup_idle_wait) # clear wait state bit l %r9,24(%r11) # return from psw_idle br %r14 cleanup_idle_insn: .long psw_idle_lpsw + 0x80000000 cleanup_idle_wait: .long 0xfffdffff /* * Integer constants */ .align 4 .Lnr_syscalls: .long NR_syscalls .Lvtimer_max: .quad 0x7fffffffffffffff /* * Symbol constants */ .Ldo_machine_check: .long s390_do_machine_check .Lhandle_mcck: .long s390_handle_mcck .Ldo_IRQ: .long do_IRQ .Ldo_extint: .long do_extint .Ldo_signal: .long do_signal .Ldo_notify_resume: .long do_notify_resume .Ldo_per_trap: .long do_per_trap .Ldo_execve: .long do_execve .Ljump_table: .long pgm_check_table .Lschedule: .long schedule #ifdef CONFIG_PREEMPT .Lpreempt_irq: .long preempt_schedule_irq #endif .Ltrace_enter: .long do_syscall_trace_enter .Ltrace_exit: .long do_syscall_trace_exit .Lschedule_tail: .long schedule_tail .Lsys_call_table: .long sys_call_table .Lsysc_per: .long sysc_per + 0x80000000 #ifdef CONFIG_TRACE_IRQFLAGS .Lhardirqs_on: .long trace_hardirqs_on_caller .Lhardirqs_off: .long trace_hardirqs_off_caller #endif #ifdef CONFIG_LOCKDEP .Llockdep_sys_exit: .long lockdep_sys_exit #endif .Lcritical_start: .long __critical_start + 0x80000000 .Lcritical_length: .long __critical_end - __critical_start .section .rodata, "a" #define SYSCALL(esa,esame,emu) .long esa .globl sys_call_table sys_call_table: #include "syscalls.S" #undef SYSCALL