cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

fsys.S (24625B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * This file contains the light-weight system call handlers (fsyscall-handlers).
      4 *
      5 * Copyright (C) 2003 Hewlett-Packard Co
      6 * 	David Mosberger-Tang <davidm@hpl.hp.com>
      7 *
      8 * 25-Sep-03 davidm	Implement fsys_rt_sigprocmask().
      9 * 18-Feb-03 louisk	Implement fsys_gettimeofday().
     10 * 28-Feb-03 davidm	Fixed several bugs in fsys_gettimeofday().  Tuned it some more,
     11 *			probably broke it along the way... ;-)
     12 * 13-Jul-04 clameter   Implement fsys_clock_gettime and revise fsys_gettimeofday to make
     13 *                      it capable of using memory based clocks without falling back to C code.
     14 * 08-Feb-07 Fenghua Yu Implement fsys_getcpu.
     15 *
     16 */
     17
     18#include <asm/asmmacro.h>
     19#include <asm/errno.h>
     20#include <asm/asm-offsets.h>
     21#include <asm/percpu.h>
     22#include <asm/thread_info.h>
     23#include <asm/sal.h>
     24#include <asm/signal.h>
     25#include <asm/unistd.h>
     26
     27#include "entry.h"
     28#include <asm/native/inst.h>
     29
     30/*
     31 * See Documentation/ia64/fsys.rst for details on fsyscalls.
     32 *
     33 * On entry to an fsyscall handler:
     34 *   r10	= 0 (i.e., defaults to "successful syscall return")
     35 *   r11	= saved ar.pfs (a user-level value)
     36 *   r15	= system call number
     37 *   r16	= "current" task pointer (in normal kernel-mode, this is in r13)
     38 *   r32-r39	= system call arguments
     39 *   b6		= return address (a user-level value)
     40 *   ar.pfs	= previous frame-state (a user-level value)
     41 *   PSR.be	= cleared to zero (i.e., little-endian byte order is in effect)
     42 *   all other registers may contain values passed in from user-mode
     43 *
     44 * On return from an fsyscall handler:
     45 *   r11	= saved ar.pfs (as passed into the fsyscall handler)
     46 *   r15	= system call number (as passed into the fsyscall handler)
     47 *   r32-r39	= system call arguments (as passed into the fsyscall handler)
     48 *   b6		= return address (as passed into the fsyscall handler)
     49 *   ar.pfs	= previous frame-state (as passed into the fsyscall handler)
     50 */
     51
     52ENTRY(fsys_ni_syscall)
     53	.prologue
     54	.altrp b6
     55	.body
     56	mov r8=ENOSYS
     57	mov r10=-1
     58	FSYS_RETURN
     59END(fsys_ni_syscall)
     60
     61ENTRY(fsys_getpid)
     62	.prologue
     63	.altrp b6
     64	.body
     65	add r17=IA64_TASK_SIGNAL_OFFSET,r16
     66	;;
     67	ld8 r17=[r17]				// r17 = current->signal
     68	add r9=TI_FLAGS+IA64_TASK_SIZE,r16
     69	;;
     70	ld4 r9=[r9]
     71	add r17=IA64_SIGNAL_PIDS_TGID_OFFSET,r17
     72	;;
     73	and r9=TIF_ALLWORK_MASK,r9
     74	ld8 r17=[r17]				// r17 = current->signal->pids[PIDTYPE_TGID]
     75	;;
     76	add r8=IA64_PID_LEVEL_OFFSET,r17
     77	;;
     78	ld4 r8=[r8]				// r8 = pid->level
     79	add r17=IA64_PID_UPID_OFFSET,r17	// r17 = &pid->numbers[0]
     80	;;
     81	shl r8=r8,IA64_UPID_SHIFT
     82	;;
     83	add r17=r17,r8				// r17 = &pid->numbers[pid->level]
     84	;;
     85	ld4 r8=[r17]				// r8 = pid->numbers[pid->level].nr
     86	;;
     87	mov r17=0
     88	;;
     89	cmp.ne p8,p0=0,r9
     90(p8)	br.spnt.many fsys_fallback_syscall
     91	FSYS_RETURN
     92END(fsys_getpid)
     93
     94ENTRY(fsys_set_tid_address)
     95	.prologue
     96	.altrp b6
     97	.body
     98	add r9=TI_FLAGS+IA64_TASK_SIZE,r16
     99	add r17=IA64_TASK_THREAD_PID_OFFSET,r16
    100	;;
    101	ld4 r9=[r9]
    102	tnat.z p6,p7=r32		// check argument register for being NaT
    103	ld8 r17=[r17]				// r17 = current->thread_pid
    104	;;
    105	and r9=TIF_ALLWORK_MASK,r9
    106	add r8=IA64_PID_LEVEL_OFFSET,r17
    107	add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
    108	;;
    109	ld4 r8=[r8]				// r8 = pid->level
    110	add r17=IA64_PID_UPID_OFFSET,r17	// r17 = &pid->numbers[0]
    111	;;
    112	shl r8=r8,IA64_UPID_SHIFT
    113	;;
    114	add r17=r17,r8				// r17 = &pid->numbers[pid->level]
    115	;;
    116	ld4 r8=[r17]				// r8 = pid->numbers[pid->level].nr
    117	;;
    118	cmp.ne p8,p0=0,r9
    119	mov r17=-1
    120	;;
    121(p6)	st8 [r18]=r32
    122(p7)	st8 [r18]=r17
    123(p8)	br.spnt.many fsys_fallback_syscall
    124	;;
    125	mov r17=0			// i must not leak kernel bits...
    126	mov r18=0			// i must not leak kernel bits...
    127	FSYS_RETURN
    128END(fsys_set_tid_address)
    129
    130#if IA64_GTOD_SEQ_OFFSET !=0
    131#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
    132#endif
    133#if IA64_ITC_JITTER_OFFSET !=0
    134#error fsys_gettimeofday incompatible with changes to struct itc_jitter_data_t
    135#endif
    136#define CLOCK_REALTIME 0
    137#define CLOCK_MONOTONIC 1
    138#define CLOCK_DIVIDE_BY_1000 0x4000
    139#define CLOCK_ADD_MONOTONIC 0x8000
    140
    141ENTRY(fsys_gettimeofday)
    142	.prologue
    143	.altrp b6
    144	.body
    145	mov r31 = r32
    146	tnat.nz p6,p0 = r33		// guard against NaT argument
    147(p6)    br.cond.spnt.few .fail_einval
    148	mov r30 = CLOCK_DIVIDE_BY_1000
    149	;;
    150.gettime:
    151	// Register map
    152	// Incoming r31 = pointer to address where to place result
    153	//          r30 = flags determining how time is processed
    154	// r2,r3 = temp r4-r7 preserved
    155	// r8 = result nanoseconds
    156	// r9 = result seconds
    157	// r10 = temporary storage for clock difference
    158	// r11 = preserved: saved ar.pfs
    159	// r12 = preserved: memory stack
    160	// r13 = preserved: thread pointer
    161	// r14 = address of mask / mask value
    162	// r15 = preserved: system call number
    163	// r16 = preserved: current task pointer
    164	// r17 = (not used)
    165	// r18 = (not used)
    166	// r19 = address of itc_lastcycle
    167	// r20 = struct fsyscall_gtod_data (= address of gtod_lock.sequence)
    168	// r21 = address of mmio_ptr
    169	// r22 = address of wall_time or monotonic_time
    170	// r23 = address of shift / value
    171	// r24 = address mult factor / cycle_last value
    172	// r25 = itc_lastcycle value
    173	// r26 = address clocksource cycle_last
    174	// r27 = (not used)
    175	// r28 = sequence number at the beginning of critical section
    176	// r29 = address of itc_jitter
    177	// r30 = time processing flags / memory address
    178	// r31 = pointer to result
    179	// Predicates
    180	// p6,p7 short term use
    181	// p8 = timesource ar.itc
    182	// p9 = timesource mmio64
    183	// p10 = timesource mmio32 - not used
    184	// p11 = timesource not to be handled by asm code
    185	// p12 = memory time source ( = p9 | p10) - not used
    186	// p13 = do cmpxchg with itc_lastcycle
    187	// p14 = Divide by 1000
    188	// p15 = Add monotonic
    189	//
    190	// Note that instructions are optimized for McKinley. McKinley can
    191	// process two bundles simultaneously and therefore we continuously
    192	// try to feed the CPU two bundles and then a stop.
    193
    194	add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
    195	tnat.nz p6,p0 = r31		// guard against Nat argument
    196(p6)	br.cond.spnt.few .fail_einval
    197	movl r20 = fsyscall_gtod_data // load fsyscall gettimeofday data address
    198	;;
    199	ld4 r2 = [r2]			// process work pending flags
    200	movl r29 = itc_jitter_data	// itc_jitter
    201	add r22 = IA64_GTOD_WALL_TIME_OFFSET,r20	// wall_time
    202	add r21 = IA64_CLKSRC_MMIO_OFFSET,r20
    203	mov pr = r30,0xc000	// Set predicates according to function
    204	;;
    205	and r2 = TIF_ALLWORK_MASK,r2
    206	add r19 = IA64_ITC_LASTCYCLE_OFFSET,r29
    207(p15)	add r22 = IA64_GTOD_MONO_TIME_OFFSET,r20	// monotonic_time
    208	;;
    209	add r26 = IA64_CLKSRC_CYCLE_LAST_OFFSET,r20	// clksrc_cycle_last
    210	cmp.ne p6, p0 = 0, r2	// Fallback if work is scheduled
    211(p6)	br.cond.spnt.many fsys_fallback_syscall
    212	;;
    213	// Begin critical section
    214.time_redo:
    215	ld4.acq r28 = [r20]	// gtod_lock.sequence, Must take first
    216	;;
    217	and r28 = ~1,r28	// And make sequence even to force retry if odd
    218	;;
    219	ld8 r30 = [r21]		// clocksource->mmio_ptr
    220	add r24 = IA64_CLKSRC_MULT_OFFSET,r20
    221	ld4 r2 = [r29]		// itc_jitter value
    222	add r23 = IA64_CLKSRC_SHIFT_OFFSET,r20
    223	add r14 = IA64_CLKSRC_MASK_OFFSET,r20
    224	;;
    225	ld4 r3 = [r24]		// clocksource mult value
    226	ld8 r14 = [r14]         // clocksource mask value
    227	cmp.eq p8,p9 = 0,r30	// use cpu timer if no mmio_ptr
    228	;;
    229	setf.sig f7 = r3	// Setup for mult scaling of counter
    230(p8)	cmp.ne p13,p0 = r2,r0	// need itc_jitter compensation, set p13
    231	ld4 r23 = [r23]		// clocksource shift value
    232	ld8 r24 = [r26]		// get clksrc_cycle_last value
    233(p9)	cmp.eq p13,p0 = 0,r30	// if mmio_ptr, clear p13 jitter control
    234	;;
    235	.pred.rel.mutex p8,p9
    236	MOV_FROM_ITC(p8, p6, r2, r10)	// CPU_TIMER. 36 clocks latency!!!
    237(p9)	ld8 r2 = [r30]		// MMIO_TIMER. Could also have latency issues..
    238(p13)	ld8 r25 = [r19]		// get itc_lastcycle value
    239	ld8 r9 = [r22],IA64_TIME_SN_SPEC_SNSEC_OFFSET	// sec
    240	;;
    241	ld8 r8 = [r22],-IA64_TIME_SN_SPEC_SNSEC_OFFSET	// snsec
    242(p13)	sub r3 = r25,r2		// Diff needed before comparison (thanks davidm)
    243	;;
    244(p13)	cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared
    245	sub r10 = r2,r24	// current_cycle - last_cycle
    246	;;
    247(p6)	sub r10 = r25,r24	// time we got was less than last_cycle
    248(p7)	mov ar.ccv = r25	// more than last_cycle. Prep for cmpxchg
    249	;;
    250(p7)	cmpxchg8.rel r3 = [r19],r2,ar.ccv
    251	;;
    252(p7)	cmp.ne p7,p0 = r25,r3	// if cmpxchg not successful
    253	;;
    254(p7)	sub r10 = r3,r24	// then use new last_cycle instead
    255	;;
    256	and r10 = r10,r14	// Apply mask
    257	;;
    258	setf.sig f8 = r10
    259	nop.i 123
    260	;;
    261	// fault check takes 5 cycles and we have spare time
    262EX(.fail_efault, probe.w.fault r31, 3)
    263	xmpy.l f8 = f8,f7	// nsec_per_cyc*(counter-last_counter)
    264	;;
    265	getf.sig r2 = f8
    266	mf
    267	;;
    268	ld4 r10 = [r20]		// gtod_lock.sequence
    269	add r8 = r8,r2		// Add xtime.nsecs
    270	;;
    271	shr.u r8 = r8,r23	// shift by factor
    272	cmp4.ne p7,p0 = r28,r10
    273(p7)	br.cond.dpnt.few .time_redo	// sequence number changed, redo
    274	// End critical section.
    275	// Now r8=tv->tv_nsec and r9=tv->tv_sec
    276	mov r10 = r0
    277	movl r2 = 1000000000
    278	add r23 = IA64_TIMESPEC_TV_NSEC_OFFSET, r31
    279(p14)	movl r3 = 2361183241434822607	// Prep for / 1000 hack
    280	;;
    281.time_normalize:
    282	mov r21 = r8
    283	cmp.ge p6,p0 = r8,r2
    284(p14)	shr.u r20 = r8, 3 // We can repeat this if necessary just wasting time
    285	;;
    286(p14)	setf.sig f8 = r20
    287(p6)	sub r8 = r8,r2
    288(p6)	add r9 = 1,r9		// two nops before the branch.
    289(p14)	setf.sig f7 = r3	// Chances for repeats are 1 in 10000 for gettod
    290(p6)	br.cond.dpnt.few .time_normalize
    291	;;
    292	// Divided by 8 though shift. Now divide by 125
    293	// The compiler was able to do that with a multiply
    294	// and a shift and we do the same
    295EX(.fail_efault, probe.w.fault r23, 3)	// This also costs 5 cycles
    296(p14)	xmpy.hu f8 = f8, f7		// xmpy has 5 cycles latency so use it
    297	;;
    298(p14)	getf.sig r2 = f8
    299	;;
    300	mov r8 = r0
    301(p14)	shr.u r21 = r2, 4
    302	;;
    303EX(.fail_efault, st8 [r31] = r9)
    304EX(.fail_efault, st8 [r23] = r21)
    305	FSYS_RETURN
    306.fail_einval:
    307	mov r8 = EINVAL
    308	mov r10 = -1
    309	FSYS_RETURN
    310.fail_efault:
    311	mov r8 = EFAULT
    312	mov r10 = -1
    313	FSYS_RETURN
    314END(fsys_gettimeofday)
    315
    316ENTRY(fsys_clock_gettime)
    317	.prologue
    318	.altrp b6
    319	.body
    320	cmp4.ltu p6, p0 = CLOCK_MONOTONIC, r32
    321	// Fallback if this is not CLOCK_REALTIME or CLOCK_MONOTONIC
    322(p6)	br.spnt.few fsys_fallback_syscall
    323	mov r31 = r33
    324	shl r30 = r32,15
    325	br.many .gettime
    326END(fsys_clock_gettime)
    327
    328/*
    329 * fsys_getcpu doesn't use the third parameter in this implementation. It reads
    330 * current_thread_info()->cpu and corresponding node in cpu_to_node_map.
    331 */
    332ENTRY(fsys_getcpu)
    333	.prologue
    334	.altrp b6
    335	.body
    336	;;
    337	add r2=TI_FLAGS+IA64_TASK_SIZE,r16
    338	tnat.nz p6,p0 = r32			// guard against NaT argument
    339	add r3=TI_CPU+IA64_TASK_SIZE,r16
    340	;;
    341	ld4 r3=[r3]				// M r3 = thread_info->cpu
    342	ld4 r2=[r2]				// M r2 = thread_info->flags
    343(p6)    br.cond.spnt.few .fail_einval		// B
    344	;;
    345	tnat.nz p7,p0 = r33			// I guard against NaT argument
    346(p7)    br.cond.spnt.few .fail_einval		// B
    347	;;
    348	cmp.ne p6,p0=r32,r0
    349	cmp.ne p7,p0=r33,r0
    350	;;
    351#ifdef CONFIG_NUMA
    352	movl r17=cpu_to_node_map
    353	;;
    354EX(.fail_efault, (p6) probe.w.fault r32, 3)		// M This takes 5 cycles
    355EX(.fail_efault, (p7) probe.w.fault r33, 3)		// M This takes 5 cycles
    356	shladd r18=r3,1,r17
    357	;;
    358	ld2 r20=[r18]				// r20 = cpu_to_node_map[cpu]
    359	and r2 = TIF_ALLWORK_MASK,r2
    360	;;
    361	cmp.ne p8,p0=0,r2
    362(p8)	br.spnt.many fsys_fallback_syscall
    363	;;
    364	;;
    365EX(.fail_efault, (p6) st4 [r32] = r3)
    366EX(.fail_efault, (p7) st2 [r33] = r20)
    367	mov r8=0
    368	;;
    369#else
    370EX(.fail_efault, (p6) probe.w.fault r32, 3)		// M This takes 5 cycles
    371EX(.fail_efault, (p7) probe.w.fault r33, 3)		// M This takes 5 cycles
    372	and r2 = TIF_ALLWORK_MASK,r2
    373	;;
    374	cmp.ne p8,p0=0,r2
    375(p8)	br.spnt.many fsys_fallback_syscall
    376	;;
    377EX(.fail_efault, (p6) st4 [r32] = r3)
    378EX(.fail_efault, (p7) st2 [r33] = r0)
    379	mov r8=0
    380	;;
    381#endif
    382	FSYS_RETURN
    383END(fsys_getcpu)
    384
    385ENTRY(fsys_fallback_syscall)
    386	.prologue
    387	.altrp b6
    388	.body
    389	/*
    390	 * We only get here from light-weight syscall handlers.  Thus, we already
    391	 * know that r15 contains a valid syscall number.  No need to re-check.
    392	 */
    393	adds r17=-1024,r15
    394	movl r14=sys_call_table
    395	;;
    396	RSM_PSR_I(p0, r26, r27)
    397	shladd r18=r17,3,r14
    398	;;
    399	ld8 r18=[r18]				// load normal (heavy-weight) syscall entry-point
    400	MOV_FROM_PSR(p0, r29, r26)		// read psr (12 cyc load latency)
    401	mov r27=ar.rsc
    402	mov r21=ar.fpsr
    403	mov r26=ar.pfs
    404END(fsys_fallback_syscall)
    405	/* FALL THROUGH */
    406GLOBAL_ENTRY(fsys_bubble_down)
    407	.prologue
    408	.altrp b6
    409	.body
    410	/*
    411	 * We get here for syscalls that don't have a lightweight
    412	 * handler.  For those, we need to bubble down into the kernel
    413	 * and that requires setting up a minimal pt_regs structure,
    414	 * and initializing the CPU state more or less as if an
    415	 * interruption had occurred.  To make syscall-restarts work,
    416	 * we setup pt_regs such that cr_iip points to the second
    417	 * instruction in syscall_via_break.  Decrementing the IP
    418	 * hence will restart the syscall via break and not
    419	 * decrementing IP will return us to the caller, as usual.
    420	 * Note that we preserve the value of psr.pp rather than
    421	 * initializing it from dcr.pp.  This makes it possible to
    422	 * distinguish fsyscall execution from other privileged
    423	 * execution.
    424	 *
    425	 * On entry:
    426	 *	- normal fsyscall handler register usage, except
    427	 *	  that we also have:
    428	 *	- r18: address of syscall entry point
    429	 *	- r21: ar.fpsr
    430	 *	- r26: ar.pfs
    431	 *	- r27: ar.rsc
    432	 *	- r29: psr
    433	 *
    434	 * We used to clear some PSR bits here but that requires slow
    435	 * serialization.  Fortunately, that isn't really necessary.
    436	 * The rationale is as follows: we used to clear bits
    437	 * ~PSR_PRESERVED_BITS in PSR.L.  Since
    438	 * PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
    439	 * ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
    440	 * However,
    441	 *
    442	 * PSR.BE : already is turned off in __kernel_syscall_via_epc()
    443	 * PSR.AC : don't care (kernel normally turns PSR.AC on)
    444	 * PSR.I  : already turned off by the time fsys_bubble_down gets
    445	 *	    invoked
    446	 * PSR.DFL: always 0 (kernel never turns it on)
    447	 * PSR.DFH: don't care --- kernel never touches f32-f127 on its own
    448	 *	    initiative
    449	 * PSR.DI : always 0 (kernel never turns it on)
    450	 * PSR.SI : always 0 (kernel never turns it on)
    451	 * PSR.DB : don't care --- kernel never enables kernel-level
    452	 *	    breakpoints
    453	 * PSR.TB : must be 0 already; if it wasn't zero on entry to
    454	 *          __kernel_syscall_via_epc, the branch to fsys_bubble_down
    455	 *          will trigger a taken branch; the taken-trap-handler then
    456	 *          converts the syscall into a break-based system-call.
    457	 */
    458	/*
    459	 * Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
    460	 * The rest we have to synthesize.
    461	 */
    462#	define PSR_ONE_BITS		((3 << IA64_PSR_CPL0_BIT)	\
    463					 | (0x1 << IA64_PSR_RI_BIT)	\
    464					 | IA64_PSR_BN | IA64_PSR_I)
    465
    466	invala					// M0|1
    467	movl r14=ia64_ret_from_syscall		// X
    468
    469	nop.m 0
    470	movl r28=__kernel_syscall_via_break	// X	create cr.iip
    471	;;
    472
    473	mov r2=r16				// A    get task addr to addl-addressable register
    474	adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
    475	mov r31=pr				// I0   save pr (2 cyc)
    476	;;
    477	st1 [r16]=r0				// M2|3 clear current->thread.on_ustack flag
    478	addl r22=IA64_RBS_OFFSET,r2		// A    compute base of RBS
    479	add r3=TI_FLAGS+IA64_TASK_SIZE,r2	// A
    480	;;
    481	ld4 r3=[r3]				// M0|1 r3 = current_thread_info()->flags
    482	lfetch.fault.excl.nt1 [r22]		// M0|1 prefetch register backing-store
    483	nop.i 0
    484	;;
    485	mov ar.rsc=0				// M2   set enforced lazy mode, pl 0, LE, loadrs=0
    486#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
    487	MOV_FROM_ITC(p0, p6, r30, r23)		// M    get cycle for accounting
    488#else
    489	nop.m 0
    490#endif
    491	nop.i 0
    492	;;
    493	mov r23=ar.bspstore			// M2 (12 cyc) save ar.bspstore
    494	mov.m r24=ar.rnat			// M2 (5 cyc) read ar.rnat (dual-issues!)
    495	nop.i 0
    496	;;
    497	mov ar.bspstore=r22			// M2 (6 cyc) switch to kernel RBS
    498	movl r8=PSR_ONE_BITS			// X
    499	;;
    500	mov r25=ar.unat				// M2 (5 cyc) save ar.unat
    501	mov r19=b6				// I0   save b6 (2 cyc)
    502	mov r20=r1				// A    save caller's gp in r20
    503	;;
    504	or r29=r8,r29				// A    construct cr.ipsr value to save
    505	mov b6=r18				// I0   copy syscall entry-point to b6 (7 cyc)
    506	addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of memory stack
    507
    508	mov r18=ar.bsp				// M2   save (kernel) ar.bsp (12 cyc)
    509	cmp.ne pKStk,pUStk=r0,r0		// A    set pKStk <- 0, pUStk <- 1
    510	br.call.sptk.many b7=ia64_syscall_setup	// B
    511	;;
    512#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
    513	// mov.m r30=ar.itc is called in advance
    514	add r16=TI_AC_STAMP+IA64_TASK_SIZE,r2
    515	add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r2
    516	;;
    517	ld8 r18=[r16],TI_AC_STIME-TI_AC_STAMP	// time at last check in kernel
    518	ld8 r19=[r17],TI_AC_UTIME-TI_AC_LEAVE	// time at leave kernel
    519	;;
    520	ld8 r20=[r16],TI_AC_STAMP-TI_AC_STIME	// cumulated stime
    521	ld8 r21=[r17]				// cumulated utime
    522	sub r22=r19,r18				// stime before leave kernel
    523	;;
    524	st8 [r16]=r30,TI_AC_STIME-TI_AC_STAMP	// update stamp
    525	sub r18=r30,r19				// elapsed time in user mode
    526	;;
    527	add r20=r20,r22				// sum stime
    528	add r21=r21,r18				// sum utime
    529	;;
    530	st8 [r16]=r20				// update stime
    531	st8 [r17]=r21				// update utime
    532	;;
    533#endif
    534	mov ar.rsc=0x3				// M2   set eager mode, pl 0, LE, loadrs=0
    535	mov rp=r14				// I0   set the real return addr
    536	and r3=_TIF_SYSCALL_TRACEAUDIT,r3	// A
    537	;;
    538	SSM_PSR_I(p0, p6, r22)			// M2   we're on kernel stacks now, reenable irqs
    539	cmp.eq p8,p0=r3,r0			// A
    540(p10)	br.cond.spnt.many ia64_ret_from_syscall	// B    return if bad call-frame or r15 is a NaT
    541
    542	nop.m 0
    543(p8)	br.call.sptk.many b6=b6			// B    (ignore return address)
    544	br.cond.spnt ia64_trace_syscall		// B
    545END(fsys_bubble_down)
    546
    547	.rodata
    548	.align 8
    549	.globl fsyscall_table
    550
    551	data8 fsys_bubble_down
    552fsyscall_table:
    553	data8 fsys_ni_syscall
    554	data8 0				// exit			// 1025
    555	data8 0				// read
    556	data8 0				// write
    557	data8 0				// open
    558	data8 0				// close
    559	data8 0				// creat		// 1030
    560	data8 0				// link
    561	data8 0				// unlink
    562	data8 0				// execve
    563	data8 0				// chdir
    564	data8 0				// fchdir		// 1035
    565	data8 0				// utimes
    566	data8 0				// mknod
    567	data8 0				// chmod
    568	data8 0				// chown
    569	data8 0				// lseek		// 1040
    570	data8 fsys_getpid		// getpid
    571	data8 0				// getppid
    572	data8 0				// mount
    573	data8 0				// umount
    574	data8 0				// setuid		// 1045
    575	data8 0				// getuid
    576	data8 0				// geteuid
    577	data8 0				// ptrace
    578	data8 0				// access
    579	data8 0				// sync			// 1050
    580	data8 0				// fsync
    581	data8 0				// fdatasync
    582	data8 0				// kill
    583	data8 0				// rename
    584	data8 0				// mkdir		// 1055
    585	data8 0				// rmdir
    586	data8 0				// dup
    587	data8 0				// pipe
    588	data8 0				// times
    589	data8 0				// brk			// 1060
    590	data8 0				// setgid
    591	data8 0				// getgid
    592	data8 0				// getegid
    593	data8 0				// acct
    594	data8 0				// ioctl		// 1065
    595	data8 0				// fcntl
    596	data8 0				// umask
    597	data8 0				// chroot
    598	data8 0				// ustat
    599	data8 0				// dup2			// 1070
    600	data8 0				// setreuid
    601	data8 0				// setregid
    602	data8 0				// getresuid
    603	data8 0				// setresuid
    604	data8 0				// getresgid		// 1075
    605	data8 0				// setresgid
    606	data8 0				// getgroups
    607	data8 0				// setgroups
    608	data8 0				// getpgid
    609	data8 0				// setpgid		// 1080
    610	data8 0				// setsid
    611	data8 0				// getsid
    612	data8 0				// sethostname
    613	data8 0				// setrlimit
    614	data8 0				// getrlimit		// 1085
    615	data8 0				// getrusage
    616	data8 fsys_gettimeofday		// gettimeofday
    617	data8 0				// settimeofday
    618	data8 0				// select
    619	data8 0				// poll			// 1090
    620	data8 0				// symlink
    621	data8 0				// readlink
    622	data8 0				// uselib
    623	data8 0				// swapon
    624	data8 0				// swapoff		// 1095
    625	data8 0				// reboot
    626	data8 0				// truncate
    627	data8 0				// ftruncate
    628	data8 0				// fchmod
    629	data8 0				// fchown		// 1100
    630	data8 0				// getpriority
    631	data8 0				// setpriority
    632	data8 0				// statfs
    633	data8 0				// fstatfs
    634	data8 0				// gettid		// 1105
    635	data8 0				// semget
    636	data8 0				// semop
    637	data8 0				// semctl
    638	data8 0				// msgget
    639	data8 0				// msgsnd		// 1110
    640	data8 0				// msgrcv
    641	data8 0				// msgctl
    642	data8 0				// shmget
    643	data8 0				// shmat
    644	data8 0				// shmdt		// 1115
    645	data8 0				// shmctl
    646	data8 0				// syslog
    647	data8 0				// setitimer
    648	data8 0				// getitimer
    649	data8 0					 		// 1120
    650	data8 0
    651	data8 0
    652	data8 0				// vhangup
    653	data8 0				// lchown
    654	data8 0				// remap_file_pages	// 1125
    655	data8 0				// wait4
    656	data8 0				// sysinfo
    657	data8 0				// clone
    658	data8 0				// setdomainname
    659	data8 0				// newuname		// 1130
    660	data8 0				// adjtimex
    661	data8 0
    662	data8 0				// init_module
    663	data8 0				// delete_module
    664	data8 0							// 1135
    665	data8 0
    666	data8 0				// quotactl
    667	data8 0				// bdflush
    668	data8 0				// sysfs
    669	data8 0				// personality		// 1140
    670	data8 0				// afs_syscall
    671	data8 0				// setfsuid
    672	data8 0				// setfsgid
    673	data8 0				// getdents
    674	data8 0				// flock		// 1145
    675	data8 0				// readv
    676	data8 0				// writev
    677	data8 0				// pread64
    678	data8 0				// pwrite64
    679	data8 0				// sysctl		// 1150
    680	data8 0				// mmap
    681	data8 0				// munmap
    682	data8 0				// mlock
    683	data8 0				// mlockall
    684	data8 0				// mprotect		// 1155
    685	data8 0				// mremap
    686	data8 0				// msync
    687	data8 0				// munlock
    688	data8 0				// munlockall
    689	data8 0				// sched_getparam	// 1160
    690	data8 0				// sched_setparam
    691	data8 0				// sched_getscheduler
    692	data8 0				// sched_setscheduler
    693	data8 0				// sched_yield
    694	data8 0				// sched_get_priority_max	// 1165
    695	data8 0				// sched_get_priority_min
    696	data8 0				// sched_rr_get_interval
    697	data8 0				// nanosleep
    698	data8 0				// nfsservctl
    699	data8 0				// prctl		// 1170
    700	data8 0				// getpagesize
    701	data8 0				// mmap2
    702	data8 0				// pciconfig_read
    703	data8 0				// pciconfig_write
    704	data8 0				// perfmonctl		// 1175
    705	data8 0				// sigaltstack
    706	data8 0				// rt_sigaction
    707	data8 0				// rt_sigpending
    708	data8 0				// rt_sigprocmask
    709	data8 0				// rt_sigqueueinfo	// 1180
    710	data8 0				// rt_sigreturn
    711	data8 0				// rt_sigsuspend
    712	data8 0				// rt_sigtimedwait
    713	data8 0				// getcwd
    714	data8 0				// capget		// 1185
    715	data8 0				// capset
    716	data8 0				// sendfile
    717	data8 0
    718	data8 0
    719	data8 0				// socket		// 1190
    720	data8 0				// bind
    721	data8 0				// connect
    722	data8 0				// listen
    723	data8 0				// accept
    724	data8 0				// getsockname		// 1195
    725	data8 0				// getpeername
    726	data8 0				// socketpair
    727	data8 0				// send
    728	data8 0				// sendto
    729	data8 0				// recv			// 1200
    730	data8 0				// recvfrom
    731	data8 0				// shutdown
    732	data8 0				// setsockopt
    733	data8 0				// getsockopt
    734	data8 0				// sendmsg		// 1205
    735	data8 0				// recvmsg
    736	data8 0				// pivot_root
    737	data8 0				// mincore
    738	data8 0				// madvise
    739	data8 0				// newstat		// 1210
    740	data8 0				// newlstat
    741	data8 0				// newfstat
    742	data8 0				// clone2
    743	data8 0				// getdents64
    744	data8 0				// getunwind		// 1215
    745	data8 0				// readahead
    746	data8 0				// setxattr
    747	data8 0				// lsetxattr
    748	data8 0				// fsetxattr
    749	data8 0				// getxattr		// 1220
    750	data8 0				// lgetxattr
    751	data8 0				// fgetxattr
    752	data8 0				// listxattr
    753	data8 0				// llistxattr
    754	data8 0				// flistxattr		// 1225
    755	data8 0				// removexattr
    756	data8 0				// lremovexattr
    757	data8 0				// fremovexattr
    758	data8 0				// tkill
    759	data8 0				// futex		// 1230
    760	data8 0				// sched_setaffinity
    761	data8 0				// sched_getaffinity
    762	data8 fsys_set_tid_address	// set_tid_address
    763	data8 0				// fadvise64_64
    764	data8 0				// tgkill		// 1235
    765	data8 0				// exit_group
    766	data8 0				// lookup_dcookie
    767	data8 0				// io_setup
    768	data8 0				// io_destroy
    769	data8 0				// io_getevents		// 1240
    770	data8 0				// io_submit
    771	data8 0				// io_cancel
    772	data8 0				// epoll_create
    773	data8 0				// epoll_ctl
    774	data8 0				// epoll_wait		// 1245
    775	data8 0				// restart_syscall
    776	data8 0				// semtimedop
    777	data8 0				// timer_create
    778	data8 0				// timer_settime
    779	data8 0				// timer_gettime 	// 1250
    780	data8 0				// timer_getoverrun
    781	data8 0				// timer_delete
    782	data8 0				// clock_settime
    783	data8 fsys_clock_gettime	// clock_gettime
    784	data8 0				// clock_getres		// 1255
    785	data8 0				// clock_nanosleep
    786	data8 0				// fstatfs64
    787	data8 0				// statfs64
    788	data8 0				// mbind
    789	data8 0				// get_mempolicy	// 1260
    790	data8 0				// set_mempolicy
    791	data8 0				// mq_open
    792	data8 0				// mq_unlink
    793	data8 0				// mq_timedsend
    794	data8 0				// mq_timedreceive	// 1265
    795	data8 0				// mq_notify
    796	data8 0				// mq_getsetattr
    797	data8 0				// kexec_load
    798	data8 0				// vserver
    799	data8 0				// waitid		// 1270
    800	data8 0				// add_key
    801	data8 0				// request_key
    802	data8 0				// keyctl
    803	data8 0				// ioprio_set
    804	data8 0				// ioprio_get		// 1275
    805	data8 0				// move_pages
    806	data8 0				// inotify_init
    807	data8 0				// inotify_add_watch
    808	data8 0				// inotify_rm_watch
    809	data8 0				// migrate_pages	// 1280
    810	data8 0				// openat
    811	data8 0				// mkdirat
    812	data8 0				// mknodat
    813	data8 0				// fchownat
    814	data8 0				// futimesat		// 1285
    815	data8 0				// newfstatat
    816	data8 0				// unlinkat
    817	data8 0				// renameat
    818	data8 0				// linkat
    819	data8 0				// symlinkat		// 1290
    820	data8 0				// readlinkat
    821	data8 0				// fchmodat
    822	data8 0				// faccessat
    823	data8 0
    824	data8 0							// 1295
    825	data8 0				// unshare
    826	data8 0				// splice
    827	data8 0				// set_robust_list
    828	data8 0				// get_robust_list
    829	data8 0				// sync_file_range	// 1300
    830	data8 0				// tee
    831	data8 0				// vmsplice
    832	data8 0
    833	data8 fsys_getcpu		// getcpu		// 1304
    834
    835	// fill in zeros for the remaining entries
    836	.zero:
    837	.space fsyscall_table + 8*NR_syscalls - .zero, 0