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1/*
2 * linux/arch/arm/kernel/entry-common.S
3 *
4 * Copyright (C) 2000 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <asm/assembler.h>
12#include <asm/unistd.h>
13#include <asm/ftrace.h>
14#include <asm/unwind.h>
15
16#ifdef CONFIG_NEED_RET_TO_USER
17#include <mach/entry-macro.S>
18#else
19 .macro arch_ret_to_user, tmp1, tmp2
20 .endm
21#endif
22
23#include "entry-header.S"
24
25
26 .align 5
27#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING))
28/*
29 * This is the fast syscall return path. We do as little as possible here,
30 * such as avoiding writing r0 to the stack. We only use this path if we
31 * have tracing and context tracking disabled - the overheads from those
32 * features make this path too inefficient.
33 */
34ret_fast_syscall:
35 UNWIND(.fnstart )
36 UNWIND(.cantunwind )
37 disable_irq_notrace @ disable interrupts
38 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
39 tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
40 bne fast_work_pending
41
42 /* perform architecture specific actions before user return */
43 arch_ret_to_user r1, lr
44
45 restore_user_regs fast = 1, offset = S_OFF
46 UNWIND(.fnend )
47ENDPROC(ret_fast_syscall)
48
49 /* Ok, we need to do extra processing, enter the slow path. */
50fast_work_pending:
51 str r0, [sp, #S_R0+S_OFF]! @ returned r0
52 /* fall through to work_pending */
53#else
54/*
55 * The "replacement" ret_fast_syscall for when tracing or context tracking
56 * is enabled. As we will need to call out to some C functions, we save
57 * r0 first to avoid needing to save registers around each C function call.
58 */
59ret_fast_syscall:
60 UNWIND(.fnstart )
61 UNWIND(.cantunwind )
62 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
63 disable_irq_notrace @ disable interrupts
64 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
65 tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
66 beq no_work_pending
67 UNWIND(.fnend )
68ENDPROC(ret_fast_syscall)
69
70 /* Slower path - fall through to work_pending */
71#endif
72
73 tst r1, #_TIF_SYSCALL_WORK
74 bne __sys_trace_return_nosave
75slow_work_pending:
76 mov r0, sp @ 'regs'
77 mov r2, why @ 'syscall'
78 bl do_work_pending
79 cmp r0, #0
80 beq no_work_pending
81 movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
82 ldmia sp, {r0 - r6} @ have to reload r0 - r6
83 b local_restart @ ... and off we go
84ENDPROC(ret_fast_syscall)
85
86/*
87 * "slow" syscall return path. "why" tells us if this was a real syscall.
88 * IRQs may be enabled here, so always disable them. Note that we use the
89 * "notrace" version to avoid calling into the tracing code unnecessarily.
90 * do_work_pending() will update this state if necessary.
91 */
92ENTRY(ret_to_user)
93ret_slow_syscall:
94 disable_irq_notrace @ disable interrupts
95ENTRY(ret_to_user_from_irq)
96 ldr r1, [tsk, #TI_FLAGS]
97 tst r1, #_TIF_WORK_MASK
98 bne slow_work_pending
99no_work_pending:
100 asm_trace_hardirqs_on save = 0
101
102 /* perform architecture specific actions before user return */
103 arch_ret_to_user r1, lr
104 ct_user_enter save = 0
105
106 restore_user_regs fast = 0, offset = 0
107ENDPROC(ret_to_user_from_irq)
108ENDPROC(ret_to_user)
109
110/*
111 * This is how we return from a fork.
112 */
113ENTRY(ret_from_fork)
114 bl schedule_tail
115 cmp r5, #0
116 movne r0, r4
117 badrne lr, 1f
118 retne r5
1191: get_thread_info tsk
120 b ret_slow_syscall
121ENDPROC(ret_from_fork)
122
123 .equ NR_syscalls,0
124#define CALL(x) .equ NR_syscalls,NR_syscalls+1
125#include "calls.S"
126
127/*
128 * Ensure that the system call table is equal to __NR_syscalls,
129 * which is the value the rest of the system sees
130 */
131.ifne NR_syscalls - __NR_syscalls
132.error "__NR_syscalls is not equal to the size of the syscall table"
133.endif
134
135#undef CALL
136#define CALL(x) .long x
137
138/*=============================================================================
139 * SWI handler
140 *-----------------------------------------------------------------------------
141 */
142
143 .align 5
144ENTRY(vector_swi)
145#ifdef CONFIG_CPU_V7M
146 v7m_exception_entry
147#else
148 sub sp, sp, #S_FRAME_SIZE
149 stmia sp, {r0 - r12} @ Calling r0 - r12
150 ARM( add r8, sp, #S_PC )
151 ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
152 THUMB( mov r8, sp )
153 THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
154 mrs r8, spsr @ called from non-FIQ mode, so ok.
155 str lr, [sp, #S_PC] @ Save calling PC
156 str r8, [sp, #S_PSR] @ Save CPSR
157 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
158#endif
159 zero_fp
160 alignment_trap r10, ip, __cr_alignment
161 enable_irq
162 ct_user_exit
163 get_thread_info tsk
164
165 /*
166 * Get the system call number.
167 */
168
169#if defined(CONFIG_OABI_COMPAT)
170
171 /*
172 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
173 * value to determine if it is an EABI or an old ABI call.
174 */
175#ifdef CONFIG_ARM_THUMB
176 tst r8, #PSR_T_BIT
177 movne r10, #0 @ no thumb OABI emulation
178 USER( ldreq r10, [lr, #-4] ) @ get SWI instruction
179#else
180 USER( ldr r10, [lr, #-4] ) @ get SWI instruction
181#endif
182 ARM_BE8(rev r10, r10) @ little endian instruction
183
184#elif defined(CONFIG_AEABI)
185
186 /*
187 * Pure EABI user space always put syscall number into scno (r7).
188 */
189#elif defined(CONFIG_ARM_THUMB)
190 /* Legacy ABI only, possibly thumb mode. */
191 tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
192 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
193 USER( ldreq scno, [lr, #-4] )
194
195#else
196 /* Legacy ABI only. */
197 USER( ldr scno, [lr, #-4] ) @ get SWI instruction
198#endif
199
200 uaccess_disable tbl
201
202 adr tbl, sys_call_table @ load syscall table pointer
203
204#if defined(CONFIG_OABI_COMPAT)
205 /*
206 * If the swi argument is zero, this is an EABI call and we do nothing.
207 *
208 * If this is an old ABI call, get the syscall number into scno and
209 * get the old ABI syscall table address.
210 */
211 bics r10, r10, #0xff000000
212 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
213 ldrne tbl, =sys_oabi_call_table
214#elif !defined(CONFIG_AEABI)
215 bic scno, scno, #0xff000000 @ mask off SWI op-code
216 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
217#endif
218
219local_restart:
220 ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
221 stmdb sp!, {r4, r5} @ push fifth and sixth args
222
223 tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
224 bne __sys_trace
225
226 cmp scno, #NR_syscalls @ check upper syscall limit
227 badr lr, ret_fast_syscall @ return address
228 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
229
230 add r1, sp, #S_OFF
2312: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
232 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
233 bcs arm_syscall
234 mov why, #0 @ no longer a real syscall
235 b sys_ni_syscall @ not private func
236
237#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
238 /*
239 * We failed to handle a fault trying to access the page
240 * containing the swi instruction, but we're not really in a
241 * position to return -EFAULT. Instead, return back to the
242 * instruction and re-enter the user fault handling path trying
243 * to page it in. This will likely result in sending SEGV to the
244 * current task.
245 */
2469001:
247 sub lr, lr, #4
248 str lr, [sp, #S_PC]
249 b ret_fast_syscall
250#endif
251ENDPROC(vector_swi)
252
253 /*
254 * This is the really slow path. We're going to be doing
255 * context switches, and waiting for our parent to respond.
256 */
257__sys_trace:
258 mov r1, scno
259 add r0, sp, #S_OFF
260 bl syscall_trace_enter
261
262 badr lr, __sys_trace_return @ return address
263 mov scno, r0 @ syscall number (possibly new)
264 add r1, sp, #S_R0 + S_OFF @ pointer to regs
265 cmp scno, #NR_syscalls @ check upper syscall limit
266 ldmccia r1, {r0 - r6} @ have to reload r0 - r6
267 stmccia sp, {r4, r5} @ and update the stack args
268 ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
269 cmp scno, #-1 @ skip the syscall?
270 bne 2b
271 add sp, sp, #S_OFF @ restore stack
272 b ret_slow_syscall
273
274__sys_trace_return:
275 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
276 mov r0, sp
277 bl syscall_trace_exit
278 b ret_slow_syscall
279
280__sys_trace_return_nosave:
281 enable_irq_notrace
282 mov r0, sp
283 bl syscall_trace_exit
284 b ret_slow_syscall
285
286 .align 5
287#ifdef CONFIG_ALIGNMENT_TRAP
288 .type __cr_alignment, #object
289__cr_alignment:
290 .word cr_alignment
291#endif
292 .ltorg
293
294/*
295 * This is the syscall table declaration for native ABI syscalls.
296 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
297 */
298#define ABI(native, compat) native
299#ifdef CONFIG_AEABI
300#define OBSOLETE(syscall) sys_ni_syscall
301#else
302#define OBSOLETE(syscall) syscall
303#endif
304
305 .type sys_call_table, #object
306ENTRY(sys_call_table)
307#include "calls.S"
308#undef ABI
309#undef OBSOLETE
310
311/*============================================================================
312 * Special system call wrappers
313 */
314@ r0 = syscall number
315@ r8 = syscall table
316sys_syscall:
317 bic scno, r0, #__NR_OABI_SYSCALL_BASE
318 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
319 cmpne scno, #NR_syscalls @ check range
320 stmloia sp, {r5, r6} @ shuffle args
321 movlo r0, r1
322 movlo r1, r2
323 movlo r2, r3
324 movlo r3, r4
325 ldrlo pc, [tbl, scno, lsl #2]
326 b sys_ni_syscall
327ENDPROC(sys_syscall)
328
329sys_sigreturn_wrapper:
330 add r0, sp, #S_OFF
331 mov why, #0 @ prevent syscall restart handling
332 b sys_sigreturn
333ENDPROC(sys_sigreturn_wrapper)
334
335sys_rt_sigreturn_wrapper:
336 add r0, sp, #S_OFF
337 mov why, #0 @ prevent syscall restart handling
338 b sys_rt_sigreturn
339ENDPROC(sys_rt_sigreturn_wrapper)
340
341sys_statfs64_wrapper:
342 teq r1, #88
343 moveq r1, #84
344 b sys_statfs64
345ENDPROC(sys_statfs64_wrapper)
346
347sys_fstatfs64_wrapper:
348 teq r1, #88
349 moveq r1, #84
350 b sys_fstatfs64
351ENDPROC(sys_fstatfs64_wrapper)
352
353/*
354 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
355 * offset, we return EINVAL.
356 */
357sys_mmap2:
358#if PAGE_SHIFT > 12
359 tst r5, #PGOFF_MASK
360 moveq r5, r5, lsr #PAGE_SHIFT - 12
361 streq r5, [sp, #4]
362 beq sys_mmap_pgoff
363 mov r0, #-EINVAL
364 ret lr
365#else
366 str r5, [sp, #4]
367 b sys_mmap_pgoff
368#endif
369ENDPROC(sys_mmap2)
370
371#ifdef CONFIG_OABI_COMPAT
372
373/*
374 * These are syscalls with argument register differences
375 */
376
377sys_oabi_pread64:
378 stmia sp, {r3, r4}
379 b sys_pread64
380ENDPROC(sys_oabi_pread64)
381
382sys_oabi_pwrite64:
383 stmia sp, {r3, r4}
384 b sys_pwrite64
385ENDPROC(sys_oabi_pwrite64)
386
387sys_oabi_truncate64:
388 mov r3, r2
389 mov r2, r1
390 b sys_truncate64
391ENDPROC(sys_oabi_truncate64)
392
393sys_oabi_ftruncate64:
394 mov r3, r2
395 mov r2, r1
396 b sys_ftruncate64
397ENDPROC(sys_oabi_ftruncate64)
398
399sys_oabi_readahead:
400 str r3, [sp]
401 mov r3, r2
402 mov r2, r1
403 b sys_readahead
404ENDPROC(sys_oabi_readahead)
405
406/*
407 * Let's declare a second syscall table for old ABI binaries
408 * using the compatibility syscall entries.
409 */
410#define ABI(native, compat) compat
411#define OBSOLETE(syscall) syscall
412
413 .type sys_oabi_call_table, #object
414ENTRY(sys_oabi_call_table)
415#include "calls.S"
416#undef ABI
417#undef OBSOLETE
418
419#endif
420
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * linux/arch/arm/kernel/entry-common.S
4 *
5 * Copyright (C) 2000 Russell King
6 */
7
8#include <asm/assembler.h>
9#include <asm/unistd.h>
10#include <asm/ftrace.h>
11#include <asm/unwind.h>
12#include <asm/memory.h>
13#ifdef CONFIG_AEABI
14#include <asm/unistd-oabi.h>
15#endif
16
17 .equ NR_syscalls, __NR_syscalls
18
19 .macro arch_ret_to_user, tmp
20#ifdef CONFIG_ARCH_IOP32X
21 mrc p15, 0, \tmp, c15, c1, 0
22 tst \tmp, #(1 << 6)
23 bicne \tmp, \tmp, #(1 << 6)
24 mcrne p15, 0, \tmp, c15, c1, 0 @ Disable cp6 access
25#endif
26 .endm
27
28#include "entry-header.S"
29
30saved_psr .req r8
31#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER)
32saved_pc .req r9
33#define TRACE(x...) x
34#else
35saved_pc .req lr
36#define TRACE(x...)
37#endif
38
39 .section .entry.text,"ax",%progbits
40 .align 5
41#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING_USER) || \
42 IS_ENABLED(CONFIG_DEBUG_RSEQ))
43/*
44 * This is the fast syscall return path. We do as little as possible here,
45 * such as avoiding writing r0 to the stack. We only use this path if we
46 * have tracing, context tracking and rseq debug disabled - the overheads
47 * from those features make this path too inefficient.
48 */
49ret_fast_syscall:
50__ret_fast_syscall:
51 UNWIND(.fnstart )
52 UNWIND(.cantunwind )
53 disable_irq_notrace @ disable interrupts
54 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
55 movs r1, r1, lsl #16
56 bne fast_work_pending
57
58
59 /* perform architecture specific actions before user return */
60 arch_ret_to_user r1
61
62 restore_user_regs fast = 1, offset = S_OFF
63 UNWIND(.fnend )
64ENDPROC(ret_fast_syscall)
65
66 /* Ok, we need to do extra processing, enter the slow path. */
67fast_work_pending:
68 str r0, [sp, #S_R0+S_OFF]! @ returned r0
69 /* fall through to work_pending */
70#else
71/*
72 * The "replacement" ret_fast_syscall for when tracing, context tracking,
73 * or rseq debug is enabled. As we will need to call out to some C functions,
74 * we save r0 first to avoid needing to save registers around each C function
75 * call.
76 */
77ret_fast_syscall:
78__ret_fast_syscall:
79 UNWIND(.fnstart )
80 UNWIND(.cantunwind )
81 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
82#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
83 /* do_rseq_syscall needs interrupts enabled. */
84 mov r0, sp @ 'regs'
85 bl do_rseq_syscall
86#endif
87 disable_irq_notrace @ disable interrupts
88 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
89 movs r1, r1, lsl #16
90 beq no_work_pending
91 UNWIND(.fnend )
92ENDPROC(ret_fast_syscall)
93
94 /* Slower path - fall through to work_pending */
95#endif
96
97 tst r1, #_TIF_SYSCALL_WORK
98 bne __sys_trace_return_nosave
99slow_work_pending:
100 mov r0, sp @ 'regs'
101 mov r2, why @ 'syscall'
102 bl do_work_pending
103 cmp r0, #0
104 beq no_work_pending
105 movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
106 ldmia sp, {r0 - r6} @ have to reload r0 - r6
107 b local_restart @ ... and off we go
108ENDPROC(ret_fast_syscall)
109
110/*
111 * "slow" syscall return path. "why" tells us if this was a real syscall.
112 * IRQs may be enabled here, so always disable them. Note that we use the
113 * "notrace" version to avoid calling into the tracing code unnecessarily.
114 * do_work_pending() will update this state if necessary.
115 */
116ENTRY(ret_to_user)
117ret_slow_syscall:
118#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
119 /* do_rseq_syscall needs interrupts enabled. */
120 enable_irq_notrace @ enable interrupts
121 mov r0, sp @ 'regs'
122 bl do_rseq_syscall
123#endif
124 disable_irq_notrace @ disable interrupts
125ENTRY(ret_to_user_from_irq)
126 ldr r1, [tsk, #TI_FLAGS]
127 movs r1, r1, lsl #16
128 bne slow_work_pending
129no_work_pending:
130 asm_trace_hardirqs_on save = 0
131
132 /* perform architecture specific actions before user return */
133 arch_ret_to_user r1
134 ct_user_enter save = 0
135
136 restore_user_regs fast = 0, offset = 0
137ENDPROC(ret_to_user_from_irq)
138ENDPROC(ret_to_user)
139
140/*
141 * This is how we return from a fork.
142 */
143ENTRY(ret_from_fork)
144 bl schedule_tail
145 cmp r5, #0
146 movne r0, r4
147 badrne lr, 1f
148 retne r5
1491: get_thread_info tsk
150 b ret_slow_syscall
151ENDPROC(ret_from_fork)
152
153/*=============================================================================
154 * SWI handler
155 *-----------------------------------------------------------------------------
156 */
157
158 .align 5
159#ifdef CONFIG_HARDEN_BRANCH_HISTORY
160ENTRY(vector_bhb_loop8_swi)
161 sub sp, sp, #PT_REGS_SIZE
162 stmia sp, {r0 - r12}
163 mov r8, #8
1641: b 2f
1652: subs r8, r8, #1
166 bne 1b
167 dsb nsh
168 isb
169 b 3f
170ENDPROC(vector_bhb_loop8_swi)
171
172 .align 5
173ENTRY(vector_bhb_bpiall_swi)
174 sub sp, sp, #PT_REGS_SIZE
175 stmia sp, {r0 - r12}
176 mcr p15, 0, r8, c7, c5, 6 @ BPIALL
177 isb
178 b 3f
179ENDPROC(vector_bhb_bpiall_swi)
180#endif
181 .align 5
182ENTRY(vector_swi)
183#ifdef CONFIG_CPU_V7M
184 v7m_exception_entry
185#else
186 sub sp, sp, #PT_REGS_SIZE
187 stmia sp, {r0 - r12} @ Calling r0 - r12
1883:
189 ARM( add r8, sp, #S_PC )
190 ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
191 THUMB( mov r8, sp )
192 THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
193 mrs saved_psr, spsr @ called from non-FIQ mode, so ok.
194 TRACE( mov saved_pc, lr )
195 str saved_pc, [sp, #S_PC] @ Save calling PC
196 str saved_psr, [sp, #S_PSR] @ Save CPSR
197 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
198#endif
199 reload_current r10, ip
200 zero_fp
201 alignment_trap r10, ip, cr_alignment
202 asm_trace_hardirqs_on save=0
203 enable_irq_notrace
204 ct_user_exit save=0
205
206 /*
207 * Get the system call number.
208 */
209
210#if defined(CONFIG_OABI_COMPAT)
211
212 /*
213 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
214 * value to determine if it is an EABI or an old ABI call.
215 */
216#ifdef CONFIG_ARM_THUMB
217 tst saved_psr, #PSR_T_BIT
218 movne r10, #0 @ no thumb OABI emulation
219 USER( ldreq r10, [saved_pc, #-4] ) @ get SWI instruction
220#else
221 USER( ldr r10, [saved_pc, #-4] ) @ get SWI instruction
222#endif
223 ARM_BE8(rev r10, r10) @ little endian instruction
224
225#elif defined(CONFIG_AEABI)
226
227 /*
228 * Pure EABI user space always put syscall number into scno (r7).
229 */
230#elif defined(CONFIG_ARM_THUMB)
231 /* Legacy ABI only, possibly thumb mode. */
232 tst saved_psr, #PSR_T_BIT @ this is SPSR from save_user_regs
233 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
234 USER( ldreq scno, [saved_pc, #-4] )
235
236#else
237 /* Legacy ABI only. */
238 USER( ldr scno, [saved_pc, #-4] ) @ get SWI instruction
239#endif
240
241 /* saved_psr and saved_pc are now dead */
242
243 uaccess_disable tbl
244 get_thread_info tsk
245
246 adr tbl, sys_call_table @ load syscall table pointer
247
248#if defined(CONFIG_OABI_COMPAT)
249 /*
250 * If the swi argument is zero, this is an EABI call and we do nothing.
251 *
252 * If this is an old ABI call, get the syscall number into scno and
253 * get the old ABI syscall table address.
254 */
255 bics r10, r10, #0xff000000
256 strne r10, [tsk, #TI_ABI_SYSCALL]
257 streq scno, [tsk, #TI_ABI_SYSCALL]
258 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
259 ldrne tbl, =sys_oabi_call_table
260#elif !defined(CONFIG_AEABI)
261 bic scno, scno, #0xff000000 @ mask off SWI op-code
262 str scno, [tsk, #TI_ABI_SYSCALL]
263 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
264#else
265 str scno, [tsk, #TI_ABI_SYSCALL]
266#endif
267 /*
268 * Reload the registers that may have been corrupted on entry to
269 * the syscall assembly (by tracing or context tracking.)
270 */
271 TRACE( ldmia sp, {r0 - r3} )
272
273local_restart:
274 ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
275 stmdb sp!, {r4, r5} @ push fifth and sixth args
276
277 tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
278 bne __sys_trace
279
280 invoke_syscall tbl, scno, r10, __ret_fast_syscall
281
282 add r1, sp, #S_OFF
2832: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
284 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
285 bcs arm_syscall
286 mov why, #0 @ no longer a real syscall
287 b sys_ni_syscall @ not private func
288
289#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
290 /*
291 * We failed to handle a fault trying to access the page
292 * containing the swi instruction, but we're not really in a
293 * position to return -EFAULT. Instead, return back to the
294 * instruction and re-enter the user fault handling path trying
295 * to page it in. This will likely result in sending SEGV to the
296 * current task.
297 */
2989001:
299 sub lr, saved_pc, #4
300 str lr, [sp, #S_PC]
301 get_thread_info tsk
302 b ret_fast_syscall
303#endif
304ENDPROC(vector_swi)
305 .ltorg
306
307 /*
308 * This is the really slow path. We're going to be doing
309 * context switches, and waiting for our parent to respond.
310 */
311__sys_trace:
312 add r0, sp, #S_OFF
313 bl syscall_trace_enter
314 mov scno, r0
315 invoke_syscall tbl, scno, r10, __sys_trace_return, reload=1
316 cmp scno, #-1 @ skip the syscall?
317 bne 2b
318 add sp, sp, #S_OFF @ restore stack
319
320__sys_trace_return_nosave:
321 enable_irq_notrace
322 mov r0, sp
323 bl syscall_trace_exit
324 b ret_slow_syscall
325
326__sys_trace_return:
327 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
328 mov r0, sp
329 bl syscall_trace_exit
330 b ret_slow_syscall
331
332 .macro syscall_table_start, sym
333 .equ __sys_nr, 0
334 .type \sym, #object
335ENTRY(\sym)
336 .endm
337
338 .macro syscall, nr, func
339 .ifgt __sys_nr - \nr
340 .error "Duplicated/unorded system call entry"
341 .endif
342 .rept \nr - __sys_nr
343 .long sys_ni_syscall
344 .endr
345 .long \func
346 .equ __sys_nr, \nr + 1
347 .endm
348
349 .macro syscall_table_end, sym
350 .ifgt __sys_nr - __NR_syscalls
351 .error "System call table too big"
352 .endif
353 .rept __NR_syscalls - __sys_nr
354 .long sys_ni_syscall
355 .endr
356 .size \sym, . - \sym
357 .endm
358
359#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
360#define __SYSCALL(nr, func) syscall nr, func
361
362/*
363 * This is the syscall table declaration for native ABI syscalls.
364 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
365 */
366 syscall_table_start sys_call_table
367#ifdef CONFIG_AEABI
368#include <calls-eabi.S>
369#else
370#include <calls-oabi.S>
371#endif
372 syscall_table_end sys_call_table
373
374/*============================================================================
375 * Special system call wrappers
376 */
377@ r0 = syscall number
378@ r8 = syscall table
379sys_syscall:
380 bic scno, r0, #__NR_OABI_SYSCALL_BASE
381 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
382 cmpne scno, #NR_syscalls @ check range
383#ifdef CONFIG_CPU_SPECTRE
384 movhs scno, #0
385 csdb
386#endif
387 stmialo sp, {r5, r6} @ shuffle args
388 movlo r0, r1
389 movlo r1, r2
390 movlo r2, r3
391 movlo r3, r4
392 ldrlo pc, [tbl, scno, lsl #2]
393 b sys_ni_syscall
394ENDPROC(sys_syscall)
395
396sys_sigreturn_wrapper:
397 add r0, sp, #S_OFF
398 mov why, #0 @ prevent syscall restart handling
399 b sys_sigreturn
400ENDPROC(sys_sigreturn_wrapper)
401
402sys_rt_sigreturn_wrapper:
403 add r0, sp, #S_OFF
404 mov why, #0 @ prevent syscall restart handling
405 b sys_rt_sigreturn
406ENDPROC(sys_rt_sigreturn_wrapper)
407
408sys_statfs64_wrapper:
409 teq r1, #88
410 moveq r1, #84
411 b sys_statfs64
412ENDPROC(sys_statfs64_wrapper)
413
414sys_fstatfs64_wrapper:
415 teq r1, #88
416 moveq r1, #84
417 b sys_fstatfs64
418ENDPROC(sys_fstatfs64_wrapper)
419
420/*
421 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
422 * offset, we return EINVAL.
423 */
424sys_mmap2:
425 str r5, [sp, #4]
426 b sys_mmap_pgoff
427ENDPROC(sys_mmap2)
428
429#ifdef CONFIG_OABI_COMPAT
430
431/*
432 * These are syscalls with argument register differences
433 */
434
435sys_oabi_pread64:
436 stmia sp, {r3, r4}
437 b sys_pread64
438ENDPROC(sys_oabi_pread64)
439
440sys_oabi_pwrite64:
441 stmia sp, {r3, r4}
442 b sys_pwrite64
443ENDPROC(sys_oabi_pwrite64)
444
445sys_oabi_truncate64:
446 mov r3, r2
447 mov r2, r1
448 b sys_truncate64
449ENDPROC(sys_oabi_truncate64)
450
451sys_oabi_ftruncate64:
452 mov r3, r2
453 mov r2, r1
454 b sys_ftruncate64
455ENDPROC(sys_oabi_ftruncate64)
456
457sys_oabi_readahead:
458 str r3, [sp]
459 mov r3, r2
460 mov r2, r1
461 b sys_readahead
462ENDPROC(sys_oabi_readahead)
463
464/*
465 * Let's declare a second syscall table for old ABI binaries
466 * using the compatibility syscall entries.
467 */
468 syscall_table_start sys_oabi_call_table
469#undef __SYSCALL_WITH_COMPAT
470#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
471#include <calls-oabi.S>
472 syscall_table_end sys_oabi_call_table
473
474#endif
475