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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#ifdef CONFIG_NEED_RET_TO_USER
20#include <mach/entry-macro.S>
21#else
22 .macro arch_ret_to_user, tmp1, tmp2
23 .endm
24#endif
25
26#include "entry-header.S"
27
28saved_psr .req r8
29#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
30saved_pc .req r9
31#define TRACE(x...) x
32#else
33saved_pc .req lr
34#define TRACE(x...)
35#endif
36
37 .section .entry.text,"ax",%progbits
38 .align 5
39#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING) || \
40 IS_ENABLED(CONFIG_DEBUG_RSEQ))
41/*
42 * This is the fast syscall return path. We do as little as possible here,
43 * such as avoiding writing r0 to the stack. We only use this path if we
44 * have tracing, context tracking and rseq debug disabled - the overheads
45 * from those features make this path too inefficient.
46 */
47ret_fast_syscall:
48__ret_fast_syscall:
49 UNWIND(.fnstart )
50 UNWIND(.cantunwind )
51 disable_irq_notrace @ disable interrupts
52 ldr r2, [tsk, #TI_ADDR_LIMIT]
53 cmp r2, #TASK_SIZE
54 blne addr_limit_check_failed
55 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
56 tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
57 bne fast_work_pending
58
59
60 /* perform architecture specific actions before user return */
61 arch_ret_to_user r1, lr
62
63 restore_user_regs fast = 1, offset = S_OFF
64 UNWIND(.fnend )
65ENDPROC(ret_fast_syscall)
66
67 /* Ok, we need to do extra processing, enter the slow path. */
68fast_work_pending:
69 str r0, [sp, #S_R0+S_OFF]! @ returned r0
70 /* fall through to work_pending */
71#else
72/*
73 * The "replacement" ret_fast_syscall for when tracing, context tracking,
74 * or rseq debug is enabled. As we will need to call out to some C functions,
75 * we save r0 first to avoid needing to save registers around each C function
76 * call.
77 */
78ret_fast_syscall:
79__ret_fast_syscall:
80 UNWIND(.fnstart )
81 UNWIND(.cantunwind )
82 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
83#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
84 /* do_rseq_syscall needs interrupts enabled. */
85 mov r0, sp @ 'regs'
86 bl do_rseq_syscall
87#endif
88 disable_irq_notrace @ disable interrupts
89 ldr r2, [tsk, #TI_ADDR_LIMIT]
90 cmp r2, #TASK_SIZE
91 blne addr_limit_check_failed
92 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
93 tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
94 beq no_work_pending
95 UNWIND(.fnend )
96ENDPROC(ret_fast_syscall)
97
98 /* Slower path - fall through to work_pending */
99#endif
100
101 tst r1, #_TIF_SYSCALL_WORK
102 bne __sys_trace_return_nosave
103slow_work_pending:
104 mov r0, sp @ 'regs'
105 mov r2, why @ 'syscall'
106 bl do_work_pending
107 cmp r0, #0
108 beq no_work_pending
109 movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
110 ldmia sp, {r0 - r6} @ have to reload r0 - r6
111 b local_restart @ ... and off we go
112ENDPROC(ret_fast_syscall)
113
114/*
115 * "slow" syscall return path. "why" tells us if this was a real syscall.
116 * IRQs may be enabled here, so always disable them. Note that we use the
117 * "notrace" version to avoid calling into the tracing code unnecessarily.
118 * do_work_pending() will update this state if necessary.
119 */
120ENTRY(ret_to_user)
121ret_slow_syscall:
122#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
123 /* do_rseq_syscall needs interrupts enabled. */
124 enable_irq_notrace @ enable interrupts
125 mov r0, sp @ 'regs'
126 bl do_rseq_syscall
127#endif
128 disable_irq_notrace @ disable interrupts
129ENTRY(ret_to_user_from_irq)
130 ldr r2, [tsk, #TI_ADDR_LIMIT]
131 cmp r2, #TASK_SIZE
132 blne addr_limit_check_failed
133 ldr r1, [tsk, #TI_FLAGS]
134 tst r1, #_TIF_WORK_MASK
135 bne slow_work_pending
136no_work_pending:
137 asm_trace_hardirqs_on save = 0
138
139 /* perform architecture specific actions before user return */
140 arch_ret_to_user r1, lr
141 ct_user_enter save = 0
142
143 restore_user_regs fast = 0, offset = 0
144ENDPROC(ret_to_user_from_irq)
145ENDPROC(ret_to_user)
146
147/*
148 * This is how we return from a fork.
149 */
150ENTRY(ret_from_fork)
151 bl schedule_tail
152 cmp r5, #0
153 movne r0, r4
154 badrne lr, 1f
155 retne r5
1561: get_thread_info tsk
157 b ret_slow_syscall
158ENDPROC(ret_from_fork)
159
160/*=============================================================================
161 * SWI handler
162 *-----------------------------------------------------------------------------
163 */
164
165 .align 5
166ENTRY(vector_swi)
167#ifdef CONFIG_CPU_V7M
168 v7m_exception_entry
169#else
170 sub sp, sp, #PT_REGS_SIZE
171 stmia sp, {r0 - r12} @ Calling r0 - r12
172 ARM( add r8, sp, #S_PC )
173 ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
174 THUMB( mov r8, sp )
175 THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
176 mrs saved_psr, spsr @ called from non-FIQ mode, so ok.
177 TRACE( mov saved_pc, lr )
178 str saved_pc, [sp, #S_PC] @ Save calling PC
179 str saved_psr, [sp, #S_PSR] @ Save CPSR
180 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
181#endif
182 zero_fp
183 alignment_trap r10, ip, __cr_alignment
184 asm_trace_hardirqs_on save=0
185 enable_irq_notrace
186 ct_user_exit save=0
187
188 /*
189 * Get the system call number.
190 */
191
192#if defined(CONFIG_OABI_COMPAT)
193
194 /*
195 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
196 * value to determine if it is an EABI or an old ABI call.
197 */
198#ifdef CONFIG_ARM_THUMB
199 tst saved_psr, #PSR_T_BIT
200 movne r10, #0 @ no thumb OABI emulation
201 USER( ldreq r10, [saved_pc, #-4] ) @ get SWI instruction
202#else
203 USER( ldr r10, [saved_pc, #-4] ) @ get SWI instruction
204#endif
205 ARM_BE8(rev r10, r10) @ little endian instruction
206
207#elif defined(CONFIG_AEABI)
208
209 /*
210 * Pure EABI user space always put syscall number into scno (r7).
211 */
212#elif defined(CONFIG_ARM_THUMB)
213 /* Legacy ABI only, possibly thumb mode. */
214 tst saved_psr, #PSR_T_BIT @ this is SPSR from save_user_regs
215 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
216 USER( ldreq scno, [saved_pc, #-4] )
217
218#else
219 /* Legacy ABI only. */
220 USER( ldr scno, [saved_pc, #-4] ) @ get SWI instruction
221#endif
222
223 /* saved_psr and saved_pc are now dead */
224
225 uaccess_disable tbl
226
227 adr tbl, sys_call_table @ load syscall table pointer
228
229#if defined(CONFIG_OABI_COMPAT)
230 /*
231 * If the swi argument is zero, this is an EABI call and we do nothing.
232 *
233 * If this is an old ABI call, get the syscall number into scno and
234 * get the old ABI syscall table address.
235 */
236 bics r10, r10, #0xff000000
237 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
238 ldrne tbl, =sys_oabi_call_table
239#elif !defined(CONFIG_AEABI)
240 bic scno, scno, #0xff000000 @ mask off SWI op-code
241 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
242#endif
243 get_thread_info tsk
244 /*
245 * Reload the registers that may have been corrupted on entry to
246 * the syscall assembly (by tracing or context tracking.)
247 */
248 TRACE( ldmia sp, {r0 - r3} )
249
250local_restart:
251 ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
252 stmdb sp!, {r4, r5} @ push fifth and sixth args
253
254 tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
255 bne __sys_trace
256
257 invoke_syscall tbl, scno, r10, __ret_fast_syscall
258
259 add r1, sp, #S_OFF
2602: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
261 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
262 bcs arm_syscall
263 mov why, #0 @ no longer a real syscall
264 b sys_ni_syscall @ not private func
265
266#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
267 /*
268 * We failed to handle a fault trying to access the page
269 * containing the swi instruction, but we're not really in a
270 * position to return -EFAULT. Instead, return back to the
271 * instruction and re-enter the user fault handling path trying
272 * to page it in. This will likely result in sending SEGV to the
273 * current task.
274 */
2759001:
276 sub lr, saved_pc, #4
277 str lr, [sp, #S_PC]
278 get_thread_info tsk
279 b ret_fast_syscall
280#endif
281ENDPROC(vector_swi)
282
283 /*
284 * This is the really slow path. We're going to be doing
285 * context switches, and waiting for our parent to respond.
286 */
287__sys_trace:
288 mov r1, scno
289 add r0, sp, #S_OFF
290 bl syscall_trace_enter
291 mov scno, r0
292 invoke_syscall tbl, scno, r10, __sys_trace_return, reload=1
293 cmp scno, #-1 @ skip the syscall?
294 bne 2b
295 add sp, sp, #S_OFF @ restore stack
296
297__sys_trace_return_nosave:
298 enable_irq_notrace
299 mov r0, sp
300 bl syscall_trace_exit
301 b ret_slow_syscall
302
303__sys_trace_return:
304 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
305 mov r0, sp
306 bl syscall_trace_exit
307 b ret_slow_syscall
308
309 .align 5
310#ifdef CONFIG_ALIGNMENT_TRAP
311 .type __cr_alignment, #object
312__cr_alignment:
313 .word cr_alignment
314#endif
315 .ltorg
316
317 .macro syscall_table_start, sym
318 .equ __sys_nr, 0
319 .type \sym, #object
320ENTRY(\sym)
321 .endm
322
323 .macro syscall, nr, func
324 .ifgt __sys_nr - \nr
325 .error "Duplicated/unorded system call entry"
326 .endif
327 .rept \nr - __sys_nr
328 .long sys_ni_syscall
329 .endr
330 .long \func
331 .equ __sys_nr, \nr + 1
332 .endm
333
334 .macro syscall_table_end, sym
335 .ifgt __sys_nr - __NR_syscalls
336 .error "System call table too big"
337 .endif
338 .rept __NR_syscalls - __sys_nr
339 .long sys_ni_syscall
340 .endr
341 .size \sym, . - \sym
342 .endm
343
344#define NATIVE(nr, func) syscall nr, func
345
346/*
347 * This is the syscall table declaration for native ABI syscalls.
348 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
349 */
350 syscall_table_start sys_call_table
351#define COMPAT(nr, native, compat) syscall nr, native
352#ifdef CONFIG_AEABI
353#include <calls-eabi.S>
354#else
355#include <calls-oabi.S>
356#endif
357#undef COMPAT
358 syscall_table_end sys_call_table
359
360/*============================================================================
361 * Special system call wrappers
362 */
363@ r0 = syscall number
364@ r8 = syscall table
365sys_syscall:
366 bic scno, r0, #__NR_OABI_SYSCALL_BASE
367 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
368 cmpne scno, #NR_syscalls @ check range
369#ifdef CONFIG_CPU_SPECTRE
370 movhs scno, #0
371 csdb
372#endif
373 stmialo sp, {r5, r6} @ shuffle args
374 movlo r0, r1
375 movlo r1, r2
376 movlo r2, r3
377 movlo r3, r4
378 ldrlo pc, [tbl, scno, lsl #2]
379 b sys_ni_syscall
380ENDPROC(sys_syscall)
381
382sys_sigreturn_wrapper:
383 add r0, sp, #S_OFF
384 mov why, #0 @ prevent syscall restart handling
385 b sys_sigreturn
386ENDPROC(sys_sigreturn_wrapper)
387
388sys_rt_sigreturn_wrapper:
389 add r0, sp, #S_OFF
390 mov why, #0 @ prevent syscall restart handling
391 b sys_rt_sigreturn
392ENDPROC(sys_rt_sigreturn_wrapper)
393
394sys_statfs64_wrapper:
395 teq r1, #88
396 moveq r1, #84
397 b sys_statfs64
398ENDPROC(sys_statfs64_wrapper)
399
400sys_fstatfs64_wrapper:
401 teq r1, #88
402 moveq r1, #84
403 b sys_fstatfs64
404ENDPROC(sys_fstatfs64_wrapper)
405
406/*
407 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
408 * offset, we return EINVAL.
409 */
410sys_mmap2:
411 str r5, [sp, #4]
412 b sys_mmap_pgoff
413ENDPROC(sys_mmap2)
414
415#ifdef CONFIG_OABI_COMPAT
416
417/*
418 * These are syscalls with argument register differences
419 */
420
421sys_oabi_pread64:
422 stmia sp, {r3, r4}
423 b sys_pread64
424ENDPROC(sys_oabi_pread64)
425
426sys_oabi_pwrite64:
427 stmia sp, {r3, r4}
428 b sys_pwrite64
429ENDPROC(sys_oabi_pwrite64)
430
431sys_oabi_truncate64:
432 mov r3, r2
433 mov r2, r1
434 b sys_truncate64
435ENDPROC(sys_oabi_truncate64)
436
437sys_oabi_ftruncate64:
438 mov r3, r2
439 mov r2, r1
440 b sys_ftruncate64
441ENDPROC(sys_oabi_ftruncate64)
442
443sys_oabi_readahead:
444 str r3, [sp]
445 mov r3, r2
446 mov r2, r1
447 b sys_readahead
448ENDPROC(sys_oabi_readahead)
449
450/*
451 * Let's declare a second syscall table for old ABI binaries
452 * using the compatibility syscall entries.
453 */
454 syscall_table_start sys_oabi_call_table
455#define COMPAT(nr, native, compat) syscall nr, compat
456#include <calls-oabi.S>
457 syscall_table_end sys_oabi_call_table
458
459#endif
460