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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 ldr r1, =TASK_SIZE
54 cmp r2, r1
55 blne addr_limit_check_failed
56 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
57 movs r1, r1, lsl #16
58 bne fast_work_pending
59
60
61 /* perform architecture specific actions before user return */
62 arch_ret_to_user r1, lr
63
64 restore_user_regs fast = 1, offset = S_OFF
65 UNWIND(.fnend )
66ENDPROC(ret_fast_syscall)
67
68 /* Ok, we need to do extra processing, enter the slow path. */
69fast_work_pending:
70 str r0, [sp, #S_R0+S_OFF]! @ returned r0
71 /* fall through to work_pending */
72#else
73/*
74 * The "replacement" ret_fast_syscall for when tracing, context tracking,
75 * or rseq debug is enabled. As we will need to call out to some C functions,
76 * we save r0 first to avoid needing to save registers around each C function
77 * call.
78 */
79ret_fast_syscall:
80__ret_fast_syscall:
81 UNWIND(.fnstart )
82 UNWIND(.cantunwind )
83 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
84#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
85 /* do_rseq_syscall needs interrupts enabled. */
86 mov r0, sp @ 'regs'
87 bl do_rseq_syscall
88#endif
89 disable_irq_notrace @ disable interrupts
90 ldr r2, [tsk, #TI_ADDR_LIMIT]
91 ldr r1, =TASK_SIZE
92 cmp r2, r1
93 blne addr_limit_check_failed
94 ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
95 movs r1, r1, lsl #16
96 beq no_work_pending
97 UNWIND(.fnend )
98ENDPROC(ret_fast_syscall)
99
100 /* Slower path - fall through to work_pending */
101#endif
102
103 tst r1, #_TIF_SYSCALL_WORK
104 bne __sys_trace_return_nosave
105slow_work_pending:
106 mov r0, sp @ 'regs'
107 mov r2, why @ 'syscall'
108 bl do_work_pending
109 cmp r0, #0
110 beq no_work_pending
111 movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
112 ldmia sp, {r0 - r6} @ have to reload r0 - r6
113 b local_restart @ ... and off we go
114ENDPROC(ret_fast_syscall)
115
116/*
117 * "slow" syscall return path. "why" tells us if this was a real syscall.
118 * IRQs may be enabled here, so always disable them. Note that we use the
119 * "notrace" version to avoid calling into the tracing code unnecessarily.
120 * do_work_pending() will update this state if necessary.
121 */
122ENTRY(ret_to_user)
123ret_slow_syscall:
124#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
125 /* do_rseq_syscall needs interrupts enabled. */
126 enable_irq_notrace @ enable interrupts
127 mov r0, sp @ 'regs'
128 bl do_rseq_syscall
129#endif
130 disable_irq_notrace @ disable interrupts
131ENTRY(ret_to_user_from_irq)
132 ldr r2, [tsk, #TI_ADDR_LIMIT]
133 ldr r1, =TASK_SIZE
134 cmp r2, r1
135 blne addr_limit_check_failed
136 ldr r1, [tsk, #TI_FLAGS]
137 movs r1, r1, lsl #16
138 bne slow_work_pending
139no_work_pending:
140 asm_trace_hardirqs_on save = 0
141
142 /* perform architecture specific actions before user return */
143 arch_ret_to_user r1, lr
144 ct_user_enter save = 0
145
146 restore_user_regs fast = 0, offset = 0
147ENDPROC(ret_to_user_from_irq)
148ENDPROC(ret_to_user)
149
150/*
151 * This is how we return from a fork.
152 */
153ENTRY(ret_from_fork)
154 bl schedule_tail
155 cmp r5, #0
156 movne r0, r4
157 badrne lr, 1f
158 retne r5
1591: get_thread_info tsk
160 b ret_slow_syscall
161ENDPROC(ret_from_fork)
162
163/*=============================================================================
164 * SWI handler
165 *-----------------------------------------------------------------------------
166 */
167
168 .align 5
169ENTRY(vector_swi)
170#ifdef CONFIG_CPU_V7M
171 v7m_exception_entry
172#else
173 sub sp, sp, #PT_REGS_SIZE
174 stmia sp, {r0 - r12} @ Calling r0 - r12
175 ARM( add r8, sp, #S_PC )
176 ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
177 THUMB( mov r8, sp )
178 THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
179 mrs saved_psr, spsr @ called from non-FIQ mode, so ok.
180 TRACE( mov saved_pc, lr )
181 str saved_pc, [sp, #S_PC] @ Save calling PC
182 str saved_psr, [sp, #S_PSR] @ Save CPSR
183 str r0, [sp, #S_OLD_R0] @ Save OLD_R0
184#endif
185 zero_fp
186 alignment_trap r10, ip, __cr_alignment
187 asm_trace_hardirqs_on save=0
188 enable_irq_notrace
189 ct_user_exit save=0
190
191 /*
192 * Get the system call number.
193 */
194
195#if defined(CONFIG_OABI_COMPAT)
196
197 /*
198 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
199 * value to determine if it is an EABI or an old ABI call.
200 */
201#ifdef CONFIG_ARM_THUMB
202 tst saved_psr, #PSR_T_BIT
203 movne r10, #0 @ no thumb OABI emulation
204 USER( ldreq r10, [saved_pc, #-4] ) @ get SWI instruction
205#else
206 USER( ldr r10, [saved_pc, #-4] ) @ get SWI instruction
207#endif
208 ARM_BE8(rev r10, r10) @ little endian instruction
209
210#elif defined(CONFIG_AEABI)
211
212 /*
213 * Pure EABI user space always put syscall number into scno (r7).
214 */
215#elif defined(CONFIG_ARM_THUMB)
216 /* Legacy ABI only, possibly thumb mode. */
217 tst saved_psr, #PSR_T_BIT @ this is SPSR from save_user_regs
218 addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
219 USER( ldreq scno, [saved_pc, #-4] )
220
221#else
222 /* Legacy ABI only. */
223 USER( ldr scno, [saved_pc, #-4] ) @ get SWI instruction
224#endif
225
226 /* saved_psr and saved_pc are now dead */
227
228 uaccess_disable tbl
229
230 adr tbl, sys_call_table @ load syscall table pointer
231
232#if defined(CONFIG_OABI_COMPAT)
233 /*
234 * If the swi argument is zero, this is an EABI call and we do nothing.
235 *
236 * If this is an old ABI call, get the syscall number into scno and
237 * get the old ABI syscall table address.
238 */
239 bics r10, r10, #0xff000000
240 eorne scno, r10, #__NR_OABI_SYSCALL_BASE
241 ldrne tbl, =sys_oabi_call_table
242#elif !defined(CONFIG_AEABI)
243 bic scno, scno, #0xff000000 @ mask off SWI op-code
244 eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
245#endif
246 get_thread_info tsk
247 /*
248 * Reload the registers that may have been corrupted on entry to
249 * the syscall assembly (by tracing or context tracking.)
250 */
251 TRACE( ldmia sp, {r0 - r3} )
252
253local_restart:
254 ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
255 stmdb sp!, {r4, r5} @ push fifth and sixth args
256
257 tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
258 bne __sys_trace
259
260 invoke_syscall tbl, scno, r10, __ret_fast_syscall
261
262 add r1, sp, #S_OFF
2632: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
264 eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
265 bcs arm_syscall
266 mov why, #0 @ no longer a real syscall
267 b sys_ni_syscall @ not private func
268
269#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
270 /*
271 * We failed to handle a fault trying to access the page
272 * containing the swi instruction, but we're not really in a
273 * position to return -EFAULT. Instead, return back to the
274 * instruction and re-enter the user fault handling path trying
275 * to page it in. This will likely result in sending SEGV to the
276 * current task.
277 */
2789001:
279 sub lr, saved_pc, #4
280 str lr, [sp, #S_PC]
281 get_thread_info tsk
282 b ret_fast_syscall
283#endif
284ENDPROC(vector_swi)
285
286 /*
287 * This is the really slow path. We're going to be doing
288 * context switches, and waiting for our parent to respond.
289 */
290__sys_trace:
291 mov r1, scno
292 add r0, sp, #S_OFF
293 bl syscall_trace_enter
294 mov scno, r0
295 invoke_syscall tbl, scno, r10, __sys_trace_return, reload=1
296 cmp scno, #-1 @ skip the syscall?
297 bne 2b
298 add sp, sp, #S_OFF @ restore stack
299
300__sys_trace_return_nosave:
301 enable_irq_notrace
302 mov r0, sp
303 bl syscall_trace_exit
304 b ret_slow_syscall
305
306__sys_trace_return:
307 str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
308 mov r0, sp
309 bl syscall_trace_exit
310 b ret_slow_syscall
311
312 .align 5
313#ifdef CONFIG_ALIGNMENT_TRAP
314 .type __cr_alignment, #object
315__cr_alignment:
316 .word cr_alignment
317#endif
318 .ltorg
319
320 .macro syscall_table_start, sym
321 .equ __sys_nr, 0
322 .type \sym, #object
323ENTRY(\sym)
324 .endm
325
326 .macro syscall, nr, func
327 .ifgt __sys_nr - \nr
328 .error "Duplicated/unorded system call entry"
329 .endif
330 .rept \nr - __sys_nr
331 .long sys_ni_syscall
332 .endr
333 .long \func
334 .equ __sys_nr, \nr + 1
335 .endm
336
337 .macro syscall_table_end, sym
338 .ifgt __sys_nr - __NR_syscalls
339 .error "System call table too big"
340 .endif
341 .rept __NR_syscalls - __sys_nr
342 .long sys_ni_syscall
343 .endr
344 .size \sym, . - \sym
345 .endm
346
347#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
348#define __SYSCALL(nr, func) syscall nr, func
349
350/*
351 * This is the syscall table declaration for native ABI syscalls.
352 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
353 */
354 syscall_table_start sys_call_table
355#ifdef CONFIG_AEABI
356#include <calls-eabi.S>
357#else
358#include <calls-oabi.S>
359#endif
360 syscall_table_end sys_call_table
361
362/*============================================================================
363 * Special system call wrappers
364 */
365@ r0 = syscall number
366@ r8 = syscall table
367sys_syscall:
368 bic scno, r0, #__NR_OABI_SYSCALL_BASE
369 cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
370 cmpne scno, #NR_syscalls @ check range
371#ifdef CONFIG_CPU_SPECTRE
372 movhs scno, #0
373 csdb
374#endif
375 stmialo sp, {r5, r6} @ shuffle args
376 movlo r0, r1
377 movlo r1, r2
378 movlo r2, r3
379 movlo r3, r4
380 ldrlo pc, [tbl, scno, lsl #2]
381 b sys_ni_syscall
382ENDPROC(sys_syscall)
383
384sys_sigreturn_wrapper:
385 add r0, sp, #S_OFF
386 mov why, #0 @ prevent syscall restart handling
387 b sys_sigreturn
388ENDPROC(sys_sigreturn_wrapper)
389
390sys_rt_sigreturn_wrapper:
391 add r0, sp, #S_OFF
392 mov why, #0 @ prevent syscall restart handling
393 b sys_rt_sigreturn
394ENDPROC(sys_rt_sigreturn_wrapper)
395
396sys_statfs64_wrapper:
397 teq r1, #88
398 moveq r1, #84
399 b sys_statfs64
400ENDPROC(sys_statfs64_wrapper)
401
402sys_fstatfs64_wrapper:
403 teq r1, #88
404 moveq r1, #84
405 b sys_fstatfs64
406ENDPROC(sys_fstatfs64_wrapper)
407
408/*
409 * Note: off_4k (r5) is always units of 4K. If we can't do the requested
410 * offset, we return EINVAL.
411 */
412sys_mmap2:
413 str r5, [sp, #4]
414 b sys_mmap_pgoff
415ENDPROC(sys_mmap2)
416
417#ifdef CONFIG_OABI_COMPAT
418
419/*
420 * These are syscalls with argument register differences
421 */
422
423sys_oabi_pread64:
424 stmia sp, {r3, r4}
425 b sys_pread64
426ENDPROC(sys_oabi_pread64)
427
428sys_oabi_pwrite64:
429 stmia sp, {r3, r4}
430 b sys_pwrite64
431ENDPROC(sys_oabi_pwrite64)
432
433sys_oabi_truncate64:
434 mov r3, r2
435 mov r2, r1
436 b sys_truncate64
437ENDPROC(sys_oabi_truncate64)
438
439sys_oabi_ftruncate64:
440 mov r3, r2
441 mov r2, r1
442 b sys_ftruncate64
443ENDPROC(sys_oabi_ftruncate64)
444
445sys_oabi_readahead:
446 str r3, [sp]
447 mov r3, r2
448 mov r2, r1
449 b sys_readahead
450ENDPROC(sys_oabi_readahead)
451
452/*
453 * Let's declare a second syscall table for old ABI binaries
454 * using the compatibility syscall entries.
455 */
456 syscall_table_start sys_oabi_call_table
457#undef __SYSCALL_WITH_COMPAT
458#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
459#include <calls-oabi.S>
460 syscall_table_end sys_oabi_call_table
461
462#endif
463