arm/kernel/entry-common.S

1 /* SPDX-License-Identifier: GPL-2.0-only */
3  *  linux/arch/arm/kernel/entry-common.S
14 #include <asm/unistd-oabi.h>
20 #include <mach/entry-macro.S>
26 #include "entry-header.S"
29 #if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
44  * have tracing, context tracking and rseq debug disabled - the overheads
55 	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing
60 	/* perform architecture specific actions before user return */
92 	ldr	r1, [tsk, #TI_FLAGS]		@ re-check for syscall tracing
98 	/* Slower path - fall through to work_pending */
109 	movlt	scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
110 	ldmia	sp, {r0 - r6}			@ have to reload r0 - r6
139 	/* perform architecture specific actions before user return */
162  *-----------------------------------------------------------------------------
171 	stmia	sp, {r0 - r12}			@ Calling r0 - r12
176 	mrs	saved_psr, spsr			@ called from non-FIQ mode, so ok.
192 #if defined(CONFIG_OABI_COMPAT)
201  USER(	ldreq	r10, [saved_pc, #-4]	)	@ get SWI instruction
203  USER(	ldr	r10, [saved_pc, #-4]	)	@ get SWI instruction
207 #elif defined(CONFIG_AEABI)
210 	 * Pure EABI user space always put syscall number into scno (r7).
212 #elif defined(CONFIG_ARM_THUMB)
216  USER(	ldreq	scno, [saved_pc, #-4]	)
220  USER(	ldr	scno, [saved_pc, #-4]	)	@ get SWI instruction
229 #if defined(CONFIG_OABI_COMPAT)
239 #elif !defined(CONFIG_AEABI)
240 	bic	scno, scno, #0xff000000		@ mask off SWI op-code
248  TRACE(	ldmia	sp, {r0 - r3}		)
260 2:	cmp	scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
266 #if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
270 	 * position to return -EFAULT. Instead, return back to the
271 	 * instruction and re-enter the user fault handling path trying
293 	cmp	scno, #-1			@ skip the syscall?
324 	.ifgt	__sys_nr - \nr
327 	.rept	\nr - __sys_nr
335 	.ifgt	__sys_nr - __NR_syscalls
338 	.rept	__NR_syscalls - __sys_nr
341 	.size	\sym, . - \sym
348  * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
353 #include <calls-eabi.S>
355 #include <calls-oabi.S>
367 		cmp	scno, #__NR_syscall - __NR_SYSCALL_BASE
456 #include <calls-oabi.S>