68d9102f76
Patch from Nicolas Pitre
The prototype for sys_fadvise64_64() is:
long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
The argument list is therefore as follows on legacy ABI:
fd: type int (r0)
offset: type long long (r1-r2)
len: type long long (r3-sp[0])
advice: type int (sp[4])
With EABI this becomes:
fd: type int (r0)
offset: type long long (r2-r3)
len: type long long (sp[0]-sp[4])
advice: type int (sp[8])
Not only do we have ABI differences here, but the EABI version requires
one additional word on the syscall stack.
To avoid the ABI mismatch and the extra stack space required with EABI
this syscall is now defined with a different argument ordering
on ARM as follows:
long sys_arm_fadvise64_64(int fd, int advice, loff_t offset, loff_t len)
This gives us the following ABI independent argument distribution:
fd: type int (r0)
advice: type int (r1)
offset: type long long (r2-r3)
len: type long long (sp[0]-sp[4])
Now, since the syscall entry code takes care of 5 registers only by
default including the store of r4 to the stack, we need a wrapper to
store r5 to the stack as well. Because that wrapper was missing and was
always required this means that sys_fadvise64_64 never worked on ARM and
therefore we can safely reuse its syscall number for our new
sys_arm_fadvise64_64 interface.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
287 lines
6.7 KiB
ArmAsm
287 lines
6.7 KiB
ArmAsm
/*
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* linux/arch/arm/kernel/entry-common.S
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*
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* Copyright (C) 2000 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/config.h>
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#include <asm/unistd.h>
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#include "entry-header.S"
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.align 5
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/*
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* This is the fast syscall return path. We do as little as
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* possible here, and this includes saving r0 back into the SVC
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* stack.
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*/
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ret_fast_syscall:
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disable_irq @ disable interrupts
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ldr r1, [tsk, #TI_FLAGS]
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tst r1, #_TIF_WORK_MASK
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bne fast_work_pending
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@ fast_restore_user_regs
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ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr
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ldr lr, [sp, #S_OFF + S_PC]! @ get pc
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msr spsr_cxsf, r1 @ save in spsr_svc
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ldmdb sp, {r1 - lr}^ @ get calling r1 - lr
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mov r0, r0
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add sp, sp, #S_FRAME_SIZE - S_PC
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movs pc, lr @ return & move spsr_svc into cpsr
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/*
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* Ok, we need to do extra processing, enter the slow path.
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*/
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fast_work_pending:
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str r0, [sp, #S_R0+S_OFF]! @ returned r0
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work_pending:
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tst r1, #_TIF_NEED_RESCHED
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bne work_resched
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tst r1, #_TIF_NOTIFY_RESUME | _TIF_SIGPENDING
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beq no_work_pending
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mov r0, sp @ 'regs'
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mov r2, why @ 'syscall'
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bl do_notify_resume
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disable_irq @ disable interrupts
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b no_work_pending
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work_resched:
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bl schedule
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/*
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* "slow" syscall return path. "why" tells us if this was a real syscall.
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*/
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ENTRY(ret_to_user)
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ret_slow_syscall:
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disable_irq @ disable interrupts
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ldr r1, [tsk, #TI_FLAGS]
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tst r1, #_TIF_WORK_MASK
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bne work_pending
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no_work_pending:
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@ slow_restore_user_regs
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ldr r1, [sp, #S_PSR] @ get calling cpsr
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ldr lr, [sp, #S_PC]! @ get pc
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msr spsr_cxsf, r1 @ save in spsr_svc
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ldmdb sp, {r0 - lr}^ @ get calling r1 - lr
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mov r0, r0
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add sp, sp, #S_FRAME_SIZE - S_PC
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movs pc, lr @ return & move spsr_svc into cpsr
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/*
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* This is how we return from a fork.
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*/
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ENTRY(ret_from_fork)
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bl schedule_tail
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get_thread_info tsk
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ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
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mov why, #1
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tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
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beq ret_slow_syscall
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mov r1, sp
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mov r0, #1 @ trace exit [IP = 1]
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bl syscall_trace
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b ret_slow_syscall
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#include "calls.S"
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/*=============================================================================
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* SWI handler
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*-----------------------------------------------------------------------------
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*/
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/* If we're optimising for StrongARM the resulting code won't
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run on an ARM7 and we can save a couple of instructions.
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--pb */
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#ifdef CONFIG_CPU_ARM710
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.macro arm710_bug_check, instr, temp
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and \temp, \instr, #0x0f000000 @ check for SWI
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teq \temp, #0x0f000000
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bne .Larm700bug
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.endm
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.Larm700bug:
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ldr r0, [sp, #S_PSR] @ Get calling cpsr
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sub lr, lr, #4
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str lr, [r8]
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msr spsr_cxsf, r0
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ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
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mov r0, r0
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ldr lr, [sp, #S_PC] @ Get PC
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add sp, sp, #S_FRAME_SIZE
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movs pc, lr
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#else
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.macro arm710_bug_check, instr, temp
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.endm
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#endif
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.align 5
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ENTRY(vector_swi)
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sub sp, sp, #S_FRAME_SIZE
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stmia sp, {r0 - r12} @ Calling r0 - r12
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add r8, sp, #S_PC
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stmdb r8, {sp, lr}^ @ Calling sp, lr
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mrs r8, spsr @ called from non-FIQ mode, so ok.
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str lr, [sp, #S_PC] @ Save calling PC
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str r8, [sp, #S_PSR] @ Save CPSR
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str r0, [sp, #S_OLD_R0] @ Save OLD_R0
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zero_fp
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/*
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* Get the system call number.
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*/
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#ifdef CONFIG_ARM_THUMB
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tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
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addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
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ldreq scno, [lr, #-4]
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#else
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ldr scno, [lr, #-4] @ get SWI instruction
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#endif
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arm710_bug_check scno, ip
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#ifdef CONFIG_ALIGNMENT_TRAP
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ldr ip, __cr_alignment
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ldr ip, [ip]
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mcr p15, 0, ip, c1, c0 @ update control register
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#endif
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enable_irq
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str r4, [sp, #-S_OFF]! @ push fifth arg
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get_thread_info tsk
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ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
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bic scno, scno, #0xff000000 @ mask off SWI op-code
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eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
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adr tbl, sys_call_table @ load syscall table pointer
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tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
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bne __sys_trace
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adr lr, ret_fast_syscall @ return address
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cmp scno, #NR_syscalls @ check upper syscall limit
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ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
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add r1, sp, #S_OFF
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2: mov why, #0 @ no longer a real syscall
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cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
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eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
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bcs arm_syscall
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b sys_ni_syscall @ not private func
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/*
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* This is the really slow path. We're going to be doing
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* context switches, and waiting for our parent to respond.
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*/
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__sys_trace:
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add r1, sp, #S_OFF
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mov r0, #0 @ trace entry [IP = 0]
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bl syscall_trace
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adr lr, __sys_trace_return @ return address
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add r1, sp, #S_R0 + S_OFF @ pointer to regs
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cmp scno, #NR_syscalls @ check upper syscall limit
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ldmccia r1, {r0 - r3} @ have to reload r0 - r3
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ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
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b 2b
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__sys_trace_return:
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str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
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mov r1, sp
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mov r0, #1 @ trace exit [IP = 1]
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bl syscall_trace
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b ret_slow_syscall
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.align 5
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#ifdef CONFIG_ALIGNMENT_TRAP
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.type __cr_alignment, #object
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__cr_alignment:
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.word cr_alignment
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#endif
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.type sys_call_table, #object
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ENTRY(sys_call_table)
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#include "calls.S"
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/*============================================================================
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* Special system call wrappers
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*/
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@ r0 = syscall number
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@ r5 = syscall table
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.type sys_syscall, #function
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sys_syscall:
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eor scno, r0, #__NR_SYSCALL_BASE
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cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
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cmpne scno, #NR_syscalls @ check range
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stmloia sp, {r5, r6} @ shuffle args
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movlo r0, r1
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movlo r1, r2
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movlo r2, r3
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movlo r3, r4
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ldrlo pc, [tbl, scno, lsl #2]
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b sys_ni_syscall
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sys_fork_wrapper:
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add r0, sp, #S_OFF
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b sys_fork
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sys_vfork_wrapper:
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add r0, sp, #S_OFF
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b sys_vfork
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sys_execve_wrapper:
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add r3, sp, #S_OFF
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b sys_execve
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sys_clone_wrapper:
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add ip, sp, #S_OFF
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str ip, [sp, #4]
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b sys_clone
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sys_sigsuspend_wrapper:
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add r3, sp, #S_OFF
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b sys_sigsuspend
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sys_rt_sigsuspend_wrapper:
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add r2, sp, #S_OFF
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b sys_rt_sigsuspend
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sys_sigreturn_wrapper:
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add r0, sp, #S_OFF
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b sys_sigreturn
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sys_rt_sigreturn_wrapper:
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add r0, sp, #S_OFF
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b sys_rt_sigreturn
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sys_sigaltstack_wrapper:
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ldr r2, [sp, #S_OFF + S_SP]
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b do_sigaltstack
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sys_futex_wrapper:
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str r5, [sp, #4] @ push sixth arg
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b sys_futex
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sys_arm_fadvise64_64_wrapper:
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str r5, [sp, #4] @ push r5 to stack
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b sys_arm_fadvise64_64
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/*
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* Note: off_4k (r5) is always units of 4K. If we can't do the requested
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* offset, we return EINVAL.
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*/
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sys_mmap2:
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#if PAGE_SHIFT > 12
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tst r5, #PGOFF_MASK
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moveq r5, r5, lsr #PAGE_SHIFT - 12
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streq r5, [sp, #4]
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beq do_mmap2
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mov r0, #-EINVAL
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RETINSTR(mov,pc, lr)
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#else
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str r5, [sp, #4]
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b do_mmap2
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#endif
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