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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1995-99, 2000- 02, 06 Ralf Baechle <ralf@linux-mips.org>
* Copyright (C) 2001 MIPS Technologies, Inc.
* Copyright (C) 2004 Thiemo Seufer
*/
#include <linux/errno.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/irqflags.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/isadep.h>
#include <asm/sysmips.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>
#include <asm/war.h>
#include <asm/asm-offsets.h>
/* Highest syscall used of any syscall flavour */
#define MAX_SYSCALL_NO __NR_O32_Linux + __NR_O32_Linux_syscalls
.align 5
NESTED(handle_sys, PT_SIZE, sp)
.set noat
SAVE_SOME
TRACE_IRQS_ON_RELOAD
STI
.set at
lw t1, PT_EPC(sp) # skip syscall on return
#if defined(CONFIG_BINFMT_IRIX)
sltiu t0, v0, MAX_SYSCALL_NO + 1 # check syscall number
#else
subu v0, v0, __NR_O32_Linux # check syscall number
sltiu t0, v0, __NR_O32_Linux_syscalls + 1
#endif
addiu t1, 4 # skip to next instruction
sw t1, PT_EPC(sp)
beqz t0, illegal_syscall
sll t0, v0, 3
la t1, sys_call_table
addu t1, t0
lw t2, (t1) # syscall routine
lw t3, 4(t1) # >= 0 if we need stack arguments
beqz t2, illegal_syscall
sw a3, PT_R26(sp) # save a3 for syscall restarting
bgez t3, stackargs
stack_done:
lw t0, TI_FLAGS($28) # syscall tracing enabled?
li t1, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
and t0, t1
bnez t0, syscall_trace_entry # -> yes
jalr t2 # Do The Real Thing (TM)
li t0, -EMAXERRNO - 1 # error?
sltu t0, t0, v0
sw t0, PT_R7(sp) # set error flag
beqz t0, 1f
negu v0 # error
sw v0, PT_R0(sp) # set flag for syscall
# restarting
1: sw v0, PT_R2(sp) # result
o32_syscall_exit:
local_irq_disable # make sure need_resched and
# signals dont change between
# sampling and return
lw a2, TI_FLAGS($28) # current->work
li t0, _TIF_ALLWORK_MASK
and t0, a2
bnez t0, o32_syscall_exit_work
j restore_partial
o32_syscall_exit_work:
j syscall_exit_work_partial
/* ------------------------------------------------------------------------ */
syscall_trace_entry:
SAVE_STATIC
move s0, t2
move a0, sp
li a1, 0
jal do_syscall_trace
move t0, s0
RESTORE_STATIC
lw a0, PT_R4(sp) # Restore argument registers
lw a1, PT_R5(sp)
lw a2, PT_R6(sp)
lw a3, PT_R7(sp)
jalr t0
li t0, -EMAXERRNO - 1 # error?
sltu t0, t0, v0
sw t0, PT_R7(sp) # set error flag
beqz t0, 1f
negu v0 # error
sw v0, PT_R0(sp) # set flag for syscall
# restarting
1: sw v0, PT_R2(sp) # result
j syscall_exit
/* ------------------------------------------------------------------------ */
/*
* More than four arguments. Try to deal with it by copying the
* stack arguments from the user stack to the kernel stack.
* This Sucks (TM).
*/
stackargs:
lw t0, PT_R29(sp) # get old user stack pointer
/*
* We intentionally keep the kernel stack a little below the top of
* userspace so we don't have to do a slower byte accurate check here.
*/
lw t5, TI_ADDR_LIMIT($28)
addu t4, t0, 32
and t5, t4
bltz t5, bad_stack # -> sp is bad
/* Ok, copy the args from the luser stack to the kernel stack.
* t3 is the precomputed number of instruction bytes needed to
* load or store arguments 6-8.
*/
la t1, 5f # load up to 3 arguments
subu t1, t3
1: lw t5, 16(t0) # argument #5 from usp
.set push
.set noreorder
.set nomacro
jr t1
addiu t1, 6f - 5f
2: lw t8, 28(t0) # argument #8 from usp
3: lw t7, 24(t0) # argument #7 from usp
4: lw t6, 20(t0) # argument #6 from usp
5: jr t1
sw t5, 16(sp) # argument #5 to ksp
sw t8, 28(sp) # argument #8 to ksp
sw t7, 24(sp) # argument #7 to ksp
sw t6, 20(sp) # argument #6 to ksp
6: j stack_done # go back
nop
.set pop
.section __ex_table,"a"
PTR 1b,bad_stack
PTR 2b,bad_stack
PTR 3b,bad_stack
PTR 4b,bad_stack
.previous
/*
* The stackpointer for a call with more than 4 arguments is bad.
* We probably should handle this case a bit more drastic.
*/
bad_stack:
negu v0 # error
sw v0, PT_R0(sp)
sw v0, PT_R2(sp)
li t0, 1 # set error flag
sw t0, PT_R7(sp)
j o32_syscall_exit
/*
* The system call does not exist in this kernel
*/
illegal_syscall:
li v0, -ENOSYS # error
sw v0, PT_R2(sp)
li t0, 1 # set error flag
sw t0, PT_R7(sp)
j o32_syscall_exit
END(handle_sys)
LEAF(mips_atomic_set)
andi v0, a1, 3 # must be word aligned
bnez v0, bad_alignment
lw v1, TI_ADDR_LIMIT($28) # in legal address range?
addiu a0, a1, 4
or a0, a0, a1
and a0, a0, v1
bltz a0, bad_address
#ifdef CONFIG_CPU_HAS_LLSC
/* Ok, this is the ll/sc case. World is sane :-) */
1: ll v0, (a1)
move a0, a2
2: sc a0, (a1)
#if R10000_LLSC_WAR
beqzl a0, 1b
#else
beqz a0, 1b
#endif
.section __ex_table,"a"
PTR 1b, bad_stack
PTR 2b, bad_stack
.previous
#else
sw a1, 16(sp)
sw a2, 20(sp)
move a0, sp
move a2, a1
li a1, 1
jal do_page_fault
lw a1, 16(sp)
lw a2, 20(sp)
/*
* At this point the page should be readable and writable unless
* there was no more memory available.
*/
1: lw v0, (a1)
2: sw a2, (a1)
.section __ex_table,"a"
PTR 1b, no_mem
PTR 2b, no_mem
.previous
#endif
sw zero, PT_R7(sp) # success
sw v0, PT_R2(sp) # result
j o32_syscall_exit # continue like a normal syscall
no_mem: li v0, -ENOMEM
jr ra
bad_address:
li v0, -EFAULT
jr ra
bad_alignment:
li v0, -EINVAL
jr ra
END(mips_atomic_set)
LEAF(sys_sysmips)
beq a0, MIPS_ATOMIC_SET, mips_atomic_set
j _sys_sysmips
END(sys_sysmips)
LEAF(sys_syscall)
#if defined(CONFIG_BINFMT_IRIX)
sltiu v0, a0, MAX_SYSCALL_NO + 1 # check syscall number
#else
subu t0, a0, __NR_O32_Linux # check syscall number
sltiu v0, t0, __NR_O32_Linux_syscalls + 1
#endif
sll t1, t0, 3
beqz v0, einval
lw t2, sys_call_table(t1) # syscall routine
#if defined(CONFIG_BINFMT_IRIX)
li v1, 4000 # nr of sys_syscall
#else
li v1, 4000 - __NR_O32_Linux # index of sys_syscall
#endif
beq t0, v1, einval # do not recurse
/* Some syscalls like execve get their arguments from struct pt_regs
and claim zero arguments in the syscall table. Thus we have to
assume the worst case and shuffle around all potential arguments.
If you want performance, don't use indirect syscalls. */
move a0, a1 # shift argument registers
move a1, a2
move a2, a3
lw a3, 16(sp)
lw t4, 20(sp)
lw t5, 24(sp)
lw t6, 28(sp)
sw t4, 16(sp)
sw t5, 20(sp)
sw t6, 24(sp)
sw a0, PT_R4(sp) # .. and push back a0 - a3, some
sw a1, PT_R5(sp) # syscalls expect them there
sw a2, PT_R6(sp)
sw a3, PT_R7(sp)
sw a3, PT_R26(sp) # update a3 for syscall restarting
jr t2
/* Unreached */
einval: li v0, -EINVAL
jr ra
END(sys_syscall)
.macro fifty ptr, nargs, from=1, to=50
sys \ptr \nargs
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