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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 - 2000, 2001 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 MIPS Technologies, Inc.
* Copyright (C) 2004 Thiemo Seufer
*
* Hairy, the userspace application uses a different argument passing
* convention than the kernel, so we have to translate things from o32
* to ABI64 calling convention. 64-bit syscalls are also processed
* here for now.
*/
#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/thread_info.h>
#include <asm/unistd.h>
#include <asm/sysmips.h>
.align 5
NESTED(handle_sys, PT_SIZE, sp)
.set noat
SAVE_SOME
TRACE_IRQS_ON_RELOAD
STI
.set at
ld t1, PT_EPC(sp) # skip syscall on return
dsubu t0, v0, __NR_O32_Linux # check syscall number
sltiu t0, t0, __NR_O32_Linux_syscalls
daddiu t1, 4 # skip to next instruction
sd t1, PT_EPC(sp)
beqz t0, not_o32_scall
#if 0
SAVE_ALL
move a1, v0
PRINT("Scall %ld\n")
RESTORE_ALL
#endif
/* We don't want to stumble over broken sign extensions from
userland. O32 does never use the upper half. */
sll a0, a0, 0
sll a1, a1, 0
sll a2, a2, 0
sll a3, a3, 0
sd a3, PT_R26(sp) # save a3 for syscall restarting
/*
* 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).
*
* 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.
*/
ld t0, PT_R29(sp) # get old user stack pointer
daddu t1, t0, 32
bltz t1, bad_stack
load_a4: lw a4, 16(t0) # argument #5 from usp
load_a5: lw a5, 20(t0) # argument #6 from usp
load_a6: lw a6, 24(t0) # argument #7 from usp
load_a7: lw a7, 28(t0) # argument #8 from usp
loads_done:
.section __ex_table,"a"
PTR load_a4, bad_stack_a4
PTR load_a5, bad_stack_a5
PTR load_a6, bad_stack_a6
PTR load_a7, bad_stack_a7
.previous
li t1, _TIF_WORK_SYSCALL_ENTRY
LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
and t0, t1, t0
bnez t0, trace_a_syscall
syscall_common:
dsll t0, v0, 3 # offset into table
ld t2, (sys32_call_table - (__NR_O32_Linux * 8))(t0)
jalr t2 # Do The Real Thing (TM)
li t0, -EMAXERRNO - 1 # error?
sltu t0, t0, v0
sd t0, PT_R7(sp) # set error flag
beqz t0, 1f
ld t1, PT_R2(sp) # syscall number
dnegu v0 # error
sd t1, PT_R0(sp) # save it for syscall restarting
1: sd v0, PT_R2(sp) # result
o32_syscall_exit:
j syscall_exit_partial
/* ------------------------------------------------------------------------ */
trace_a_syscall:
SAVE_STATIC
sd a4, PT_R8(sp) # Save argument registers
sd a5, PT_R9(sp)
sd a6, PT_R10(sp)
sd a7, PT_R11(sp) # For indirect syscalls
move a0, sp
/*
* absolute syscall number is in v0 unless we called syscall(__NR_###)
* where the real syscall number is in a0
* note: NR_syscall is the first O32 syscall but the macro is
* only defined when compiling with -mabi=32 (CONFIG_32BIT)
* therefore __NR_O32_Linux is used (4000)
*/
.set push
.set reorder
subu t1, v0, __NR_O32_Linux
move a1, v0
bnez t1, 1f /* __NR_syscall at offset 0 */
ld a1, PT_R4(sp) /* Arg1 for __NR_syscall case */
.set pop
1: jal syscall_trace_enter
bltz v0, 1f # seccomp failed? Skip syscall
RESTORE_STATIC
ld v0, PT_R2(sp) # Restore syscall (maybe modified)
ld a0, PT_R4(sp) # Restore argument registers
ld a1, PT_R5(sp)
ld a2, PT_R6(sp)
ld a3, PT_R7(sp)
ld a4, PT_R8(sp)
ld a5, PT_R9(sp)
ld a6, PT_R10(sp)
ld a7, PT_R11(sp) # For indirect syscalls
dsubu t0, v0, __NR_O32_Linux # check (new) syscall number
sltiu t0, t0, __NR_O32_Linux_syscalls
beqz t0, not_o32_scall
j syscall_common
1: j syscall_exit
/* ------------------------------------------------------------------------ */
/*
* The stackpointer for a call with more than 4 arguments is bad.
*/
bad_stack:
li v0, EFAULT
sd v0, PT_R2(sp)
li t0, 1 # set error flag
sd t0, PT_R7(sp)
j o32_syscall_exit
bad_stack_a4:
li a4, 0
b load_a5
bad_stack_a5:
li a5, 0
b load_a6
bad_stack_a6:
li a6, 0
b load_a7
bad_stack_a7:
li a7, 0
b loads_done
not_o32_scall:
/*
* This is not an o32 compatibility syscall, pass it on
* to the 64-bit syscall handlers.
*/
#ifdef CONFIG_MIPS32_N32
j handle_sysn32
#else
j handle_sys64
#endif
END(handle_sys)
LEAF(sys32_syscall)
subu t0, a0, __NR_O32_Linux # check syscall number
sltiu v0, t0, __NR_O32_Linux_syscalls
beqz t0, einval # do not recurse
dsll t1, t0, 3
beqz v0, einval
ld t2, sys32_call_table(t1) # syscall routine
move a0, a1 # shift argument registers
move a1, a2
move a2, a3
move a3, a4
move a4, a5
move a5, a6
move a6, a7
jr t2
/* Unreached */
einval: li v0, -ENOSYS
jr ra
END(sys32_syscall)
#define __SYSCALL(nr, entry) PTR entry
.align 3
.type sys32_call_table,@object
EXPORT(sys32_call_table)
#include <asm/syscall_table_64_o32.h>
#undef __SYSCALL
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