root/arch/mips/kernel/scall64-n32.S

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01 by Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  * Copyright (C) 2001 MIPS Technologies, Inc.
   9  */
  10 #include <linux/errno.h>
  11 #include <asm/asm.h>
  12 #include <asm/asmmacro.h>
  13 #include <asm/irqflags.h>
  14 #include <asm/mipsregs.h>
  15 #include <asm/regdef.h>
  16 #include <asm/stackframe.h>
  17 #include <asm/thread_info.h>
  18 #include <asm/unistd.h>
  19 
  20 #ifndef CONFIG_MIPS32_O32
  21 /* No O32, so define handle_sys here */
  22 #define handle_sysn32 handle_sys
  23 #endif
  24 
  25         .align  5
  26 NESTED(handle_sysn32, PT_SIZE, sp)
  27 #ifndef CONFIG_MIPS32_O32
  28         .set    noat
  29         SAVE_SOME
  30         TRACE_IRQS_ON_RELOAD
  31         STI
  32         .set    at
  33 #endif
  34 
  35         dsubu   t0, v0, __NR_N32_Linux  # check syscall number
  36         sltiu   t0, t0, __NR_N32_Linux_syscalls
  37 
  38 #ifndef CONFIG_MIPS32_O32
  39         ld      t1, PT_EPC(sp)          # skip syscall on return
  40         daddiu  t1, 4                   # skip to next instruction
  41         sd      t1, PT_EPC(sp)
  42 #endif
  43         beqz    t0, not_n32_scall
  44 
  45         sd      a3, PT_R26(sp)          # save a3 for syscall restarting
  46 
  47         li      t1, _TIF_WORK_SYSCALL_ENTRY
  48         LONG_L  t0, TI_FLAGS($28)       # syscall tracing enabled?
  49         and     t0, t1, t0
  50         bnez    t0, n32_syscall_trace_entry
  51 
  52 syscall_common:
  53         dsll    t0, v0, 3               # offset into table
  54         ld      t2, (sysn32_call_table - (__NR_N32_Linux * 8))(t0)
  55 
  56         jalr    t2                      # Do The Real Thing (TM)
  57 
  58         li      t0, -EMAXERRNO - 1      # error?
  59         sltu    t0, t0, v0
  60         sd      t0, PT_R7(sp)           # set error flag
  61         beqz    t0, 1f
  62 
  63         ld      t1, PT_R2(sp)           # syscall number
  64         dnegu   v0                      # error
  65         sd      t1, PT_R0(sp)           # save it for syscall restarting
  66 1:      sd      v0, PT_R2(sp)           # result
  67 
  68         j       syscall_exit_partial
  69 
  70 /* ------------------------------------------------------------------------ */
  71 
  72 n32_syscall_trace_entry:
  73         SAVE_STATIC
  74         move    a0, sp
  75         move    a1, v0
  76         jal     syscall_trace_enter
  77 
  78         bltz    v0, 1f                  # seccomp failed? Skip syscall
  79 
  80         RESTORE_STATIC
  81         ld      v0, PT_R2(sp)           # Restore syscall (maybe modified)
  82         ld      a0, PT_R4(sp)           # Restore argument registers
  83         ld      a1, PT_R5(sp)
  84         ld      a2, PT_R6(sp)
  85         ld      a3, PT_R7(sp)
  86         ld      a4, PT_R8(sp)
  87         ld      a5, PT_R9(sp)
  88 
  89         dsubu   t2, v0, __NR_N32_Linux  # check (new) syscall number
  90         sltiu   t0, t2, __NR_N32_Linux_syscalls
  91         beqz    t0, not_n32_scall
  92 
  93         j       syscall_common
  94 
  95 1:      j       syscall_exit
  96 
  97 not_n32_scall:
  98         /* This is not an n32 compatibility syscall, pass it on to
  99            the n64 syscall handlers.  */
 100         j       handle_sys64
 101 
 102         END(handle_sysn32)
 103 
 104 #define __SYSCALL(nr, entry)    PTR entry
 105         .type   sysn32_call_table, @object
 106 EXPORT(sysn32_call_table)
 107 #include <asm/syscall_table_64_n32.h>
 108 #undef __SYSCALL