glibc/sysdeps/unix/sysv/linux/mips/sysdep-cancel.h

/* Copyright (C) 2003-2016 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library.  If not, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <sysdeps/generic/sysdep.h>
#include <tls.h>
#ifndef __ASSEMBLER__
# include <nptl/pthreadP.h>
#endif

#if IS_IN (libc) || IS_IN (libpthread) || IS_IN (librt)

# ifdef __PIC__
#  define PSEUDO_CPLOAD .cpload t9;
#  define PSEUDO_ERRJMP la t9, __syscall_error; jr t9;
#  define PSEUDO_SAVEGP sw gp, 32(sp); cfi_rel_offset (gp, 32);
#  define PSEUDO_LOADGP lw gp, 32(sp);
# else
#  define PSEUDO_CPLOAD
#  define PSEUDO_ERRJMP j __syscall_error;
#  define PSEUDO_SAVEGP
#  define PSEUDO_LOADGP
# endif

# undef PSEUDO
# define PSEUDO(name, syscall_name, args)				      \
      .align 2;								      \
      .set nomips16;							      \
  L(pseudo_start):							      \
      cfi_startproc;							      \
  99: PSEUDO_ERRJMP							      \
  .type __##syscall_name##_nocancel, @function;				      \
  .globl __##syscall_name##_nocancel;					      \
  __##syscall_name##_nocancel:						      \
    .set noreorder;							      \
    PSEUDO_CPLOAD							      \
    li v0, SYS_ify(syscall_name);					      \
    syscall;								      \
    .set reorder;							      \
    bne a3, zero, 99b;					       		      \
    ret;								      \
    cfi_endproc;							      \
  .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel;	      \
  ENTRY (name)								      \
    .set noreorder;							      \
    PSEUDO_CPLOAD							      \
    .set reorder;							      \
    SINGLE_THREAD_P(v1);						      \
    bne zero, v1, L(pseudo_cancel);					      \
    .set noreorder;							      \
    li v0, SYS_ify(syscall_name);					      \
    syscall;								      \
    .set reorder;							      \
    bne a3, zero, 99b;					       		      \
    ret;								      \
  L(pseudo_cancel):							      \
    SAVESTK_##args;						              \
    sw ra, 28(sp);							      \
    cfi_rel_offset (ra, 28);						      \
    PSEUDO_SAVEGP							      \
    PUSHARGS_##args;			/* save syscall args */	      	      \
    CENABLE;								      \
    PSEUDO_LOADGP							      \
    sw v0, 44(sp);			/* save mask */			      \
    POPARGS_##args;			/* restore syscall args */	      \
    .set noreorder;							      \
    li v0, SYS_ify (syscall_name);				      	      \
    syscall;								      \
    .set reorder;							      \
    sw v0, 36(sp);			/* save syscall result */             \
    sw a3, 40(sp);			/* save syscall error flag */	      \
    lw a0, 44(sp);			/* pass mask as arg1 */		      \
    CDISABLE;								      \
    PSEUDO_LOADGP							      \
    lw v0, 36(sp);			/* restore syscall result */          \
    lw a3, 40(sp);			/* restore syscall error flag */      \
    lw ra, 28(sp);			/* restore return address */	      \
    .set noreorder;							      \
    bne a3, zero, 99b;							      \
     RESTORESTK;						              \
  L(pseudo_end):							      \
    .set reorder;

# undef PSEUDO_END
# define PSEUDO_END(sym) cfi_endproc; .end sym; .size sym,.-sym

# define PUSHARGS_0	/* nothing to do */
# define PUSHARGS_1	PUSHARGS_0 sw a0, 0(sp); cfi_rel_offset (a0, 0);
# define PUSHARGS_2	PUSHARGS_1 sw a1, 4(sp); cfi_rel_offset (a1, 4);
# define PUSHARGS_3	PUSHARGS_2 sw a2, 8(sp); cfi_rel_offset (a2, 8);
# define PUSHARGS_4	PUSHARGS_3 sw a3, 12(sp); cfi_rel_offset (a3, 12);
# define PUSHARGS_5	PUSHARGS_4 /* handled by SAVESTK_## */
# define PUSHARGS_6	PUSHARGS_5
# define PUSHARGS_7	PUSHARGS_6

# define POPARGS_0	/* nothing to do */
# define POPARGS_1	POPARGS_0 lw a0, 0(sp);
# define POPARGS_2	POPARGS_1 lw a1, 4(sp);
# define POPARGS_3	POPARGS_2 lw a2, 8(sp);
# define POPARGS_4	POPARGS_3 lw a3, 12(sp);
# define POPARGS_5	POPARGS_4 /* args already in new stackframe */
# define POPARGS_6	POPARGS_5
# define POPARGS_7	POPARGS_6


# define STKSPACE	48
# define SAVESTK_0 	subu sp, STKSPACE; cfi_adjust_cfa_offset(STKSPACE)
# define SAVESTK_1      SAVESTK_0
# define SAVESTK_2      SAVESTK_1
# define SAVESTK_3      SAVESTK_2
# define SAVESTK_4      SAVESTK_3
# define SAVESTK_5      lw t0, 16(sp);		\
			SAVESTK_0;		\
			sw t0, 16(sp)

# define SAVESTK_6      lw t0, 16(sp);		\
			lw t1, 20(sp);		\
			SAVESTK_0;		\
			sw t0, 16(sp);		\
			sw t1, 20(sp)

# define SAVESTK_7      lw t0, 16(sp);		\
			lw t1, 20(sp);		\
			lw t2, 24(sp);		\
			SAVESTK_0;		\
			sw t0, 16(sp);		\
			sw t1, 20(sp);		\
			sw t2, 24(sp)

# define RESTORESTK 	addu sp, STKSPACE; cfi_adjust_cfa_offset(-STKSPACE)


# ifdef __PIC__
/* We use jalr rather than jal.  This means that the assembler will not
   automatically restore $gp (in case libc has multiple GOTs) so we must
   do it manually - which we have to do anyway since we don't use .cprestore.
   It also shuts up the assembler warning about not using .cprestore.  */
#  define PSEUDO_JMP(sym) la t9, sym; jalr t9;
# else
#  define PSEUDO_JMP(sym) jal sym;
# endif

# if IS_IN (libpthread)
#  define CENABLE	PSEUDO_JMP (__pthread_enable_asynccancel)
#  define CDISABLE	PSEUDO_JMP (__pthread_disable_asynccancel)
# elif IS_IN (librt)
#  define CENABLE	PSEUDO_JMP (__librt_enable_asynccancel)
#  define CDISABLE	PSEUDO_JMP (__librt_disable_asynccancel)
# else
#  define CENABLE	PSEUDO_JMP (__libc_enable_asynccancel)
#  define CDISABLE	PSEUDO_JMP (__libc_disable_asynccancel)
# endif

# ifndef __ASSEMBLER__
#  define SINGLE_THREAD_P						\
	__builtin_expect (THREAD_GETMEM (THREAD_SELF,			\
					 header.multiple_threads)	\
			  == 0, 1)
# else
#  define SINGLE_THREAD_P(reg)						\
	READ_THREAD_POINTER(reg);					\
	lw reg, MULTIPLE_THREADS_OFFSET(reg)
#endif

#elif !defined __ASSEMBLER__

# define SINGLE_THREAD_P 1
# define NO_CANCELLATION 1

#endif

#ifndef __ASSEMBLER__
# define RTLD_SINGLE_THREAD_P \
  __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
				   header.multiple_threads) == 0, 1)
#endif