UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity
OpenCloudOS-Kernel/arch/mips/vdso/sigreturn.S

50 lines
930 B
ArmAsm
Raw Normal View History

MIPS: Initial implementation of a VDSO Add an initial implementation of a proper (i.e. an ELF shared library) VDSO. With this commit it does not export any symbols, it only replaces the current signal return trampoline page. A later commit will add user implementations of gettimeofday()/clock_gettime(). To support both new toolchains and old ones which don't generate ABI flags section, we define its content manually and then use a tool (genvdso) to patch up the section to have the correct name and type. genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the kernel, and generates a C file containing a "struct mips_vdso_image" containing both the VDSO data and these offsets. This C file is compiled into the kernel. On 64-bit kernels we require a different VDSO for each supported ABI, so we may build up to 3 different VDSOs. The VDSO to use is selected by the mips_abi structure. A kernel/user shared data page is created and mapped below the VDSO image. This is currently empty, but will be used by the user time function implementations which are added later. [markos.chandras@imgtec.com: - Add more comments - Move abi detection in genvdso.h since it's the get_symbol function that needs it. - Add an R6 specific way to calculate the base address of VDSO in order to avoid the branch instruction which affects performance. - Do not patch .gnu.attributes since it's not needed for dynamic linking. - Simplify Makefile a little bit. - checkpatch fixes - Restrict VDSO support for binutils < 2.25 for pre-R6 - Include atomic64.h for O32 variant on MIPS64] Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11337/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-21 16:54:38 +08:00
/*
* Copyright (C) 2015 Imagination Technologies
* Author: Alex Smith <alex.smith@imgtec.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include "vdso.h"
#include <uapi/asm/unistd.h>
#include <asm/regdef.h>
#include <asm/asm.h>
.section .text
.cfi_sections .debug_frame
LEAF(__vdso_rt_sigreturn)
.cfi_startproc
.frame sp, 0, ra
.mask 0x00000000, 0
.fmask 0x00000000, 0
.cfi_signal_frame
li v0, __NR_rt_sigreturn
syscall
.cfi_endproc
END(__vdso_rt_sigreturn)
#if _MIPS_SIM == _MIPS_SIM_ABI32
LEAF(__vdso_sigreturn)
.cfi_startproc
.frame sp, 0, ra
.mask 0x00000000, 0
.fmask 0x00000000, 0
.cfi_signal_frame
li v0, __NR_sigreturn
syscall
.cfi_endproc
END(__vdso_sigreturn)
#endif