ARM 系统调用的接口是什么,它在 Linux 内核中是在哪里定义的?

声明:本页面是StackOverFlow热门问题的中英对照翻译,遵循CC BY-SA 4.0协议,如果您需要使用它,必须同样遵循CC BY-SA许可,注明原文地址和作者信息,同时你必须将它归于原作者(不是我):StackOverFlow 原文地址: http://stackoverflow.com/questions/12946958/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me): StackOverFlow

提示:将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间:2020-08-06 14:37:45  来源:igfitidea点击:

What is the interface for ARM system calls and where is it defined in the Linux kernel?

linuxlinux-kernelarmsystem-calls

提问by shingaridavesh

I have read about system calls in Linux, and everywhere description is given regarding x86 architecture (0x80interrupt and SYSENTER). But I am not able to track down the files and process for a system call in ARM architecture. Can anyone please help.

我已经阅读了 Linux 中的系统调用,并且到处都给出了关于 x86 架构(0x80中断和SYSENTER)的描述。但是我无法在 ARM 架构中跟踪系统调用的文件和进程。任何人都可以请帮忙。

Few relevant files which I got to know are:

我知道的几个相关文件是:

arch/arm/kernel/calls.S

arch/arm/内核/calls.S

arch/arm/kernel/entry-common.S (explanation needed)

arch/arm/kernel/entry-common.S(需要解释)

采纳答案by auselen

In ARM world, you do a software interrupt(mechanism to signal the kernel) by supervisor call / svc(previously called SWI).

在 ARM 世界中,您software interrupt通过supervisor call / svc(以前称为 SWI)执行(向内核发送信号的机制)。

ARM assembly (UAL) syntax looks like this:

ARM 汇编 (UAL) 语法如下所示:

SVC{<c>}{<q>} {#}<imm>

(In Linux you need to pass #0)

(在 Linux 中你需要通过 #0)

You should cheat from other projects like bionicor uClibc.

您应该从仿生uClibc等其他项目中作弊。

回答by Aki Suihkonen

The disassembly of hello world in n900 shows svc #0

n900中hello world的拆解显示 svc #0

http://brnz.org/hbr/?m=201102

http://brnz.org/hbr/?m=201102

回答by Calmarius

More generic answer than what you asked.

比你问的更通用的答案。

On Linux the man syscall (2)is a good start to find out how to make a system call in various architectures.

在 Linux 上,这man syscall (2)是了解如何在各种体系结构中进行系统调用的良好开端。

Copied from that manpage:

从该联机帮助页复制:

Architecture calling conventions
    Every architecture has its own way of invoking and passing arguments
    to the kernel.  The details for various architectures are listed in
    the two tables below.

    The first table lists the instruction used to transition to kernel
    mode (which might not be the fastest or best way to transition to the
    kernel, so you might have to refer to vdso(7)), the register used to
    indicate the system call number, the register used to return the sys‐
    tem call result, and the register used to signal an error.

    arch/ABI    instruction           syscall #  retval  error    Notes
    ────────────────────────────────────────────────────────────────────
    alpha       callsys               v0         a0      a3       [1]
    arc         trap0                 r8         r0      -
    arm/OABI    swi NR                -          a1      -        [2]
    arm/EABI    swi 0x0               r7         r0      -
    arm64       svc #0                x8         x0      -
    blackfin    excpt 0x0             P0         R0      -
    i386        int 
0   common  restart_syscall     sys_restart_syscall
1   common  exit            sys_exit
2   common  fork            sys_fork
3   common  read            sys_read
4   common  write           sys_write
5   common  open            sys_open
6   common  close           sys_close
x80 eax eax - ia64 break 0x100000 r15 r8 r10 [1] m68k trap #0 d0 d0 - microblaze brki r14,8 r12 r3 - mips syscall v0 v0 a3 [1] nios2 trap r2 r2 r7 parisc ble 0x100(%sr2, %r0) r20 r28 - powerpc sc r0 r3 r0 [1] riscv scall a7 a0 - s390 svc 0 r1 r2 - [3] s390x svc 0 r1 r2 - [3] superh trap #0x17 r3 r0 - [4] sparc/32 t 0x10 g1 o0 psr/csr [1] sparc/64 t 0x6d g1 o0 psr/csr [1] tile swint1 R10 R00 R01 [1] x86-64 syscall rax rax - [5] x32 syscall rax rax - [5] xtensa syscall a2 a2 - Notes: [1] On a few architectures, a register is used as a boolean (0 indicating no error, and -1 indicating an error) to signal that the system call failed. The actual error value is still contained in the return register. On sparc, the carry bit (csr) in the processor status register (psr) is used instead of a full register. [2] NR is the system call number. [3] For s390 and s390x, NR (the system call number) may be passed directly with svc NR if it is less than 256. [4] On SuperH, the trap number controls the maximum number of arguments passed. A trap #0x10 can be used with only 0-argu‐ ment system calls, a trap #0x11 can be used with 0- or 1-argument system calls, and so on up to trap #0x17 for 7-argument system calls. [5] The x32 ABI uses the same instruction as the x86-64 ABI and is used on the same processors. To differentiate between them, the bit mask __X32_SYSCALL_BIT is bitwise-ORed into the system call number for system calls under the x32 ABI. Both system call tables are available though, so setting the bit is not a hard requirement. The second table shows the registers used to pass the system call arguments. arch/ABI arg1 arg2 arg3 arg4 arg5 arg6 arg7 Notes ────────────────────────────────────────────────────────────── alpha a0 a1 a2 a3 a4 a5 - arc r0 r1 r2 r3 r4 r5 - arm/OABI a1 a2 a3 a4 v1 v2 v3 arm/EABI r0 r1 r2 r3 r4 r5 r6 arm64 x0 x1 x2 x3 x4 x5 - blackfin R0 R1 R2 R3 R4 R5 - i386 ebx ecx edx esi edi ebp - ia64 out0 out1 out2 out3 out4 out5 - m68k d1 d2 d3 d4 d5 a0 - microblaze r5 r6 r7 r8 r9 r10 - mips/o32 a0 a1 a2 a3 - - - [1] mips/n32,64 a0 a1 a2 a3 a4 a5 - nios2 r4 r5 r6 r7 r8 r9 - parisc r26 r25 r24 r23 r22 r21 - powerpc r3 r4 r5 r6 r7 r8 r9 riscv a0 a1 a2 a3 a4 a5 - s390 r2 r3 r4 r5 r6 r7 - s390x r2 r3 r4 r5 r6 r7 - superh r4 r5 r6 r7 r0 r1 r2 sparc/32 o0 o1 o2 o3 o4 o5 - sparc/64 o0 o1 o2 o3 o4 o5 - tile R00 R01 R02 R03 R04 R05 - x86-64 rdi rsi rdx r10 r8 r9 - x32 rdi rsi rdx r10 r8 r9 - xtensa a6 a3 a4 a5 a8 a9 - Notes: [1] The mips/o32 system call convention passes arguments 5 through 8 on the user stack. Note that these tables don't cover the entire calling convention—some architectures may indiscriminately clobber other registers not listed here.

So it depends whether the system uses OABI or EABI.

所以要看系统是使用OABI还是EABI。

So in EABI you use r7to pass the system call number, use r0-r6to pass the arguments, use SWI 0to make the system call, expect the result in r0.

所以在 EABI 中你r7用来传递系统调用号,r0-r6用来传递参数,SWI 0用来进行系统调用,期望结果在r0.

In OABI everything is the same except you use SWI <number>to make a system call.

在 OABI 中,除了您SWI <number>用来进行系统调用之外,一切都相同。

回答by mja

If you're looking for syscall number in Linux system, take a look at w3challs.

如果您正在 Linux 系统中寻找系统调用号,请查看 w3challs

That site helps finding out which syscall number and which registers used for passing arguments. It supports many architectures listed below:

该站点有助于找出用于传递参数的系统调用号和寄存器。它支持下面列出的许多架构:



Edit: Filed https://w3challs.com/forum/general/dev/bugs#04to track the incorrect bug.

编辑:提交https://w3challs.com/forum/general/dev/bugs#04以跟踪错误的错误。

回答by fxsc

arm system call numbers

arm 系统调用号

v4.19 defines them at arch/arm/tools/syscall.tbl: https://github.com/torvalds/linux/blob/v4.19/arch/arm/tools/syscall.tbl

v4.19 在arch/arm/tools/syscall.tbl以下位置定义它们:https: //github.com/torvalds/linux/blob/v4.19/arch/arm/tools/syscall.tbl

Excerpt:

摘抄:

##代码##

I have tested that exitand writehave those exact numbers on this Linux assembly hello worldon QEMU user mode.

我已经测试过,exit并在 QEMU 用户模式下的这个 Linux 程序集 hello worldwrite有这些确切的数字。

arm64 system call numbers

arm64 系统调用号

aarch64 uses a new mechanism, see: https://reverseengineering.stackexchange.com/questions/16917/arm64-syscalls-table/18834#18834

aarch64 使用了新机制,参见:https://reverseengineering.stackexchange.com/questions/16917/arm64-syscalls-table/18834#18834