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。但我无法追踪 ARM 架构中系统调用的文件和进程。任何人都可以请帮忙。
我知道的几个相关文件是：
拱/臂/内核/calls.S
arch/arm/kernel/entry-common.S（需要解释）
问问题
38195 次
5 回答
16
比你问的更通用的答案。
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。
从该手册页复制：
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 $0x80 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.
所以这取决于系统是使用OABI还是EABI。
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.
SWI <number>在 OABI 中，除了您用于进行系统调用之外，一切都相同。
于 2016-08-11T20:56:42.693 回答
3
n900中hello world的拆解显示svc #0
于 2012-10-18T04:21:45.527 回答
2
如果您正在寻找 Linux 系统中的系统调用号，请查看 w3challs。
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：
- Linux x86
- Linux x86_64
- Linux ARM
- Linux ARM（拇指模式）
- Linux IA64（安腾）
- Linux Mips o32
- Linux Mips n32
- Linux Mips n64
- Linux Sparc（32 位）
- Linux Sparc64
- Linux PowerPC（32 位）
- Linux PowerPC64
- 视窗 x86
- 视窗 x86_64
- OS X BSD
编辑：提交https://w3challs.com/forum/general/dev/bugs#04以跟踪错误的错误。
于 2018-08-14T09:06:02.717 回答
0
arm 系统调用号
v4.19 将它们定义在arch/arm/tools/syscall.tbl：https ://github.com/torvalds/linux/blob/v4.19/arch/arm/tools/syscall.tbl
摘抄：
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
我已经对此进行了测试，exit并且在 QEMU 用户模式下的这个 Linux 程序集 hello worldwrite上有了这些确切的数字。
arm64 系统调用号
aarch64 使用了新的机制，参见：https ://reverseengineering.stackexchange.com/questions/16917/arm64-syscalls-table/18834#18834
于 2018-11-20T16:59:21.423 回答