Linux System Call Tables

Numbers, names and arguments of the Linux system calls for 8 architectures, one table per kernel version. The tables are generated from the kernel sources, so each entry links to the place where the system call is defined. To find the number of a system call on every architecture at once, use the comparison table.

Tables (kernel version × architecture)

Kernel	x86-64	x86 (i386)	ARM (EABI)	AArch64	RISC-V 64	MIPS o32	MIPS n64	PowerPC64	All
Linux 7.2	421	461	424	327	328	445	374	424	compare
Linux 6.18	419	459	422	325	326	443	372	422	compare
Linux 5.15	396	438	401	304	304	422	352	401	compare
Linux 4.7	329	—	—	—	—	—	—	—

Each cell is the number of entries of the table. Linux 4.7 is the historical hand-written x86-64 table of this site.

Calling conventions

Arch	Instruction	Number	Arg 1	Arg 2	Arg 3	Arg 4	Arg 5	Arg 6	Return	Clobbered / error
x86-64	syscall	rax	rdi	rsi	rdx	r10	r8	r9	rax	rcx, r11
x86 (i386)	int 0x80	eax	ebx	ecx	edx	esi	edi	ebp	eax	—
ARM (EABI)	svc #0	r7	r0	r1	r2	r3	r4	r5	r0	—
AArch64	svc #0	x8	x0	x1	x2	x3	x4	x5	x0	—
RISC-V 64	ecall	a7	a0	a1	a2	a3	a4	a5	a0	—
MIPS o32	syscall	v0	a0	a1	a2	a3	sp+16	sp+20	v0	a3 = error flag
MIPS n64	syscall	v0	a0	a1	a2	a3	a4	a5	v0	a3 = error flag
PowerPC64	sc	r0	r3	r4	r5	r6	r7	r8	r3	CR0.SO = error flag

A return value between -4095 and -1 is an error (-errno); libc turns it into -1 and sets errno (MIPS and PowerPC flag errors separately, see below). Function call ABIs are on the calling conventions cheat sheet.

Changes between versions (x86-64)

System call numbers never change once allocated: new system calls get the next free number, removed ones become reserved. Since Linux 5.1 new system calls get the same number on every architecture (424 and up, plus the 4000/5000 base on MIPS), except on Alpha.

Linux 6.18 → 7.2 +2 / −0

Linux 5.15 → 6.18 +23 / −0

Linux 4.7 → 5.15 +31 / −0

Numbers from the architecture system call tables (arch/*/.../syscall*.tbl, scripts/syscall.tbl), prototypes from the SYSCALL_DEFINE macros of each kernel tree.