Linux syscall tables

Linux syscall tables in one place, grouped by architecture: system calls for 27 architectures with their numbers, arguments and registers, from Linux 3.3 to 7.3.

Architectures

Every architecture's table, with the full history of when each syscall appeared and when it was dropped, is also a plain JSON file at /<arch>/syscalls.json, for example /x64/syscalls.json.

Calling conventions

Number in NR, arguments in ARG0 to ARG5, then the instruction. The result comes back in RETURN.

ARCHINSTRUCTIONNRRETURNARG0ARG1ARG2ARG3ARG4ARG5
x64syscallraxrax rdirsirdxr10r8r9
x86int 0x80eaxeax ebxecxedxesiediebp
arm64svc #0x8x0 x0x1x2x3x4x5
armsvc #0r7r0 r0r1r2r3r4r5
riscv64ecalla7a0 a0a1a2a3a4a5
ia32int 0x80eaxeax ebxecxedxesiediebp
x32syscallraxrax rdirsirdxr10r8r9
loongarch64syscall 0a7a0 a0a1a2a3a4a5
ppc64scr0r3 r3r4r5r6r7r8
ppcscr0r3 r3r4r5r6r7r8
s390xsvc 0r1r2 r2r3r4r5r6r7
mips64syscallv0v0 a0a1a2a3a4a5
mipsn32syscallv0v0 a0a1a2a3a4a5
mipso32syscallv0v0 a0a1a2a3sp+16sp+20
alphacallsysv0v0 a0a1a2a3a4a5
arctrap0r8r0 r0r1r2r3r4r5
cskytrap 0r7a0 a0a1a2a3r4r5
hexagontrap0(#1)r6r0 r0r1r2r3r4r5
m68ktrap #0d0d0 d1d2d3d4d5a0
microblazebrki r14,8r12r3 r5r6r7r8r9r10
nios2trapr2r2 r4r5r6r7r8r9
openriscl.sys 1r11r11 r3r4r5r6r7r8
pariscble 0x100(%sr2, %r0)r20r28 r26r25r24r23r22r21
shtrapa #31r3r0 r4r5r6r7r0r1
sparct 0x10g1o0 o0o1o2o3o4o5
sparc64t 0x6dg1o0 o0o1o2o3o4o5
xtensasyscalla2a2 a6a3a4a5a8a9

API

curl https://api.syscall.sh/v2/syscalls/x64/read

Any kernel release, diffs between releases and more in the API docs.

New here?

The guide walks through making a syscall by hand on x64, arm64 and riscv64, and explains what everything on this site means. The releases page shows which syscalls each kernel release added or removed, and compare puts two architectures side by side. If you live in Emacs, syscall.el brings all of it there.