Syscall Interface

Linux-compatible syscall numbers and kernel syscall initialisation. More...

Macros
#define	SYS_read   0
#define	SYS_write   1
#define	SYS_open   2
#define	SYS_close   3
#define	SYS_stat   4
#define	SYS_fstat   5
#define	SYS_lstat   6
#define	SYS_waitpid   7 /* wait4 is a superset; this is for waitpid() */
#define	SYS_lseek   8
#define	SYS_mmap   9
#define	SYS_mprotect   10
#define	SYS_munmap   11
#define	SYS_signal   13
#define	SYS_sigreturn   15 /* return from signal handler; SA_RESTART decision here */
#define	SYS_ioctl   16
#define	SYS_pread64   17
#define	SYS_pwrite64   18
#define	SYS_access   21
#define	SYS_pipe   22
#define	SYS_poll   23
#define	SYS_select   24
#define	SYS_dup   32
#define	SYS_dup2   33
#define	SYS_nanosleep   35
#define	SYS_getpid   39
#define	SYS_fork   57
#define	SYS_execve   59
#define	SYS_exit   60
#define	SYS_wait4   61 /* waitpid is implemented via this */
#define	SYS_kill   62
#define	SYS_gettimeofday   96
#define	SYS_sysinfo   99
#define	SYS_chmod   90
#define	SYS_statfs   137
#define	SYS_fstatfs   138
#define	SYS_mknod   133
#define	SYS_fcntl   72
#define	SYS_ftruncate   77
#define	SYS_getdents   78
#define	SYS_brk   79
#define	SYS_getcwd   80
#define	SYS_chdir   81
#define	SYS_rename   82
#define	SYS_mkdir   83
#define	SYS_rmdir   84
#define	SYS_unlink   87
#define	SYS_symlink   88
#define	SYS_readlink   89
#define	SYS_ptrace   101
#define	SYS_setpgid   109
#define	SYS_getppid   110
#define	SYS_setsid   112
#define	SYS_mount   165
#define	SYS_umount   166
#define	SYS_sigaction   174
#define	SYS_sched_getcpu   318
#define	SYS_clock_gettime   228
#define	SYS_socket   41
#define	SYS_connect   42
#define	SYS_accept   43
#define	SYS_sendto   44
#define	SYS_recvfrom   45
#define	SYS_shutdown   48
#define	SYS_bind   49
#define	SYS_listen   50
#define	SYS_socketpair   53
#define	SYS_setsockopt   54
#define	SYS_getsockopt   55
#define	SYS_clone   56
#define	SYS_arch_prctl   158
#define	SYS_gettid   186
#define	SYS_futex   202
#define	SYS_set_tid_address   218
#define	SYS_setitimer_miniOS   452 /* miniOS setitimer(): set ITIMER_REAL precisely */
#define	SYS_alarm_miniOS   453 /* miniOS alarm(): set ITIMER_REAL in seconds */
#define	SYS_register_sigtrampoline   454 /* register userspace signal trampoline VA */

Functions
void	syscall_save_restart_state (uint64_t nr, uint64_t a1, uint64_t a2, uint64_t a3, uint64_t a4, uint64_t a5, uint64_t a6)
void	syscall_init (void)
	Writes IA32_LSTAR MSR to the address of syscall_entry (the NASM entry stub in syscall.asm), writes IA32_STAR MSR with kernel CS (0x08) and user CS (0x1B) selectors, writes IA32_FMASK to mask IF during syscall entry (interrupts disabled at syscall boundary), and sets SCE bit in IA32_EFER. Called once by the BSP during boot.
void	syscall_get_saved_user_rdi_rsi_rdx (uint64_t *out_rdi, uint64_t *out_rsi, uint64_t *out_rdx)
	The SYSCALL instruction clobbers RCX and R11; arguments in RDI/RSI/RDX are preserved by the syscall.asm stub in per-CPU scratch space. This helper exposes them to kernel C code (e.g., SYS_execve handler) that needs all three argument registers.

Detailed Description

Linux-compatible syscall numbers and kernel syscall initialisation.

Defines SYS_* constants matching the Linux x86-64 ABI syscall table. The syscall entry point (syscall.asm) dispatches on RAX to the kernel syscall dispatcher in syscall.c, which fans out to four independent compilation units: syscall_mm.c (memory, brk, mmap, gettimeofday, clock_gettime), syscall_fs.c (VFS, poll, select, pipe, dup, ioctl, getdents, fcntl), syscall_proc.c (fork, execve, exit, wait, signals), and syscall_net.c (socket, bind, connect, sendto, recvfrom, accept). Supports 45+ syscalls covering file I/O, process management, memory management, networking, signals, and terminal control.

Macro Definition Documentation

SYS_accept

#define SYS_accept   43

SYS_access

#define SYS_access   21

SYS_alarm_miniOS

#define SYS_alarm_miniOS   453 /* miniOS alarm(): set ITIMER_REAL in seconds */

SYS_arch_prctl

#define SYS_arch_prctl   158

SYS_bind

#define SYS_bind   49

SYS_brk

#define SYS_brk   79

SYS_chdir

#define SYS_chdir   81

SYS_chmod

#define SYS_chmod   90

SYS_clock_gettime

#define SYS_clock_gettime   228

SYS_clone

#define SYS_clone   56

SYS_close

#define SYS_close   3

SYS_connect

#define SYS_connect   42

SYS_dup

#define SYS_dup   32

SYS_dup2

#define SYS_dup2   33

SYS_execve

#define SYS_execve   59

SYS_exit

#define SYS_exit   60

SYS_fcntl

#define SYS_fcntl   72

SYS_fork

#define SYS_fork   57

SYS_fstat

#define SYS_fstat   5

SYS_fstatfs

#define SYS_fstatfs   138

SYS_ftruncate

#define SYS_ftruncate   77

SYS_futex

#define SYS_futex   202

SYS_getcwd

#define SYS_getcwd   80

SYS_getdents

#define SYS_getdents   78

SYS_getpid

#define SYS_getpid   39

SYS_getppid

#define SYS_getppid   110

SYS_getsockopt

#define SYS_getsockopt   55

SYS_gettid

#define SYS_gettid   186

SYS_gettimeofday

#define SYS_gettimeofday   96

SYS_ioctl

#define SYS_ioctl   16

SYS_kill

#define SYS_kill   62

SYS_listen

#define SYS_listen   50

SYS_lseek

#define SYS_lseek   8

SYS_lstat

#define SYS_lstat   6

SYS_mkdir

#define SYS_mkdir   83

SYS_mknod

#define SYS_mknod   133

SYS_mmap

#define SYS_mmap   9

SYS_mount

#define SYS_mount   165

SYS_mprotect

#define SYS_mprotect   10

SYS_munmap

#define SYS_munmap   11

SYS_nanosleep

#define SYS_nanosleep   35

SYS_open

#define SYS_open   2

SYS_pipe

#define SYS_pipe   22

SYS_poll

#define SYS_poll   23

SYS_pread64

#define SYS_pread64   17

SYS_ptrace

#define SYS_ptrace   101

SYS_pwrite64

#define SYS_pwrite64   18

SYS_read

#define SYS_read   0

SYS_readlink

#define SYS_readlink   89

SYS_recvfrom

#define SYS_recvfrom   45

SYS_register_sigtrampoline

#define SYS_register_sigtrampoline   454 /* register userspace signal trampoline VA */

SYS_rename

#define SYS_rename   82

SYS_rmdir

#define SYS_rmdir   84

SYS_sched_getcpu

#define SYS_sched_getcpu   318

SYS_select

#define SYS_select   24

SYS_sendto

#define SYS_sendto   44

SYS_set_tid_address

#define SYS_set_tid_address   218

SYS_setitimer_miniOS

#define SYS_setitimer_miniOS   452 /* miniOS setitimer(): set ITIMER_REAL precisely */

SYS_setpgid

#define SYS_setpgid   109

SYS_setsid

#define SYS_setsid   112

SYS_setsockopt

#define SYS_setsockopt   54

SYS_shutdown

#define SYS_shutdown   48

SYS_sigaction

#define SYS_sigaction   174

SYS_signal

#define SYS_signal   13

SYS_sigreturn

#define SYS_sigreturn   15 /* return from signal handler; SA_RESTART decision here */

SYS_socket

#define SYS_socket   41

SYS_socketpair

#define SYS_socketpair   53

SYS_stat

#define SYS_stat   4

SYS_statfs

#define SYS_statfs   137

SYS_symlink

#define SYS_symlink   88

SYS_sysinfo

#define SYS_sysinfo   99

SYS_umount

#define SYS_umount   166

SYS_unlink

#define SYS_unlink   87

SYS_wait4

#define SYS_wait4   61 /* waitpid is implemented via this */

SYS_waitpid

#define SYS_waitpid   7 /* wait4 is a superset; this is for waitpid() */

SYS_write

#define SYS_write   1

Function Documentation

syscall_get_saved_user_rdi_rsi_rdx()

void syscall_get_saved_user_rdi_rsi_rdx	(	uint64_t *	out_rdi,
		uint64_t *	out_rsi,
		uint64_t *	out_rdx )

The SYSCALL instruction clobbers RCX and R11; arguments in RDI/RSI/RDX are preserved by the syscall.asm stub in per-CPU scratch space. This helper exposes them to kernel C code (e.g., SYS_execve handler) that needs all three argument registers.

syscall_get_saved_user_rdi_rsi_rdx() - Retrieve user-mode argument registers saved at syscall entry.

Parameters

out_rdi	Output pointer; set to the user's RDI value at SYSCALL entry.
out_rsi	Output pointer; set to the user's RSI value at SYSCALL entry.
out_rdx	Output pointer; set to the user's RDX value at SYSCALL entry.

Here is the call graph for this function:

syscall_init()

void syscall_init

(

void

)

Writes IA32_LSTAR MSR to the address of syscall_entry (the NASM entry stub in syscall.asm), writes IA32_STAR MSR with kernel CS (0x08) and user CS (0x1B) selectors, writes IA32_FMASK to mask IF during syscall entry (interrupts disabled at syscall boundary), and sets SCE bit in IA32_EFER. Called once by the BSP during boot.

syscall_init() - Initialise the SYSCALL/SYSRET mechanism.

Here is the call graph for this function:

Here is the caller graph for this function:

syscall_save_restart_state()

void syscall_save_restart_state	(	uint64_t	nr,
		uint64_t	a1,
		uint64_t	a2,
		uint64_t	a3,
		uint64_t	a4,
		uint64_t	a5,
		uint64_t	a6 )

syscall_save_restart_state() - Save syscall nr + args for SA_RESTART replay. @nr, @a1..@a6: Syscall number and all 6 arguments at syscall entry.

Called as the FIRST action in syscall_dispatch(). Records the syscall state in the current thread so SYS_sigreturn can replay it if SA_RESTART applies. Clears syscall_restart_pending (set by blocking syscalls that were interrupted).

Here is the call graph for this function:

Here is the caller graph for this function: