diff options
Diffstat (limited to 'kernel/sys_process.cc')
| -rw-r--r-- | kernel/sys_process.cc | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/kernel/sys_process.cc b/kernel/sys_process.cc new file mode 100644 index 0000000..438ad1b --- /dev/null +++ b/kernel/sys_process.cc @@ -0,0 +1,185 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Copyright (C) 2026 Richard Qin */ + +/* + * Process Control System Calls + * + * Implements: exit, exit_group, getpid, gettid, getppid, + * sched_yield, clone (stub), wait4 (stub), + * set_tid_address, getuid, getgid. + * + * Reference: docs/specs/syscall.md §7.1 + */ + +#include "lume/klog.h" +#include <lume/types.h> +#include <lume/task.h> +#include <lume/sched.h> +#include <lume/errno.h> +#include <lume/uaccess.h> +#include <lume/wait.h> + +/* External: task lifecycle (kernel/task.cc) */ +extern void task_exit(int code); +extern int32 do_wait4(int32 wait_pid, int options, int32* exit_code); +extern int32 task_clone(arch::TrapFrame* tf, uint64 clone_flags, + uint64 child_stack, uint64 parent_tidptr, + uint64 child_tidptr, uint64 tls); +extern int32 task_fork(arch::TrapFrame* tf); + +/* ====================================================================== + * sys_exit / sys_exit_group + * ====================================================================== */ + +int64 sys_exit(uint64 code, uint64, uint64, uint64, uint64, uint64) +{ + task_exit(static_cast<int>(code & 0xFF)); + __builtin_unreachable(); +} + +int64 sys_exit_group(uint64 code, uint64, uint64, uint64, uint64, uint64) +{ + /* Phase 2: single-threaded, equivalent to sys_exit. + * Phase 3: kill all threads in tgid then exit. */ + task_exit(static_cast<int>(code & 0xFF)); + __builtin_unreachable(); +} + +/* ====================================================================== + * sys_getpid / sys_gettid / sys_getppid + * ====================================================================== */ + +int64 sys_getpid(uint64, uint64, uint64, uint64, uint64, uint64) +{ + return current_task()->tgid; /* Linux: getpid() returns tgid */ +} + +int64 sys_gettid(uint64, uint64, uint64, uint64, uint64, uint64) +{ + return current_task()->pid; /* Linux: gettid() returns real tid */ +} + +int64 sys_getppid(uint64, uint64, uint64, uint64, uint64, uint64) +{ + TaskControlBlock* parent = current_task()->parent; + return parent ? parent->tgid : 0; +} + +/* ====================================================================== + * sys_sched_yield + * ====================================================================== */ + +int64 sys_sched_yield_wrapper(uint64, uint64, uint64, uint64, uint64, uint64) +{ + sched_yield(); + return 0; +} + +int64 sys_clone_wrapper(uint64 flags, uint64 child_stack, + uint64 ptid, uint64 ctid, uint64 tls, uint64) +{ + arch::TrapFrame* tf = current_task()->trapframe; + if (!tf) return -EINVAL; + + return task_clone(tf, flags, child_stack, ptid, ctid, tls); +} + +/* ======================================================================== + * sys_wait4 — Wait for child to exit + * ======================================================================== */ + +int64 sys_wait4_wrapper(uint64 pid, uint64 wstatus_ptr, + uint64 options, uint64, uint64, uint64) +{ + int32 exit_code = 0; + int32 child_pid = do_wait4(static_cast<int32>(pid), + static_cast<int>(options), + &exit_code); + + if (child_pid < 0) return child_pid; + + /* exit_code is already in Linux wstatus format */ + if (wstatus_ptr != 0) { + if (copy_to_user(wstatus_ptr, &exit_code, sizeof(int)) < 0) + return -EFAULT; + } + + return child_pid; +} + +/* ====================================================================== + * sys_set_tid_address — musl libc calls this very early + * ====================================================================== */ + +int64 sys_set_tid_address(uint64 tidptr, uint64, uint64, + uint64, uint64, uint64) +{ + /* Store clear_child_tid pointer — on exit, kernel writes 0 here + * and does futex_wake (enables pthread_join). */ + current_task()->clear_child_tid = tidptr; + return current_task()->pid; +} + +/* ====================================================================== + * sys_getuid / sys_getgid — Phase 2: always root + * ====================================================================== */ + +int64 sys_getuid(uint64, uint64, uint64, uint64, uint64, uint64) +{ + return 0; /* root */ +} + +int64 sys_getgid(uint64, uint64, uint64, uint64, uint64, uint64) +{ + return 0; /* root */ +} + +/* ====================================================================== + * sys_nanosleep (SYS_nanosleep = 101) + * ====================================================================== */ +#include <lume/wait.h> +#include <lume/kprintf.h> +#include <lume/timer.h> + +struct linux_timespec { + int64 tv_sec; + int64 tv_nsec; +}; + +static void nanosleep_wakeup(TimerList* t) { + TaskControlBlock* task = static_cast<TaskControlBlock*>(t->data); + task->state = TaskState::Runnable; + sched_enqueue(task); +} + +int64 sys_nanosleep(uint64 req_ptr, uint64 rem_ptr, uint64, uint64, uint64, uint64) { + if (req_ptr == 0) return -EINVAL; + + linux_timespec req; + if (copy_from_user(&req, req_ptr, sizeof(req)) != 0) { + return -EFAULT; + } + + uint64 target = *(volatile uint64*)&g_jiffies + (req.tv_sec * 100) + (req.tv_nsec / 10000000); + + TaskControlBlock* curr = current_task(); + curr->state = TaskState::Sleeping; + + TimerList t; + t.init(nanosleep_wakeup); + t.expires = target; + t.data = curr; + + add_timer(&t); + + if (*(volatile uint64*)&g_jiffies < target) { + schedule(); + } else { + curr->state = TaskState::Running; + } + + + del_timer(&t); + + return 0; +} |