#include <proc.h>
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#include <kmalloc.h>
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#include <string.h>
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#include <sync.h>
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#include <pmm.h>
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#include <error.h>
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#include <sched.h>
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#include <elf.h>
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#include <vmm.h>
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#include <trap.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <unistd.h>
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#include <fs.h>
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#include <vfs.h>
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#include <sysfile.h>
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/* ------------- process/thread mechanism design&implementation -------------
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(an simplified Linux process/thread mechanism )
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introduction:
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ucore implements a simple process/thread mechanism. process contains the independent memory sapce, at least one threads
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for execution, the kernel data(for management), processor state (for context switch), files(in lab6), etc. ucore needs to
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manage all these details efficiently. In ucore, a thread is just a special kind of process(share process's memory).
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------------------------------
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process state : meaning -- reason
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PROC_UNINIT : uninitialized -- alloc_proc
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PROC_SLEEPING : sleeping -- try_free_pages, do_wait, do_sleep
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PROC_RUNNABLE : runnable(maybe running) -- proc_init, wakeup_proc,
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PROC_ZOMBIE : almost dead -- do_exit
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-----------------------------
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process state changing:
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alloc_proc RUNNING
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+ +--<----<--+
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+ + proc_run +
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V +-->---->--+
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PROC_UNINIT -- proc_init/wakeup_proc --> PROC_RUNNABLE -- try_free_pages/do_wait/do_sleep --> PROC_SLEEPING --
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A + +
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| +--- do_exit --> PROC_ZOMBIE +
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+ +
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-----------------------wakeup_proc----------------------------------
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-----------------------------
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process relations
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parent: proc->parent (proc is children)
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children: proc->cptr (proc is parent)
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older sibling: proc->optr (proc is younger sibling)
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younger sibling: proc->yptr (proc is older sibling)
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-----------------------------
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related syscall for process:
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SYS_exit : process exit, -->do_exit
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SYS_fork : create child process, dup mm -->do_fork-->wakeup_proc
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SYS_wait : wait process -->do_wait
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SYS_exec : after fork, process execute a program -->load a program and refresh the mm
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SYS_clone : create child thread -->do_fork-->wakeup_proc
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SYS_yield : process flag itself need resecheduling, -- proc->need_sched=1, then scheduler will rescheule this process
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SYS_sleep : process sleep -->do_sleep
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SYS_kill : kill process -->do_kill-->proc->flags |= PF_EXITING
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-->wakeup_proc-->do_wait-->do_exit
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SYS_getpid : get the process's pid
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*/
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// the process set's list
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list_entry_t proc_list;
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#define HASH_SHIFT 10
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#define HASH_LIST_SIZE (1 << HASH_SHIFT)
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#define pid_hashfn(x) (hash32(x, HASH_SHIFT))
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// has list for process set based on pid
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static list_entry_t hash_list[HASH_LIST_SIZE];
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// idle proc
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struct proc_struct *idleproc = NULL;
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// init proc
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struct proc_struct *initproc = NULL;
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// current proc
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struct proc_struct *current = NULL;
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static int nr_process = 0;
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void kernel_thread_entry(void);
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void forkrets(struct trapframe *tf);
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void switch_to(struct context *from, struct context *to);
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// alloc_proc - alloc a proc_struct and init all fields of proc_struct
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static struct proc_struct *
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alloc_proc(void) {
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struct proc_struct *proc = kmalloc(sizeof(struct proc_struct));
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if (proc != NULL) {
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//LAB4:EXERCISE1 YOUR CODE
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/*
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* below fields in proc_struct need to be initialized
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* enum proc_state state; // Process state
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* int pid; // Process ID
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* int runs; // the running times of Proces
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* uintptr_t kstack; // Process kernel stack
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* volatile bool need_resched; // bool value: need to be rescheduled to release CPU?
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* struct proc_struct *parent; // the parent process
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* struct mm_struct *mm; // Process's memory management field
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* struct context context; // Switch here to run process
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* struct trapframe *tf; // Trap frame for current interrupt
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* uintptr_t cr3; // CR3 register: the base addr of Page Directroy Table(PDT)
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* uint32_t flags; // Process flag
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* char name[PROC_NAME_LEN + 1]; // Process name
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*/
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//LAB5 YOUR CODE : (update LAB4 steps)
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/*
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* below fields(add in LAB5) in proc_struct need to be initialized
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* uint32_t wait_state; // waiting state
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* struct proc_struct *cptr, *yptr, *optr; // relations between processes
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*/
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//LAB6 YOUR CODE : (update LAB5 steps)
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/*
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* below fields(add in LAB6) in proc_struct need to be initialized
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* struct run_queue *rq; // running queue contains Process
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* list_entry_t run_link; // the entry linked in run queue
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* int time_slice; // time slice for occupying the CPU
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* skew_heap_entry_t lab6_run_pool; // FOR LAB6 ONLY: the entry in the run pool
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* uint32_t lab6_stride; // FOR LAB6 ONLY: the current stride of the process
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* uint32_t lab6_priority; // FOR LAB6 ONLY: the priority of process, set by lab6_set_priority(uint32_t)
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*/
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//LAB8:EXERCISE2 YOUR CODE HINT:need add some code to init fs in proc_struct, ...
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}
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return proc;
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}
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// set_proc_name - set the name of proc
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char *
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set_proc_name(struct proc_struct *proc, const char *name) {
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memset(proc->name, 0, sizeof(proc->name));
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return memcpy(proc->name, name, PROC_NAME_LEN);
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}
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// get_proc_name - get the name of proc
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char *
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get_proc_name(struct proc_struct *proc) {
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static char name[PROC_NAME_LEN + 1];
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memset(name, 0, sizeof(name));
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return memcpy(name, proc->name, PROC_NAME_LEN);
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}
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// set_links - set the relation links of process
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static void
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set_links(struct proc_struct *proc) {
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list_add(&proc_list, &(proc->list_link));
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proc->yptr = NULL;
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if ((proc->optr = proc->parent->cptr) != NULL) {
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proc->optr->yptr = proc;
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}
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proc->parent->cptr = proc;
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nr_process ++;
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}
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// remove_links - clean the relation links of process
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static void
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remove_links(struct proc_struct *proc) {
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list_del(&(proc->list_link));
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if (proc->optr != NULL) {
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proc->optr->yptr = proc->yptr;
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}
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if (proc->yptr != NULL) {
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proc->yptr->optr = proc->optr;
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}
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else {
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proc->parent->cptr = proc->optr;
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}
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nr_process --;
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}
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// get_pid - alloc a unique pid for process
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static int
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get_pid(void) {
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static_assert(MAX_PID > MAX_PROCESS);
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struct proc_struct *proc;
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list_entry_t *list = &proc_list, *le;
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static int next_safe = MAX_PID, last_pid = MAX_PID;
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if (++ last_pid >= MAX_PID) {
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last_pid = 1;
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goto inside;
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}
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if (last_pid >= next_safe) {
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inside:
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next_safe = MAX_PID;
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repeat:
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le = list;
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while ((le = list_next(le)) != list) {
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proc = le2proc(le, list_link);
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if (proc->pid == last_pid) {
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if (++ last_pid >= next_safe) {
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if (last_pid >= MAX_PID) {
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last_pid = 1;
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}
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next_safe = MAX_PID;
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goto repeat;
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}
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}
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else if (proc->pid > last_pid && next_safe > proc->pid) {
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next_safe = proc->pid;
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}
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}
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}
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return last_pid;
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}
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// proc_run - make process "proc" running on cpu
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// NOTE: before call switch_to, should load base addr of "proc"'s new PDT
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void
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proc_run(struct proc_struct *proc) {
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if (proc != current) {
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bool intr_flag;
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struct proc_struct *prev = current, *next = proc;
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local_intr_save(intr_flag);
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{
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current = proc;
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load_esp0(next->kstack + KSTACKSIZE);
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lcr3(next->cr3);
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switch_to(&(prev->context), &(next->context));
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}
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local_intr_restore(intr_flag);
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}
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}
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// forkret -- the first kernel entry point of a new thread/process
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// NOTE: the addr of forkret is setted in copy_thread function
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// after switch_to, the current proc will execute here.
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static void
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forkret(void) {
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forkrets(current->tf);
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}
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// hash_proc - add proc into proc hash_list
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static void
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hash_proc(struct proc_struct *proc) {
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list_add(hash_list + pid_hashfn(proc->pid), &(proc->hash_link));
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}
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// unhash_proc - delete proc from proc hash_list
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static void
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unhash_proc(struct proc_struct *proc) {
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list_del(&(proc->hash_link));
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}
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// find_proc - find proc frome proc hash_list according to pid
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struct proc_struct *
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find_proc(int pid) {
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if (0 < pid && pid < MAX_PID) {
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list_entry_t *list = hash_list + pid_hashfn(pid), *le = list;
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while ((le = list_next(le)) != list) {
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struct proc_struct *proc = le2proc(le, hash_link);
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if (proc->pid == pid) {
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return proc;
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}
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}
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}
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return NULL;
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}
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// kernel_thread - create a kernel thread using "fn" function
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// NOTE: the contents of temp trapframe tf will be copied to
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// proc->tf in do_fork-->copy_thread function
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int
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kernel_thread(int (*fn)(void *), void *arg, uint32_t clone_flags) {
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struct trapframe tf;
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memset(&tf, 0, sizeof(struct trapframe));
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tf.tf_cs = KERNEL_CS;
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tf.tf_ds = tf.tf_es = tf.tf_ss = KERNEL_DS;
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tf.tf_regs.reg_ebx = (uint32_t)fn;
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tf.tf_regs.reg_edx = (uint32_t)arg;
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tf.tf_eip = (uint32_t)kernel_thread_entry;
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return do_fork(clone_flags | CLONE_VM, 0, &tf);
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}
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// setup_kstack - alloc pages with size KSTACKPAGE as process kernel stack
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static int
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setup_kstack(struct proc_struct *proc) {
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struct Page *page = alloc_pages(KSTACKPAGE);
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if (page != NULL) {
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proc->kstack = (uintptr_t)page2kva(page);
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return 0;
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}
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return -E_NO_MEM;
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}
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// put_kstack - free the memory space of process kernel stack
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static void
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put_kstack(struct proc_struct *proc) {
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free_pages(kva2page((void *)(proc->kstack)), KSTACKPAGE);
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}
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// setup_pgdir - alloc one page as PDT
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static int
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setup_pgdir(struct mm_struct *mm) {
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struct Page *page;
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if ((page = alloc_page()) == NULL) {
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return -E_NO_MEM;
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}
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pde_t *pgdir = page2kva(page);
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memcpy(pgdir, boot_pgdir, PGSIZE);
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pgdir[PDX(VPT)] = PADDR(pgdir) | PTE_P | PTE_W;
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mm->pgdir = pgdir;
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return 0;
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}
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// put_pgdir - free the memory space of PDT
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static void
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put_pgdir(struct mm_struct *mm) {
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free_page(kva2page(mm->pgdir));
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}
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// copy_mm - process "proc" duplicate OR share process "current"'s mm according clone_flags
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// - if clone_flags & CLONE_VM, then "share" ; else "duplicate"
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static int
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copy_mm(uint32_t clone_flags, struct proc_struct *proc) {
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struct mm_struct *mm, *oldmm = current->mm;
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/* current is a kernel thread */
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if (oldmm == NULL) {
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return 0;
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}
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if (clone_flags & CLONE_VM) {
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mm = oldmm;
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goto good_mm;
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}
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int ret = -E_NO_MEM;
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if ((mm = mm_create()) == NULL) {
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goto bad_mm;
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}
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if (setup_pgdir(mm) != 0) {
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goto bad_pgdir_cleanup_mm;
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}
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lock_mm(oldmm);
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{
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ret = dup_mmap(mm, oldmm);
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}
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unlock_mm(oldmm);
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if (ret != 0) {
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goto bad_dup_cleanup_mmap;
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}
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good_mm:
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mm_count_inc(mm);
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proc->mm = mm;
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proc->cr3 = PADDR(mm->pgdir);
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return 0;
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bad_dup_cleanup_mmap:
|
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exit_mmap(mm);
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put_pgdir(mm);
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bad_pgdir_cleanup_mm:
|
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mm_destroy(mm);
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bad_mm:
|
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return ret;
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}
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// copy_thread - setup the trapframe on the process's kernel stack top and
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// - setup the kernel entry point and stack of process
|
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static void
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copy_thread(struct proc_struct *proc, uintptr_t esp, struct trapframe *tf) {
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proc->tf = (struct trapframe *)(proc->kstack + KSTACKSIZE) - 1;
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*(proc->tf) = *tf;
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proc->tf->tf_regs.reg_eax = 0;
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proc->tf->tf_esp = esp;
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proc->tf->tf_eflags |= FL_IF;
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|
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proc->context.eip = (uintptr_t)forkret;
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proc->context.esp = (uintptr_t)(proc->tf);
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}
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|
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//copy_files&put_files function used by do_fork in LAB8
|
|
//copy the files_struct from current to proc
|
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static int
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copy_files(uint32_t clone_flags, struct proc_struct *proc) {
|
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struct files_struct *filesp, *old_filesp = current->filesp;
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assert(old_filesp != NULL);
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if (clone_flags & CLONE_FS) {
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filesp = old_filesp;
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goto good_files_struct;
|
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}
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|
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int ret = -E_NO_MEM;
|
|
if ((filesp = files_create()) == NULL) {
|
|
goto bad_files_struct;
|
|
}
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|
|
if ((ret = dup_files(filesp, old_filesp)) != 0) {
|
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goto bad_dup_cleanup_fs;
|
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}
|
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|
|
good_files_struct:
|
|
files_count_inc(filesp);
|
|
proc->filesp = filesp;
|
|
return 0;
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|
|
bad_dup_cleanup_fs:
|
|
files_destroy(filesp);
|
|
bad_files_struct:
|
|
return ret;
|
|
}
|
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|
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//decrease the ref_count of files, and if ref_count==0, then destroy files_struct
|
|
static void
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put_files(struct proc_struct *proc) {
|
|
struct files_struct *filesp = proc->filesp;
|
|
if (filesp != NULL) {
|
|
if (files_count_dec(filesp) == 0) {
|
|
files_destroy(filesp);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* do_fork - parent process for a new child process
|
|
* @clone_flags: used to guide how to clone the child process
|
|
* @stack: the parent's user stack pointer. if stack==0, It means to fork a kernel thread.
|
|
* @tf: the trapframe info, which will be copied to child process's proc->tf
|
|
*/
|
|
int
|
|
do_fork(uint32_t clone_flags, uintptr_t stack, struct trapframe *tf) {
|
|
int ret = -E_NO_FREE_PROC;
|
|
struct proc_struct *proc;
|
|
if (nr_process >= MAX_PROCESS) {
|
|
goto fork_out;
|
|
}
|
|
ret = -E_NO_MEM;
|
|
//LAB4:EXERCISE2 YOUR CODE
|
|
//LAB8:EXERCISE2 YOUR CODE HINT:how to copy the fs in parent's proc_struct?
|
|
/*
|
|
* Some Useful MACROs, Functions and DEFINEs, you can use them in below implementation.
|
|
* MACROs or Functions:
|
|
* alloc_proc: create a proc struct and init fields (lab4:exercise1)
|
|
* setup_kstack: alloc pages with size KSTACKPAGE as process kernel stack
|
|
* copy_mm: process "proc" duplicate OR share process "current"'s mm according clone_flags
|
|
* if clone_flags & CLONE_VM, then "share" ; else "duplicate"
|
|
* copy_thread: setup the trapframe on the process's kernel stack top and
|
|
* setup the kernel entry point and stack of process
|
|
* hash_proc: add proc into proc hash_list
|
|
* get_pid: alloc a unique pid for process
|
|
* wakeup_proc: set proc->state = PROC_RUNNABLE
|
|
* VARIABLES:
|
|
* proc_list: the process set's list
|
|
* nr_process: the number of process set
|
|
*/
|
|
|
|
// 1. call alloc_proc to allocate a proc_struct
|
|
// 2. call setup_kstack to allocate a kernel stack for child process
|
|
// 3. call copy_mm to dup OR share mm according clone_flag
|
|
// 4. call copy_thread to setup tf & context in proc_struct
|
|
// 5. insert proc_struct into hash_list && proc_list
|
|
// 6. call wakeup_proc to make the new child process RUNNABLE
|
|
// 7. set ret vaule using child proc's pid
|
|
|
|
//LAB5 YOUR CODE : (update LAB4 steps)
|
|
/* Some Functions
|
|
* set_links: set the relation links of process. ALSO SEE: remove_links: lean the relation links of process
|
|
* -------------------
|
|
* update step 1: set child proc's parent to current process, make sure current process's wait_state is 0
|
|
* update step 5: insert proc_struct into hash_list && proc_list, set the relation links of process
|
|
*/
|
|
|
|
fork_out:
|
|
return ret;
|
|
|
|
bad_fork_cleanup_fs: //for LAB8
|
|
put_files(proc);
|
|
bad_fork_cleanup_kstack:
|
|
put_kstack(proc);
|
|
bad_fork_cleanup_proc:
|
|
kfree(proc);
|
|
goto fork_out;
|
|
}
|
|
|
|
// do_exit - called by sys_exit
|
|
// 1. call exit_mmap & put_pgdir & mm_destroy to free the almost all memory space of process
|
|
// 2. set process' state as PROC_ZOMBIE, then call wakeup_proc(parent) to ask parent reclaim itself.
|
|
// 3. call scheduler to switch to other process
|
|
int
|
|
do_exit(int error_code) {
|
|
if (current == idleproc) {
|
|
panic("idleproc exit.\n");
|
|
}
|
|
if (current == initproc) {
|
|
panic("initproc exit.\n");
|
|
}
|
|
|
|
struct mm_struct *mm = current->mm;
|
|
if (mm != NULL) {
|
|
lcr3(boot_cr3);
|
|
if (mm_count_dec(mm) == 0) {
|
|
exit_mmap(mm);
|
|
put_pgdir(mm);
|
|
mm_destroy(mm);
|
|
}
|
|
current->mm = NULL;
|
|
}
|
|
put_files(current); //for LAB8
|
|
current->state = PROC_ZOMBIE;
|
|
current->exit_code = error_code;
|
|
|
|
bool intr_flag;
|
|
struct proc_struct *proc;
|
|
local_intr_save(intr_flag);
|
|
{
|
|
proc = current->parent;
|
|
if (proc->wait_state == WT_CHILD) {
|
|
wakeup_proc(proc);
|
|
}
|
|
while (current->cptr != NULL) {
|
|
proc = current->cptr;
|
|
current->cptr = proc->optr;
|
|
|
|
proc->yptr = NULL;
|
|
if ((proc->optr = initproc->cptr) != NULL) {
|
|
initproc->cptr->yptr = proc;
|
|
}
|
|
proc->parent = initproc;
|
|
initproc->cptr = proc;
|
|
if (proc->state == PROC_ZOMBIE) {
|
|
if (initproc->wait_state == WT_CHILD) {
|
|
wakeup_proc(initproc);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
local_intr_restore(intr_flag);
|
|
|
|
schedule();
|
|
panic("do_exit will not return!! %d.\n", current->pid);
|
|
}
|
|
|
|
//load_icode_read is used by load_icode in LAB8
|
|
static int
|
|
load_icode_read(int fd, void *buf, size_t len, off_t offset) {
|
|
int ret;
|
|
if ((ret = sysfile_seek(fd, offset, LSEEK_SET)) != 0) {
|
|
return ret;
|
|
}
|
|
if ((ret = sysfile_read(fd, buf, len)) != len) {
|
|
return (ret < 0) ? ret : -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
// load_icode - called by sys_exec-->do_execve
|
|
|
|
static int
|
|
load_icode(int fd, int argc, char **kargv) {
|
|
/* LAB8:EXERCISE2 YOUR CODE HINT:how to load the file with handler fd in to process's memory? how to setup argc/argv?
|
|
* MACROs or Functions:
|
|
* mm_create - create a mm
|
|
* setup_pgdir - setup pgdir in mm
|
|
* load_icode_read - read raw data content of program file
|
|
* mm_map - build new vma
|
|
* pgdir_alloc_page - allocate new memory for TEXT/DATA/BSS/stack parts
|
|
* lcr3 - update Page Directory Addr Register -- CR3
|
|
*/
|
|
/* (1) create a new mm for current process
|
|
* (2) create a new PDT, and mm->pgdir= kernel virtual addr of PDT
|
|
* (3) copy TEXT/DATA/BSS parts in binary to memory space of process
|
|
* (3.1) read raw data content in file and resolve elfhdr
|
|
* (3.2) read raw data content in file and resolve proghdr based on info in elfhdr
|
|
* (3.3) call mm_map to build vma related to TEXT/DATA
|
|
* (3.4) callpgdir_alloc_page to allocate page for TEXT/DATA, read contents in file
|
|
* and copy them into the new allocated pages
|
|
* (3.5) callpgdir_alloc_page to allocate pages for BSS, memset zero in these pages
|
|
* (4) call mm_map to setup user stack, and put parameters into user stack
|
|
* (5) setup current process's mm, cr3, reset pgidr (using lcr3 MARCO)
|
|
* (6) setup uargc and uargv in user stacks
|
|
* (7) setup trapframe for user environment
|
|
* (8) if up steps failed, you should cleanup the env.
|
|
*/
|
|
}
|
|
|
|
// this function isn't very correct in LAB8
|
|
static void
|
|
put_kargv(int argc, char **kargv) {
|
|
while (argc > 0) {
|
|
kfree(kargv[-- argc]);
|
|
}
|
|
}
|
|
|
|
static int
|
|
copy_kargv(struct mm_struct *mm, int argc, char **kargv, const char **argv) {
|
|
int i, ret = -E_INVAL;
|
|
if (!user_mem_check(mm, (uintptr_t)argv, sizeof(const char *) * argc, 0)) {
|
|
return ret;
|
|
}
|
|
for (i = 0; i < argc; i ++) {
|
|
char *buffer;
|
|
if ((buffer = kmalloc(EXEC_MAX_ARG_LEN + 1)) == NULL) {
|
|
goto failed_nomem;
|
|
}
|
|
if (!copy_string(mm, buffer, argv[i], EXEC_MAX_ARG_LEN + 1)) {
|
|
kfree(buffer);
|
|
goto failed_cleanup;
|
|
}
|
|
kargv[i] = buffer;
|
|
}
|
|
return 0;
|
|
|
|
failed_nomem:
|
|
ret = -E_NO_MEM;
|
|
failed_cleanup:
|
|
put_kargv(i, kargv);
|
|
return ret;
|
|
}
|
|
|
|
// do_execve - call exit_mmap(mm)&put_pgdir(mm) to reclaim memory space of current process
|
|
// - call load_icode to setup new memory space accroding binary prog.
|
|
int
|
|
do_execve(const char *name, int argc, const char **argv) {
|
|
static_assert(EXEC_MAX_ARG_LEN >= FS_MAX_FPATH_LEN);
|
|
struct mm_struct *mm = current->mm;
|
|
if (!(argc >= 1 && argc <= EXEC_MAX_ARG_NUM)) {
|
|
return -E_INVAL;
|
|
}
|
|
|
|
char local_name[PROC_NAME_LEN + 1];
|
|
memset(local_name, 0, sizeof(local_name));
|
|
|
|
char *kargv[EXEC_MAX_ARG_NUM];
|
|
const char *path;
|
|
|
|
int ret = -E_INVAL;
|
|
|
|
lock_mm(mm);
|
|
if (name == NULL) {
|
|
snprintf(local_name, sizeof(local_name), "<null> %d", current->pid);
|
|
}
|
|
else {
|
|
if (!copy_string(mm, local_name, name, sizeof(local_name))) {
|
|
unlock_mm(mm);
|
|
return ret;
|
|
}
|
|
}
|
|
if ((ret = copy_kargv(mm, argc, kargv, argv)) != 0) {
|
|
unlock_mm(mm);
|
|
return ret;
|
|
}
|
|
path = argv[0];
|
|
unlock_mm(mm);
|
|
files_closeall(current->filesp);
|
|
|
|
/* sysfile_open will check the first argument path, thus we have to use a user-space pointer, and argv[0] may be incorrect */
|
|
int fd;
|
|
if ((ret = fd = sysfile_open(path, O_RDONLY)) < 0) {
|
|
goto execve_exit;
|
|
}
|
|
if (mm != NULL) {
|
|
lcr3(boot_cr3);
|
|
if (mm_count_dec(mm) == 0) {
|
|
exit_mmap(mm);
|
|
put_pgdir(mm);
|
|
mm_destroy(mm);
|
|
}
|
|
current->mm = NULL;
|
|
}
|
|
ret= -E_NO_MEM;;
|
|
if ((ret = load_icode(fd, argc, kargv)) != 0) {
|
|
goto execve_exit;
|
|
}
|
|
put_kargv(argc, kargv);
|
|
set_proc_name(current, local_name);
|
|
return 0;
|
|
|
|
execve_exit:
|
|
put_kargv(argc, kargv);
|
|
do_exit(ret);
|
|
panic("already exit: %e.\n", ret);
|
|
}
|
|
|
|
// do_yield - ask the scheduler to reschedule
|
|
int
|
|
do_yield(void) {
|
|
current->need_resched = 1;
|
|
return 0;
|
|
}
|
|
|
|
// do_wait - wait one OR any children with PROC_ZOMBIE state, and free memory space of kernel stack
|
|
// - proc struct of this child.
|
|
// NOTE: only after do_wait function, all resources of the child proces are free.
|
|
int
|
|
do_wait(int pid, int *code_store) {
|
|
struct mm_struct *mm = current->mm;
|
|
if (code_store != NULL) {
|
|
if (!user_mem_check(mm, (uintptr_t)code_store, sizeof(int), 1)) {
|
|
return -E_INVAL;
|
|
}
|
|
}
|
|
|
|
struct proc_struct *proc;
|
|
bool intr_flag, haskid;
|
|
repeat:
|
|
haskid = 0;
|
|
if (pid != 0) {
|
|
proc = find_proc(pid);
|
|
if (proc != NULL && proc->parent == current) {
|
|
haskid = 1;
|
|
if (proc->state == PROC_ZOMBIE) {
|
|
goto found;
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
proc = current->cptr;
|
|
for (; proc != NULL; proc = proc->optr) {
|
|
haskid = 1;
|
|
if (proc->state == PROC_ZOMBIE) {
|
|
goto found;
|
|
}
|
|
}
|
|
}
|
|
if (haskid) {
|
|
current->state = PROC_SLEEPING;
|
|
current->wait_state = WT_CHILD;
|
|
schedule();
|
|
if (current->flags & PF_EXITING) {
|
|
do_exit(-E_KILLED);
|
|
}
|
|
goto repeat;
|
|
}
|
|
return -E_BAD_PROC;
|
|
|
|
found:
|
|
if (proc == idleproc || proc == initproc) {
|
|
panic("wait idleproc or initproc.\n");
|
|
}
|
|
if (code_store != NULL) {
|
|
*code_store = proc->exit_code;
|
|
}
|
|
local_intr_save(intr_flag);
|
|
{
|
|
unhash_proc(proc);
|
|
remove_links(proc);
|
|
}
|
|
local_intr_restore(intr_flag);
|
|
put_kstack(proc);
|
|
kfree(proc);
|
|
return 0;
|
|
}
|
|
|
|
// do_kill - kill process with pid by set this process's flags with PF_EXITING
|
|
int
|
|
do_kill(int pid) {
|
|
struct proc_struct *proc;
|
|
if ((proc = find_proc(pid)) != NULL) {
|
|
if (!(proc->flags & PF_EXITING)) {
|
|
proc->flags |= PF_EXITING;
|
|
if (proc->wait_state & WT_INTERRUPTED) {
|
|
wakeup_proc(proc);
|
|
}
|
|
return 0;
|
|
}
|
|
return -E_KILLED;
|
|
}
|
|
return -E_INVAL;
|
|
}
|
|
|
|
// kernel_execve - do SYS_exec syscall to exec a user program called by user_main kernel_thread
|
|
static int
|
|
kernel_execve(const char *name, const char **argv) {
|
|
int argc = 0, ret;
|
|
while (argv[argc] != NULL) {
|
|
argc ++;
|
|
}
|
|
asm volatile (
|
|
"int %1;"
|
|
: "=a" (ret)
|
|
: "i" (T_SYSCALL), "0" (SYS_exec), "d" (name), "c" (argc), "b" (argv)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
#define __KERNEL_EXECVE(name, path, ...) ({ \
|
|
const char *argv[] = {path, ##__VA_ARGS__, NULL}; \
|
|
cprintf("kernel_execve: pid = %d, name = \"%s\".\n", \
|
|
current->pid, name); \
|
|
kernel_execve(name, argv); \
|
|
})
|
|
|
|
#define KERNEL_EXECVE(x, ...) __KERNEL_EXECVE(#x, #x, ##__VA_ARGS__)
|
|
|
|
#define KERNEL_EXECVE2(x, ...) KERNEL_EXECVE(x, ##__VA_ARGS__)
|
|
|
|
#define __KERNEL_EXECVE3(x, s, ...) KERNEL_EXECVE(x, #s, ##__VA_ARGS__)
|
|
|
|
#define KERNEL_EXECVE3(x, s, ...) __KERNEL_EXECVE3(x, s, ##__VA_ARGS__)
|
|
|
|
// user_main - kernel thread used to exec a user program
|
|
static int
|
|
user_main(void *arg) {
|
|
#ifdef TEST
|
|
#ifdef TESTSCRIPT
|
|
KERNEL_EXECVE3(TEST, TESTSCRIPT);
|
|
#else
|
|
KERNEL_EXECVE2(TEST);
|
|
#endif
|
|
#else
|
|
KERNEL_EXECVE(sh);
|
|
#endif
|
|
panic("user_main execve failed.\n");
|
|
}
|
|
|
|
// init_main - the second kernel thread used to create user_main kernel threads
|
|
static int
|
|
init_main(void *arg) {
|
|
int ret;
|
|
if ((ret = vfs_set_bootfs("disk0:")) != 0) {
|
|
panic("set boot fs failed: %e.\n", ret);
|
|
}
|
|
|
|
size_t nr_free_pages_store = nr_free_pages();
|
|
size_t kernel_allocated_store = kallocated();
|
|
|
|
int pid = kernel_thread(user_main, NULL, 0);
|
|
if (pid <= 0) {
|
|
panic("create user_main failed.\n");
|
|
}
|
|
extern void check_sync(void);
|
|
check_sync(); // check philosopher sync problem
|
|
|
|
while (do_wait(0, NULL) == 0) {
|
|
schedule();
|
|
}
|
|
|
|
fs_cleanup();
|
|
|
|
cprintf("all user-mode processes have quit.\n");
|
|
assert(initproc->cptr == NULL && initproc->yptr == NULL && initproc->optr == NULL);
|
|
assert(nr_process == 2);
|
|
assert(list_next(&proc_list) == &(initproc->list_link));
|
|
assert(list_prev(&proc_list) == &(initproc->list_link));
|
|
|
|
cprintf("init check memory pass.\n");
|
|
return 0;
|
|
}
|
|
|
|
// proc_init - set up the first kernel thread idleproc "idle" by itself and
|
|
// - create the second kernel thread init_main
|
|
void
|
|
proc_init(void) {
|
|
int i;
|
|
|
|
list_init(&proc_list);
|
|
for (i = 0; i < HASH_LIST_SIZE; i ++) {
|
|
list_init(hash_list + i);
|
|
}
|
|
|
|
if ((idleproc = alloc_proc()) == NULL) {
|
|
panic("cannot alloc idleproc.\n");
|
|
}
|
|
|
|
idleproc->pid = 0;
|
|
idleproc->state = PROC_RUNNABLE;
|
|
idleproc->kstack = (uintptr_t)bootstack;
|
|
idleproc->need_resched = 1;
|
|
|
|
if ((idleproc->filesp = files_create()) == NULL) {
|
|
panic("create filesp (idleproc) failed.\n");
|
|
}
|
|
files_count_inc(idleproc->filesp);
|
|
|
|
set_proc_name(idleproc, "idle");
|
|
nr_process ++;
|
|
|
|
current = idleproc;
|
|
|
|
int pid = kernel_thread(init_main, NULL, 0);
|
|
if (pid <= 0) {
|
|
panic("create init_main failed.\n");
|
|
}
|
|
|
|
initproc = find_proc(pid);
|
|
set_proc_name(initproc, "init");
|
|
|
|
assert(idleproc != NULL && idleproc->pid == 0);
|
|
assert(initproc != NULL && initproc->pid == 1);
|
|
}
|
|
|
|
// cpu_idle - at the end of kern_init, the first kernel thread idleproc will do below works
|
|
void
|
|
cpu_idle(void) {
|
|
while (1) {
|
|
if (current->need_resched) {
|
|
schedule();
|
|
}
|
|
}
|
|
}
|
|
|
|
//FOR LAB6, set the process's priority (bigger value will get more CPU time)
|
|
void
|
|
lab6_set_priority(uint32_t priority)
|
|
{
|
|
if (priority == 0)
|
|
current->lab6_priority = 1;
|
|
else current->lab6_priority = priority;
|
|
}
|
|
|
|
// do_sleep - set current process state to sleep and add timer with "time"
|
|
// - then call scheduler. if process run again, delete timer first.
|
|
int
|
|
do_sleep(unsigned int time) {
|
|
if (time == 0) {
|
|
return 0;
|
|
}
|
|
bool intr_flag;
|
|
local_intr_save(intr_flag);
|
|
timer_t __timer, *timer = timer_init(&__timer, current, time);
|
|
current->state = PROC_SLEEPING;
|
|
current->wait_state = WT_TIMER;
|
|
add_timer(timer);
|
|
local_intr_restore(intr_flag);
|
|
|
|
schedule();
|
|
|
|
del_timer(timer);
|
|
return 0;
|
|
}
|