kern

changeset 72:3941e82b07f2
- implemented syscalls: exit, waitpid, getppid - moved sys_whatever functions out of syscall.c into more reasonable files - putting all the definitions that must be synced with userland to include/kdef.h
author: John Tsiombikas <nuclear@member.fsf.org>
date: Sat, 15 Oct 2011 07:45:56 +0300
parents: c7bd6ec7b946
children: b4b7198986a6
files: Makefile include/kdef.h src/klibc/errno.h src/proc.c src/proc.h src/sched.c src/sched.h src/syscall.c src/syscall.h src/timer.c src/timer.h src/vm.c src/vm.h
diffstat: 13 files changed, 265 insertions(+), 44 deletions(-) [+]
[-]

Makefile 6

include/kdef.h 55

src/klibc/errno.h 5

src/proc.c 129

src/proc.h 12

src/sched.c 14

src/sched.h 1

src/syscall.c 38

src/syscall.h 11

src/timer.c 11

src/timer.h 1

src/vm.c 22

src/vm.h 4 Makefile 6 include/kdef.h 55 src/klibc/errno.h 5 src/proc.c 129 src/proc.h 12 src/sched.c 14 src/sched.h 1 src/syscall.c 38 src/syscall.h 11 src/timer.c 11 src/timer.h 1 src/vm.c 22 src/vm.h 4
Makefile 6
include/kdef.h 55
     1.1 --- a/Makefile	Thu Oct 13 05:22:35 2011 +0300
     1.2 +++ b/Makefile	Sat Oct 15 07:45:56 2011 +0300
     1.3 @@ -1,4 +1,5 @@
     1.4  ifneq ($(shell uname -m), i386)
     1.5 +	# -m32 instructs the compiler to produce 32bit code
     1.6  	ccemu = -m32
     1.7  
     1.8  	ifeq ($(shell uname -s), FreeBSD)
     1.9 @@ -18,11 +19,10 @@
    1.10  
    1.11  CC = gcc
    1.12  
    1.13 -inc = -Isrc -Isrc/klibc -Isrc/boot
    1.14 +inc = -Isrc -Isrc/klibc -Isrc/boot -Iinclude
    1.15  
    1.16  # -nostdinc instructs the compiler to ignore standard include directories
    1.17 -# -m32 instructs the compiler to produce 32bit code (in case we have a 64bit compiler)
    1.18 -CFLAGS = $(ccemu) -Wall -g -nostdinc -fno-builtin $(inc)
    1.19 +CFLAGS = $(ccemu) -Wall -g -nostdinc -fno-builtin $(inc) -DKERNEL
    1.20  ASFLAGS = $(ccemu) -g -nostdinc -fno-builtin $(inc)
    1.21  
    1.22  bin = kernel.elf

     2.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     2.2 +++ b/include/kdef.h	Sat Oct 15 07:45:56 2011 +0300
     2.3 @@ -0,0 +1,55 @@
     2.4 +/* definitions that must be in-sync between kernel and user space */
     2.5 +#ifndef KERNEL_DEFS_H_
     2.6 +#define KERNEL_DEFS_H_
     2.7 +
     2.8 +/* --- defines for sys/wait.h */
     2.9 +#if defined(KERNEL) || defined(KDEF_WAIT_H)
    2.10 +#define WNOHANG		1
    2.11 +
    2.12 +#define WEXITSTATUS(s)	((s) & _WSTATUS_MASK)
    2.13 +#define WCOREDUMP(s)	((s) & _WCORE_BIT)
    2.14 +
    2.15 +#define WIFEXITED(s)	(_WREASON(s) == _WREASON_EXITED)
    2.16 +#define WIFSIGNALED(s)	(_WREASON(s) == _WREASON_SIGNALED)
    2.17 +
    2.18 +/* implementation details */
    2.19 +#define _WSTATUS_MASK		0xff
    2.20 +
    2.21 +#define _WREASON_SHIFT		8
    2.22 +#define _WREASON_MASK		0xf00
    2.23 +#define _WREASON(s)			(((s) & _WREASON_MASK) >> _WREASON_SHIFT)
    2.24 +
    2.25 +#define _WREASON_EXITED		1
    2.26 +#define _WREASON_SIGNALED	2
    2.27 +
    2.28 +#define _WCORE_BIT			0x1000
    2.29 +#endif	/* sys/wait.h */
    2.30 +
    2.31 +
    2.32 +
    2.33 +/* --- defines for errno.h */
    2.34 +#if defined(KERNEL) || defined(KDEF_ERRNO_H)
    2.35 +#define EAGAIN		1
    2.36 +#define EINVAL		2
    2.37 +#define ECHILD		3
    2.38 +#endif	/* errno.h */
    2.39 +
    2.40 +
    2.41 +/* --- defines for syscall.h */
    2.42 +#if defined(KERNEL) || defined(KDEF_SYSCALL_H)
    2.43 +
    2.44 +#define SYSCALL_INT		0x80
    2.45 +
    2.46 +#define SYS_HELLO		0
    2.47 +#define SYS_SLEEP		1
    2.48 +#define SYS_FORK		2
    2.49 +#define SYS_EXIT		3
    2.50 +#define SYS_WAITPID		4
    2.51 +#define SYS_GETPID		5
    2.52 +#define SYS_GETPPID		6
    2.53 +
    2.54 +#define NUM_SYSCALLS	7
    2.55 +
    2.56 +#endif	/* syscall.h */
    2.57 +
    2.58 +#endif	/* KERNEL_DEFS_H_ */

     3.1 --- a/src/klibc/errno.h	Thu Oct 13 05:22:35 2011 +0300
     3.2 +++ b/src/klibc/errno.h	Sat Oct 15 07:45:56 2011 +0300
     3.3 @@ -1,6 +1,9 @@
     3.4  #ifndef ERRNO_H_
     3.5  #define ERRNO_H_
     3.6  
     3.7 -#define EAGAIN		1
     3.8 +/* all kernel-definitions that should be shared with user space
     3.9 + * are in include/kdef.h
    3.10 + */
    3.11 +#include "kdef.h"
    3.12  
    3.13  #endif	/* ERRNO_H_ */

     4.1 --- a/src/proc.c	Thu Oct 13 05:22:35 2011 +0300
     4.2 +++ b/src/proc.c	Sat Oct 15 07:45:56 2011 +0300
     4.3 @@ -12,6 +12,7 @@
     4.4  #include "syscall.h"
     4.5  #include "sched.h"
     4.6  #include "tss.h"
     4.7 +#include "kdef.h"
     4.8  
     4.9  #define	FLAGS_INTR_BIT	(1 << 9)
    4.10  
    4.11 @@ -138,7 +139,7 @@
    4.12  	intr_ret(ifrm);
    4.13  }
    4.14  
    4.15 -int fork(void)
    4.16 +int sys_fork(void)
    4.17  {
    4.18  	int i, pid;
    4.19  	struct process *p, *parent;
    4.20 @@ -189,8 +190,13 @@
    4.21  	/* initialize the rest of the process structure */
    4.22  	p->id = pid;
    4.23  	p->parent = parent->id;
    4.24 +	p->child_list = 0;
    4.25  	p->next = p->prev = 0;
    4.26  
    4.27 +	/* add to the child list */
    4.28 +	p->sib_next = parent->child_list;
    4.29 +	parent->child_list = p;
    4.30 +
    4.31  	/* will be copied on write */
    4.32  	p->user_stack_pg = parent->user_stack_pg;
    4.33  
    4.34 @@ -203,6 +209,105 @@
    4.35  	return pid;
    4.36  }
    4.37  
    4.38 +int sys_exit(int status)
    4.39 +{
    4.40 +	struct process *p, *child;
    4.41 +
    4.42 +	p = get_current_proc();
    4.43 +
    4.44 +	/* TODO deliver SIGCHLD to the parent */
    4.45 +
    4.46 +	/* find any child processes and make init adopt them */
    4.47 +	child = p->child_list;
    4.48 +	while(child) {
    4.49 +		child->parent = 1;
    4.50 +		child = child->sib_next;
    4.51 +	}
    4.52 +
    4.53 +	cleanup_vm(p);
    4.54 +
    4.55 +	/* remove it from the runqueue */
    4.56 +	remove_proc(p->id);
    4.57 +
    4.58 +	/* make it a zombie until its parent reaps it */
    4.59 +	p->state = STATE_ZOMBIE;
    4.60 +	p->exit_status = (status & _WSTATUS_MASK) | (_WREASON_EXITED << _WREASON_SHIFT);
    4.61 +
    4.62 +	/* wakeup any processes waiting for it
    4.63 +	 * we're waking up the parent's address, because waitpid waits
    4.64 +	 * on it's own process struct, not knowing which child will die
    4.65 +	 * first.
    4.66 +	 */
    4.67 +	wakeup(get_process(p->parent));
    4.68 +	return 0;
    4.69 +}
    4.70 +
    4.71 +int sys_waitpid(int pid, int *status, int opt)
    4.72 +{
    4.73 +	struct process *p, *child;
    4.74 +
    4.75 +	p = get_current_proc();
    4.76 +
    4.77 +restart:
    4.78 +	if(pid <= 0) {
    4.79 +		/* search for zombie children */
    4.80 +		child = p->child_list;
    4.81 +		while(child) {
    4.82 +			if(child->state == STATE_ZOMBIE) {
    4.83 +				break;
    4.84 +			}
    4.85 +			child = child->sib_next;
    4.86 +		}
    4.87 +	} else {
    4.88 +		if(!(child = get_process(pid)) || child->parent != p->id) {
    4.89 +			return -ECHILD;
    4.90 +		}
    4.91 +		if(child->state != STATE_ZOMBIE) {
    4.92 +			child = 0;
    4.93 +		}
    4.94 +	}
    4.95 +
    4.96 +	/* found ? */
    4.97 +	if(child) {
    4.98 +		int res;
    4.99 +		struct process *prev, dummy;
   4.100 +
   4.101 +		if(status) {
   4.102 +			*status = child->exit_status;
   4.103 +		}
   4.104 +		res = child->id;
   4.105 +
   4.106 +		/* remove it from our children list */
   4.107 +		dummy.sib_next = p->child_list;
   4.108 +		prev = &dummy;
   4.109 +		while(prev->next) {
   4.110 +			if(prev->next == child) {
   4.111 +				prev->next = child->next;
   4.112 +				break;
   4.113 +			}
   4.114 +		}
   4.115 +		p->child_list = dummy.next;
   4.116 +
   4.117 +		/* invalidate the id */
   4.118 +		child->id = 0;
   4.119 +		return res;
   4.120 +	}
   4.121 +
   4.122 +	/* not found, wait or sod off */
   4.123 +	if(!(opt & WNOHANG)) {
   4.124 +		/* wait on our own process struct because
   4.125 +		 * we have no way of knowing which child will
   4.126 +		 * die first.
   4.127 +		 * exit will wakeup the parent structure...
   4.128 +		 */
   4.129 +		wait(p);
   4.130 +		/* done waiting, restart waitpid */
   4.131 +		goto restart;
   4.132 +	}
   4.133 +
   4.134 +	return 0;	/* he's not dead jim */
   4.135 +}
   4.136 +
   4.137  void context_switch(int pid)
   4.138  {
   4.139  	static struct process *prev, *new;
   4.140 @@ -262,5 +367,25 @@
   4.141  
   4.142  struct process *get_process(int pid)
   4.143  {
   4.144 -	return &proc[pid];
   4.145 +	struct process *p = proc + pid;
   4.146 +	if(p->id != pid) {
   4.147 +		printf("get_process called with invalid pid: %d\n", pid);
   4.148 +		return 0;
   4.149 +	}
   4.150 +	return p;
   4.151  }
   4.152 +
   4.153 +int sys_getpid(void)
   4.154 +{
   4.155 +	return cur_pid;
   4.156 +}
   4.157 +
   4.158 +int sys_getppid(void)
   4.159 +{
   4.160 +	struct process *p = get_current_proc();
   4.161 +
   4.162 +	if(!p) {
   4.163 +		return 0;
   4.164 +	}
   4.165 +	return p->parent;
   4.166 +}

     5.1 --- a/src/proc.h	Thu Oct 13 05:22:35 2011 +0300
     5.2 +++ b/src/proc.h	Sat Oct 15 07:45:56 2011 +0300
     5.3 @@ -27,6 +27,8 @@
     5.4  	int id, parent;
     5.5  	enum proc_state state;
     5.6  
     5.7 +	int exit_status;
     5.8 +
     5.9  	/* when blocked it's waiting for a wakeup on this address */
    5.10  	void *wait_addr;
    5.11  
    5.12 @@ -44,12 +46,17 @@
    5.13  
    5.14  	struct context ctx;
    5.15  
    5.16 +	struct process *child_list;
    5.17 +
    5.18  	struct process *next, *prev;	/* for the scheduler queues */
    5.19 +	struct process *sib_next;		/* for the sibling list */
    5.20  };
    5.21  
    5.22  void init_proc(void);
    5.23  
    5.24 -int fork(void);
    5.25 +int sys_fork(void);
    5.26 +int sys_exit(int status);
    5.27 +int sys_waitpid(int pid, int *status, int opt);
    5.28  
    5.29  void context_switch(int pid);
    5.30  
    5.31 @@ -58,6 +65,9 @@
    5.32  struct process *get_current_proc(void);
    5.33  struct process *get_process(int pid);
    5.34  
    5.35 +int sys_getpid(void);
    5.36 +int sys_getppid(void);
    5.37 +
    5.38  /* defined in proc-asm.S */
    5.39  uint32_t get_instr_ptr(void);
    5.40  uint32_t get_caller_instr_ptr(void);

     6.1 --- a/src/sched.c	Thu Oct 13 05:22:35 2011 +0300
     6.2 +++ b/src/sched.c	Sat Oct 15 07:45:56 2011 +0300
     6.3 @@ -75,6 +75,20 @@
     6.4  	set_intr_state(istate);
     6.5  }
     6.6  
     6.7 +void remove_proc(int pid)
     6.8 +{
     6.9 +	int istate;
    6.10 +	struct process *proc;
    6.11 +
    6.12 +	istate = get_intr_state();
    6.13 +	disable_intr();
    6.14 +
    6.15 +	proc = get_process(pid);
    6.16 +	remove(&runq, proc);
    6.17 +
    6.18 +	set_intr_state(istate);
    6.19 +}
    6.20 +
    6.21  /* block the process until we get a wakeup call for address ev */
    6.22  void wait(void *wait_addr)
    6.23  {

     7.1 --- a/src/sched.h	Thu Oct 13 05:22:35 2011 +0300
     7.2 +++ b/src/sched.h	Sat Oct 15 07:45:56 2011 +0300
     7.3 @@ -6,6 +6,7 @@
     7.4  void schedule(void);
     7.5  
     7.6  void add_proc(int pid);
     7.7 +void remove_proc(int pid);
     7.8  
     7.9  void wait(void *wait_addr);
    7.10  void wakeup(void *wait_addr);

     8.1 --- a/src/syscall.c	Thu Oct 13 05:22:35 2011 +0300
     8.2 +++ b/src/syscall.c	Sat Oct 15 07:45:56 2011 +0300
     8.3 @@ -10,16 +10,16 @@
     8.4  static void syscall(int inum);
     8.5  
     8.6  static int sys_hello(void);
     8.7 -static int sys_sleep(int sec);
     8.8 -static int sys_fork(void);
     8.9 -static int sys_getpid(void);
    8.10  
    8.11  void init_syscall(void)
    8.12  {
    8.13  	sys_func[SYS_HELLO] = sys_hello;
    8.14 -	sys_func[SYS_SLEEP] = sys_sleep;
    8.15 -	sys_func[SYS_FORK] = sys_fork;
    8.16 -	sys_func[SYS_GETPID] = sys_getpid;
    8.17 +	sys_func[SYS_SLEEP] = sys_sleep;		/* timer.c */
    8.18 +	sys_func[SYS_FORK] = sys_fork;			/* proc.c */
    8.19 +	sys_func[SYS_EXIT] = sys_exit;			/* proc.c */
    8.20 +	sys_func[SYS_WAITPID] = sys_waitpid;	/* proc.c */
    8.21 +	sys_func[SYS_GETPID] = sys_getpid;		/* proc.c */
    8.22 +	sys_func[SYS_GETPPID] = sys_getppid;	/* proc.c */
    8.23  
    8.24  	interrupt(SYSCALL_INT, syscall);
    8.25  }
    8.26 @@ -41,6 +41,12 @@
    8.27  	 * so that it'll be restored into eax before returning to userland.
    8.28  	 */
    8.29  	frm->regs.eax = sys_func[idx](frm->regs.ebx, frm->regs.ecx, frm->regs.edx, frm->regs.esi, frm->regs.edi);
    8.30 +
    8.31 +	/* we don't necessarily want to return to the same process
    8.32 +	 * might have blocked or exited or whatever, so call schedule
    8.33 +	 * to decide what's going to run next.
    8.34 +	 */
    8.35 +	schedule();
    8.36  }
    8.37  
    8.38  static int sys_hello(void)
    8.39 @@ -48,23 +54,3 @@
    8.40  	printf("process %d says hello!\n", get_current_pid());
    8.41  	return 0;
    8.42  }
    8.43 -
    8.44 -static int sys_sleep(int sec)
    8.45 -{
    8.46 -	printf("process %d will sleep for %d seconds\n", get_current_pid(), sec);
    8.47 -	sleep(sec * 1000); /* timer.c */
    8.48 -	return 0;
    8.49 -}
    8.50 -
    8.51 -static int sys_fork(void)
    8.52 -{
    8.53 -	printf("process %d is forking\n", get_current_pid());
    8.54 -	return fork(); /* proc.c */
    8.55 -}
    8.56 -
    8.57 -static int sys_getpid(void)
    8.58 -{
    8.59 -	int pid = get_current_pid();
    8.60 -	printf("process %d getpid\n", pid);
    8.61 -	return pid;
    8.62 -}

     9.1 --- a/src/syscall.h	Thu Oct 13 05:22:35 2011 +0300
     9.2 +++ b/src/syscall.h	Sat Oct 15 07:45:56 2011 +0300
     9.3 @@ -1,15 +1,8 @@
     9.4  #ifndef SYSCALL_H_
     9.5  #define SYSCALL_H_
     9.6  
     9.7 -#define SYSCALL_INT		0x80
     9.8 -
     9.9 -/* when we get rid of test_proc.S we'll turn this into an enum */
    9.10 -#define SYS_HELLO		0
    9.11 -#define SYS_SLEEP		1
    9.12 -#define SYS_FORK		2
    9.13 -#define SYS_GETPID		3
    9.14 -
    9.15 -#define NUM_SYSCALLS	4
    9.16 +#define KDEF_SYSCALL_H
    9.17 +#include "kdef.h"
    9.18  
    9.19  #ifndef ASM
    9.20  void init_syscall(void);

    10.1 --- a/src/timer.c	Thu Oct 13 05:22:35 2011 +0300
    10.2 +++ b/src/timer.c	Sat Oct 15 07:45:56 2011 +0300
    10.3 @@ -75,13 +75,20 @@
    10.4  	interrupt(IRQ_TO_INTR(0), timer_handler);
    10.5  }
    10.6  
    10.7 +int sys_sleep(int sec)
    10.8 +{
    10.9 +	printf("process %d will sleep for %d seconds\n", get_current_pid(), sec);
   10.10 +	sleep(sec * 1000); /* timer.c */
   10.11 +
   10.12 +	/* TODO if interrupted, return the remaining seconds */
   10.13 +	return 0;
   10.14 +}
   10.15 +
   10.16  void sleep(unsigned long msec)
   10.17  {
   10.18  	int ticks, tsum, istate;
   10.19  	struct timer_event *ev, *node;
   10.20  
   10.21 -	printf("sleep(%lu)\n", msec);
   10.22 -
   10.23  	if((ticks = MSEC_TO_TICKS(msec)) <= 0) {
   10.24  		return;
   10.25  	}

    11.1 --- a/src/timer.h	Thu Oct 13 05:22:35 2011 +0300
    11.2 +++ b/src/timer.h	Sat Oct 15 07:45:56 2011 +0300
    11.3 @@ -5,6 +5,7 @@
    11.4  
    11.5  void init_timer(void);
    11.6  
    11.7 +int sys_sleep(int sec);
    11.8  void sleep(unsigned long msec);
    11.9  
   11.10  #endif	/* _TIMER_H_ */

    12.1 --- a/src/vm.c	Thu Oct 13 05:22:35 2011 +0300
    12.2 +++ b/src/vm.c	Sat Oct 15 07:45:56 2011 +0300
    12.3 @@ -803,6 +803,28 @@
    12.4  	pdest->ctx.pgtbl_paddr = paddr;
    12.5  }
    12.6  
    12.7 +/* cleanup_vm called by exit to clean up any memory used by the process */
    12.8 +void cleanup_vm(struct process *p)
    12.9 +{
   12.10 +	struct rbnode *vmnode;
   12.11 +
   12.12 +	/* go through the vm map and reduce refcounts all around
   12.13 +	 * when a ref goes to 0, free the physical page
   12.14 +	 */
   12.15 +	rb_begin(&p->vmmap);
   12.16 +	while((vmnode = rb_next(&p->vmmap))) {
   12.17 +		struct vm_page *page = vmnode->data;
   12.18 +		if(--page->nref <= 0) {
   12.19 +			/* free the physical page if nref goes to 0 */
   12.20 +			free_phys_page(PAGE_TO_ADDR(page->ppage));
   12.21 +		}
   12.22 +	}
   12.23 +
   12.24 +	/* destroying the tree will free the nodes */
   12.25 +	rb_destroy(&p->vmmap);
   12.26 +}
   12.27 +
   12.28 +
   12.29  int get_page_bit(int pgnum, uint32_t bit, int wholepath)
   12.30  {
   12.31  	int tidx = PAGE_TO_PGTBL(pgnum);

    13.1 --- a/src/vm.h	Thu Oct 13 05:22:35 2011 +0300
    13.2 +++ b/src/vm.h	Sat Oct 15 07:45:56 2011 +0300
    13.3 @@ -78,7 +78,11 @@
    13.4  int pgalloc_vrange(int start, int num);
    13.5  void pgfree(int start, int num);
    13.6  
    13.7 +/* don't be fooled by the fact these two accept process arguments
    13.8 + * they in fact work only for the "current" process (psrc and p)
    13.9 + */
   13.10  void clone_vm(struct process *pdest, struct process *psrc, int cow);
   13.11 +void cleanup_vm(struct process *p);
   13.12  
   13.13  int get_page_bit(int pgnum, uint32_t bit, int wholepath);
   13.14  void set_page_bit(int pgnum, uint32_t bit, int wholepath);