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cos2000v2/lib/process.c

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/*******************************************************************************/
/* COS2000 - Compatible Operating System - LGPL v3 - Hordé Nicolas */
/* */
#include "types.h"
#include "process.h"
#include "memory.h"
#include "gdt.h"
process *processes;
tid_t current;
pid_t lastpid;
static u8 elf_errors1[] = "Aucune signature ELF";
static u8 elf_errors2[] = "Fichier au format ELF mais non 32 bits";
static u8 elf_errors3[] = "ELF non LSB";
static u8 elf_errors4[] = "ELF mauvaise version";
static u8 elf_errors5[] = "ELF pour OS ne correspondant pas";
static u8 elf_errors6[] = "Mauvais type de machine";
static u8 *elf_errors[] =
{ &elf_errors1, &elf_errors2, &elf_errors3, &elf_errors4,
&elf_errors5, &elf_errors6
};
/*******************************************************************************/
/* Vérifie la signature ELF
0 - RAS
1 - Pas la signature ELF
2 - pas ELF32
3 - pas bon organisation LSB/MSB
4 - pas bonne version ELF
5 - pas bon OS
6 - pas bon type machine */
u32 iself(u8 * src)
{
elf32 *header = (elf32 *) src;
if (header->e_ident[EI_MAG0] == ELFMAG0
&& header->e_ident[EI_MAG1] == ELFMAG1
&& header->e_ident[EI_MAG2] == ELFMAG2
&& header->e_ident[EI_MAG3] == ELFMAG3)
{
if (header->e_ident[EI_CLASS] != ELFCLASS32)
return 2;
if (header->e_ident[EI_DATA] != ELFDATA2LSB)
return 3;
if (header->e_ident[EI_VERSION] != EV_CURRENT
|| header->e_version != EV_CURRENT)
return 4;
if (header->e_ident[EI_OSABI] != ELFOSABI_COS2000)
return 5;
if (header->e_machine != EM_386)
return 6;
return 0;
}
else
return 1;
}
/*******************************************************************************/
/* Met fin à une tâche */
/* SYSCALL
{
"ID":5,
"LIBRARY":"libsys",
"NAME":"exit",
"INTERNALNAME":"processexit",
"DESCRIPTION":"End a task for user or kernel domain",
"ARGS": [
{"TYPE":"u32","NAME":"resultcode","DESCRIPTION":"Code result of the execution"}
],
"RETURN":"void"
}
END */
void processexit(void)
{
deleteprocess(getcurrentpid());
switchtask(maketid(1,1));
}
/*******************************************************************************/
/* Charge le fichier ELF en mémoire et mets à jour les informations sur le processus */
u32 loadelf(u8 * src, pid_t pid)
{
u8 *ptr;
u8 code;
u32 v_begin, v_end;
elf32 *header;
elf32p *program;
u32 i;
header = (elf32 *) src;
program = (elf32p *) (src + header->e_phoff);
code = iself(src);
process *aprocess=findprocess(pid);
if (aprocess==NULL) return NULL;
if (code != 0)
{
printf("Erreur de chargement ELF, %s !\r\n",
elf_errors[code - 1]);
return NULL;
}
for (i = 0; i < header->e_phnum; i++, program++)
{
if (program->p_type == PT_LOAD)
{
v_begin = program->p_vaddr;
v_end = program->p_vaddr + program->p_memsz;
if (v_begin < USER_CODE)
{
printf("Ne peut charger l'executable en desssous de l'adresse %X\r\n", USER_CODE);
return 0;
}
if (v_end > USER_STACK)
{
printf("Ne peut charger l'executable au desssus de l'adresse %X\r\n", USER_STACK);
return 0;
}
if (program->p_flags == PF_X + PF_R)
{
aprocess->exec_low = (u8 *) v_begin;
aprocess->exec_high = (u8 *) v_end;
}
if (program->p_flags == PF_W + PF_R)
{
aprocess->bss_low = (u8 *) v_begin;
aprocess->bss_high = (u8 *) v_end;
}
memcpy((u8 *) (src + program->p_offset),
(u8 *) v_begin, program->p_filesz, 0);
if (program->p_memsz > program->p_filesz)
for (i = program->p_filesz, ptr =
(u8 *) program->p_vaddr;
i < program->p_memsz; i++)
ptr[i] = 0;
}
}
return header->e_entry;
}
/*******************************************************************************/
/* Initialise la liste des processus */
void initprocesses(void)
{
u32 i = 0;
processes = (process *) vmalloc(sizeof(process) * MAXNUMPROCESS);
while (i < MAXNUMPROCESS)
{
processes[i].pid = NULL;
processes[i++].status = PROCESS_STATUS_FREE;
}
pid_t pid=getfreepid();
process *aprocess=findprocess(pid);
if (aprocess==NULL) return NULL;
aprocess->pid = pid;
aprocess->result = 0;
aprocess->status = PROCESS_STATUS_READY;
aprocess->iskernel = true;
TAILQ_INIT(&aprocess->task_head);
current=createtask(pid,getinitretry(),true);
}
/*******************************************************************************/
/* Récupère un emplacement dans la liste des processus */
pid_t getfreepid(void)
{
u32 i = lastpid;
u32 parsed = 0;
while (processes[i++].status != PROCESS_STATUS_FREE
&& parsed++ < MAXNUMPROCESS)
{
if (i >= MAXNUMPROCESS)
i = 0;
}
if (parsed > MAXNUMPROCESS)
{
printf("PANIC: plus d'emplacement disponible pour un novueau processus\n");
return NULL;
}
lastpid=i;
return (pid_t)i;
}
/*******************************************************************************/
/* Récupère un emplacement dans la liste des tâche du processus donné */
tid_t getfreeptid(pid_t pid)
{
process *aprocess=findprocess(pid);
if (aprocess==NULL) return maketid(0,0);
u32 number=0;
task *next;
TAILQ_FOREACH(next, &aprocess->task_head, tailq)
if (next->tid.number>number)
number=next->tid.number;
number++;
return maketid(pid,number);
}
/*******************************************************************************/
/* Récupère le PID du processus courant */
pid_t getcurrentpid(void)
{
return current.pid;
}
/*******************************************************************************/
/* Récupère le TID de la tâche courante */
tid_t getcurrenttid(void)
{
return current;
}
/*******************************************************************************/
/* Change la tâche désigné dans le TID */
tid_t maketid(pid_t pid, u32 number)
{
tid_t newtid;
newtid.pid=pid;
newtid.number=number;
return newtid;
}
/*******************************************************************************/
/* Récupère l'adresse d'un processus */
process* findprocess(pid_t pid)
{
if ((u32)pid>0)
return &processes[(u32)pid-1];
else
return NULL;
}
/*******************************************************************************/
/* Récupère l'adresse du processus courant */
process* findcurrentprocess(void)
{
return &processes[(u32)getcurrentpid()-1];
}
/*******************************************************************************/
/* Bascule vers une tâche */
void switchtask(tid_t tid)
{
tid_t previous = current;
task *atask = findtask(tid);
if (atask==NULL) return;
process *aprocess=findprocess(tid.pid);
if (aprocess==NULL) return;
current = tid;
if (!aprocess->iskernel)
setTSS(atask->kernel_stack.ss0, atask->kernel_stack.esp0);
else
setTSS(0x0, 0x0);
atask->dump.eflags = (atask->dump.eflags | 0x200) & 0xFFFFBFFF;
createdump(atask->dump);
if (atask->dump.cs==SEL_KERNEL_CODE)
restcpu_kernel();
else
restcpu_user();
iret();
}
/*******************************************************************************/
/* Cherche l'adresse d'une tâche */
task* findtask(tid_t tid)
{
process *aprocess=findprocess(tid.pid);
if (aprocess==NULL) return NULL;
task *next;
TAILQ_FOREACH(next, &aprocess->task_head, tailq)
if (next->tid.number==tid.number)
return next;
}
/*******************************************************************************/
/* Cherche l'adresse de la tâche courante */
task* findcurrenttask(void)
{
return findtask(getcurrenttid());
}
/*******************************************************************************/
/* Détruit une tâche */
void deletetask(tid_t tid)
{
stoptask(tid);
process* aprocess=findprocess(tid.pid);
if (aprocess==NULL) return;
task *atask=findtask(tid);
if (atask==NULL) return;
TAILQ_REMOVE(&aprocess->task_head, atask, tailq);
vfree(atask);
}
/*******************************************************************************/
/* Execute une tâche */
void runtask(tid_t tid)
{
task *atask=findtask(tid);
if (atask==NULL) return;
if (atask->status == TASK_STATUS_READY)
{
atask->status = TASK_STATUS_RUN;
switchtask(tid);
}
}
/*******************************************************************************/
/* Initialise une tâche */
tid_t createtask(pid_t pid,u8 *entry, bool kerneltask)
{
tid_t tid;
tid.pid=pid;
process* aprocess=findprocess(pid);
if (aprocess==NULL) return maketid(0,0);
task *new = (task *) vmalloc(sizeof(task));
TAILQ_INSERT_TAIL(&aprocess->task_head, new, tailq);
page *astack = virtual_page_getfree();
if (kerneltask)
{
new->dump.ss = SEL_KERNEL_STACK;
new->dump.esp =
(u32) astack->vaddr + PAGESIZE - 16;
new->dump.eflags = 0x0;
new->dump.cs = SEL_KERNEL_CODE;
new->dump.ds = SEL_KERNEL_DATA;
new->dump.es = SEL_KERNEL_DATA;
new->dump.fs = SEL_KERNEL_DATA;
new->dump.gs = SEL_KERNEL_DATA;
new->dump.cr3 = KERNEL_PD_ADDR;
}
else
{
new->kernel_stack.ss0 = SEL_KERNEL_STACK;
new->kernel_stack.esp0 =
(u32) astack->vaddr + PAGESIZE - 16;
new->dump.ss = SEL_USER_STACK | RPL_RING3;
new->dump.esp = USER_STACK - 16;
new->dump.eflags = 0x0;
new->dump.cs = SEL_USER_CODE | RPL_RING3;
new->dump.ds = SEL_USER_DATA | RPL_RING3;
new->dump.es = SEL_USER_DATA | RPL_RING3;
new->dump.fs = SEL_USER_DATA | RPL_RING3;
new->dump.gs = SEL_USER_DATA | RPL_RING3;
new->dump.cr3 = aprocess->pdd->addr->paddr;
}
new->tid=getfreeptid(pid);
new->dump.eip = aprocess->entry;
new->dump.eax = 0;
new->dump.ecx = 0;
new->dump.edx = 0;
new->dump.ebx = 0;
new->dump.ebp = 0;
new->dump.esi = 0;
new->dump.edi = 0;
new->status = TASK_STATUS_READY;
return new->tid;
}
/*******************************************************************************/
/* Arrête une tâche */
void stoptask(tid_t tid)
{
task *atask=findtask(tid);
if (atask==NULL) return;
atask->status=TASK_STATUS_STOP;
}
/*******************************************************************************/
/* Initialise un processus */
pid_t createprocess(u8 *src, bool kerneltask)
{
tid_t previous = current;
current.pid = getfreepid();
current.number = 0;
process* new=findcurrentprocess();
if (new==NULL) return NULL;
new->pid = current.pid;
new->pdd = virtual_pd_create();
TAILQ_INIT(&new->page_head);
TAILQ_INIT(&new->task_head);
new->iskernel=kerneltask;
setCR3(new->pdd->addr->paddr);
new->entry = loadelf(src, new->pid);
createtask(new->pid,new->entry, new->iskernel);
current = previous;
process* old=findcurrentprocess();
if (old==NULL) return NULL;
u32 cr3=KERNEL_PD_ADDR;
if (old->pdd!=NULL)
cr3=old->pdd->addr->paddr;
setCR3(cr3);
new->status=PROCESS_STATUS_READY;
return new->pid;
}
/*******************************************************************************/
/* Détruit un processus */
void deleteprocess(pid_t pid)
{
stopprocess(pid);
process* aprocess=findprocess(pid);
if (aprocess==NULL) return;
task *next;
TAILQ_FOREACH(next, &aprocess->task_head, tailq)
deletetask(next->tid);
aprocess->status = PROCESS_STATUS_FREE;
}
/*******************************************************************************/
/* Execute un processus */
void runprocess(pid_t pid)
{
process* aprocess=findprocess(pid);
if (aprocess==NULL) return;
if (aprocess->status == PROCESS_STATUS_READY)
{
aprocess->status = PROCESS_STATUS_RUN;
tid_t tid=maketid(pid,1);
task *atask=findtask(tid);
if (atask==NULL) return;
atask->status=TASK_STATUS_RUN;
switchtask(tid);
}
}
/*******************************************************************************/
/* Arrête un processus */
void stopprocess(pid_t pid)
{
process* aprocess=findprocess(pid);
if (aprocess==NULL) return;
if (aprocess->status == PROCESS_STATUS_RUN)
{
aprocess->status = PROCESS_STATUS_READY;
task *next;
TAILQ_FOREACH(next, &aprocess->task_head, tailq)
next->status=TASK_STATUS_READY;
}
}
/*******************************************************************************/
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