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#include <kernel/arch/generic.h>
#include <kernel/mem.h>
#include <kernel/panic.h>
#include <kernel/proc.h>
#include <kernel/syscalls.h>
#include <stdint.h>
_Noreturn void _syscall_exit(const char *msg, size_t len) {
process_current->state = PS_DEAD;
// check if our parent is awaiting our death
if (process_current->parent->state == PS_WAITS4CHILDDEATH) {
// how cruel
process_current->state = PS_DEADER;
process_current->parent->state = PS_RUNNING;
process_switch(process_current->parent);
}
process_current = process_find(PS_RUNNING);
if (process_current)
process_switch(process_current);
tty_const("last process returned. ");
panic();
}
int _syscall_await(char *buf, int *len) {
// find any already dead children
for (struct process *iter = process_current->child;
iter; iter = iter->sibling) {
if (iter->state == PS_DEAD) {
iter->state = PS_DEADER;
// TODO copy return message
return 0;
}
}
// no dead children yet
// TODO check if the process even has children
process_current->state = PS_WAITS4CHILDDEATH;
process_current = process_find(PS_RUNNING);
if (process_current)
process_switch(process_current);
tty_const("this error will be fixed in the next commit."); // TODO
panic();
}
int _syscall_fork() {
struct process *child = process_fork(process_current);
regs_savereturn(&child->regs, 0);
return 1;
}
int _syscall_debuglog(const char *msg, size_t len) {
struct virt_iter iter;
size_t written;
virt_iter_new(&iter, msg, len, process_current->pages, true, false);
while (virt_iter_next(&iter)) {
tty_write(iter.frag, iter.frag_len);
written += iter.frag_len;
}
return written;
}
int syscall_handler(int num, int a, int b, int c) {
switch (num) {
case _SYSCALL_EXIT:
_syscall_exit((void*)a, b);
case _SYSCALL_AWAIT:
return _syscall_await((void*)a, (void*)b);
case _SYSCALL_FORK:
return _syscall_fork();
case _SYSCALL_DEBUGLOG:
return _syscall_debuglog((void*)a, b);
default:
tty_const("unknown syscall ");
panic();
}
}
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