diff --git a/defs.h b/defs.h
index 693fc20873f587bb32650c57108562d15183d3d0..8731c27b92aefdfc00bd0b4a1b80d7975d0beb00 100644
--- a/defs.h
+++ b/defs.h
@@ -42,6 +42,11 @@ int strncmp(const char*, const char*, uint);
// syscall.c
void syscall(void);
+int fetchint(struct proc*, uint, int*);
+int fetchbyte(struct proc*, uint, char*);
+int fetcharg(int, void*);
+int checkstring(uint);
+int putint(struct proc*, uint, int);
// picirq.c
void pic_init(void);
diff --git a/syscall.c b/syscall.c
index c6d459916696bf0ba63ca4d95048c4f94bb191e2..f75714afd5a418d78f6ff67c1f5e681fb36db8c7 100644
--- a/syscall.c
+++ b/syscall.c
@@ -81,523 +81,25 @@ putint(struct proc *p, uint addr, int x)
return 0;
}
-int
-sys_pipe(void)
-{
- struct fd *rfd = 0, *wfd = 0;
- int f1 = -1, f2 = -1;
- struct proc *p = curproc[cpu()];
- uint fdp;
-
- if(pipe_alloc(&rfd, &wfd) < 0)
- goto oops;
- if((f1 = fd_ualloc()) < 0)
- goto oops;
- p->fds[f1] = rfd;
- if((f2 = fd_ualloc()) < 0)
- goto oops;
- p->fds[f2] = wfd;
- if(fetcharg(0, &fdp) < 0)
- goto oops;
- if(putint(p, fdp, f1) < 0)
- goto oops;
- if(putint(p, fdp+4, f2) < 0)
- goto oops;
- return 0;
-
- oops:
- if(rfd)
- fd_close(rfd);
- if(wfd)
- fd_close(wfd);
- if(f1 >= 0)
- p->fds[f1] = 0;
- if(f2 >= 0)
- p->fds[f2] = 0;
- return -1;
-}
-
-int
-sys_write(void)
-{
- int fd, n, ret;
- uint addr;
- struct proc *p = curproc[cpu()];
-
- if(fetcharg(0, &fd) < 0 || fetcharg(1, &addr) < 0 || fetcharg(2, &n) < 0)
- return -1;
- if(fd < 0 || fd >= NOFILE)
- return -1;
- if(p->fds[fd] == 0)
- return -1;
- if(addr + n > p->sz)
- return -1;
-
- ret = fd_write(p->fds[fd], p->mem + addr, n);
- return ret;
-}
-
-int
-sys_read(void)
-{
- int fd, n, ret;
- uint addr;
- struct proc *p = curproc[cpu()];
-
- if(fetcharg(0, &fd) < 0 || fetcharg(1, &addr) < 0 || fetcharg(2, &n) < 0)
- return -1;
- if(fd < 0 || fd >= NOFILE)
- return -1;
- if(p->fds[fd] == 0)
- return -1;
- if(addr + n > p->sz)
- return -1;
- ret = fd_read(p->fds[fd], p->mem + addr, n);
- return ret;
-}
-
-int
-sys_close(void)
-{
- int fd;
- struct proc *p = curproc[cpu()];
-
- if(fetcharg(0, &fd) < 0)
- return -1;
- if(fd < 0 || fd >= NOFILE)
- return -1;
- if(p->fds[fd] == 0)
- return -1;
- fd_close(p->fds[fd]);
- p->fds[fd] = 0;
- return 0;
-}
-
-int
-sys_fork(void)
-{
- struct proc *np;
-
- if((np = copyproc(curproc[cpu()])) == 0)
- return -1;
- np->state = RUNNABLE;
- return np->pid;
-}
-
-int
-sys_exit(void)
-{
- proc_exit();
- return 0; // not reached
-}
-
-int
-sys_wait(void)
-{
- return proc_wait();
-}
-
-int
-sys_kill(void)
-{
- int pid;
-
- if(fetcharg(0, &pid) < 0)
- return -1;
- return proc_kill(pid);
-}
-
-int
-sys_open(void)
-{
- struct proc *cp = curproc[cpu()];
- struct inode *ip, *dp;
- uint arg0, arg1;
- int ufd;
- struct fd *fd;
- int l;
- char *last;
-
- if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0)
- return -1;
- if((l = checkstring(arg0)) < 0)
- return -1;
-
- if(arg1 & O_CREATE){
- dp = namei(cp->mem + arg0, NAMEI_CREATE, 0, &last, &ip);
- if(dp){
- ip = mknod1(dp, last, T_FILE, 0, 0);
- iput(dp);
- if(ip == 0)
- return -1;
- } else if(ip == 0){
- return -1;
- } else if(ip->type == T_DIR){
- iput(ip);
- return -1;
- }
- } else {
- ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0);
- if(ip == 0)
- return -1;
- }
- if(ip->type == T_DIR && ((arg1 & O_RDWR) || (arg1 & O_WRONLY))){
- iput(ip);
- return -1;
- }
-
- if((fd = fd_alloc()) == 0){
- iput(ip);
- return -1;
- }
- if((ufd = fd_ualloc()) < 0){
- iput(ip);
- fd_close(fd);
- return -1;
- }
-
- iunlock(ip);
- fd->type = FD_FILE;
- if(arg1 & O_RDWR) {
- fd->readable = 1;
- fd->writable = 1;
- } else if(arg1 & O_WRONLY) {
- fd->readable = 0;
- fd->writable = 1;
- } else {
- fd->readable = 1;
- fd->writable = 0;
- }
- fd->ip = ip;
- fd->off = 0;
- cp->fds[ufd] = fd;
-
- return ufd;
-}
-
-int
-sys_mknod(void)
-{
- struct proc *cp = curproc[cpu()];
- struct inode *nip;
- uint arg0, arg1, arg2, arg3;
- int l;
-
- if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0 ||
- fetcharg(2, &arg2) < 0 || fetcharg(3, &arg3) < 0)
- return -1;
-
- if((l = checkstring(arg0)) < 0)
- return -1;
-
- if(l >= DIRSIZ)
- return -1;
-
- nip = mknod(cp->mem + arg0, (short) arg1, (short) arg2, (short) arg3);
- if(nip)
- iput(nip);
- return (nip == 0) ? -1 : 0;
-}
-
-int
-sys_mkdir(void)
-{
- struct proc *cp = curproc[cpu()];
- struct inode *nip;
- struct inode *dp;
- uint arg0;
- int l;
- struct dirent de;
- char *last;
-
- if(fetcharg(0, &arg0) < 0)
- return -1;
-
- if((l = checkstring(arg0)) < 0)
- return -1;
-
- dp = namei(cp->mem + arg0, NAMEI_CREATE, 0, &last, 0);
- if(dp == 0)
- return -1;
-
- nip = mknod1(dp, last, T_DIR, 0, 0);
- if(nip == 0){
- iput(dp);
- return -1;
- }
-
- dp->nlink += 1;
- iupdate(dp);
-
- memset(de.name, '\0', DIRSIZ);
- de.name[0] = '.';
- de.inum = nip->inum;
- writei(nip, (char*) &de, 0, sizeof(de));
-
- de.inum = dp->inum;
- de.name[1] = '.';
- writei(nip, (char*) &de, sizeof(de), sizeof(de));
-
- iput(dp);
- iput(nip);
-
- return 0;
-}
-
-
-int
-sys_chdir(void)
-{
- struct proc *cp = curproc[cpu()];
- struct inode *ip;
- uint arg0;
- int l;
-
- if(fetcharg(0, &arg0) < 0)
- return -1;
-
- if((l = checkstring(arg0)) < 0)
- return -1;
-
- if((ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0)) == 0)
- return -1;
-
- if(ip == cp->cwd) {
- iput(ip);
- return 0;
- }
-
- if(ip->type != T_DIR) {
- iput(ip);
- return -1;
- }
-
- idecref(cp->cwd);
- cp->cwd = ip;
- iunlock(cp->cwd);
- return 0;
-}
-
-int
-sys_unlink(void)
-{
- struct proc *cp = curproc[cpu()];
- uint arg0;
- int r;
-
- if(fetcharg(0, &arg0) < 0)
- return -1;
- if(checkstring(arg0) < 0)
- return -1;
- r = unlink(cp->mem + arg0);
- return r;
-}
-
-int
-sys_fstat(void)
-{
- struct proc *cp = curproc[cpu()];
- uint fd, addr;
- int r;
-
- if(fetcharg(0, &fd) < 0)
- return -1;
- if(fetcharg(1, &addr) < 0)
- return -1;
- if(fd < 0 || fd >= NOFILE)
- return -1;
- if(cp->fds[fd] == 0)
- return -1;
- if(addr + sizeof(struct stat) > cp->sz)
- return -1;
- r = fd_stat(cp->fds[fd], (struct stat*)(cp->mem + addr));
- return r;
-}
-
-int
-sys_dup(void)
-{
- struct proc *cp = curproc[cpu()];
- uint fd, ufd1;
-
- if(fetcharg(0, &fd) < 0)
- return -1;
- if(fd < 0 || fd >= NOFILE)
- return -1;
- if(cp->fds[fd] == 0)
- return -1;
- if((ufd1 = fd_ualloc()) < 0)
- return -1;
- cp->fds[ufd1] = cp->fds[fd];
- fd_incref(cp->fds[ufd1]);
- return ufd1;
-}
-
-int
-sys_link(void)
-{
- struct proc *cp = curproc[cpu()];
- uint name1, name2;
- int r;
-
- if(fetcharg(0, &name1) < 0 || checkstring(name1) < 0)
- return -1;
- if(fetcharg(1, &name2) < 0 || checkstring(name2) < 0)
- return -1;
- r = link(cp->mem + name1, cp->mem + name2);
- return r;
-}
-
-int
-sys_getpid(void)
-{
- struct proc *cp = curproc[cpu()];
- return cp->pid;
-}
-
-
-int
-sys_sbrk(void)
-{
- uint addr;
- int n;
- struct proc *cp = curproc[cpu()];
-
- if(fetcharg(0, &n) < 0)
- return -1;
- if((addr = growproc(n)) == 0xffffffff)
- return -1;
- setupsegs(cp);
- return addr;
-}
-
-int
-sys_exec(void)
-{
- struct proc *cp = curproc[cpu()];
- uint arg0, arg1, sz=0, ap, sp, p1, p2;
- int i, nargs, argbytes, len;
- struct inode *ip;
- struct elfhdr elf;
- struct proghdr ph;
- char *mem = 0;
-
- if(fetcharg(0, &arg0) < 0)
- return -1;
- if(fetcharg(1, &arg1) < 0)
- return -1;
- if(checkstring(arg0) < 0)
- return -1;
- ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0);
- if(ip == 0)
- return -1;
-
- if(readi(ip, (char*)&elf, 0, sizeof(elf)) < sizeof(elf))
- goto bad;
-
- if(elf.magic != ELF_MAGIC)
- goto bad;
-
- sz = 0;
- for(i = 0; i < elf.phnum; i++){
- if(readi(ip, (char*)&ph, elf.phoff + i * sizeof(ph),
- sizeof(ph)) != sizeof(ph))
- goto bad;
- if(ph.type != ELF_PROG_LOAD)
- continue;
- if(ph.memsz < ph.filesz)
- goto bad;
- sz += ph.memsz;
- }
-
- sz += 4096 - (sz % 4096);
- sz += 4096;
-
- mem = kalloc(sz);
- if(mem == 0)
- goto bad;
- memset(mem, 0, sz);
-
- // arg1 is a pointer to an array of pointers to string.
- nargs = 0;
- argbytes = 0;
- for(i = 0; ; i++){
- if(fetchint(cp, arg1 + 4*i, &ap) < 0)
- goto bad;
- if(ap == 0)
- break;
- len = checkstring(ap);
- if(len < 0)
- goto bad;
- nargs++;
- argbytes += len + 1;
- }
-
- // argn\0
- // ...
- // arg0\0
- // 0
- // ptr to argn
- // ...
- // 12: ptr to arg0
- // 8: argv (points to ptr to arg0)
- // 4: argc
- // 0: fake return pc
- sp = sz - argbytes - (nargs+1)*4 - 4 - 4 - 4;
- *(uint*)(mem + sp) = 0xffffffff;
- *(uint*)(mem + sp + 4) = nargs;
- *(uint*)(mem + sp + 8) = (uint)(sp + 12);
-
- p1 = sp + 12;
- p2 = sp + 12 + (nargs + 1) * 4;
- for(i = 0; i < nargs; i++){
- fetchint(cp, arg1 + 4*i, &ap);
- len = checkstring(ap);
- memmove(mem + p2, cp->mem + ap, len + 1);
- *(uint*)(mem + p1) = p2;
- p1 += 4;
- p2 += len + 1;
- }
- *(uint*)(mem + p1) = 0;
-
- // commit to the new image.
- kfree(cp->mem, cp->sz);
- cp->sz = sz;
- cp->mem = mem;
- mem = 0;
-
- for(i = 0; i < elf.phnum; i++){
- if(readi(ip, (char*)&ph, elf.phoff + i * sizeof(ph),
- sizeof(ph)) != sizeof(ph))
- goto bad2;
- if(ph.type != ELF_PROG_LOAD)
- continue;
- if(ph.va + ph.memsz > sz)
- goto bad2;
- if(readi(ip, cp->mem + ph.va, ph.offset, ph.filesz) != ph.filesz)
- goto bad2;
- memset(cp->mem + ph.va + ph.filesz, 0, ph.memsz - ph.filesz);
- }
-
- iput(ip);
-
- cp->tf->eip = elf.entry;
- cp->tf->esp = sp;
- setupsegs(cp);
-
- return 0;
-
- bad:
- if(mem)
- kfree(mem, sz);
- iput(ip);
- return -1;
-
- bad2:
- iput(ip);
- proc_exit();
- return 0;
-}
+extern int sys_chdir(void);
+extern int sys_close(void);
+extern int sys_dup(void);
+extern int sys_exec(void);
+extern int sys_exit(void);
+extern int sys_fork(void);
+extern int sys_fstat(void);
+extern int sys_getpid(void);
+extern int sys_kill(void);
+extern int sys_link(void);
+extern int sys_mkdir(void);
+extern int sys_mknod(void);
+extern int sys_open(void);
+extern int sys_pipe(void);
+extern int sys_read(void);
+extern int sys_sbrk(void);
+extern int sys_unlink(void);
+extern int sys_wait(void);
+extern int sys_write(void);
void
syscall(void)
diff --git a/syscall.h b/syscall.h
index 4efd2555f5e22309fd168c01db7e22eca8fc154d..0ef0c870c331bd86711e22af55f3eb5d858a05ac 100644
--- a/syscall.h
+++ b/syscall.h
@@ -1,20 +1,20 @@
-#define SYS_fork 1
-#define SYS_exit 2
-#define SYS_wait 3
-#define SYS_pipe 4
-#define SYS_write 5
-#define SYS_read 6
-#define SYS_close 7
-#define SYS_kill 9
-#define SYS_exec 10
-#define SYS_open 11
-#define SYS_mknod 12
+#define SYS_fork 1
+#define SYS_exit 2
+#define SYS_wait 3
+#define SYS_pipe 4
+#define SYS_write 5
+#define SYS_read 6
+#define SYS_close 7
+#define SYS_kill 9
+#define SYS_exec 10
+#define SYS_open 11
+#define SYS_mknod 12
#define SYS_unlink 13
-#define SYS_fstat 14
-#define SYS_link 15
-#define SYS_mkdir 16
-#define SYS_chdir 17
-#define SYS_dup 18
+#define SYS_fstat 14
+#define SYS_link 15
+#define SYS_mkdir 16
+#define SYS_chdir 17
+#define SYS_dup 18
#define SYS_getpid 19
-#define SYS_sbrk 20
+#define SYS_sbrk 20
diff --git a/sysfile.c b/sysfile.c
new file mode 100644
index 0000000000000000000000000000000000000000..f533e0115405335ed6f9c2f121a43f7030001a79
--- /dev/null
+++ b/sysfile.c
@@ -0,0 +1,477 @@
+#include "types.h"
+#include "stat.h"
+#include "param.h"
+#include "mmu.h"
+#include "proc.h"
+#include "defs.h"
+#include "x86.h"
+#include "traps.h"
+#include "syscall.h"
+#include "spinlock.h"
+#include "buf.h"
+#include "fs.h"
+#include "fsvar.h"
+#include "elf.h"
+#include "fd.h"
+#include "fcntl.h"
+
+int
+sys_pipe(void)
+{
+ struct fd *rfd = 0, *wfd = 0;
+ int f1 = -1, f2 = -1;
+ struct proc *p = curproc[cpu()];
+ uint fdp;
+
+ if(pipe_alloc(&rfd, &wfd) < 0)
+ goto oops;
+ if((f1 = fd_ualloc()) < 0)
+ goto oops;
+ p->fds[f1] = rfd;
+ if((f2 = fd_ualloc()) < 0)
+ goto oops;
+ p->fds[f2] = wfd;
+ if(fetcharg(0, &fdp) < 0)
+ goto oops;
+ if(putint(p, fdp, f1) < 0)
+ goto oops;
+ if(putint(p, fdp+4, f2) < 0)
+ goto oops;
+ return 0;
+
+ oops:
+ if(rfd)
+ fd_close(rfd);
+ if(wfd)
+ fd_close(wfd);
+ if(f1 >= 0)
+ p->fds[f1] = 0;
+ if(f2 >= 0)
+ p->fds[f2] = 0;
+ return -1;
+}
+
+int
+sys_write(void)
+{
+ int fd, n, ret;
+ uint addr;
+ struct proc *p = curproc[cpu()];
+
+ if(fetcharg(0, &fd) < 0 || fetcharg(1, &addr) < 0 || fetcharg(2, &n) < 0)
+ return -1;
+ if(fd < 0 || fd >= NOFILE)
+ return -1;
+ if(p->fds[fd] == 0)
+ return -1;
+ if(addr + n > p->sz)
+ return -1;
+
+ ret = fd_write(p->fds[fd], p->mem + addr, n);
+ return ret;
+}
+
+int
+sys_read(void)
+{
+ int fd, n, ret;
+ uint addr;
+ struct proc *p = curproc[cpu()];
+
+ if(fetcharg(0, &fd) < 0 || fetcharg(1, &addr) < 0 || fetcharg(2, &n) < 0)
+ return -1;
+ if(fd < 0 || fd >= NOFILE)
+ return -1;
+ if(p->fds[fd] == 0)
+ return -1;
+ if(addr + n > p->sz)
+ return -1;
+ ret = fd_read(p->fds[fd], p->mem + addr, n);
+ return ret;
+}
+
+int
+sys_close(void)
+{
+ int fd;
+ struct proc *p = curproc[cpu()];
+
+ if(fetcharg(0, &fd) < 0)
+ return -1;
+ if(fd < 0 || fd >= NOFILE)
+ return -1;
+ if(p->fds[fd] == 0)
+ return -1;
+ fd_close(p->fds[fd]);
+ p->fds[fd] = 0;
+ return 0;
+}
+
+int
+sys_open(void)
+{
+ struct proc *cp = curproc[cpu()];
+ struct inode *ip, *dp;
+ uint arg0, arg1;
+ int ufd;
+ struct fd *fd;
+ int l;
+ char *last;
+
+ if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0)
+ return -1;
+ if((l = checkstring(arg0)) < 0)
+ return -1;
+
+ if(arg1 & O_CREATE){
+ dp = namei(cp->mem + arg0, NAMEI_CREATE, 0, &last, &ip);
+ if(dp){
+ ip = mknod1(dp, last, T_FILE, 0, 0);
+ iput(dp);
+ if(ip == 0)
+ return -1;
+ } else if(ip == 0){
+ return -1;
+ } else if(ip->type == T_DIR){
+ iput(ip);
+ return -1;
+ }
+ } else {
+ ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0);
+ if(ip == 0)
+ return -1;
+ }
+ if(ip->type == T_DIR && ((arg1 & O_RDWR) || (arg1 & O_WRONLY))){
+ iput(ip);
+ return -1;
+ }
+
+ if((fd = fd_alloc()) == 0){
+ iput(ip);
+ return -1;
+ }
+ if((ufd = fd_ualloc()) < 0){
+ iput(ip);
+ fd_close(fd);
+ return -1;
+ }
+
+ iunlock(ip);
+ fd->type = FD_FILE;
+ if(arg1 & O_RDWR) {
+ fd->readable = 1;
+ fd->writable = 1;
+ } else if(arg1 & O_WRONLY) {
+ fd->readable = 0;
+ fd->writable = 1;
+ } else {
+ fd->readable = 1;
+ fd->writable = 0;
+ }
+ fd->ip = ip;
+ fd->off = 0;
+ cp->fds[ufd] = fd;
+
+ return ufd;
+}
+
+int
+sys_mknod(void)
+{
+ struct proc *cp = curproc[cpu()];
+ struct inode *nip;
+ uint arg0, arg1, arg2, arg3;
+ int l;
+
+ if(fetcharg(0, &arg0) < 0 || fetcharg(1, &arg1) < 0 ||
+ fetcharg(2, &arg2) < 0 || fetcharg(3, &arg3) < 0)
+ return -1;
+
+ if((l = checkstring(arg0)) < 0)
+ return -1;
+
+ if(l >= DIRSIZ)
+ return -1;
+
+ nip = mknod(cp->mem + arg0, (short) arg1, (short) arg2, (short) arg3);
+ if(nip)
+ iput(nip);
+ return (nip == 0) ? -1 : 0;
+}
+
+int
+sys_mkdir(void)
+{
+ struct proc *cp = curproc[cpu()];
+ struct inode *nip;
+ struct inode *dp;
+ uint arg0;
+ int l;
+ struct dirent de;
+ char *last;
+
+ if(fetcharg(0, &arg0) < 0)
+ return -1;
+
+ if((l = checkstring(arg0)) < 0)
+ return -1;
+
+ dp = namei(cp->mem + arg0, NAMEI_CREATE, 0, &last, 0);
+ if(dp == 0)
+ return -1;
+
+ nip = mknod1(dp, last, T_DIR, 0, 0);
+ if(nip == 0){
+ iput(dp);
+ return -1;
+ }
+
+ dp->nlink += 1;
+ iupdate(dp);
+
+ memset(de.name, '\0', DIRSIZ);
+ de.name[0] = '.';
+ de.inum = nip->inum;
+ writei(nip, (char*) &de, 0, sizeof(de));
+
+ de.inum = dp->inum;
+ de.name[1] = '.';
+ writei(nip, (char*) &de, sizeof(de), sizeof(de));
+
+ iput(dp);
+ iput(nip);
+
+ return 0;
+}
+
+
+int
+sys_chdir(void)
+{
+ struct proc *cp = curproc[cpu()];
+ struct inode *ip;
+ uint arg0;
+ int l;
+
+ if(fetcharg(0, &arg0) < 0)
+ return -1;
+
+ if((l = checkstring(arg0)) < 0)
+ return -1;
+
+ if((ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0)) == 0)
+ return -1;
+
+ if(ip == cp->cwd) {
+ iput(ip);
+ return 0;
+ }
+
+ if(ip->type != T_DIR) {
+ iput(ip);
+ return -1;
+ }
+
+ idecref(cp->cwd);
+ cp->cwd = ip;
+ iunlock(cp->cwd);
+ return 0;
+}
+
+int
+sys_unlink(void)
+{
+ struct proc *cp = curproc[cpu()];
+ uint arg0;
+ int r;
+
+ if(fetcharg(0, &arg0) < 0)
+ return -1;
+ if(checkstring(arg0) < 0)
+ return -1;
+ r = unlink(cp->mem + arg0);
+ return r;
+}
+
+int
+sys_fstat(void)
+{
+ struct proc *cp = curproc[cpu()];
+ uint fd, addr;
+ int r;
+
+ if(fetcharg(0, &fd) < 0)
+ return -1;
+ if(fetcharg(1, &addr) < 0)
+ return -1;
+ if(fd < 0 || fd >= NOFILE)
+ return -1;
+ if(cp->fds[fd] == 0)
+ return -1;
+ if(addr + sizeof(struct stat) > cp->sz)
+ return -1;
+ r = fd_stat(cp->fds[fd], (struct stat*)(cp->mem + addr));
+ return r;
+}
+
+int
+sys_dup(void)
+{
+ struct proc *cp = curproc[cpu()];
+ uint fd, ufd1;
+
+ if(fetcharg(0, &fd) < 0)
+ return -1;
+ if(fd < 0 || fd >= NOFILE)
+ return -1;
+ if(cp->fds[fd] == 0)
+ return -1;
+ if((ufd1 = fd_ualloc()) < 0)
+ return -1;
+ cp->fds[ufd1] = cp->fds[fd];
+ fd_incref(cp->fds[ufd1]);
+ return ufd1;
+}
+
+int
+sys_link(void)
+{
+ struct proc *cp = curproc[cpu()];
+ uint name1, name2;
+ int r;
+
+ if(fetcharg(0, &name1) < 0 || checkstring(name1) < 0)
+ return -1;
+ if(fetcharg(1, &name2) < 0 || checkstring(name2) < 0)
+ return -1;
+ r = link(cp->mem + name1, cp->mem + name2);
+ return r;
+}
+
+int
+sys_exec(void)
+{
+ struct proc *cp = curproc[cpu()];
+ uint arg0, arg1, sz=0, ap, sp, p1, p2;
+ int i, nargs, argbytes, len;
+ struct inode *ip;
+ struct elfhdr elf;
+ struct proghdr ph;
+ char *mem = 0;
+
+ if(fetcharg(0, &arg0) < 0)
+ return -1;
+ if(fetcharg(1, &arg1) < 0)
+ return -1;
+ if(checkstring(arg0) < 0)
+ return -1;
+ ip = namei(cp->mem + arg0, NAMEI_LOOKUP, 0, 0, 0);
+ if(ip == 0)
+ return -1;
+
+ if(readi(ip, (char*)&elf, 0, sizeof(elf)) < sizeof(elf))
+ goto bad;
+
+ if(elf.magic != ELF_MAGIC)
+ goto bad;
+
+ sz = 0;
+ for(i = 0; i < elf.phnum; i++){
+ if(readi(ip, (char*)&ph, elf.phoff + i * sizeof(ph),
+ sizeof(ph)) != sizeof(ph))
+ goto bad;
+ if(ph.type != ELF_PROG_LOAD)
+ continue;
+ if(ph.memsz < ph.filesz)
+ goto bad;
+ sz += ph.memsz;
+ }
+
+ sz += 4096 - (sz % 4096);
+ sz += 4096;
+
+ mem = kalloc(sz);
+ if(mem == 0)
+ goto bad;
+ memset(mem, 0, sz);
+
+ // arg1 is a pointer to an array of pointers to string.
+ nargs = 0;
+ argbytes = 0;
+ for(i = 0; ; i++){
+ if(fetchint(cp, arg1 + 4*i, &ap) < 0)
+ goto bad;
+ if(ap == 0)
+ break;
+ len = checkstring(ap);
+ if(len < 0)
+ goto bad;
+ nargs++;
+ argbytes += len + 1;
+ }
+
+ // argn\0
+ // ...
+ // arg0\0
+ // 0
+ // ptr to argn
+ // ...
+ // 12: ptr to arg0
+ // 8: argv (points to ptr to arg0)
+ // 4: argc
+ // 0: fake return pc
+ sp = sz - argbytes - (nargs+1)*4 - 4 - 4 - 4;
+ *(uint*)(mem + sp) = 0xffffffff;
+ *(uint*)(mem + sp + 4) = nargs;
+ *(uint*)(mem + sp + 8) = (uint)(sp + 12);
+
+ p1 = sp + 12;
+ p2 = sp + 12 + (nargs + 1) * 4;
+ for(i = 0; i < nargs; i++){
+ fetchint(cp, arg1 + 4*i, &ap);
+ len = checkstring(ap);
+ memmove(mem + p2, cp->mem + ap, len + 1);
+ *(uint*)(mem + p1) = p2;
+ p1 += 4;
+ p2 += len + 1;
+ }
+ *(uint*)(mem + p1) = 0;
+
+ // commit to the new image.
+ kfree(cp->mem, cp->sz);
+ cp->sz = sz;
+ cp->mem = mem;
+ mem = 0;
+
+ for(i = 0; i < elf.phnum; i++){
+ if(readi(ip, (char*)&ph, elf.phoff + i * sizeof(ph),
+ sizeof(ph)) != sizeof(ph))
+ goto bad2;
+ if(ph.type != ELF_PROG_LOAD)
+ continue;
+ if(ph.va + ph.memsz > sz)
+ goto bad2;
+ if(readi(ip, cp->mem + ph.va, ph.offset, ph.filesz) != ph.filesz)
+ goto bad2;
+ memset(cp->mem + ph.va + ph.filesz, 0, ph.memsz - ph.filesz);
+ }
+
+ iput(ip);
+
+ cp->tf->eip = elf.entry;
+ cp->tf->esp = sp;
+ setupsegs(cp);
+
+ return 0;
+
+ bad:
+ if(mem)
+ kfree(mem, sz);
+ iput(ip);
+ return -1;
+
+ bad2:
+ iput(ip);
+ proc_exit();
+ return 0;
+}
diff --git a/sysproc.c b/sysproc.c
new file mode 100644
index 0000000000000000000000000000000000000000..f648c0eaaa966ceab7cc620cf9c5937a88b78b2d
--- /dev/null
+++ b/sysproc.c
@@ -0,0 +1,72 @@
+#include "types.h"
+#include "stat.h"
+#include "param.h"
+#include "mmu.h"
+#include "proc.h"
+#include "defs.h"
+#include "x86.h"
+#include "traps.h"
+#include "syscall.h"
+#include "spinlock.h"
+#include "buf.h"
+#include "fs.h"
+#include "fsvar.h"
+#include "elf.h"
+#include "fd.h"
+#include "fcntl.h"
+
+int
+sys_fork(void)
+{
+ struct proc *np;
+
+ if((np = copyproc(curproc[cpu()])) == 0)
+ return -1;
+ np->state = RUNNABLE;
+ return np->pid;
+}
+
+int
+sys_exit(void)
+{
+ proc_exit();
+ return 0; // not reached
+}
+
+int
+sys_wait(void)
+{
+ return proc_wait();
+}
+
+int
+sys_kill(void)
+{
+ int pid;
+
+ if(fetcharg(0, &pid) < 0)
+ return -1;
+ return proc_kill(pid);
+}
+
+int
+sys_getpid(void)
+{
+ struct proc *cp = curproc[cpu()];
+ return cp->pid;
+}
+
+int
+sys_sbrk(void)
+{
+ uint addr;
+ int n;
+ struct proc *cp = curproc[cpu()];
+
+ if(fetcharg(0, &n) < 0)
+ return -1;
+ if((addr = growproc(n)) == 0xffffffff)
+ return -1;
+ setupsegs(cp);
+ return addr;
+}