// Grow or shrink a file to exactly a specified size.
// If growing a file, then fills the new space with zeros.
// Returns 0 if successful, or returns -1 and sets errno on error.
int
fileino_truncate(int ino, off_t newsize)
{
assert(fileino_isvalid(ino));
assert(newsize >= 0 && newsize <= FILE_MAXSIZE);
size_t oldsize = files->fi[ino].size;
size_t oldpagelim = ROUNDUP(files->fi[ino].size, PAGESIZE);
size_t newpagelim = ROUNDUP(newsize, PAGESIZE);
if (newsize > oldsize) {
// Grow the file and fill the new space with zeros.
sys_get(SYS_PERM | SYS_READ | SYS_WRITE, 0, NULL, NULL,
FILEDATA(ino) + oldpagelim,
newpagelim - oldpagelim);
memset(FILEDATA(ino) + oldsize, 0, newsize - oldsize);
} else if (newsize > 0) {
// Shrink the file, but not all the way to empty.
// Would prefer to use SYS_ZERO to free the file content,
// but SYS_ZERO isn't guaranteed to work at page granularity.
sys_get(SYS_PERM, 0, NULL, NULL,
FILEDATA(ino) + newpagelim, FILE_MAXSIZE - newpagelim);
} else {
// Shrink the file to empty. Use SYS_ZERO to free completely.
sys_get(SYS_ZERO, 0, NULL, NULL, FILEDATA(ino), FILE_MAXSIZE);
}
files->fi[ino].size = newsize;
files->fi[ino].ver++; // truncation is always an exclusive change
return 0;
}
/*
* Register application in ctx. As the matter of fact it is normal
* to register it in app->ctx, but that depends on what you want.
*/
int
register_app(struct ctx_t *ctx, struct app_t *app)
{
struct str_t *app_name;
log(ctx, 0, "register app: %s\n", app->name);
/* Main application */
app_name = sys_get(ctx, "app");
if(NULL == app_name)
{
app_name = sys_create(ctx, "app", T_STR);
if(NULL == app_name)
return E_NOMEM;
}
else
log(ctx,1,"already got app [%s]!\n", app_name);
app_name->str = app->name;
app_name->len = strlen(app->name);
if(!add_app(ctx, app))
return E_SYS;
return E_NONE;
}
/*
* Only ints here
* Priority funcs are now generic so if you need make your own print
*/
void
print_parsers(struct ctx_t *src)
{
struct parser_t *p;
struct store_t *sys;
struct store_t *bs;
int i,j;
sys = sys_get(src, "parser");
if(NULL == sys)
log(ctx,4,"no parsers found\n");
else
{
log(ctx,4,"found parser array size %d\n", sys->last);
for(i = 0; i < sys->last; i++)
{
bs = store_idx_get(sys, i);
for(j = 0; j < bs->last; j++)
{
p = store_idx_get(bs, j);
log(src,4,"%s[%d] ", p->name, p->prio);
}
log(ctx,4,"\n");
}
log(ctx,4,"\n");
}
}
void *
parser_sys_init(struct ctx_t *dst)
{
struct store_t *sys;
if(NULL == SYS(dst))
return NULL;
log(dst, 4, "parser sys init\n");
sys = sys_get(dst, "parser");
if(NULL == sys)
{
log(dst, 4, "create parser sys\n");
sys = sys_create(dst, "parser", T_STORE);
if(NULL == sys)
return NULL;
store_set(sys, 2, sizeof(struct store_t), parserbscmp);
}
return sys;
}
void app_init_current( t_app *app)
{
char path[_PATH_];
if( sys_get( "pwd", path, _PATH_))
{
s_cp( app->path_current, path, _PATH_);
}
else
{
printf("[APP] Error, can't get current directory\n");
}
}
intptr_t
exec_copyargs(char *const argv[])
{
// Give the process a nice big 4MB, zero-filled stack.
sys_get(SYS_ZERO | SYS_PERM | SYS_READ | SYS_WRITE, 0, NULL,
NULL, (void*)VM_SCRATCHLO, PTSIZE);
#if SOL >= 4
// How many arguments?
int argc;
for (argc = 0; argv[argc] != NULL; argc++)
;
// Make room for the argv array
intptr_t esp = VM_STACKHI;
intptr_t scratchofs = VM_SCRATCHLO - (VM_STACKHI-PTSIZE);
esp -= (argc+1) * sizeof(intptr_t); // room for arguments plus NULL
intptr_t dargv = esp;
// Copy the argument strings
int i;
for (i = 0; i < argc; i++) {
int len = strlen(argv[i]);
esp -= len+1;
strcpy((void*)esp + scratchofs, argv[i]);
((intptr_t*)(dargv + scratchofs))[i] = esp;
}
esp &= ~3; // get esp word-aligned again
// Push the arguments to main()
esp -= 4; *(intptr_t*)(esp + scratchofs) = dargv;
esp -= 4; *(intptr_t*)(esp + scratchofs) = argc;
#else // ! SOL >= 4
// Lab 4: insert your code here to copy our command-line arguments
// onto the new process's stack, taking into account the fact that
// the stack area is mapped at VM_SCRATCHLO to VM_SCRATCHLO+PTSIZE
// in _our_ address space while we're copying the arguments,
// but the pointers we're writing into this space will be
// interpreted by the newly executed process,
// where the stack will be mapped from VM_STACKHI-PTSIZE to VM_STACKHI.
warn("exec_copyargs not implemented yet");
intptr_t esp = VM_STACKHI; // no arguments - fix this.
#endif // ! SOL >= 4
// Copy the stack into its correct position in child 0.
sys_put(SYS_COPY, 0, NULL, (void*)VM_SCRATCHLO,
(void*)VM_STACKHI-PTSIZE, PTSIZE);
return esp;
}
/*
* Add app to context
* Creates system called app->name and put app in it
*/
int
add_app(struct ctx_t *ctx, struct app_t *app)
{
struct app_t *sys;
sys = sys_get(ctx, app->name);
if(NULL == sys)
{
sys = sys_create(ctx, app->name, T_APP);
if(NULL == sys)
return E_NOMEM;
}
else
log(ctx,1,"warn: already got [%s] system!\n", app->name);
memcpy(sys, app, sizeof(struct app_t));
return E_NONE;
}
// Write 'count' data elements each of size 'eltsize'
// starting at absolute byte offset 'ofs' within the file in inode 'ino'.
// Returns the number of elements actually written,
// which should always be equal to the 'count' input parameter
// unless an error occurs, in which case this function
// returns -1 and sets errno appropriately.
// Since PIOS files can be up to only FILE_MAXSIZE bytes in size (4MB),
// one particular reason an error might occur is if an application
// tries to grow a file beyond this maximum file size,
// in which case this function generates the EFBIG error.
ssize_t
fileino_write(int ino, off_t ofs, const void *buf, size_t eltsize, size_t count)
{
assert(fileino_isreg(ino));
assert(ofs >= 0);
assert(eltsize > 0);
fileinode *fi = &files->fi[ino];
assert(fi->size <= FILE_MAXSIZE);
#if SOL >= 4
// Return an error if we'd be growing the file too big.
size_t len = eltsize * count;
size_t lim = ofs + len;
if (lim < ofs || lim > FILE_MAXSIZE) {
errno = EFBIG;
return -1;
}
// Grow the file as necessary.
if (lim > fi->size) {
size_t oldpagelim = ROUNDUP(fi->size, PAGESIZE);
size_t newpagelim = ROUNDUP(lim, PAGESIZE);
if (newpagelim > oldpagelim)
sys_get(SYS_PERM | SYS_READ | SYS_WRITE, 0, NULL, NULL,
FILEDATA(ino) + oldpagelim,
newpagelim - oldpagelim);
fi->size = lim;
}
// Write the data.
memmove(FILEDATA(ino) + ofs, buf, len);
return count;
#else // ! SOL >= 4
// Lab 4: insert your file writing code here.
warn("fileino_write() not implemented");
errno = EINVAL;
return -1;
#endif // ! SOL >= 4
}
void app_init_home( t_app *app)
{
int size = 16;
char name[size];
int size_home = _PATH_;
char path_home[size_home];
sys_get( "whoami", name, size);
s_cp( path_home, "/home/", size_home);
s_cat( path_home, name, size);
s_cat( path_home, "/.minuit/", size_home);
if( !sys_file_exists( path_home))
{
printf("Creating minuit home directory: %s\n", path_home);
mkdir( path_home, 0777);
}
s_cp( app->path_home, path_home, _PATH_);
}
void *
parser_scope_init(struct ctx_t *scope)
{
struct store_t *sys;
if(NULL == SYS(scope))
return NULL;
sys = sys_get(scope, "parser");
if(NULL == sys)
{
sys = sys_create(scope, "parser", T_STORE);
if(NULL == sys)
return NULL;
store_set(sys, 2, sizeof(struct store_t), pbscmp);
}
return sys;
}
void migrate(int node)
{
cprintf("testmigr: migrating to node %d...\n", node);
sys_get(0, (node << 8) | 0, NULL, NULL, NULL, 0);
cprintf("testmigr: now on node %d.\n", node);
}
void
proc_check(void)
{
// Spawn 2 child processes, executing on statically allocated stacks.
cprintf("in proc_check()\n");
int i;
for (i = 0; i < 4; i++) {
// Setup register state for child
uint32_t *esp = (uint32_t*) &child_stack[i][PAGESIZE];
*--esp = i; // push argument to child() function
*--esp = 0; // fake return address
child_state.tf.eip = (uint32_t) child;
child_state.tf.esp = (uint32_t) esp;
// Use PUT syscall to create each child,
// but only start the first 2 children for now.
cprintf("spawning child %d\n", i);
sys_put(SYS_REGS | (i < 2 ? SYS_START : 0), i, &child_state,
NULL, NULL, 0);
}
cprintf("proc_check() created childs\n");
// Wait for both children to complete.
// This should complete without preemptive scheduling
// when we're running on a 2-processor machine.
for (i = 0; i < 2; i++) {
cprintf("waiting for child %d\n", i);
sys_get(SYS_REGS, i, &child_state, NULL, NULL, 0);
}
cprintf("proc_check() 2-child test succeeded\n");
// (Re)start all four children, and wait for them.
// This will require preemptive scheduling to complete
// if we have less than 4 CPUs.
cprintf("proc_check: spawning 4 children\n");
for (i = 0; i < 4; i++) {
cprintf("spawning child %d\n", i);
sys_put(SYS_START, i, NULL, NULL, NULL, 0);
}
// Wait for all 4 children to complete.
for (i = 0; i < 4; i++)
sys_get(0, i, NULL, NULL, NULL, 0);
cprintf("proc_check() 4-child test succeeded\n");
// Now do a trap handling test using all 4 children -
// but they'll _think_ they're all child 0!
// (We'll lose the register state of the other children.)
i = 0;
sys_get(SYS_REGS, i, &child_state, NULL, NULL, 0);
// get child 0's state
assert(recovargs == NULL);
do {
sys_put(SYS_REGS | SYS_START, i, &child_state, NULL, NULL, 0);
sys_get(SYS_REGS, i, &child_state, NULL, NULL, 0);
if (recovargs) { // trap recovery needed
trap_check_args *args = recovargs;
cprintf("recover from trap %d\n",
child_state.tf.trapno);
child_state.tf.eip = (uint32_t) args->reip;
args->trapno = child_state.tf.trapno;
} else
assert(child_state.tf.trapno == T_SYSCALL);
i = (i+1) % 4; // rotate to next child proc
} while (child_state.tf.trapno != T_SYSCALL);
assert(recovargs == NULL);
cprintf("proc_check() trap reflection test succeeded\n");
cprintf("proc_check() succeeded!\n");
}
int
exec_readelf(const char *path)
{
// We'll load the ELF image into a scratch area in our address space.
sys_get(SYS_ZERO, 0, NULL, NULL, (void*)VM_SCRATCHLO, EXEMAX);
// Open the ELF image to load.
filedesc *fd = filedesc_open(NULL, path, O_RDONLY, 0);
if (fd == NULL)
return -1;
void *imgdata = FILEDATA(fd->ino);
size_t imgsize = files->fi[fd->ino].size;
// Make sure it looks like an ELF image.
elfhdr *eh = imgdata;
if (imgsize < sizeof(*eh) || eh->e_magic != ELF_MAGIC) {
warn("exec_readelf: ELF header not found");
goto err;
}
// Load each program segment into the scratch area
proghdr *ph = imgdata + eh->e_phoff;
proghdr *eph = ph + eh->e_phnum;
if (imgsize < (void*)eph - imgdata) {
warn("exec_readelf: ELF program header truncated");
goto err;
}
for (; ph < eph; ph++) {
if (ph->p_type != ELF_PROG_LOAD)
continue;
// The executable should fit in the first 4MB of user space.
intptr_t valo = ph->p_va;
intptr_t vahi = valo + ph->p_memsz;
if (valo < VM_USERLO || valo > VM_USERLO+EXEMAX ||
vahi < valo || vahi > VM_USERLO+EXEMAX) {
warn("exec_readelf: executable image too large "
"(%d bytes > %d max)", vahi-valo, EXEMAX);
goto err;
}
// Map all pages the segment touches in our scratch region.
// They've already been zeroed by the SYS_ZERO above.
intptr_t scratchofs = VM_SCRATCHLO - VM_USERLO;
intptr_t pagelo = ROUNDDOWN(valo, PAGESIZE);
intptr_t pagehi = ROUNDUP(vahi, PAGESIZE);
sys_get(SYS_PERM | SYS_READ | SYS_WRITE, 0, NULL, NULL,
(void*)pagelo + scratchofs, pagehi - pagelo);
// Initialize the file-loaded part of the ELF image.
// (We could use copy-on-write if SYS_COPY
// supports copying at arbitrary page boundaries.)
intptr_t filelo = ph->p_offset;
intptr_t filehi = filelo + ph->p_filesz;
if (filelo < 0 || filelo > imgsize
|| filehi < filelo || filehi > imgsize) {
warn("exec_readelf: loaded section out of bounds");
goto err;
}
memcpy((void*)valo + scratchofs, imgdata + filelo,
filehi - filelo);
// Finally, remove write permissions on read-only segments.
if (!(ph->p_flags & ELF_PROG_FLAG_WRITE))
sys_get(SYS_PERM | SYS_READ, 0, NULL, NULL,
(void*)pagelo + scratchofs, pagehi - pagelo);
}
// Copy the ELF image into its correct position in child 0.
sys_put(SYS_COPY, 0, NULL, (void*)VM_SCRATCHLO,
(void*)VM_USERLO, EXEMAX);
// The new program should have the same entrypoint as we do!
if (eh->e_entry != (intptr_t)start) {
warn("exec_readelf: executable has a different start address");
goto err;
}
filedesc_close(fd); // Done with the ELF file
return 0;
err:
filedesc_close(fd);
return -1;
}