Imperial-MEng/pintos_22
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'virtual-memory' into 'ethan-stack-growth'

Browse Source 
# Conflicts:
#   src/Makefile.build
This commit is contained in:
Demetriades, Themis
2024-11-30 23:21:16 +00:00
parent 13de832586 5682974f9d
commit d8edc6d3fe
7 changed files with 353 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
src/userprog/process.c
View File

@@ -24,6 +24,9 @@
#include "threads/vaddr.h"
#include "threads/synch.h"
#include "devices/timer.h"
#ifdef VM
#include "vm/frame.h"
#endif
/* Defines the native number of bytes processed by the processor
(for the purposes of alignment). */
@@ -113,7 +116,10 @@ process_execute (const char *cmd)
return tid;
}
static void *get_usr_kpage (enum palloc_flags flags, void *upage);
static void free_usr_kpage (void *kpage);
static bool install_page (void *upage, void *kpage, bool writable);
static bool process_init_stack (char *cmd_saveptr, void **esp, char *file_name);
static void *push_to_stack (void **esp, void *data, size_t data_size);
#define push_var_to_stack(esp, var) (push_to_stack (esp, &var, sizeof (var)))
@@ -251,12 +257,13 @@ process_init_stack (char *cmd_saveptr, void **esp, char *file_name)
int pages_needed = DIV_CEIL (overflow_bytes, PGSIZE);
/* Allocate the pages and map them to the user process. */
void *upage;
uint8_t *kpage;
for (int i = 1; i < pages_needed + 1; i++)
{
uint8_t *kpage = palloc_get_page (PAL_USER | PAL_ZERO);
if (!install_page (((uint8_t *) PHYS_BASE) - PGSIZE * (i + 1),
kpage, true))
return false;
upage = ((uint8_t *) PHYS_BASE) - PGSIZE * (i + 1);
kpage = get_usr_kpage (PAL_ZERO, upage);
if (!install_page (upage, kpage, true)) return false;
}
}
@@ -704,7 +711,7 @@ load_segment (struct file *file, off_t ofs, uint8_t *upage,
if (kpage == NULL){
/* Get a new page of memory. */
kpage = palloc_get_page (PAL_USER);
kpage = get_usr_kpage (0, upage);
if (kpage == NULL){
return false;
}
@@ -712,7 +719,7 @@ load_segment (struct file *file, off_t ofs, uint8_t *upage,
/* Add the page to the process's address space. */
if (!install_page (upage, kpage, writable))
{
palloc_free_page (kpage);
free_usr_kpage (kpage);
return false;
}
@@ -746,19 +753,53 @@ setup_stack (void **esp)
{
uint8_t *kpage;
bool success = false;
kpage = palloc_get_page (PAL_USER | PAL_ZERO);
void *upage = ((uint8_t *) PHYS_BASE) - PGSIZE;
kpage = get_usr_kpage (PAL_ZERO, upage);
if (kpage != NULL)
{
success = install_page (((uint8_t *) PHYS_BASE) - PGSIZE, kpage, true);
success = install_page (upage, kpage, true);
if (success)
*esp = PHYS_BASE;
else
palloc_free_page (kpage);
free_usr_kpage (kpage);
}
return success;
}
/* Claims a page from the user pool for ownership by the current thread
and returns its kernel address, updating the frame table if VM
is enabled. Requires the intended virtual address for where the page
will be installed. */
static void *
get_usr_kpage (enum palloc_flags flags, void *upage)
{
void *page;
#ifdef VM
struct thread *t = thread_current ();
if (pagedir_get_page (t->pagedir, upage) != NULL)
return NULL;
else
page = frame_alloc (flags, upage, t);
#else
page = palloc_get_page (flags | PAL_USER);
#endif
return page;
}
/* Frees a page belonging to a user process given its kernel address,
updating the frame table if VM is enabled. */
static void
free_usr_kpage (void *kpage)
{
#ifdef VM
frame_free (kpage);
#else
palloc_free_page (kpage);
#endif
}
/* Adds a mapping from user virtual address UPAGE to kernel
virtual address KPAGE to the page table.
If WRITABLE is true, the user process may modify the page;