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

Fix bug in userprog-merge where file writes were denied in the wrong thread

Browse Source
This commit is contained in:
Themis Demetriades
2024-11-12 16:22:32 +00:00
parent b0400693ae
commit d878dbc132
2 changed files with 9 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
src/threads/synch.c
View File

@@ -260,6 +260,7 @@ lock_acquire (struct lock *lock)
ASSERT (!lock_held_by_current_thread (lock)); ASSERT (!lock_held_by_current_thread (lock));
struct thread *t = thread_current (); struct thread *t = thread_current ();
ASSERT (t->waiting_lock == NULL);
enum intr_level old_level = intr_disable (); enum intr_level old_level = intr_disable ();
if (lock->holder != NULL) if (lock->holder != NULL)

9
src/userprog/process.c
View File

@@ -126,9 +126,16 @@ start_process (void *proc_start_data)
if_.gs = if_.fs = if_.es = if_.ds = if_.ss = SEL_UDSEG; if_.gs = if_.fs = if_.es = if_.ds = if_.ss = SEL_UDSEG;
if_.cs = SEL_UCSEG; if_.cs = SEL_UCSEG;
if_.eflags = FLAG_IF | FLAG_MBS; if_.eflags = FLAG_IF | FLAG_MBS;
lock_acquire (&filesys_lock); lock_acquire (&filesys_lock);
/* Prevent writing to the file being executed. */
struct file *exec_file = filesys_open (data->file_name);
thread_current ()->exec_file = exec_file;
file_deny_write(exec_file);
success = load (data->file_name, &if_.eip, &if_.esp); success = load (data->file_name, &if_.eip, &if_.esp);
lock_release (&filesys_lock); lock_release (&filesys_lock);
/* If load failed, quit. */ /* If load failed, quit. */