From 1df54429d71495c3833fc74d29c894a3091e3b7d Mon Sep 17 00:00:00 2001
From: Joshua Saxby <joshua.a.saxby@gmail.com>
Date: Thu, 5 Dec 2019 08:29:39 +0000
Subject: [PATCH] Fix both the close() and seek() system calls
---
Makefile.build | 1 +
userprog/syscall.c | 3 +++
userprog/syscall_close.c | 4 ++--
userprog/syscall_seek.c | 6 +++---
userprog/system_calls.h | 6 ++++++
5 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/Makefile.build b/Makefile.build
index 79cfbd7..c54f871 100644
--- a/Makefile.build
+++ b/Makefile.build
@@ -75,6 +75,7 @@ userprog_SRC += userprog/syscall_read.c
userprog_SRC += userprog/syscall_filesize.c
userprog_SRC += userprog/syscall_tell.c
userprog_SRC += userprog/syscall_seek.c
+userprog_SRC += userprog/syscall_close.c
# No virtual memory code yet.
#vm_SRC = vm/file.c # Some file.
diff --git a/userprog/syscall.c b/userprog/syscall.c
index c429f13..845508a 100644
--- a/userprog/syscall.c
+++ b/userprog/syscall.c
@@ -91,6 +91,9 @@ syscall_handler (struct intr_frame *f UNUSED)
case SYSCALL_SEEK:
syscall_seek(f);
break;
+ case SYSCALL_CLOSE:
+ syscall_close(f);
+ break;
default:
printf ("WARNING: Invalid Syscall (%d)\n", syscall_number);
thread_exit ();
diff --git a/userprog/syscall_close.c b/userprog/syscall_close.c
index 651173b..8508962 100644
--- a/userprog/syscall_close.c
+++ b/userprog/syscall_close.c
@@ -14,7 +14,7 @@
void syscall_close(struct intr_frame *f) {
// pop off first int argument from interrupt frame
- int* file_descriptor = (void*)(*(int*)f->esp + 1);
+ int file_descriptor = *((int*)f->esp + 1);
// Get file associated with file_descriptor
struct file *file = get_associated_file_pointer(file_descriptor);
if (file == NULL) { // Checking if file is empty or non-existent
@@ -25,4 +25,4 @@ void syscall_close(struct intr_frame *f) {
file_close(file);
// Remove the file_descriptor
disassociate_file_descriptor(file_descriptor);
-}
\ No newline at end of file
+}
diff --git a/userprog/syscall_seek.c b/userprog/syscall_seek.c
index a623496..9a665a1 100644
--- a/userprog/syscall_seek.c
+++ b/userprog/syscall_seek.c
@@ -13,10 +13,10 @@
void syscall_seek(struct intr_frame *f) {
// pop off first int argument from interrupt frame
- int* file_descriptor = (void*)*((int*)f->esp + 1);
+ int file_descriptor = *((int*)f->esp + 1);
// pop off second int argument from interrupt frame
- int* file_pos = (void*)(*(int*)f->esp + 2);
+ unsigned file_pos = *((unsigned*)((int*)f->esp + 2));
struct file *file = get_associated_file_pointer(file_descriptor);
// Seek through the file
file_seek(file, file_pos);
-}
\ No newline at end of file
+}
diff --git a/userprog/system_calls.h b/userprog/system_calls.h
index 4f955ad..49b8145 100644
--- a/userprog/system_calls.h
+++ b/userprog/system_calls.h
@@ -82,6 +82,12 @@ void syscall_tell(struct intr_frame *f);
*/
void syscall_seek(struct intr_frame *f);
+/*
+ * Closes file descriptor fd. Exiting or terminating a process implicitly closes
+ * all its open file descriptors, as if by calling this function for each one.
+ */
+void syscall_close(struct intr_frame *f);
+
/*
* special additional stuff for handling file descriptors because they're annoying
*/
--
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