From f5f3e51c9e3e1fdd7284f86ade2c3379f1a864c2 Mon Sep 17 00:00:00 2001
From: sambarr <s3-barr@>
Date: Thu, 13 Jul 2023 14:42:20 +0100
Subject: [PATCH] setup stack and started syscalls
---
src/threads/thread.c | 2 +
src/userprog/process.c | 134 +++++++++++++++++++++++++++++++++++++++--
src/userprog/syscall.c | 36 ++++++++++-
3 files changed, 165 insertions(+), 7 deletions(-)
diff --git a/src/threads/thread.c b/src/threads/thread.c
index 052302f..1551f61 100644
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -188,7 +188,9 @@ thread_create (const char *name, int priority,
return TID_ERROR;
/* Initialize thread. */
+ //printf("Starting init_thread\n");
init_thread (t, name, priority);
+ //printf("Finished init_thread\n");
tid = t->tid = allocate_tid ();
/* Stack frame for kernel_thread(). */
diff --git a/src/userprog/process.c b/src/userprog/process.c
index d51339a..a4fbbee 100644
--- a/src/userprog/process.c
+++ b/src/userprog/process.c
@@ -29,6 +29,8 @@ tid_t
process_execute (const char *file_name)
{
char *fn_copy;
+ char *process_name;
+ char *save_ptr;
tid_t tid;
/* Make a copy of FILE_NAME.
@@ -38,9 +40,13 @@ process_execute (const char *file_name)
return TID_ERROR;
strlcpy (fn_copy, file_name, PGSIZE);
- /* Create a new thread to execute FILE_NAME. */
- tid = thread_create (file_name, PRI_DEFAULT, start_process, fn_copy);
+ // Extract process name from file
+ process_name = fn_copy + strlen(fn_copy)+1;
+ strlcpy(process_name, file_name, strlen(file_name)+1);
+ process_name = strtok_r(process_name, " ", &save_ptr);
+ /* Create a new thread to execute FILE_NAME. */
+ tid = thread_create (process_name, PRI_DEFAULT, start_process, fn_copy);
if (tid == TID_ERROR)
palloc_free_page (fn_copy);
return tid;
@@ -61,6 +67,7 @@ start_process (void *file_name_)
if_.cs = SEL_UCSEG;
if_.eflags = FLAG_IF | FLAG_MBS;
+ printf("Starting Load\n");
success = load (file_name, &if_.eip, &if_.esp);
/* If load failed, quit. */
@@ -103,6 +110,8 @@ process_exit (void)
struct thread *cur = thread_current ();
uint32_t *pd;
+ printf("%s:exit_code(%d)\n",cur->name);
+
/* Destroy the current process's page directory and switch back
to the kernel-only page directory. */
pd = cur->pagedir;
@@ -200,7 +209,7 @@ struct Elf32_Phdr
#define PF_W 2 /* Writable. */
#define PF_R 4 /* Readable. */
-static bool setup_stack (void **esp);
+static bool setup_stack (void **esp, char *file_name);
static bool validate_segment (const struct Elf32_Phdr *, struct file *);
static bool load_segment (struct file *file, off_t ofs, uint8_t *upage,
uint32_t read_bytes, uint32_t zero_bytes,
@@ -227,7 +236,14 @@ load (const char *file_name, void (**eip) (void), void **esp)
process_activate ();
/* Open executable file. */
- file = filesys_open (file_name);
+ char * fn_cp = malloc(strlen(file_name)+1);
+ strlcpy(fn_cp, file_name, strlen(file_name)+1);
+ char * save_ptr;
+ fn_cp = strtok_r(fn_cp," ", &save_ptr);
+
+ printf("Looking for file: %s\n",fn_cp);
+ file = filesys_open (fn_cp);
+ free(fn_cp);
if (file == NULL)
{
@@ -308,7 +324,7 @@ load (const char *file_name, void (**eip) (void), void **esp)
}
/* Set up stack. */
- if (!setup_stack (esp))
+ if (!setup_stack (esp, file_name))
goto done;
/* Start address. */
@@ -430,14 +446,51 @@ load_segment (struct file *file, off_t ofs, uint8_t *upage,
return true;
}
+// Used in setupstack to reverse tokens
+void reverse(char* begin, char* end)
+{
+ char temp;
+ while (begin < end) {
+ temp = *begin;
+ *begin++ = *end;
+ *end-- = temp;
+ }
+}
+
+// Function to reverse words*/
+void reverseWords(char* s)
+{
+ char* word_begin = s;
+
+ // Word boundary
+ char* temp = s;
+
+ // Reversing individual words as
+ // explained in the first step
+ while (*temp) {
+ temp++;
+ if (*temp == '\0') {
+ reverse(word_begin, temp - 1);
+ }
+ else if (*temp == ' ') {
+ reverse(word_begin, temp - 1);
+ word_begin = temp + 1;
+ }
+ }
+
+ // Reverse the entire string
+ reverse(s, temp - 1);
+}
+
/* Create a minimal stack by mapping a zeroed page at the top of
user virtual memory. */
static bool
-setup_stack (void **esp)
+setup_stack (void **esp, char *file_name)
{
uint8_t *kpage;
bool success = false;
+ printf("Setting up stack\n");
kpage = palloc_get_page (PAL_USER | PAL_ZERO);
if (kpage != NULL)
{
@@ -447,6 +500,75 @@ setup_stack (void **esp)
} else
palloc_free_page (kpage);
}
+
+ char *token;
+ char *save_ptr;
+
+ // Initial size of 2, will be incremented as needed
+ int argv_size = 2;
+ int argc = 0;
+ char ** argv = malloc(argv_size * sizeof(char *));
+
+ // Convert char* to char array
+ char str[100];
+ for (int j=0; j<strlen(file_name)+1; j++)
+ {
+ str[j] = file_name[j];
+ }
+
+ // Reverse the filename such that arguments are first
+ reverseWords(str);
+ char *rev;
+ rev=str;
+
+ for (token = strtok_r(rev, " ", &save_ptr); token!=NULL;
+ token = strtok_r(NULL, " ", &save_ptr))
+ {
+ *esp -= strlen(token) + 1;
+ argv[argc] = *esp;
+ argc++;
+
+ if (argc >= 64)
+ {
+ free(argv);
+ return false;
+ }
+
+ if (argc >= argv_size)
+ {
+ argv_size *= 2;
+ argv = realloc(argv, argv_size* sizeof(char*));
+ }
+ memcpy(*esp,token,strlen(token)+1);
+
+ //hex_dump(PHYS_BASE, *esp, PHYS_BASE-(*esp),true);
+ }
+
+ argv[argc] = 0;
+
+ // Load
+ int i = 0;
+ for (i=argc; i>=0; i--)
+ {
+ *esp -= sizeof(char*);
+ memcpy(*esp, &argv[i], sizeof(char*));
+ }
+
+ //Push argv address to stack
+ token = *esp;
+ *esp-=sizeof(char**);
+ memcpy(*esp,&token,sizeof(char**));
+
+ // Push argc to stack
+ *esp -= sizeof(int);
+ memcpy(*esp, &argc, sizeof(int));
+
+ // Push NULL Pointer
+ *esp -= sizeof(void*);
+ memcpy(*esp, &argv[argc], sizeof(void*));
+ free(argv);
+
+ hex_dump(PHYS_BASE, *esp, PHYS_BASE-(*esp),true);
return success;
}
diff --git a/src/userprog/syscall.c b/src/userprog/syscall.c
index 0463515..08e82c9 100644
--- a/src/userprog/syscall.c
+++ b/src/userprog/syscall.c
@@ -3,8 +3,11 @@
#include <syscall-nr.h>
#include "threads/interrupt.h"
#include "threads/thread.h"
+#include "devices/shutdown.h"
static void syscall_handler (struct intr_frame *);
+void syscall_exit(int status);
+void syscall_halt(void);
void
syscall_init (void)
@@ -14,8 +17,39 @@ syscall_init (void)
static void
-syscall_handler (struct intr_frame *f UNUSED)
+syscall_handler (struct intr_frame *f)
{
printf ("system call!\n");
+ int sys_code = *(int*)f->esp;
+
+ printf("System call number: %d\n", sys_code);
+
+ switch(sys_code) {
+
+ case SYS_EXIT:
+ printf("Running SYS_EXIT\n");
+ //syscall_exit();
+ break;
+
+ case SYS_HALT:
+ printf("Running SYS_HALT\n");
+ syscall_halt();
+ break;
+
+ default:
+ printf("Unknown Syscall number\n");
+ break;
+ }
+
thread_exit ();
}
+
+
+/* System Call Implementations*/
+
+void syscall_exit(int status);
+
+void syscall_halt()
+{
+ shutdown_power_off();
+}
--
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