From f0ceac4c2e11a8cfd62ccb0a693178cae7c44d82 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Sat, 16 May 2020 16:21:42 +0200
Subject: Added page-aligned allocation for page-fix

Not completely finished!
---
 src/kernel/fs/elf.c        |  5 ++++-
 src/kernel/memory/alloc.c  |  8 ++++++++
 src/kernel/memory/alloc.h  |  1 +
 src/kernel/memory/paging.c | 17 +++++++++++------
 src/kernel/memory/paging.h |  2 +-
 src/kernel/tasks/process.c |  2 +-
 src/kernel/tasks/process.h |  2 +-
 7 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/kernel/fs/elf.c b/src/kernel/fs/elf.c
index ba9251a..3279784 100644
--- a/src/kernel/fs/elf.c
+++ b/src/kernel/fs/elf.c
@@ -51,8 +51,11 @@ struct process *elf_load(char *path)
 	strcpy(proc->name, path);
 	proc->registers.eip = header->entry;
 
+	log("1");
 	paging_switch_directory(proc->cr3);
+	log("2");
 	u32 stk = (u32)malloc(PAGE_SIZE);
+	log("3");
 	proc->registers.useresp = 0x40000000 - (PAGE_SIZE / 2);
 	proc->registers.ebp = proc->registers.useresp;
 	proc->registers.esp = proc->registers.useresp;
@@ -79,4 +82,4 @@ struct process *elf_load(char *path)
 
 	paging_switch_directory(prev_dir);
 	return proc;
-}
+}
\ No newline at end of file
diff --git a/src/kernel/memory/alloc.c b/src/kernel/memory/alloc.c
index a4fb60a..904be3a 100644
--- a/src/kernel/memory/alloc.c
+++ b/src/kernel/memory/alloc.c
@@ -361,6 +361,14 @@ void *malloc(u32 req_size)
 	return NULL;
 }
 
+// Definitely improveable
+void *valloc(u32 req_size)
+{
+	u32 mask = l_page_size - 1;
+	u32 mem = malloc(req_size + l_page_size);
+	return (void *)((mem + mask) & ~mask);
+}
+
 void free(void *ptr)
 {
 	struct liballoc_minor *min;
diff --git a/src/kernel/memory/alloc.h b/src/kernel/memory/alloc.h
index 6c4290e..2e8697f 100644
--- a/src/kernel/memory/alloc.h
+++ b/src/kernel/memory/alloc.h
@@ -4,6 +4,7 @@
 #include <stdint.h>
 
 void *malloc(u32);
+void *valloc(u32 req_size); // Page-aligned
 void *realloc(void *, u32);
 void *calloc(u32, u32);
 void free(void *);
diff --git a/src/kernel/memory/paging.c b/src/kernel/memory/paging.c
index de93ffb..380b7e0 100644
--- a/src/kernel/memory/paging.c
+++ b/src/kernel/memory/paging.c
@@ -13,12 +13,13 @@ void paging_init(u32 *dir, int user)
 {
 	for (u32 i = 0; i < 1024; i++) {
 		for (u32 j = 0; j < 1024; j++) {
-			current_page_tables[i][j] = ((j * 0x1000) + (i * 0x400000)) | PT_RW;
+			current_page_tables[i][j] =
+				((j * 0x1000) + (i * 0x400000)) | PT_RW | (user ? PT_USER : 0);
 		}
 	}
 
 	for (u32 i = 0; i < 1024; i++) {
-		current_page_directory[i] = ((u32)current_page_tables[i]) | PD_RW | PD_PRESENT;
+		dir[i] = ((u32)current_page_tables[i]) | PD_RW | PD_PRESENT | (user ? PD_USER : 0);
 	}
 }
 
@@ -26,6 +27,7 @@ extern void KERNEL_END();
 void paging_install(u32 multiboot_address)
 {
 	paging_switch_directory(kernel_page_directory);
+	current_page_tables = kernel_page_tables;
 	paging_init(current_page_directory, 0);
 
 	// if mmap approach didn't work
@@ -40,7 +42,8 @@ void paging_install(u32 multiboot_address)
 
 u32 *paging_make_directory(int user)
 {
-	u32 *dir = malloc(1024 * 1024 * 32);
+	u32 *dir = valloc(1024 * 1024 * 32);
+	current_page_tables = valloc(1024 * 1024 * 32);
 
 	paging_init(dir, user);
 
@@ -68,9 +71,11 @@ void paging_enable()
 
 void paging_switch_directory(u32 *dir)
 {
-	current_page_tables = kernel_page_tables;
+	current_page_tables = (u32(*)[1024])dir;
 	current_page_directory = dir;
-	asm("mov %0, %%cr3" ::"r"(current_page_directory));
+	log("huh");
+	asm("mov %0, %%cr3" ::"r"(dir));
+	log("huh");
 }
 
 void invlpg(u32 addr)
@@ -189,4 +194,4 @@ u32 paging_get_used_pages()
 		}
 	}
 	return n;
-}
+}
\ No newline at end of file
diff --git a/src/kernel/memory/paging.h b/src/kernel/memory/paging.h
index 8857381..9f37ed6 100644
--- a/src/kernel/memory/paging.h
+++ b/src/kernel/memory/paging.h
@@ -51,4 +51,4 @@ void paging_set_user(u32 virt, u32 count);
 u32 paging_find_pages(u32 count);
 u32 paging_alloc_pages(u32 count);
 
-#endif
+#endif
\ No newline at end of file
diff --git a/src/kernel/tasks/process.c b/src/kernel/tasks/process.c
index 75419ba..f90df89 100644
--- a/src/kernel/tasks/process.c
+++ b/src/kernel/tasks/process.c
@@ -232,4 +232,4 @@ u32 uspawn(char *path)
 	log("Spawned");
 	process_force_switch();
 	return 0;
-}
+}
\ No newline at end of file
diff --git a/src/kernel/tasks/process.h b/src/kernel/tasks/process.h
index 00f0f07..96ef44b 100644
--- a/src/kernel/tasks/process.h
+++ b/src/kernel/tasks/process.h
@@ -65,4 +65,4 @@ extern u32 stack_hold;
 #define WAIT_ERROR (-1)
 #define WAIT_OKAY 0
 
-#endif
+#endif
\ No newline at end of file
-- 
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