From 70bf2a210423e9cb9766c786c1bb0cd828019d54 Mon Sep 17 00:00:00 2001
From: KAAAsS <admin@kaaass.net>
Date: Sun, 16 May 2021 17:17:26 +0800
Subject: [PATCH] finish exec3.9 and lab 3

---
 lab3/.gdbinit                     |  2 +-
 lab3/CMakeLists.txt               |  2 +-
 lab3/kernel/exception/exception.c |  5 +++++
 lab3/kernel/exception/pgfault.c   | 23 +++++++++++++++++++++++
 lab3/kernel/mm/vm_syscall.c       | 31 +++++++++++++++++++++++++++++++
 note.org                          |  8 ++++++++
 6 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/lab3/.gdbinit b/lab3/.gdbinit
index 598decb..98f1327 100644
--- a/lab3/.gdbinit
+++ b/lab3/.gdbinit
@@ -13,4 +13,4 @@ define add-symbol-file-auto
 end
 
 add-symbol-file-auto ./build/kernel.img
-add-symbol-file-auto ./user/build/ramdisk/hello.bin
+add-symbol-file-auto ./user/build/ramdisk/testpf.bin
diff --git a/lab3/CMakeLists.txt b/lab3/CMakeLists.txt
index 5588960..adc2b48 100644
--- a/lab3/CMakeLists.txt
+++ b/lab3/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required (VERSION 3.14)
 
 set(CMAKE_VERBOSE_MAKEFILE on)
 
-set(CMAKE_BUILD_TYPE "Debug")  # "Release" or "Debug"
+set(CMAKE_BUILD_TYPE "Release")  # "Release" or "Debug"
 set(CHCORE_PLAT "raspi3")
 set(CHCORE_ARCH "aarch64")
 
diff --git a/lab3/kernel/exception/exception.c b/lab3/kernel/exception/exception.c
index 8a141f9..70c5649 100644
--- a/lab3/kernel/exception/exception.c
+++ b/lab3/kernel/exception/exception.c
@@ -53,6 +53,11 @@ void handle_entry_c(int type, u64 esr, u64 address)
             // Unknown instruction
             kinfo("%s", UNKNOWN);
             sys_exit(-ESUPPORT);
+            break;
+        case ESR_EL1_EC_DABT_LEL:
+        case ESR_EL1_EC_DABT_CEL:
+            do_page_fault(esr, address);
+            break;
 	default:
 		kdebug("Unsupported Exception ESR %lx\n", esr);
 		break;
diff --git a/lab3/kernel/exception/pgfault.c b/lab3/kernel/exception/pgfault.c
index 33588d7..483120a 100644
--- a/lab3/kernel/exception/pgfault.c
+++ b/lab3/kernel/exception/pgfault.c
@@ -69,6 +69,7 @@ int handle_trans_fault(struct vmspace *vmspace, vaddr_t fault_addr)
 	struct pmobject *pmo;
 	paddr_t pa;
 	u64 offset;
+	int ret;
 
 	/*
 	 * Lab3: your code here
@@ -86,6 +87,28 @@ int handle_trans_fault(struct vmspace *vmspace, vaddr_t fault_addr)
 	 * are recorded in a radix tree for easy management. Such code
 	 * has been omitted in our lab for simplification.
 	 */
+	vmr = find_vmr_for_va(vmspace, fault_addr);
+	if (vmr == NULL) {
+        return -ENOMAPPING;
+	}
+
+	pmo = vmr->pmo;
+	if (pmo->type != PMO_ANONYM) {
+	    return -ENOMAPPING;
+	}
+
+	// 分配物理页
+	pa = virt_to_phys(kmalloc(PAGE_SIZE));
+	if ((void *) pa == NULL) {
+        return -ENOMAPPING;
+	}
+	// 应该调用但是此处省略：commit_page_to_pmo(pmo, ..., pa);
+
+	// 映射
+    ret = map_range_in_pgtbl(vmspace->pgtbl, ROUND_DOWN(fault_addr, PAGE_SIZE), pa, PAGE_SIZE, vmr->perm);
+	if (ret != 0) {
+        return -ENOMAPPING;
+	}
 
 	return 0;
 }
diff --git a/lab3/kernel/mm/vm_syscall.c b/lab3/kernel/mm/vm_syscall.c
index e567303..453130a 100644
--- a/lab3/kernel/mm/vm_syscall.c
+++ b/lab3/kernel/mm/vm_syscall.c
@@ -348,6 +348,37 @@ u64 sys_handle_brk(u64 addr)
 	 *
 	 */
 
+	if (vmspace->heap_vmr != NULL) {
+        retval = vmspace->heap_vmr->start + vmspace->heap_vmr->size;
+	} else {
+        retval = vmspace->user_current_heap;
+	}
+
+	if (addr == 0) {
+        // 初始化堆
+        if (vmspace->heap_vmr != NULL) {
+            // 已经初始化
+            return -EINVAL;
+        }
+
+        // 创建堆 PMO 对象
+        pmo = obj_alloc(TYPE_PMO, sizeof(*pmo));
+        if (!pmo) {
+            return -ENOMEM;
+        }
+        pmo_init(pmo, PMO_ANONYM, 0, 0);
+
+        // 初始化堆映射
+        vmspace->heap_vmr = init_heap_vmr(vmspace, vmspace->user_current_heap, pmo);
+	} else if (vmspace->heap_vmr != NULL && addr > retval) {
+	    // 增长堆
+        vmspace->heap_vmr->size = addr - vmspace->heap_vmr->start;
+        retval = addr;
+	} else if (vmspace->heap_vmr != NULL && addr < retval) {
+	    // 缩减堆
+        retval = -EINVAL;
+	}
+
 	/*
 	 * return origin heap addr on failure;
 	 * return new heap addr on success.
diff --git a/note.org b/note.org
index ae49152..e235e26 100644
--- a/note.org
+++ b/note.org
@@ -173,3 +173,11 @@ process_create_root、thread_create_main 直接写在注释里面了。
 *** 练习8
 
 这个是最离谱的。所谓退出其实就是输出里出现了“breakpoint”。实际上程序并不会退出（评测机倒是会）。
+
+*** 练习9
+
+这个的关键是分配一页。我直接用了 kernel 统一的 kmalloc，反正大小够大肯定是用伙伴堆。
+
+正常情况下还需要调用 commit_page_to_pmo 记录具体的分配物理页，要不然无法回收。但是注释说为了简便起见就不做了。
+
+顺便吐槽一下开了 Debug 日志就没办法通过样例了，因为 brk 样例触发缺页中断会输出一个 Debug，正好在"0,[Debug]...1,2,..."。