From db916dd9d597b1af38de1a87cd4e8b0f07cc227c Mon Sep 17 00:00:00 2001
From: vandechat96 <vandechat96@gmail.com>
Date: Wed, 10 May 2023 23:28:02 +0200
Subject: [PATCH] correct nmi handler / map page on pagefault (temp sol)

---
 src/arch/x86_64/interrupt/exception.rs | 17 ++++++++++++--
 src/arch/x86_64/interrupt/handler.rs   | 31 +++++++++++++++++---------
 src/syscall/mod.rs                     |  6 ++---
 3 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/src/arch/x86_64/interrupt/exception.rs b/src/arch/x86_64/interrupt/exception.rs
index 2cf1fdc..7462d76 100644
--- a/src/arch/x86_64/interrupt/exception.rs
+++ b/src/arch/x86_64/interrupt/exception.rs
@@ -1,3 +1,4 @@
+use syscall::Scheme;
 use crate::{
     interrupt::stack_trace,
     ptrace,
@@ -6,6 +7,7 @@ use crate::{
     interrupt_stack,
     interrupt_error,
 };
+use crate::scheme::memory::MemoryScheme;
 
 extern {
     fn ksignal(signal: usize);
@@ -13,6 +15,8 @@ extern {
 
 interrupt_stack!(divide_by_zero, |stack| {
     println!("Divide by zero");
+    const ADDR: usize = 0xDEADC0DE;
+    println!("value {}", unsafe { (ADDR as *const u8).read_volatile() });
     stack.dump();
     stack_trace();
     ksignal(SIGFPE);
@@ -144,8 +148,17 @@ interrupt_error!(page, |stack| {
     println!("  Instruction fetch: {}", stack.code & 1 << 4 != 0);
     stack.dump();
     stack_trace();
-    ksignal(SIGSEGV);
-    loop{};
+    // ksignal(SIGSEGV);
+
+    use crate::arch::paging::PAGE_SIZE;
+    use crate::syscall::data::Map;
+
+    let aligned_addr: usize = cr2 / PAGE_SIZE * PAGE_SIZE;
+    println!("{:x?}",aligned_addr);
+    let map = Map { offset: 0, address: aligned_addr, size: PAGE_SIZE, flags: MapFlags::MAP_FIXED_NOREPLACE | MapFlags::MAP_PRIVATE | MapFlags::PROT_READ | MapFlags::PROT_WRITE };
+    // let _ = syscall::fmap(!0, &map).expect("failed to re-map address");
+    let _ = MemoryScheme.fmap(!0,  &map ).expect("IDK") ;
+    //loop{}
 });
 
 interrupt_stack!(fpu_fault, |stack| {
diff --git a/src/arch/x86_64/interrupt/handler.rs b/src/arch/x86_64/interrupt/handler.rs
index 27991be..af157a8 100644
--- a/src/arch/x86_64/interrupt/handler.rs
+++ b/src/arch/x86_64/interrupt/handler.rs
@@ -443,8 +443,8 @@ macro_rules! interrupt_stack {
                 pop_scratch!(),
 
                 $rstor1!(),
-                 "
-                 // call {p2}
+                "
+                //call {p2}
                 ",
                 "iretq\n",
             ),
@@ -489,8 +489,8 @@ macro_rules! nmi_handler {
             }
              core::arch::asm!(concat!(
                 "
+                //call {frsp}
                 push rdx
-                // replace test come from kernel
                 cmp QWORD PTR [rsp + 8*2], {GDT_KERNEL_CODE}
                 jne first_nmi
                 ",
@@ -502,7 +502,7 @@ macro_rules! nmi_handler {
                 // if nmi stack
                 "
                 lea rdx, [rsp + 6*8]
-                cmp 4*8[rsp], rdx
+                cmp [rsp + 4*8], rdx
                 ja first_nmi
                 ",
                 // nested nmi
@@ -519,9 +519,9 @@ macro_rules! nmi_handler {
                 // prepare
                 "
                 1:
-                lea	    rdx, -1*8[rsp]
+                lea	    rdx, [rsp - 8]
                 mov 	rsp, rdx
-                lea  	rdx, -10*8[rsp]
+                lea  	rdx, [rsp - 10*8]
                 push    {GDT_KERNEL_DATA}
                 push	rdx
                 pushf
@@ -567,7 +567,7 @@ macro_rules! nmi_handler {
                 "
                 end_repeat_nmi:
                 ",
-                swapgs_iff_ring3_fast!(),
+                 swapgs_iff_ring3_fast!(),
                 "
                 push rax
                 ",
@@ -578,14 +578,15 @@ macro_rules! nmi_handler {
                 mov rdi,rsp
                 call {inner}
                 ",
-                // restore_gbase_paranoid!(),
+                // restore_gsbase_paranoid!(),
                 pop_preserved!(),
                 pop_scratch!(),
                 swapgs_iff_ring3_fast!(),
+                // remove extra frames and reset nmi exec var
                 "
                 //call {frsp}
                 7:
-                add	    rsp,$(6*8)
+                add	    rsp,$(12*8)
 
                 mov QWORD PTR 5*8[rsp], $0
 
@@ -600,6 +601,12 @@ macro_rules! nmi_handler {
             GDT_KERNEL_CODE = const(crate::gdt::GDT_KERNEL_CODE),
             GDT_KERNEL_DATA = const(crate::gdt::GDT_KERNEL_DATA),
 
+            // IA32_GS_BASE = const(x86::msr::IA32_GS_BASE),
+            // KERNEL_PERCPU_SHIFT = const(crate::KERNEL_PERCPU_SHIFT),
+            // KERNEL_PERCPU_OFFSET = const(crate::KERNEL_PERCPU_OFFSET),
+            //
+            // gdt_cpu_id_offset = const(crate::gdt::GDT_CPU_ID_CONTAINER * core::mem::size_of::<crate::gdt::GdtEntry>()),
+
             options(noreturn),
 
             );
@@ -672,8 +679,11 @@ macro_rules! interrupt_error {
                     $code
                 }
             }
-
+             fn hello(){
+                println!("hello int");
+            }
             core::arch::asm!(concat!(
+                //"call {hello}\n",
                 swapgs_iff_ring3_fast_errorcode!(),
                 // Move rax into code's place, put code in last instead (to be
                 // compatible with InterruptStack)
@@ -711,6 +721,7 @@ macro_rules! interrupt_error {
             ),
 
             inner = sym inner,
+            hello = sym hello,
 
             options(noreturn));
         }
diff --git a/src/syscall/mod.rs b/src/syscall/mod.rs
index e43a060..6d21158 100644
--- a/src/syscall/mod.rs
+++ b/src/syscall/mod.rs
@@ -62,9 +62,9 @@ pub mod validate;
 
 fn nmi_t() -> Result<usize>{
     println!("Yo");
-    // unsafe {
-    //     divide_by_zero();
-    // }
+    unsafe {
+        crate::arch::interrupt::exception::divide_by_zero();
+    }
     Ok(0)
 }