task: push error stack instead of normal one

Signed-off-by: Andy-Python-Programmer <[email protected]>

Author: Andy-Python-Programmer

src/aero_kernel/src/arch/x86_64/syscall.rs

@@ -6,7 +6,7 @@ use crate::mem::paging::VirtAddr;
 use crate::userland::scheduler;
 use crate::utils::io;
 
-use super::interrupts::InterruptStack;
+use super::interrupts::InterruptErrorStack;
 
 extern "C" {
     fn x86_64_syscall_handler();
@@ -54,7 +54,9 @@ fn arch_prctl(command: usize, address: usize) -> Result<usize, AeroSyscallError>
 }
 
 #[no_mangle]
-extern "C" fn x86_64_do_syscall(stack: &mut InterruptStack) {
+extern "C" fn x86_64_do_syscall(stack: &mut InterruptErrorStack) {
+    let stack = &mut stack.stack;
+
     let syscall_number = stack.scratch.rax as usize; // syscall number
     let a = stack.scratch.rdi as usize; // argument 1
     let b = stack.scratch.rsi as usize; // argument 2

src/aero_kernel/src/arch/x86_64/syscall_handler.asm

@@ -79,12 +79,19 @@ x86_64_syscall_handler:
     push r14
     push r15
 
+    ; push a "fake" error code to match with the layout of the
+    ; `InterruptErrorStack` structure.
+    push 0
+
     mov rdi, rsp
 
     cld
     call x86_64_do_syscall
     cli
 
+    ; pop the "fake" error code
+    add rsp, 8
+
     ; pop the preserved registers
     pop r15
     pop r14

src/aero_kernel/src/arch/x86_64/task.asm

@@ -44,6 +44,9 @@ iretq_init:
     jmp generic_iretq_init
 
 generic_iretq_init:
+    ; pop the error code
+    add rsp, 8
+
     ; pop the preserved registers
     pop r15
     pop r14

src/aero_kernel/src/arch/x86_64/task.rs

@@ -40,7 +40,7 @@ use alloc::vec::Vec;
 use core::alloc::Layout;
 use core::ptr::Unique;
 
-use crate::arch::interrupts::InterruptStack;
+use crate::arch::interrupts::InterruptErrorStack;
 use crate::fs::cache::DirCacheItem;
 use crate::mem::paging::*;
 use crate::syscall::ExecArgs;
@@ -147,13 +147,13 @@ impl ArchTask {
         let mut stack_ptr = task_stack as u64;
         let mut stack = StackHelper::new(&mut stack_ptr);
 
-        let kframe = unsafe { stack.offset::<InterruptStack>() };
+        let kframe = unsafe { stack.offset::<InterruptErrorStack>() };
 
-        kframe.iret.ss = 0x10; // kernel stack segment
-        kframe.iret.cs = 0x08; // kernel code segment
-        kframe.iret.rip = entry_point.as_u64();
-        kframe.iret.rsp = unsafe { task_stack.sub(8) as u64 };
-        kframe.iret.rflags = if enable_interrupts { 0x200 } else { 0x00 };
+        kframe.stack.iret.ss = 0x10; // kernel stack segment
+        kframe.stack.iret.cs = 0x08; // kernel code segment
+        kframe.stack.iret.rip = entry_point.as_u64();
+        kframe.stack.iret.rsp = unsafe { task_stack.sub(8) as u64 };
+        kframe.stack.iret.rflags = if enable_interrupts { 0x200 } else { 0x00 };
 
         extern "C" {
             fn iretq_init();
@@ -208,11 +208,11 @@ impl ArchTask {
         let mut new_stack = StackHelper::new(&mut new_stack_ptr);
 
         unsafe {
-            let registers_frame = new_stack.offset::<InterruptStack>();
-            let old_registers_frame = old_stack.offset::<InterruptStack>();
+            let registers_frame = new_stack.offset::<InterruptErrorStack>();
+            let old_registers_frame = old_stack.offset::<InterruptErrorStack>();
 
             *registers_frame = *old_registers_frame;
-            registers_frame.scratch.rax = 0x00; // Set the syscall result to 0
+            registers_frame.stack.scratch.rax = 0x00; // Set the syscall result to 0
         }
 
         // Prepare the trampoline...