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Returning from Exceptions: Take stack_frame as reference

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Philipp Oppermann
2016-10-30 18:44:49 +01:00
parent e129da8cc2
commit 67857bde2f
1 changed files with 14 additions and 14 deletions
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28
blog/post/11-returning-from-exceptions.md
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@@ -40,7 +40,7 @@ Let's start by defining a handler function for the breakpoint exception:
```rust
// in src/interrupts/mod.rs
extern "C" fn breakpoint_handler(stack_frame: *const ExceptionStackFrame) -> !
extern "C" fn breakpoint_handler(stack_frame: &ExceptionStackFrame) -> !
{
let stack_frame = unsafe { &*stack_frame };
println!("\nEXCEPTION: BREAKPOINT at {:#x}\n{:#?}",
@@ -157,7 +157,7 @@ macro_rules! handler {
sub rsp, 8 // align the stack pointer
call $0"
:: "i"($name as extern "C" fn(
*const ExceptionStackFrame)) // no longer diverging
&ExceptionStackFrame)) // no longer diverging
: "rdi" : "intel", "volatile");
// new
@@ -180,16 +180,16 @@ We've changed the handler function type, so we need to adjust our existing excep
// in src/interrupts/mod.rs
extern "C" fn divide_by_zero_handler(
- stack_frame: *const ExceptionStackFrame) -> ! {...}
+ stack_frame: *const ExceptionStackFrame) {...}
- stack_frame: &ExceptionStackFrame) -> ! {...}
+ stack_frame: &ExceptionStackFrame) {...}
extern "C" fn invalid_opcode_handler(
- stack_frame: *const ExceptionStackFrame) -> ! {...}
+ stack_frame: *const ExceptionStackFrame) {...}
- stack_frame: &ExceptionStackFrame) -> ! {...}
+ stack_frame: &ExceptionStackFrame) {...}
extern "C" fn breakpoint_handler(
- stack_frame: *const ExceptionStackFrame) -> ! {
+ stack_frame: *const ExceptionStackFrame) {
- stack_frame: &ExceptionStackFrame) -> ! {
+ stack_frame: &ExceptionStackFrame) {
println!(...);
- loop {}
}
@@ -386,7 +386,7 @@ macro_rules! handler {
// sub rsp, 8 (stack is aligned already)
call $0"
:: "i"($name as
extern "C" fn(*const ExceptionStackFrame))
extern "C" fn(&ExceptionStackFrame))
: "rdi" : "intel", "volatile");
restore_scratch_registers!();
@@ -742,7 +742,7 @@ macro_rules! handler_with_error_code {
sub rsp, 8 // align the stack pointer
call $0"
:: "i"($name as extern "C" fn(
*const ExceptionStackFrame, u64))
&ExceptionStackFrame, u64))
: "rdi","rsi" : "intel");
asm!("iretq" :::: "intel", "volatile");
::core::intrinsics::unreachable();
@@ -760,7 +760,7 @@ Now we can make our `page_fault_handler` non-diverging:
```diff
// in src/interrupts/mod.rs
extern "C" fn page_fault_handler(stack_frame: *const ExceptionStackFrame,
extern "C" fn page_fault_handler(stack_frame: &ExceptionStackFrame,
- error_code: u64) -> ! { ... }
+ error_code: u64) { ... }
```
@@ -783,7 +783,7 @@ macro_rules! handler_with_error_code {
call $0
add rsp, 8 // undo stack pointer alignment
" :: "i"($name as extern "C" fn(
*const ExceptionStackFrame, u64))
&ExceptionStackFrame, u64))
: "rdi","rsi" : "intel");
restore_scratch_registers!();
asm!("iretq" :::: "intel", "volatile");
@@ -816,7 +816,7 @@ macro_rules! handler_with_error_code {
call $0
add rsp, 8 // undo stack pointer alignment
" :: "i"($name as extern "C" fn(
*const ExceptionStackFrame, u64))
&ExceptionStackFrame, u64))
: "rdi","rsi" : "intel");
restore_scratch_registers!();
asm!("add rsp, 8 // pop error code
@@ -872,7 +872,7 @@ Therefore we update our `page_fault_handler`:
{{< highlight rust "hl_lines=10 11 12 13 14 15 16" >}}
// in src/interrupts/mod.rs
extern "C" fn page_fault_handler(stack_frame: *const ExceptionStackFrame,
extern "C" fn page_fault_handler(stack_frame: &ExceptionStackFrame,
error_code: u64)
{
use x86::controlregs;