From cdcb34486b6bea4923d1e257f90ce0756c6ac7e4 Mon Sep 17 00:00:00 2001
From: jD91mZM2 <me@krake.one>
Date: Tue, 7 Jul 2020 13:32:10 +0200
Subject: [PATCH] Keep singlestep across signals
---
src/arch/x86_64/macros.rs | 4 ++++
src/context/switch.rs | 12 ++++++++++--
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/src/arch/x86_64/macros.rs b/src/arch/x86_64/macros.rs
index 22fe5a3..5e9002f 100644
--- a/src/arch/x86_64/macros.rs
+++ b/src/arch/x86_64/macros.rs
@@ -323,6 +323,10 @@ impl InterruptStack {
self.iret.rflags &= !(1 << 8);
}
}
+ /// Checks if the trap flag is enabled, see `set_singlestep`
+ pub fn is_singlestep(&self) -> bool {
+ self.iret.rflags & 1 << 8 == 1 << 8
+ }
}
macro_rules! interrupt_push {
diff --git a/src/context/switch.rs b/src/context/switch.rs
index 6e10825..8516557 100644
--- a/src/context/switch.rs
+++ b/src/context/switch.rs
@@ -1,10 +1,11 @@
use core::sync::atomic::Ordering;
-use crate::context::{arch, contexts, Context, Status, CONTEXT_ID};
use crate::context::signal::signal_handler;
+use crate::context::{arch, contexts, Context, Status, CONTEXT_ID};
use crate::gdt;
-use crate::interrupt;
use crate::interrupt::irq::PIT_TICKS;
+use crate::interrupt;
+use crate::ptrace;
use crate::time;
unsafe fn update(context: &mut Context, cpu_id: usize) {
@@ -16,6 +17,8 @@ unsafe fn update(context: &mut Context, cpu_id: usize) {
// Restore from signal, must only be done from another context to avoid overwriting the stack!
if context.ksig_restore && ! context.running {
+ let was_singlestep = ptrace::regs_for(context).map(|s| s.is_singlestep()).unwrap_or(false);
+
let ksig = context.ksig.take().expect("context::switch: ksig not set with ksig_restore");
context.arch = ksig.0;
@@ -33,6 +36,11 @@ unsafe fn update(context: &mut Context, cpu_id: usize) {
context.ksig_restore = false;
+ // Keep singlestep flag across jumps
+ if let Some(regs) = ptrace::regs_for_mut(context) {
+ regs.set_singlestep(was_singlestep);
+ }
+
context.unblock();
}
--
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