From da7b813fa9da617494048b8acee3d6ec21ba8a03 Mon Sep 17 00:00:00 2001
From: jD91mZM2 <me@krake.one>
Date: Sat, 15 Aug 2020 17:22:34 +0200
Subject: [PATCH] Investigate why user heap isn't mapped
Took me way too long to spot this :D
---
src/syscall/process.rs | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/syscall/process.rs b/src/syscall/process.rs
index e051197..9062d5f 100644
--- a/src/syscall/process.rs
+++ b/src/syscall/process.rs
@@ -455,14 +455,14 @@ pub fn clone(flags: CloneFlags, stack_base: usize) -> Result<ContextId> {
// Copy user heap mapping, if found
if let Some(heap_shared) = heap_opt {
- //TODO: find out why this gets unmapped (perhaps it is never mapped)
+ // This will not always be mapped. `context.heap` starts off
+ // with a size of zero, and then any call to `brk` increases
+ // it. But, if `brk` doesn't increase it, it's zero.
if let Some(frame) = active_table.p4()[crate::USER_HEAP_PML4].pointed_frame() {
let flags = active_table.p4()[crate::USER_HEAP_PML4].flags();
active_table.with(&mut new_table, &mut temporary_page, |mapper| {
mapper.p4_mut()[crate::USER_HEAP_PML4].set(frame, flags);
});
- } else {
- println!("clone: user heap not mapped for {:X?}", heap_shared);
}
context.heap = Some(heap_shared);
}
--
GitLab