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Fixed x64 memory leaks upon process termination.

This commit is contained in:
Jonas 'Sortie' Termansen 2012-03-17 18:14:57 +01:00
parent 0364ce6f55
commit 4f3e22140c
3 changed files with 24 additions and 5 deletions
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4
sortix/x64/boot.s
View File

@ -78,8 +78,8 @@ multiboot_entry:
addl $0x1000, %edi
# Page-Directory (no user-space access here)
movl $0x24203, (%edi) # (First 2 MiB)
movl $0x25203, 8(%edi) # (Second 2 MiB)
movl $0x24003, (%edi) # (First 2 MiB)
movl $0x25003, 8(%edi) # (Second 2 MiB)
addl $0x1000, %edi
# Page-Table

22
sortix/x64/memorymanagement.cpp
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@ -35,6 +35,7 @@ namespace Sortix
{
extern size_t stackused;
extern size_t stacklength;
void ExtendStack();
}
namespace Memory
@ -131,17 +132,34 @@ namespace Sortix
void DestroyAddressSpace()
{
// Look up the last few entries used for the fractal mapping. These
// cannot be unmapped as that would destroy the world. Instead, we
// will remember them, switch to another adress space, and safely
// mark them as unused. Also handling the forking related pages.
addr_t fractal3 = (PMLS[4] + 0)->entry[510UL];
addr_t fork2 = (PMLS[3] + 510UL)->entry[0];
addr_t fractal2 = (PMLS[3] + 510UL)->entry[510];
addr_t fork1 = (PMLS[2] + 510UL * 512UL + 510UL)->entry[0];
addr_t fractal1 = (PMLS[2] + 510UL * 512UL + 510UL)->entry[510];
addr_t dir = currentdir;
// First let's do the safe part. Garbage collect any PML1/0's left
// behind by user-space. These are completely safe to delete.
RecursiveFreeUserspacePages(TOPPMLLEVEL, 0);
// TODO: Right now this just leaks memory.
// Switch to the address space from when the world was originally
// created. It should contain the kernel, the whole kernel, and
// nothing but the kernel.
PML* const BOOTPML4 = (PML* const) 0x21000UL;
SwitchAddressSpace((addr_t) BOOTPML4);
// Now safely mark the pages as unused.
Page::Put(fractal3 & PML_ADDRESS);
Page::Put(fractal2 & PML_ADDRESS);
Page::Put(fractal1 & PML_ADDRESS);
Page::Put(fork2 & PML_ADDRESS);
Page::Put(fork1 & PML_ADDRESS);
Page::Put(dir & PML_ADDRESS);
}
const size_t KERNEL_STACK_SIZE = 256UL * 1024UL;

3
sortix/x86/memorymanagement.cpp
View File

@ -140,7 +140,8 @@ namespace Sortix
// Make sure Page::Put does NOT cause any Page::Get's internally!
const size_t NUM_PAGES = 2;
if ( Page::stacklength - Page::stackused < NUM_PAGES ) { Page::ExtendStack(); }
size_t pagestackfree = Page::stacklength - Page::stackused;
if ( pagestackfree < NUM_PAGES ) { Page::ExtendStack(); }
addr_t fractal1 = PMLS[2]->entry[1022];