[haiku-commits] BRANCH pdziepak-github.aslr - src/system/kernel/arch/x86/64 src/system/kernel/arch/x86/32 headers/private/system
- From: pdziepak-github.aslr <community@xxxxxxxxxxxx>
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Mon, 25 Feb 2013 16:15:37 +0100 (CET)
added 1 changeset to branch 'refs/remotes/pdziepak-github/aslr'
old head: 0000000000000000000000000000000000000000
new head: fe9b18223abc0c92e2bbf3d80df8dfaf22e680a8
overview: https://github.com/pdziepak/Haiku/compare/fe9b182
----------------------------------------------------------------------------
fe9b182: arch: randomize initial user stack pointer
Inside the page randomization of initial user stack pointer is not only a part
of ASLR implementation but also a performance improvement that helps
eliminating aligned 64 kB data access.
Minimal user stack size is increased to 8 kB in order to ensure that
regardless
of initial stack pointer value there is still enough space on stack.
[ Pawel Dziepak <pdziepak@xxxxxxxxxxx> ]
----------------------------------------------------------------------------
Commit: fe9b18223abc0c92e2bbf3d80df8dfaf22e680a8
Author: Pawel Dziepak <pdziepak@xxxxxxxxxxx>
Date: Mon Feb 25 02:26:49 2013 UTC
----------------------------------------------------------------------------
3 files changed, 21 insertions(+), 1 deletion(-)
headers/private/system/thread_defs.h | 2 +-
src/system/kernel/arch/x86/32/thread.cpp | 10 ++++++++++
src/system/kernel/arch/x86/64/thread.cpp | 10 ++++++++++
----------------------------------------------------------------------------
diff --git a/headers/private/system/thread_defs.h
b/headers/private/system/thread_defs.h
index 2d55937..3d7a3c1 100644
--- a/headers/private/system/thread_defs.h
+++ b/headers/private/system/thread_defs.h
@@ -15,7 +15,7 @@
#define USER_STACK_GUARD_SIZE (4 * B_PAGE_SIZE) // 16 kB
#define USER_MAIN_THREAD_STACK_SIZE (16 * 1024 * 1024) // 16 MB
#define USER_STACK_SIZE (256 * 1024)
// 256 kB
-#define MIN_USER_STACK_SIZE (4 * 1024)
// 4 KB
+#define MIN_USER_STACK_SIZE (8 * 1024)
// 8 kB
#define MAX_USER_STACK_SIZE (16 * 1024 * 1024)
// 16 MB
diff --git a/src/system/kernel/arch/x86/32/thread.cpp
b/src/system/kernel/arch/x86/32/thread.cpp
index 5878aac..9e13a7e 100644
--- a/src/system/kernel/arch/x86/32/thread.cpp
+++ b/src/system/kernel/arch/x86/32/thread.cpp
@@ -200,6 +200,14 @@ arch_thread_dump_info(void *info)
}
+static addr_t
+arch_randomize_stack_pointer(addr_t value)
+{
+ value -= rand() & (B_PAGE_SIZE - 1);
+ return value & ~0xful;
+}
+
+
/*! Sets up initial thread context and enters user space
*/
status_t
@@ -214,6 +222,8 @@ arch_thread_enter_userspace(Thread* thread, addr_t entry,
void* args1,
TRACE(("arch_thread_enter_userspace: entry 0x%lx, args %p %p, "
"ustack_top 0x%lx\n", entry, args1, args2, stackTop));
+ stackTop = arch_randomize_stack_pointer(stackTop);
+
// copy the little stub that calls exit_thread() when the thread entry
// function returns, as well as the arguments of the entry function
stackTop -= codeSize;
diff --git a/src/system/kernel/arch/x86/64/thread.cpp
b/src/system/kernel/arch/x86/64/thread.cpp
index 0379777..8c5c2fa 100644
--- a/src/system/kernel/arch/x86/64/thread.cpp
+++ b/src/system/kernel/arch/x86/64/thread.cpp
@@ -197,6 +197,14 @@ arch_thread_dump_info(void* info)
}
+static addr_t
+arch_randomize_stack_pointer(addr_t value)
+{
+ value -= rand() & (B_PAGE_SIZE - 1);
+ return value & ~0xful;
+}
+
+
/*! Sets up initial thread context and enters user space
*/
status_t
@@ -208,6 +216,8 @@ arch_thread_enter_userspace(Thread* thread, addr_t entry,
void* args1,
TRACE("arch_thread_enter_userspace: entry %#lx, args %p %p, "
"stackTop %#lx\n", entry, args1, args2, stackTop);
+ stackTop = arch_randomize_stack_pointer(stackTop);
+
// Copy the little stub that calls exit_thread() when the thread entry
// function returns.
// TODO: This will become a problem later if we want to support execute
Other related posts:
- » [haiku-commits] BRANCH pdziepak-github.aslr - src/system/kernel/arch/x86/64 src/system/kernel/arch/x86/32 headers/private/system - pdziepak-github . aslr
