mirror of
https://github.com/Divested-Mobile/DivestOS-Build.git
synced 2024-10-01 01:35:54 -04:00
75 lines
2.1 KiB
Diff
75 lines
2.1 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Daniel Micay <danielmicay@gmail.com>
|
|
Date: Sun, 8 Feb 2015 01:18:54 -0500
|
|
Subject: [PATCH] replace brk and sbrk with stubs
|
|
|
|
Pretend that there is never room to grow the heap in order to prevent
|
|
usage of these unsafe legacy functions. There are likely no users of
|
|
these in practice as it is inherently broken to use them outside of
|
|
malloc.
|
|
---
|
|
libc/bionic/brk.cpp | 48 ++++++++-------------------------------------
|
|
1 file changed, 8 insertions(+), 40 deletions(-)
|
|
|
|
diff --git a/libc/bionic/brk.cpp b/libc/bionic/brk.cpp
|
|
index 566c33a7a..ef9305513 100644
|
|
--- a/libc/bionic/brk.cpp
|
|
+++ b/libc/bionic/brk.cpp
|
|
@@ -29,48 +29,16 @@
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
|
|
-#if defined(__LP64__)
|
|
-static void* __bionic_brk;
|
|
-#else
|
|
-void* __bionic_brk; // Accidentally exported by the NDK.
|
|
+#if !defined(__LP64__)
|
|
+void* __bionic_brk = reinterpret_cast<void*>(-1); // Accidentally exported by the NDK.
|
|
#endif
|
|
|
|
-extern "C" void* __brk(void* __addr);
|
|
-
|
|
-int brk(void* end_data) {
|
|
- __bionic_brk = __brk(end_data);
|
|
- if (__bionic_brk < end_data) {
|
|
- errno = ENOMEM;
|
|
- return -1;
|
|
- }
|
|
- return 0;
|
|
+int brk(void*) {
|
|
+ errno = ENOMEM;
|
|
+ return -1;
|
|
}
|
|
|
|
-void* sbrk(ptrdiff_t increment) {
|
|
- // Initialize __bionic_brk if necessary.
|
|
- if (__bionic_brk == nullptr) {
|
|
- __bionic_brk = __brk(nullptr);
|
|
- }
|
|
-
|
|
- // Don't ask the kernel if we already know the answer.
|
|
- if (increment == 0) {
|
|
- return __bionic_brk;
|
|
- }
|
|
-
|
|
- // Avoid overflow.
|
|
- uintptr_t old_brk = reinterpret_cast<uintptr_t>(__bionic_brk);
|
|
- if ((increment > 0 && static_cast<uintptr_t>(increment) > (UINTPTR_MAX - old_brk)) ||
|
|
- (increment < 0 && static_cast<uintptr_t>(-increment) > old_brk)) {
|
|
- errno = ENOMEM;
|
|
- return reinterpret_cast<void*>(-1);
|
|
- }
|
|
-
|
|
- void* desired_brk = reinterpret_cast<void*>(old_brk + increment);
|
|
- __bionic_brk = __brk(desired_brk);
|
|
- if (__bionic_brk < desired_brk) {
|
|
- errno = ENOMEM;
|
|
- return reinterpret_cast<void*>(-1);
|
|
- }
|
|
-
|
|
- return reinterpret_cast<void*>(old_brk);
|
|
+void* sbrk(ptrdiff_t) {
|
|
+ errno = ENOMEM;
|
|
+ return reinterpret_cast<void*>(-1);
|
|
}
|