DivestOS/Patches/LineageOS-16.0/android_bionic/0002-Graphene_Bionic_Hardening-1.patch
Tad 1df7c7f1d4 Churn
Signed-off-by: Tad <tad@spotco.us>
2022-03-15 19:16:19 -04:00

164 lines
6.4 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Thu, 5 Feb 2015 21:53:16 -0500
Subject: [PATCH] add a real explicit_bzero implementation
Clang, GCC and other compilers special-case standard C functions like
memset. Calls to memset will be optimized out.
OpenBSD provides explicit_bzero to work around this but Android simply
defines it as memset so nothing prevents it from being optimized away.
This implementation uses a memory read constraint via empty inline
assembly rather than something that may be broken via link-time
optimization in the future.
---
libc/Android.bp | 1 +
libc/bionic/explicit_bzero.cpp | 7 +++++++
libc/include/string.h | 1 +
libc/libc.arm.map | 1 +
libc/libc.arm64.map | 1 +
libc/libc.map.txt | 1 +
libc/libc.mips.map | 1 +
libc/libc.mips64.map | 1 +
libc/libc.x86.map | 1 +
libc/libc.x86_64.map | 1 +
libc/upstream-openbsd/android/include/openbsd-compat.h | 2 --
11 files changed, 16 insertions(+), 2 deletions(-)
create mode 100644 libc/bionic/explicit_bzero.cpp
diff --git a/libc/Android.bp b/libc/Android.bp
index 5b3495ff2..72a7d9635 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1361,6 +1361,7 @@ cc_library_static {
"bionic/eventfd_read.cpp",
"bionic/eventfd_write.cpp",
"bionic/exec.cpp",
+ "bionic/explicit_bzero.cpp",
"bionic/faccessat.cpp",
"bionic/fchmod.cpp",
"bionic/fchmodat.cpp",
diff --git a/libc/bionic/explicit_bzero.cpp b/libc/bionic/explicit_bzero.cpp
new file mode 100644
index 000000000..b06daa138
--- /dev/null
+++ b/libc/bionic/explicit_bzero.cpp
@@ -0,0 +1,7 @@
+#include <string.h>
+
+void* explicit_bzero(void* s, size_t n) {
+ void *ptr = memset(s, 0, n);
+ __asm__ __volatile__("" : : "r"(ptr) : "memory");
+ return ptr;
+}
diff --git a/libc/include/string.h b/libc/include/string.h
index 54d5e1c80..533677777 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -56,6 +56,7 @@ void* mempcpy(void* __dst, const void* __src, size_t __n) __INTRODUCED_IN(23);
#endif
void* memmove(void* __dst, const void* __src, size_t __n);
void* memset(void* __dst, int __ch, size_t __n);
+void* explicit_bzero(void *s, size_t n);
void* memmem(const void* __haystack, size_t __haystack_size, const void* __needle, size_t __needle_size) __attribute_pure__;
char* strchr(const char* __s, int __ch) __attribute_pure__;
diff --git a/libc/libc.arm.map b/libc/libc.arm.map
index b0f96a9ff..28ad4913f 100644
--- a/libc/libc.arm.map
+++ b/libc/libc.arm.map
@@ -330,6 +330,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/libc.arm64.map b/libc/libc.arm64.map
index 6b0e41549..ee2010890 100644
--- a/libc/libc.arm64.map
+++ b/libc/libc.arm64.map
@@ -260,6 +260,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 85c9a581c..6c7e3eb36 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -332,6 +332,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/libc.mips.map b/libc/libc.mips.map
index 9e760c242..12faa5d86 100644
--- a/libc/libc.mips.map
+++ b/libc/libc.mips.map
@@ -328,6 +328,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/libc.mips64.map b/libc/libc.mips64.map
index 6b0e41549..ee2010890 100644
--- a/libc/libc.mips64.map
+++ b/libc/libc.mips64.map
@@ -260,6 +260,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/libc.x86.map b/libc/libc.x86.map
index 2855f9e22..8be30d842 100644
--- a/libc/libc.x86.map
+++ b/libc/libc.x86.map
@@ -326,6 +326,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/libc.x86_64.map b/libc/libc.x86_64.map
index 6b0e41549..ee2010890 100644
--- a/libc/libc.x86_64.map
+++ b/libc/libc.x86_64.map
@@ -260,6 +260,7 @@ LIBC {
execvp;
execvpe; # introduced=21
exit;
+ explicit_bzero;
faccessat; # introduced-arm=16 introduced-arm64=21 introduced-mips=16 introduced-mips64=21 introduced-x86=16 introduced-x86_64=21
fallocate; # introduced=21
fallocate64; # introduced=21
diff --git a/libc/upstream-openbsd/android/include/openbsd-compat.h b/libc/upstream-openbsd/android/include/openbsd-compat.h
index f17814931..929e61eed 100644
--- a/libc/upstream-openbsd/android/include/openbsd-compat.h
+++ b/libc/upstream-openbsd/android/include/openbsd-compat.h
@@ -65,8 +65,6 @@ extern const char* __progname;
/* OpenBSD has this, but we can't really implement it correctly on Linux. */
#define issetugid() 0
-#define explicit_bzero(p, s) memset(p, 0, s)
-
/* OpenBSD has these in <sys/param.h>, but "ALIGN" isn't something we want to reserve. */
#define ALIGNBYTES (sizeof(uintptr_t) - 1)
#define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) &~ ALIGNBYTES)