Update Art 7.0.0 stack guard patch
Backport of https://android-review.googlesource.com/#/c/427061/.
R=ricow@google.com
Bug: 63151667
Change-Id: I30eec226c4a914b0b22d9344d44281b83e18fcf0
diff --git a/tools/linux/README.art-versions b/tools/linux/README.art-versions
index ed0fa3b..0bb6fd8 100644
--- a/tools/linux/README.art-versions
+++ b/tools/linux/README.art-versions
@@ -29,7 +29,59 @@
art-7.0.0
---------
-Build from branch android-7.0.0_r21.
+Build from branch android-7.0.0_r21 with the following patch:
+
+diff --git a/runtime/thread.cc b/runtime/thread.cc
+index 16f30cded..acdd995e9 100644
+--- a/runtime/thread.cc
++++ b/runtime/thread.cc
+@@ -554,6 +554,12 @@ void Thread::InstallImplicitProtection() {
+ // AddressSanitizer does not like the part of this functions that reads every stack page.
+ // Looks a lot like an out-of-bounds access.
+
++ //
++ // Accesses too far below the current machine register corresponding to the stack pointer (e.g.,
++ // ESP on x86[-32], SP on ARM) might cause a SIGSEGV (at least on x86 with newer kernels). We
++ // thus have to move the stack pointer. We do this portably by using a recursive function with a
++ // large stack frame size.
++
+ // (Defensively) first remove the protection on the protected region as will want to read
+ // and write it. Ignore errors.
+ UnprotectStack();
+@@ -561,12 +567,26 @@ void Thread::InstallImplicitProtection() {
+ VLOG(threads) << "Need to map in stack for thread at " << std::hex <<
+ static_cast<void*>(pregion);
+
+- // Read every page from the high address to the low.
+- volatile uint8_t dont_optimize_this;
+- UNUSED(dont_optimize_this);
+- for (uint8_t* p = stack_top; p >= pregion; p -= kPageSize) {
+- dont_optimize_this = *p;
+- }
++ struct RecurseDownStack {
++ // This function has an intentionally large stack size.
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Wframe-larger-than="
++ NO_INLINE
++ static void Touch(uintptr_t target) {
++ volatile size_t zero = 0;
++ // Use a large local volatile array to ensure a large frame size. Do not use anything close
++ // to a full page for ASAN. It would be nice to ensure the frame size is at most a page, but
++ // there is no pragma support for this.
++ volatile char space[kPageSize - 256];
++ char sink ATTRIBUTE_UNUSED = space[zero];
++ if (reinterpret_cast<uintptr_t>(space) >= target + kPageSize) {
++ Touch(target);
++ }
++ zero *= 2; // Try to avoid tail recursion.
++ }
++#pragma GCC diagnostic pop
++ };
++ RecurseDownStack::Touch(reinterpret_cast<uintptr_t>(pregion));
+
+ VLOG(threads) << "(again) installing stack protected region at " << std::hex <<
+ static_cast<void*>(pregion) << " to " <<
+
mkdir 7.0.0_r21
cd 7.0.0_r21
@@ -37,6 +89,9 @@
repo sync
source build/envsetup.sh
lunch aosp_angler-userdebug
+ cd art
+ <apply patch>
+ cd ..
m -j24
m -j24 build-art
m -j24 test-art-host
diff --git a/tools/linux/art-7.0.0.tar.gz.sha1 b/tools/linux/art-7.0.0.tar.gz.sha1
index 55f7b1c..faae6a3 100644
--- a/tools/linux/art-7.0.0.tar.gz.sha1
+++ b/tools/linux/art-7.0.0.tar.gz.sha1
@@ -1 +1 @@
-6c2200d6ccca3bef135858736cd1eb0fa336bf65
\ No newline at end of file
+c044d5c8441d8b67e60febce580c252ac7bdde0f
\ No newline at end of file
