forked from OSchip/llvm-project
5d2be1a188
Summary: This refactors some common support related to shadow memory setup from asan and hwasan into sanitizer_common. This should not only reduce code duplication but also make these facilities available for new compiler-rt uses (e.g. heap profiling). In most cases the separate copies of the code were either identical, or at least functionally identical. A few notes: In ProtectGap, the asan version checked the address against an upper bound (kZeroBaseMaxShadowStart, which is (2^18). I have created a copy of kZeroBaseMaxShadowStart in hwasan_mapping.h, with the same value, as it isn't clear why that code should not do the same check. If it shouldn't, I can remove this and guard this check so that it only happens for asan. In asan's InitializeShadowMemory, in the dynamic shadow case it was setting __asan_shadow_memory_dynamic_address to 0 (which then sets both macro SHADOW_OFFSET as well as macro kLowShadowBeg to 0) before calling FindDynamicShadowStart(). AFAICT this is only needed because FindDynamicShadowStart utilizes kHighShadowEnd to get the shadow size, and kHighShadowEnd is a macro invoking MEM_TO_SHADOW(kHighMemEnd) which in turn invokes: (((kHighMemEnd) >> SHADOW_SCALE) + (SHADOW_OFFSET)) I.e. it computes the shadow space needed by kHighMemEnd (the shift), and adds the offset. Since we only want the shadow space here, the earlier setting of SHADOW_OFFSET to 0 via __asan_shadow_memory_dynamic_address accomplishes this. In the hwasan version, it simply gets the shadow space via "MemToShadowSize(kHighMemEnd)", where MemToShadowSize just does the shift. I've simplified the asan handling to do the same thing, and therefore was able to remove the setting of the SHADOW_OFFSET via __asan_shadow_memory_dynamic_address to 0. Reviewers: vitalybuka, kcc, eugenis Subscribers: dberris, #sanitizers, llvm-commits, davidxl Tags: #sanitizers Differential Revision: https://reviews.llvm.org/D83247 |
||
|---|---|---|
| .. | ||
| scripts | ||
| .clang-format | ||
| CMakeLists.txt | ||
| hwasan.cpp | ||
| hwasan.h | ||
| hwasan.syms.extra | ||
| hwasan_allocator.cpp | ||
| hwasan_allocator.h | ||
| hwasan_blacklist.txt | ||
| hwasan_checks.h | ||
| hwasan_dynamic_shadow.cpp | ||
| hwasan_dynamic_shadow.h | ||
| hwasan_exceptions.cpp | ||
| hwasan_flags.h | ||
| hwasan_flags.inc | ||
| hwasan_globals.cpp | ||
| hwasan_globals.h | ||
| hwasan_interceptors.cpp | ||
| hwasan_interceptors_vfork.S | ||
| hwasan_interface_internal.h | ||
| hwasan_linux.cpp | ||
| hwasan_malloc_bisect.h | ||
| hwasan_mapping.h | ||
| hwasan_memintrinsics.cpp | ||
| hwasan_new_delete.cpp | ||
| hwasan_poisoning.cpp | ||
| hwasan_poisoning.h | ||
| hwasan_report.cpp | ||
| hwasan_report.h | ||
| hwasan_setjmp.S | ||
| hwasan_tag_mismatch_aarch64.S | ||
| hwasan_thread.cpp | ||
| hwasan_thread.h | ||
| hwasan_thread_list.cpp | ||
| hwasan_thread_list.h | ||
| hwasan_type_test.cpp | ||