[compiler-rt] 7641c22 - [NFC][hwasan] Store shadow bytes early (#66682)
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 20 21:26:35 PDT 2023
Author: Vitaly Buka
Date: 2023-09-20T21:26:20-07:00
New Revision: 7641c220a03f6ecef13a5ec76d1b2056ff7bbde5
URL: https://github.com/llvm/llvm-project/commit/7641c220a03f6ecef13a5ec76d1b2056ff7bbde5
DIFF: https://github.com/llvm/llvm-project/commit/7641c220a03f6ecef13a5ec76d1b2056ff7bbde5.diff
LOG: [NFC][hwasan] Store shadow bytes early (#66682)
Added:
Modified:
compiler-rt/lib/hwasan/hwasan_report.cpp
Removed:
################################################################################
diff --git a/compiler-rt/lib/hwasan/hwasan_report.cpp b/compiler-rt/lib/hwasan/hwasan_report.cpp
index c32d9195abcef2b..c89f09989e94283 100644
--- a/compiler-rt/lib/hwasan/hwasan_report.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_report.cpp
@@ -25,6 +25,7 @@
#include "sanitizer_common/sanitizer_array_ref.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flags.h"
+#include "sanitizer_common/sanitizer_internal_defs.h"
#include "sanitizer_common/sanitizer_mutex.h"
#include "sanitizer_common/sanitizer_report_decorator.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
@@ -321,56 +322,61 @@ static uptr GetGlobalSizeFromDescriptor(uptr ptr) {
void ReportStats() {}
-static void PrintTagInfoAroundAddr(tag_t *tag_ptr, uptr num_rows,
- void (*print_tag)(InternalScopedString &s,
- tag_t *tag)) {
+template <typename PrintTag>
+static void PrintTagInfoAroundAddr(uptr addr, uptr num_rows,
+ InternalScopedString &s,
+ PrintTag print_tag) {
const uptr row_len = 16; // better be power of two.
- tag_t *center_row_beg = reinterpret_cast<tag_t *>(
- RoundDownTo(reinterpret_cast<uptr>(tag_ptr), row_len));
- tag_t *beg_row = center_row_beg - row_len * (num_rows / 2);
- tag_t *end_row = center_row_beg + row_len * ((num_rows + 1) / 2);
- InternalScopedString s;
- for (tag_t *row = beg_row; row < end_row; row += row_len) {
+ uptr center_row_beg = RoundDownTo(addr, row_len);
+ uptr beg_row = center_row_beg - row_len * (num_rows / 2);
+ uptr end_row = center_row_beg + row_len * ((num_rows + 1) / 2);
+ for (uptr row = beg_row; row < end_row; row += row_len) {
s.Append(row == center_row_beg ? "=>" : " ");
- s.AppendF("%p:", (void *)ShadowToMem(reinterpret_cast<uptr>(row)));
+ s.AppendF("%p:", (void *)ShadowToMem(row));
for (uptr i = 0; i < row_len; i++) {
- s.Append(row + i == tag_ptr ? "[" : " ");
- print_tag(s, &row[i]);
- s.Append(row + i == tag_ptr ? "]" : " ");
+ s.Append(row + i == addr ? "[" : " ");
+ print_tag(s, row + i);
+ s.Append(row + i == addr ? "]" : " ");
}
s.AppendF("\n");
}
- Printf("%s", s.data());
}
-static void PrintTagsAroundAddr(tag_t *tag_ptr) {
- Printf(
+template <typename GetTag, typename GetShortTag>
+static void PrintTagsAroundAddr(uptr addr, GetTag get_tag,
+ GetShortTag get_short_tag) {
+ InternalScopedString s;
+ addr = MemToShadow(addr);
+ s.AppendF(
"Memory tags around the buggy address (one tag corresponds to %zd "
"bytes):\n",
kShadowAlignment);
- PrintTagInfoAroundAddr(tag_ptr, 17, [](InternalScopedString &s, tag_t *tag) {
- s.AppendF("%02x", *tag);
- });
+ PrintTagInfoAroundAddr(addr, 17, s,
+ [&](InternalScopedString &s, uptr tag_addr) {
+ tag_t tag = get_tag(tag_addr);
+ s.AppendF("%02x", tag);
+ });
- Printf(
+ s.AppendF(
"Tags for short granules around the buggy address (one tag corresponds "
"to %zd bytes):\n",
kShadowAlignment);
- PrintTagInfoAroundAddr(tag_ptr, 3, [](InternalScopedString &s, tag_t *tag) {
- uptr granule_addr = ShadowToMem(reinterpret_cast<uptr>(tag));
- if (*tag >= 1 && *tag <= kShadowAlignment &&
- IsAccessibleMemoryRange(granule_addr, kShadowAlignment)) {
- s.AppendF("%02x",
- *reinterpret_cast<u8 *>(granule_addr + kShadowAlignment - 1));
- } else {
- s.AppendF("..");
- }
- });
- Printf(
+ PrintTagInfoAroundAddr(addr, 3, s,
+ [&](InternalScopedString &s, uptr tag_addr) {
+ tag_t tag = get_tag(tag_addr);
+ if (tag >= 1 && tag <= kShadowAlignment) {
+ tag_t short_tag = get_short_tag(tag_addr);
+ s.AppendF("%02x", short_tag);
+ } else {
+ s.AppendF("..");
+ }
+ });
+ s.AppendF(
"See "
"https://clang.llvm.org/docs/"
"HardwareAssistedAddressSanitizerDesign.html#short-granules for a "
"description of short granule tags\n");
+ Printf("%s", s.data());
}
static uptr GetTopPc(const StackTrace *stack) {
@@ -390,7 +396,8 @@ class BaseReport {
ptr_tag(GetTagFromPointer(tagged_addr)),
heap(CopyHeapChunk()),
allocations(CopyAllocations()),
- candidate(FindBufferOverflowCandidate()) {}
+ candidate(FindBufferOverflowCandidate()),
+ shadow(CopyShadow()) {}
protected:
struct OverflowCandidate {
@@ -428,6 +435,15 @@ class BaseReport {
bool is_allocated = false;
};
+ struct Shadow {
+ uptr addr = 0;
+ tag_t tags[512] = {};
+ tag_t short_tags[ARRAY_SIZE(tags)] = {};
+ };
+
+ Shadow CopyShadow() const;
+ tag_t GetTagCopy(uptr addr) const;
+ tag_t GetShortTagCopy(uptr addr) const;
HeapChunk CopyHeapChunk() const;
Allocations CopyAllocations();
OverflowCandidate FindBufferOverflowCandidate() const;
@@ -447,8 +463,49 @@ class BaseReport {
const HeapChunk heap;
const Allocations allocations;
const OverflowCandidate candidate;
+
+ const Shadow shadow;
};
+BaseReport::Shadow BaseReport::CopyShadow() const {
+ Shadow result;
+ if (!MemIsApp(untagged_addr))
+ return result;
+
+ result.addr = MemToShadow(untagged_addr) - ARRAY_SIZE(result.tags) / 2;
+ for (uptr i = 0; i < ARRAY_SIZE(result.tags); ++i) {
+ uptr tag_addr = result.addr + i;
+ if (!MemIsShadow(tag_addr))
+ continue;
+ result.tags[i] = *reinterpret_cast<tag_t *>(tag_addr);
+ uptr granule_addr = ShadowToMem(tag_addr);
+ if (1 <= result.tags[i] && result.tags[i] <= kShadowAlignment &&
+ IsAccessibleMemoryRange(granule_addr, kShadowAlignment)) {
+ result.short_tags[i] =
+ *reinterpret_cast<tag_t *>(granule_addr + kShadowAlignment - 1);
+ }
+ }
+ return result;
+}
+
+tag_t BaseReport::GetTagCopy(uptr addr) const {
+ if (addr < shadow.addr)
+ return 0;
+ uptr idx = addr - shadow.addr;
+ if (idx >= ARRAY_SIZE(shadow.tags))
+ return 0;
+ return shadow.tags[idx];
+}
+
+tag_t BaseReport::GetShortTagCopy(uptr addr) const {
+ if (addr < shadow.addr)
+ return 0;
+ uptr idx = addr - shadow.addr;
+ if (idx >= ARRAY_SIZE(shadow.short_tags))
+ return 0;
+ return shadow.short_tags[idx];
+}
+
BaseReport::HeapChunk BaseReport::CopyHeapChunk() const {
HeapChunk result = {};
if (MemIsShadow(untagged_addr))
@@ -721,15 +778,6 @@ class InvalidFreeReport : public BaseReport {
};
InvalidFreeReport::~InvalidFreeReport() {
- tag_t *tag_ptr = nullptr;
- tag_t mem_tag = 0;
- if (MemIsApp(untagged_addr)) {
- tag_ptr = reinterpret_cast<tag_t *>(MemToShadow(untagged_addr));
- if (MemIsShadow(reinterpret_cast<uptr>(tag_ptr)))
- mem_tag = *tag_ptr;
- else
- tag_ptr = nullptr;
- }
Decorator d;
Printf("%s", d.Error());
uptr pc = GetTopPc(stack);
@@ -743,16 +791,19 @@ InvalidFreeReport::~InvalidFreeReport() {
SanitizerToolName, bug_type, untagged_addr, pc);
}
Printf("%s", d.Access());
- if (tag_ptr)
- Printf("tags: %02x/%02x (ptr/mem)\n", ptr_tag, mem_tag);
+ if (shadow.addr)
+ Printf("tags: %02x/%02x (ptr/mem)\n", ptr_tag, GetTagCopy(untagged_addr));
Printf("%s", d.Default());
stack->Print();
PrintAddressDescription();
- if (tag_ptr)
- PrintTagsAroundAddr(tag_ptr);
+ if (shadow.addr) {
+ PrintTagsAroundAddr(
+ untagged_addr, [&](uptr addr) { return GetTagCopy(addr); },
+ [&](uptr addr) { return GetShortTagCopy(addr); });
+ }
MaybePrintAndroidHelpUrl();
ReportErrorSummary(bug_type, stack);
@@ -834,8 +885,9 @@ TailOverwrittenReport::~TailOverwrittenReport() {
Printf("%s", s.data());
GetCurrentThread()->Announce();
- tag_t *tag_ptr = reinterpret_cast<tag_t*>(MemToShadow(untagged_addr));
- PrintTagsAroundAddr(tag_ptr);
+ PrintTagsAroundAddr(
+ untagged_addr, [&](uptr addr) { return GetTagCopy(addr); },
+ [&](uptr addr) { return GetShortTagCopy(addr); });
MaybePrintAndroidHelpUrl();
ReportErrorSummary(bug_type, stack);
@@ -912,7 +964,9 @@ TagMismatchReport::~TagMismatchReport() {
PrintAddressDescription();
t->Announce();
- PrintTagsAroundAddr(tag_ptr);
+ PrintTagsAroundAddr(
+ untagged_addr + offset, [&](uptr addr) { return GetTagCopy(addr); },
+ [&](uptr addr) { return GetShortTagCopy(addr); });
if (registers_frame)
ReportRegisters(registers_frame, pc);
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