dcb88a7068
This patch adds the workaround for running ASan builds on Windows 11 24H2 that was merged to llvm-project after issue #114793 on github. Differential Revision: https://phabricator.services.mozilla.com/D228165
108 lines
3.9 KiB
Diff
108 lines
3.9 KiB
Diff
From 69ebac7ad6ae1db9bb19cf3a19ea978af6034ca3 Mon Sep 17 00:00:00 2001
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From: Hans Wennborg <hans@hanshq.net>
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Date: Fri, 20 Dec 2024 11:03:17 +0100
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Subject: [PATCH] [win/asan] Don't intercept memset etc. in ntdll (#120397)
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When ntdll was added to the list of of "interesting DLLs" list (in
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d58230b9dcb3b312a2da8f874daa0cc8dc27da9b), the intention was not to
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intercept the "mini CRT" functions it exports. OverrideFunction would
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only intercept the *first* function it found when searching the list of
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DLLs, and ntdll was put last in that list.
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However, after 42cdfbcf3e92466754c175cb0e1e237e9f66749e,
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OverrideFunction intercepts *all* matching functions in those DLLs. As
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a side-effect, the runtime would now intercept functions like memset
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etc. also in ntdll.
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This causes a problem when ntdll-internal functions like
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RtlDispatchException call the intercepted memset, which tries to
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inspect uncommitted shadow memory, raising an exception, and getting
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stuck in that loop until the stack overflows.
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Since we never intended to intercept ntdll's memset etc., the simplest
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fix seems to be to actively ignore ntdll when intercepting those
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functions.
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Fixes #114793
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---
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.../lib/interception/interception_win.cpp | 32 ++++++++++++++++---
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1 file changed, 28 insertions(+), 4 deletions(-)
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diff --git a/compiler-rt/lib/interception/interception_win.cpp b/compiler-rt/lib/interception/interception_win.cpp
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index 8e9d9462b005..4ad440d95da4 100644
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--- a/compiler-rt/lib/interception/interception_win.cpp
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+++ b/compiler-rt/lib/interception/interception_win.cpp
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@@ -208,6 +208,18 @@ static char* _strchr(char* str, char c) {
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return nullptr;
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}
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+static int _strcmp(const char *s1, const char *s2) {
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+ while (true) {
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+ unsigned c1 = *s1;
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+ unsigned c2 = *s2;
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+ if (c1 != c2) return (c1 < c2) ? -1 : 1;
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+ if (c1 == 0) break;
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+ s1++;
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+ s2++;
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+ }
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+ return 0;
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+}
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+
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static void _memset(void *p, int value, size_t sz) {
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for (size_t i = 0; i < sz; ++i)
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((char*)p)[i] = (char)value;
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@@ -971,8 +983,7 @@ static void **InterestingDLLsAvailable() {
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"libc++.dll", // libc++
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"libunwind.dll", // libunwind
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# endif
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- // NTDLL should go last as it exports some functions that we should
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- // override in the CRT [presumably only used internally].
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+ // NTDLL must go last as it gets special treatment in OverrideFunction.
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"ntdll.dll",
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NULL
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};
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@@ -1029,7 +1040,7 @@ uptr InternalGetProcAddress(void *module, const char *func_name) {
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for (DWORD i = 0; i < exports->NumberOfNames; i++) {
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RVAPtr<char> name(module, names[i]);
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- if (!strcmp(func_name, name)) {
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+ if (!_strcmp(func_name, name)) {
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DWORD index = ordinals[i];
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RVAPtr<char> func(module, functions[index]);
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@@ -1067,9 +1078,22 @@ uptr InternalGetProcAddress(void *module, const char *func_name) {
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bool OverrideFunction(
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const char *func_name, uptr new_func, uptr *orig_old_func) {
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+ static const char *kNtDllIgnore[] = {
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+ "memcmp", "memcpy", "memmove", "memset"
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+ };
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+
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bool hooked = false;
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void **DLLs = InterestingDLLsAvailable();
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for (size_t i = 0; DLLs[i]; ++i) {
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+ if (DLLs[i + 1] == nullptr) {
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+ // This is the last DLL, i.e. NTDLL. It exports some functions that
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+ // we only want to override in the CRT.
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+ for (const char *ignored : kNtDllIgnore) {
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+ if (_strcmp(func_name, ignored) == 0)
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+ return hooked;
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+ }
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+ }
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+
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uptr func_addr = InternalGetProcAddress(DLLs[i], func_name);
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if (func_addr &&
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OverrideFunction(func_addr, new_func, orig_old_func)) {
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@@ -1123,7 +1147,7 @@ bool OverrideImportedFunction(const char *module_to_patch,
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RVAPtr<IMAGE_IMPORT_BY_NAME> import_by_name(
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module, name_table->u1.ForwarderString);
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const char *funcname = &import_by_name->Name[0];
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- if (strcmp(funcname, function_name) == 0)
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+ if (_strcmp(funcname, function_name) == 0)
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break;
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}
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}
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--
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2.42.0.windows.2
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