[clang] [compiler-rt] Move interceptors for libresolv functions to MSan (PR #119071)
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Sat Dec 7 07:05:44 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang
Author: Aaron Puchert (aaronpuchert)
<details>
<summary>Changes</summary>
The functions are not relevant for most sanitizers and only required for MSan to see which regions have been written to. This eliminates a link dependency for all other sanitizers and fixes #<!-- -->59007: while `-lresolv` had been added for the static runtime in 6dce56b2a308, it wasn't added to the shared runtimes.
Instead of just moving the interceptors, we adapt them to MSan conventions:
* We don't skip intercepting when `msan_init_is_running` is true, but directly call ENSURE_MSAN_INITED() like most other interceptors. It seems unlikely that these functions are called during initialization.
* We don't unpoison `errno`, because none of the functions is specified to use it.
---
Full diff: https://github.com/llvm/llvm-project/pull/119071.diff
5 Files Affected:
- (modified) clang/lib/Driver/ToolChains/CommonArgs.cpp (+1-1)
- (modified) compiler-rt/lib/msan/msan_interceptors.cpp (+76)
- (modified) compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc (-78)
- (modified) compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h (-2)
- (removed) compiler-rt/test/sanitizer_common/TestCases/Linux/b64.cpp (-42)
``````````diff
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 7d3d7f8f03c491..03dbdc27975b42 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1410,7 +1410,7 @@ void tools::linkSanitizerRuntimeDeps(const ToolChain &TC,
// libresolv.a, even if exists, is an empty archive to satisfy POSIX -lresolv
// requirement.
if (TC.getTriple().isOSLinux() && !TC.getTriple().isAndroid() &&
- !TC.getTriple().isMusl())
+ !TC.getTriple().isMusl() && TC.getSanitizerArgs(Args).needsMsanRt())
CmdArgs.push_back("-lresolv");
}
diff --git a/compiler-rt/lib/msan/msan_interceptors.cpp b/compiler-rt/lib/msan/msan_interceptors.cpp
index f05c20618780b7..b2098d8a26d229 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cpp
+++ b/compiler-rt/lib/msan/msan_interceptors.cpp
@@ -1358,6 +1358,79 @@ INTERCEPTOR(int, forkpty, int *aparent, char *name, const void *termp,
#define MSAN_MAYBE_INTERCEPT_FORKPTY
#endif
+#if SANITIZER_LINUX && !SANITIZER_ANDROID
+INTERCEPTOR(int, __b64_ntop, unsigned char const *src, SIZE_T srclength,
+ char *target, SIZE_T targsize) {
+ ENSURE_MSAN_INITED();
+ CHECK_UNPOISONED(src, srclength);
+ InterceptorScope interceptor_scope;
+ int res = REAL(__b64_ntop)(src, srclength, target, targsize);
+ if (res >= 0)
+ __msan_unpoison(target, res + 1);
+ return res;
+}
+INTERCEPTOR(int, __b64_pton, char const *src, char *target, SIZE_T targsize) {
+ ENSURE_MSAN_INITED();
+ CHECK_UNPOISONED(src, internal_strlen(src) + 1);
+ InterceptorScope interceptor_scope;
+ int res = REAL(__b64_pton)(src, target, targsize);
+ if (res >= 0)
+ __msan_unpoison(target, res);
+ return res;
+}
+# define MSAN_MAYBE_INTERCEPT___B64_TO \
+ MSAN_INTERCEPT_FUNC(__b64_ntop); \
+ COMMON_INTERCEPT_FUNCTION(__b64_pton);
+#else
+# define MSAN_MAYBE_INTERCEPT___B64_TO
+#endif
+
+#if SANITIZER_LINUX && !SANITIZER_ANDROID
+# if __GLIBC_PREREQ(2, 34)
+// Changed with https://sourceware.org/git/?p=glibc.git;h=640bbdf
+# define DN_COMP_INTERCEPTOR_NAME dn_comp
+# define DN_EXPAND_INTERCEPTOR_NAME dn_expand
+# else
+# define DN_COMP_INTERCEPTOR_NAME __dn_comp
+# define DN_EXPAND_INTERCEPTOR_NAME __dn_expand
+# endif
+INTERCEPTOR(int, DN_COMP_INTERCEPTOR_NAME, unsigned char *exp_dn,
+ unsigned char *comp_dn, int length, unsigned char **dnptrs,
+ unsigned char **lastdnptr) {
+ ENSURE_MSAN_INITED();
+ InterceptorScope interceptor_scope;
+ int res = REAL(DN_COMP_INTERCEPTOR_NAME)(exp_dn, comp_dn, length, dnptrs,
+ lastdnptr);
+ if (res >= 0) {
+ __msan_unpoison(comp_dn, res);
+ if (dnptrs && lastdnptr) {
+ unsigned char **p = dnptrs;
+ for (; p != lastdnptr && *p; ++p);
+ if (p != lastdnptr)
+ ++p;
+ __msan_unpoison(dnptrs, (p - dnptrs) * sizeof(*p));
+ }
+ }
+ return res;
+}
+INTERCEPTOR(int, DN_EXPAND_INTERCEPTOR_NAME, unsigned char const *base,
+ unsigned char const *end, unsigned char const *src, char *dest,
+ int space) {
+ ENSURE_MSAN_INITED();
+ // TODO: add read check if __dn_comp intercept added
+ InterceptorScope interceptor_scope;
+ int res = REAL(DN_EXPAND_INTERCEPTOR_NAME)(base, end, src, dest, space);
+ if (res >= 0)
+ __msan_unpoison(dest, internal_strlen(dest) + 1);
+ return res;
+}
+# define MSAN_MAYBE_INTERCEPT_DN_COMP_EXPAND \
+ MSAN_INTERCEPT_FUNC(DN_COMP_INTERCEPTOR_NAME); \
+ MSAN_INTERCEPT_FUNC(DN_EXPAND_INTERCEPTOR_NAME);
+#else
+# define MSAN_MAYBE_INTERCEPT_DN_COMP_EXPAND
+#endif
+
struct MSanInterceptorContext {
bool in_interceptor_scope;
};
@@ -1916,6 +1989,9 @@ void InitializeInterceptors() {
MSAN_MAYBE_INTERCEPT_OPENPTY;
MSAN_MAYBE_INTERCEPT_FORKPTY;
+ MSAN_MAYBE_INTERCEPT___B64_TO;
+ MSAN_MAYBE_INTERCEPT_DN_COMP_EXPAND;
+
inited = 1;
}
} // namespace __msan
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index ba3693dbd11f63..9cf99a192dba49 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -2538,82 +2538,6 @@ INTERCEPTOR(int, glob64, const char *pattern, int flags,
#define INIT_GLOB64
#endif // SANITIZER_INTERCEPT_GLOB64
-#if SANITIZER_INTERCEPT___B64_TO
-INTERCEPTOR(int, __b64_ntop, unsigned char const *src, SIZE_T srclength,
- char *target, SIZE_T targsize) {
- void *ctx;
- COMMON_INTERCEPTOR_ENTER(ctx, __b64_ntop, src, srclength, target, targsize);
- COMMON_INTERCEPTOR_READ_RANGE(ctx, src, srclength);
- int res = REAL(__b64_ntop)(src, srclength, target, targsize);
- if (res >= 0)
- COMMON_INTERCEPTOR_WRITE_RANGE(ctx, target, res + 1);
- return res;
-}
-INTERCEPTOR(int, __b64_pton, char const *src, char *target, SIZE_T targsize) {
- void *ctx;
- COMMON_INTERCEPTOR_ENTER(ctx, __b64_pton, src, target, targsize);
- COMMON_INTERCEPTOR_READ_RANGE(ctx, src, internal_strlen(src) + 1);
- int res = REAL(__b64_pton)(src, target, targsize);
- if (res >= 0)
- COMMON_INTERCEPTOR_WRITE_RANGE(ctx, target, res);
- return res;
-}
-#define INIT___B64_TO \
- COMMON_INTERCEPT_FUNCTION(__b64_ntop); \
- COMMON_INTERCEPT_FUNCTION(__b64_pton);
-#else // SANITIZER_INTERCEPT___B64_TO
-#define INIT___B64_TO
-#endif // SANITIZER_INTERCEPT___B64_TO
-
-#if SANITIZER_INTERCEPT_DN_COMP_EXPAND
-# if __GLIBC_PREREQ(2, 34)
-// Changed with https://sourceware.org/git/?p=glibc.git;h=640bbdf
-# define DN_COMP_INTERCEPTOR_NAME dn_comp
-# define DN_EXPAND_INTERCEPTOR_NAME dn_expand
-# else
-# define DN_COMP_INTERCEPTOR_NAME __dn_comp
-# define DN_EXPAND_INTERCEPTOR_NAME __dn_expand
-# endif
-INTERCEPTOR(int, DN_COMP_INTERCEPTOR_NAME, unsigned char *exp_dn,
- unsigned char *comp_dn, int length, unsigned char **dnptrs,
- unsigned char **lastdnptr) {
- void *ctx;
- COMMON_INTERCEPTOR_ENTER(ctx, DN_COMP_INTERCEPTOR_NAME, exp_dn, comp_dn,
- length, dnptrs, lastdnptr);
- int res = REAL(DN_COMP_INTERCEPTOR_NAME)(exp_dn, comp_dn, length, dnptrs,
- lastdnptr);
- if (res >= 0) {
- COMMON_INTERCEPTOR_WRITE_RANGE(ctx, comp_dn, res);
- if (dnptrs && lastdnptr) {
- unsigned char **p = dnptrs;
- for (; p != lastdnptr && *p; ++p)
- ;
- if (p != lastdnptr)
- ++p;
- COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dnptrs, (p - dnptrs) * sizeof(*p));
- }
- }
- return res;
-}
-INTERCEPTOR(int, DN_EXPAND_INTERCEPTOR_NAME, unsigned char const *base,
- unsigned char const *end, unsigned char const *src, char *dest,
- int space) {
- void *ctx;
- COMMON_INTERCEPTOR_ENTER(ctx, DN_EXPAND_INTERCEPTOR_NAME, base, end, src,
- dest, space);
- // TODO: add read check if __dn_comp intercept added
- int res = REAL(DN_EXPAND_INTERCEPTOR_NAME)(base, end, src, dest, space);
- if (res >= 0)
- COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dest, internal_strlen(dest) + 1);
- return res;
-}
-# define INIT_DN_COMP_EXPAND \
- COMMON_INTERCEPT_FUNCTION(DN_COMP_INTERCEPTOR_NAME); \
- COMMON_INTERCEPT_FUNCTION(DN_EXPAND_INTERCEPTOR_NAME);
-#else // SANITIZER_INTERCEPT_DN_COMP_EXPAND
-# define INIT_DN_COMP_EXPAND
-#endif // SANITIZER_INTERCEPT_DN_COMP_EXPAND
-
#if SANITIZER_INTERCEPT_POSIX_SPAWN
template <class RealSpawnPtr>
@@ -10346,8 +10270,6 @@ static void InitializeCommonInterceptors() {
INIT_TIMESPEC_GET;
INIT_GLOB;
INIT_GLOB64;
- INIT___B64_TO;
- INIT_DN_COMP_EXPAND;
INIT_POSIX_SPAWN;
INIT_WAIT;
INIT_WAIT4;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 190cad7cf7c3f7..b4940b66da9717 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -266,8 +266,6 @@ SANITIZER_WEAK_IMPORT void *aligned_alloc(__sanitizer::usize __alignment,
#define SANITIZER_INTERCEPT_TIMESPEC_GET SI_LINUX
#define SANITIZER_INTERCEPT_GLOB (SI_GLIBC || SI_SOLARIS)
#define SANITIZER_INTERCEPT_GLOB64 SI_GLIBC
-#define SANITIZER_INTERCEPT___B64_TO SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_DN_COMP_EXPAND SI_LINUX_NOT_ANDROID
#define SANITIZER_INTERCEPT_POSIX_SPAWN SI_POSIX
#define SANITIZER_INTERCEPT_WAIT SI_POSIX
#define SANITIZER_INTERCEPT_INET SI_POSIX
diff --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/b64.cpp b/compiler-rt/test/sanitizer_common/TestCases/Linux/b64.cpp
deleted file mode 100644
index 96fd0138648b34..00000000000000
--- a/compiler-rt/test/sanitizer_common/TestCases/Linux/b64.cpp
+++ /dev/null
@@ -1,42 +0,0 @@
-// RUN: %clangxx %s -o %t && %run %t %p
-
-#include <assert.h>
-#include <resolv.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-
-int main(int iArgc, char *szArgv[]) {
- // Check NTOP writing
- const char *src = "base64 test data";
- size_t src_len = strlen(src);
- size_t dst_len = ((src_len + 2) / 3) * 4 + 1;
- char dst[dst_len];
- int res = b64_ntop(reinterpret_cast<const unsigned char *>(src), src_len, dst,
- dst_len);
- assert(res >= 0);
- assert(strcmp(dst, "YmFzZTY0IHRlc3QgZGF0YQ==") == 0);
-
- // Check PTON writing
- unsigned char target[dst_len];
- res = b64_pton(dst, target, dst_len);
- assert(res >= 0);
- assert(strncmp(reinterpret_cast<const char *>(target), src, res) == 0);
-
- // Check NTOP writing for zero length src
- src = "";
- src_len = strlen(src);
- assert(((src_len + 2) / 3) * 4 + 1 < dst_len);
- res = b64_ntop(reinterpret_cast<const unsigned char *>(src), src_len, dst,
- dst_len);
- assert(res >= 0);
- assert(strcmp(dst, "") == 0);
-
- // Check PTON writing for zero length src
- dst[0] = '\0';
- res = b64_pton(dst, target, dst_len);
- assert(res >= 0);
- assert(strncmp(reinterpret_cast<const char *>(target), src, res) == 0);
-
- return 0;
-}
``````````
</details>
https://github.com/llvm/llvm-project/pull/119071
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