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Move interceptors for libresolv functions to MSan (#119071)
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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 6dce56b, 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.
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@aaronpuchert
aaronpuchert authored Dec 9, 2024
1 parent e55c167 commit f5f9650
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2 changes: 1 addition & 1 deletion clang/lib/Driver/ToolChains/CommonArgs.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -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");
}

Expand Down
39 changes: 20 additions & 19 deletions clang/test/Driver/sanitizer-ld.c
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@
// CHECK-ASAN-LINUX: "-lpthread"
// CHECK-ASAN-LINUX: "-lrt"
// CHECK-ASAN-LINUX: "-ldl"
// CHECK-ASAN-LINUX: "-lresolv"
// CHECK-ASAN-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=address -fno-sanitize-link-runtime -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand Down Expand Up @@ -143,7 +143,7 @@
// CHECK-ASAN-LINUX-CXX: "-lpthread"
// CHECK-ASAN-LINUX-CXX: "-lrt"
// CHECK-ASAN-LINUX-CXX: "-ldl"
// CHECK-ASAN-LINUX-CXX: "-lresolv"
// CHECK-ASAN-LINUX-CXX-NOT: "-lresolv"

// RUN: %clang -### %s -o /dev/null -fsanitize=address \
// RUN: --target=i386-unknown-linux -fuse-ld=ld -stdlib=platform \
Expand Down Expand Up @@ -292,7 +292,7 @@
// CHECK-TSAN-LINUX-CXX: "-lpthread"
// CHECK-TSAN-LINUX-CXX: "-lrt"
// CHECK-TSAN-LINUX-CXX: "-ldl"
// CHECK-TSAN-LINUX-CXX: "-lresolv"
// CHECK-TSAN-LINUX-CXX-NOT: "-lresolv"

// RUN: %clang -fsanitize=thread -fno-sanitize-link-runtime -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand Down Expand Up @@ -365,7 +365,7 @@
// CHECK-UBSAN-LINUX-NOT: libclang_rt.ubsan_standalone_cxx
// CHECK-UBSAN-LINUX-NOT: "-lstdc++"
// CHECK-UBSAN-LINUX: "-lpthread"
// CHECK-UBSAN-LINUX: "-lresolv"
// CHECK-UBSAN-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=undefined -fno-sanitize-link-runtime -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand Down Expand Up @@ -438,7 +438,7 @@
// CHECK-UBSAN-LINUX-CXX: "-lstdc++"
// CHECK-UBSAN-LINUX-CXX-NOT: libclang_rt.asan
// CHECK-UBSAN-LINUX-CXX: "-lpthread"
// CHECK-UBSAN-LINUX-CXX: "-lresolv"
// CHECK-UBSAN-LINUX-CXX-NOT: "-lresolv"

// RUN: %clang -fsanitize=undefined -fsanitize-minimal-runtime -### %s 2>&1 \
// RUN: --target=i386-unknown-linux -fuse-ld=ld \
Expand All @@ -448,7 +448,7 @@
// CHECK-UBSAN-MINIMAL-LINUX: "{{.*}}ld{{(.exe)?}}"
// CHECK-UBSAN-MINIMAL-LINUX: "--whole-archive" "{{.*}}libclang_rt.ubsan_minimal.a" "--no-whole-archive"
// CHECK-UBSAN-MINIMAL-LINUX: "-lpthread"
// CHECK-UBSAN-MINIMAL-LINUX: "-lresolv"
// CHECK-UBSAN-MINIMAL-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=undefined -fsanitize-minimal-runtime -### %s 2>&1 \
// RUN: --target=x86_64-apple-darwin -fuse-ld=ld \
Expand Down Expand Up @@ -485,7 +485,7 @@
// CHECK-ASAN-UBSAN-LINUX-NOT: libclang_rt.ubsan
// CHECK-ASAN-UBSAN-LINUX-NOT: "-lstdc++"
// CHECK-ASAN-UBSAN-LINUX: "-lpthread"
// CHECK-ASAN-UBSAN-LINUX: "-lresolv"
// CHECK-ASAN-UBSAN-LINUX-NOT: "-lresolv"

// RUN: %clangxx -fsanitize=address,undefined -### %s 2>&1 \
// RUN: --target=i386-unknown-linux -fuse-ld=ld -stdlib=platform \
Expand All @@ -498,7 +498,7 @@
// CHECK-ASAN-UBSAN-LINUX-CXX-NOT: libclang_rt.ubsan
// CHECK-ASAN-UBSAN-LINUX-CXX: "-lstdc++"
// CHECK-ASAN-UBSAN-LINUX-CXX: "-lpthread"
// CHECK-ASAN-UBSAN-LINUX-CXX: "-lresolv"
// CHECK-ASAN-UBSAN-LINUX-CXX-NOT: "-lresolv"

// RUN: %clangxx -fsanitize=memory,undefined -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand Down Expand Up @@ -541,7 +541,7 @@
// CHECK-LSAN-LINUX: libclang_rt.lsan.a"
// CHECK-LSAN-LINUX: "-lpthread"
// CHECK-LSAN-LINUX: "-ldl"
// CHECK-LSAN-LINUX: "-lresolv"
// CHECK-LSAN-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=leak -fno-sanitize-link-runtime -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand All @@ -564,7 +564,7 @@
// CHECK-LSAN-COV-LINUX-NOT: libclang_rt.ubsan
// CHECK-LSAN-COV-LINUX: "-lpthread"
// CHECK-LSAN-COV-LINUX: "-ldl"
// CHECK-LSAN-COV-LINUX: "-lresolv"
// CHECK-LSAN-COV-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=leak,address -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand All @@ -586,7 +586,7 @@
// CHECK-ASAN-COV-LINUX-NOT: libclang_rt.ubsan
// CHECK-ASAN-COV-LINUX-NOT: "-lstdc++"
// CHECK-ASAN-COV-LINUX: "-lpthread"
// CHECK-ASAN-COV-LINUX: "-lresolv"
// CHECK-ASAN-COV-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=memory -fsanitize-coverage=func -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand All @@ -610,7 +610,7 @@
// CHECK-DFSAN-COV-LINUX-NOT: libclang_rt.ubsan
// CHECK-DFSAN-COV-LINUX-NOT: "-lstdc++"
// CHECK-DFSAN-COV-LINUX: "-lpthread"
// CHECK-DFSAN-COV-LINUX: "-lresolv"
// CHECK-DFSAN-COV-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=undefined -fsanitize-coverage=func -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand All @@ -621,7 +621,7 @@
// CHECK-UBSAN-COV-LINUX: "--whole-archive" "{{.*}}libclang_rt.ubsan_standalone.a" "--no-whole-archive"
// CHECK-UBSAN-COV-LINUX-NOT: "-lstdc++"
// CHECK-UBSAN-COV-LINUX: "-lpthread"
// CHECK-UBSAN-COV-LINUX: "-lresolv"
// CHECK-UBSAN-COV-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize-coverage=func -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand All @@ -632,7 +632,7 @@
// CHECK-COV-LINUX: "--whole-archive" "{{.*}}libclang_rt.ubsan_standalone.a" "--no-whole-archive"
// CHECK-COV-LINUX-NOT: "-lstdc++"
// CHECK-COV-LINUX: "-lpthread"
// CHECK-COV-LINUX: "-lresolv"
// CHECK-COV-LINUX-NOT: "-lresolv"

// RUN: %clang -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld -fsanitize=numerical \
Expand All @@ -644,7 +644,8 @@
// CHECK-NSAN-LINUX-NOT: "-lc"
// CHECK-NSAN-LINUX-NOT: libclang_rt.ubsan
// CHECK-NSAN-LINUX: libclang_rt.nsan.a"
// CHECK-NSAN-LINUX: "-lpthread" "-lrt" "-lm" "-ldl" "-lresolv"
// CHECK-NSAN-LINUX: "-lpthread" "-lrt" "-lm" "-ldl"
// CHECK-NSAN-LINUX-NOT: "-lresolv"

// RUN: %clang -### %s 2>&1 --target=x86_64-unknown-linux -fuse-ld=ld -fsanitize=numerical -shared-libsan \
// RUN: -resource-dir=%S/Inputs/resource_dir \
Expand Down Expand Up @@ -757,7 +758,7 @@
// CHECK-SAFESTACK-LINUX: libclang_rt.safestack.a"
// CHECK-SAFESTACK-LINUX: "-lpthread"
// CHECK-SAFESTACK-LINUX: "-ldl"
// CHECK-SAFESTACK-LINUX: "-lresolv"
// CHECK-SAFESTACK-LINUX-NOT: "-lresolv"

// RUN: %clang -fsanitize=shadow-call-stack -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld \
Expand Down Expand Up @@ -957,7 +958,7 @@
// CHECK-SCUDO-LINUX-NOT: "-lstdc++"
// CHECK-SCUDO-LINUX: "-lpthread"
// CHECK-SCUDO-LINUX: "-ldl"
// CHECK-SCUDO-LINUX: "-lresolv"
// CHECK-SCUDO-LINUX-NOT: "-lresolv"

// RUN: %clang -### %s -o %t.so -shared 2>&1 \
// RUN: --target=i386-unknown-linux -fuse-ld=ld -fsanitize=scudo -shared-libsan \
Expand Down Expand Up @@ -1018,7 +1019,7 @@
// CHECK-HWASAN-X86-64-LINUX: "-lpthread"
// CHECK-HWASAN-X86-64-LINUX: "-lrt"
// CHECK-HWASAN-X86-64-LINUX: "-ldl"
// CHECK-HWASAN-X86-64-LINUX: "-lresolv"
// CHECK-HWASAN-X86-64-LINUX-NOT: "-lresolv"

// RUN: %clang -### %s 2>&1 \
// RUN: --target=x86_64-unknown-linux -fuse-ld=ld -fsanitize=hwaddress \
Expand Down Expand Up @@ -1067,7 +1068,7 @@
// CHECK-HWASAN-AARCH64-LINUX: "-lpthread"
// CHECK-HWASAN-AARCH64-LINUX: "-lrt"
// CHECK-HWASAN-AARCH64-LINUX: "-ldl"
// CHECK-HWASAN-AARCH64-LINUX: "-lresolv"
// CHECK-HWASAN-AARCH64-LINUX-NOT: "-lresolv"

// RUN: %clang -### %s 2>&1 \
// RUN: --target=aarch64-unknown-linux -fuse-ld=ld -fsanitize=hwaddress \
Expand Down
76 changes: 76 additions & 0 deletions compiler-rt/lib/msan/msan_interceptors.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
};
Expand Down Expand Up @@ -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
78 changes: 0 additions & 78 deletions compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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;
Expand Down
2 changes: 0 additions & 2 deletions compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
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