https://github.com/rorth created https://github.com/llvm/llvm-project/pull/98001

At the end of the recent flurry of Illumos (and implicitly Solaris) safestack 
patches, the tests were disabled in
b0260c5b1052f8e3ff1ec77dc42a11f42da762cc without explanation.

After re-enabling them, there were many problems on Solaris:

- Every single testcase failed to link:

  ``` Undefined                 first referenced
   symbol                           in file
  __safestack_unsafe_stack_ptr        buffer-copy-vla.o
  __safestack_init                    (command line)
  ld: fatal: symbol referencing errors
  ```

  The problem is that `-u __safestack_init` was passed to the linker after the 
corresponding version of `libclang_rt.safestack-*.a`.  Since the Solaris linker 
(like Unix linkers for decades) respects the command line argument order 
(unlike e.g. GNU ld which uses GNU getopt), this cannot work.  Fixed by moving 
the `-u` arg further to the front.  Two affected testcases were adjusted 
accordingly.

* While 540fd42c755f20f7b79c6c79493ec36d8cb9b3d3 enabled safestack on Solaris 
unconditionally, it ignored that Solaris also exists on SPARC and forgot to 
enable SPARC support.  This patch fixes that.

- Afterwards, the tests still fail to link with undefined references to 
`__sanitizer_internal_memset` etc.  These are from 
`sanitizer_redefine_builtins.h`.  Definitions live in `sanitizer_libc.cpp.o` 
and were added to the safestack runtime lib as is already the case e.g. for 
asan and ubsan.  Why GNU ld allows the link to complete with those symbols 
undefined is beyond me.

- The `pthread*.c` tests `FAIL` with

  ``` safestack CHECK failed: 
/vol/llvm/src/llvm-project/local/compiler-rt/lib/safestack/safestack.cpp:227 
size ```

  The problem is that `pthread_attr_init` initializes the `stacksize` attribute 
to 0, signifying the default.  Unless explicitly overridded, it stays that way. 
 I think this is allowed by XPG7.  Since safestack cannot deal with this, I set 
`size` to the defaults documented in `pthread_create(3C)`.  Unfortunately, 
there's no macro for those values outside of private `libc` headers.

- The Solaris `syscall` interface isn't stable.  This is not just a theoretical 
concern, but the syscalls have changed incompatibly several times in the past.  
Therefore this patch switches the implementations of `TgKill` (where 
`SYS_lwp_kill` doesn't exist on Solaris 11.4 anyway), `Mmap`, `Munmap`, and 
`Mprotect` to the same `_REAL*` solution already used in 
`sanitizer_solaris.cpp`.  Instead of duplicating what's already in 
`sanitizer_common`, it seems way better to me to just reuse those 
implementations, though.  A subsequent patch does just that.

With those changes, safestack compiles and all tests `PASS`.

Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`, 
`x86_64-pc-linux-gnu`, and `sparc64-unknown-linux-gnu`.

>From f8de9c3c2dbde4021f0d32a55c8a385221c0f749 Mon Sep 17 00:00:00 2001
From: Rainer Orth <r...@gcc.gnu.org>
Date: Mon, 8 Jul 2024 10:28:42 +0200
Subject: [PATCH] [safestack] Various Solaris fixes

At the end of the recent flurry of Illumos (and implicitly Solaris)
safestack patches, the tests were disabled in
b0260c5b1052f8e3ff1ec77dc42a11f42da762cc without explanation.

After re-enabling them, there were many problems on Solaris:

- Every single testcase failed to link:

  ```
  Undefined                     first referenced
   symbol                           in file
  __safestack_unsafe_stack_ptr        buffer-copy-vla.o
  __safestack_init                    (command line)
  ld: fatal: symbol referencing errors
  ```

  The problem is that `-u __safestack_init` was passed to the linker after
  the corresponding version of `libclang_rt.safestack-*.a`.  Since the
  Solaris linker (like Unix linkers for decades) respects the command line
  argument order (unlike e.g. GNU ld which uses GNU getopt), this cannot
  work.  Fixed by moving the `-u` arg further to the front.  Two affected
  testcases were fixed accordingly.

* While 540fd42c755f20f7b79c6c79493ec36d8cb9b3d3 enabled safestack on
  Solaris unconditionally, it ignored that Solaris also exists on SPARC and
  forgot to enable SPARC support.  This patch fixes that.

- Afterwards, the tests still fail to link with undefined references to
  `__sanitizer_internal_memset` etc.  These are from
  `sanitizer_redefine_builtins.h`.  Definitions live in
  `sanitizer_libc.cpp.o` and were added to the safestack runtime lib as is
  already the case e.g. for asan and ubsan.  Why GNU ld allows the link to
  complete with those undefined is beyond me.

- The `pthread*.c` tests `FAIL` with

  ```
  safestack CHECK failed: 
/vol/llvm/src/llvm-project/local/compiler-rt/lib/safestack/safestack.cpp:227 
size
  ```

  The problem is that `pthread_attr_init` initializes the `stacksize`
  attribute to 0, signifying the default.  Unless explicitly overridded, it
  stays that way.  I think this is allowed by XPG7.  Since safestack cannot
  deal with this, I set `size` to the defaults documented in
  `pthread_create(3C)`.  Unfortunately, there's no macro for those values
  outside of private `libc` headers.

- The Solaris `syscall` interface isn't stable.  This is not just a
  theoretical concern, but the syscalls have changed incompatibly several
  times in the past.  Therefore this patch switches the implementations of
  `TgKill` (where `SYS_lwp_kill` doesn't exist on Solaris 11.4 anyway),
  `Mmap`, `Munmap`, and `Mprotect` to the same `_REAL*` solution already
  used in `sanitizer_solaris.cpp`.  Instead of duplicating what's already
  in `sanitizer_common`, it seems way better to me to just reuse those
  implementations, though.  A subsequent patch does just that.

With those changes, safestack compiles and all tests `PASS`.

Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`,
`x86_64-pc-linux-gnu`, and `sparc64-unknown-linux-gnu`.
---
 clang/lib/Driver/ToolChains/CommonArgs.cpp    | 10 +++---
 clang/test/Driver/ohos.c                      |  2 +-
 clang/test/Driver/sanitizer-ld.c              |  2 +-
 .../cmake/Modules/AllSupportedArchDefs.cmake  |  2 +-
 compiler-rt/lib/safestack/CMakeLists.txt      |  2 ++
 compiler-rt/lib/safestack/safestack.cpp       | 11 ++++++
 .../lib/safestack/safestack_platform.h        | 35 +++++++++++++++----
 compiler-rt/test/safestack/lit.cfg.py         |  2 +-
 8 files changed, 51 insertions(+), 15 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp 
b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index c56a0c2c46c47..fd70398027be9 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1543,6 +1543,12 @@ bool tools::addSanitizerRuntimes(const ToolChain &TC, 
const ArgList &Args,
                              RequiredSymbols);
   }
 
+  // -u options must be added before the runtime libs that resolve them.
+  for (auto S : RequiredSymbols) {
+    CmdArgs.push_back("-u");
+    CmdArgs.push_back(Args.MakeArgString(S));
+  }
+
   // Inject libfuzzer dependencies.
   if (SanArgs.needsFuzzer() && SanArgs.linkRuntimes() &&
       !Args.hasArg(options::OPT_shared)) {
@@ -1575,10 +1581,6 @@ bool tools::addSanitizerRuntimes(const ToolChain &TC, 
const ArgList &Args,
     addSanitizerRuntime(TC, Args, CmdArgs, RT, false, false);
     AddExportDynamic |= !addSanitizerDynamicList(TC, Args, CmdArgs, RT);
   }
-  for (auto S : RequiredSymbols) {
-    CmdArgs.push_back("-u");
-    CmdArgs.push_back(Args.MakeArgString(S));
-  }
   // If there is a static runtime with no dynamic list, force all the symbols
   // to be dynamic to be sure we export sanitizer interface functions.
   if (AddExportDynamic)
diff --git a/clang/test/Driver/ohos.c b/clang/test/Driver/ohos.c
index b1ce61e7227b6..8de4e6de57f7f 100644
--- a/clang/test/Driver/ohos.c
+++ b/clang/test/Driver/ohos.c
@@ -95,8 +95,8 @@
 // RUN:     | FileCheck %s -check-prefix=CHECK-SAFESTACK
 // CHECK-SAFESTACK: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-SAFESTACK: "-fsanitize=safe-stack"
-// CHECK-SAFESTACK: 
"[[RESOURCE_DIR]]{{/|\\\\}}lib{{/|\\\\}}arm-liteos-ohos{{/|\\\\}}libclang_rt.safestack.a"
 // CHECK-SAFESTACK: "__safestack_init"
+// CHECK-SAFESTACK: 
"[[RESOURCE_DIR]]{{/|\\\\}}lib{{/|\\\\}}arm-liteos-ohos{{/|\\\\}}libclang_rt.safestack.a"
 
 // RUN: %clang %s -### --target=arm-liteos \
 // RUN:     -fsanitize=address 2>&1 \
diff --git a/clang/test/Driver/sanitizer-ld.c b/clang/test/Driver/sanitizer-ld.c
index 93702f456229f..ca2db69bc09d8 100644
--- a/clang/test/Driver/sanitizer-ld.c
+++ b/clang/test/Driver/sanitizer-ld.c
@@ -728,8 +728,8 @@
 // CHECK-SAFESTACK-LINUX: "{{(.*[^-.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
 // CHECK-SAFESTACK-LINUX-NOT: "-lc"
 // CHECK-SAFESTACK-LINUX-NOT: whole-archive
-// CHECK-SAFESTACK-LINUX: libclang_rt.safestack.a"
 // CHECK-SAFESTACK-LINUX: "-u" "__safestack_init"
+// CHECK-SAFESTACK-LINUX: libclang_rt.safestack.a"
 // CHECK-SAFESTACK-LINUX: "-lpthread"
 // CHECK-SAFESTACK-LINUX: "-ldl"
 // CHECK-SAFESTACK-LINUX: "-lresolv"
diff --git a/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake 
b/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
index ac4a71202384d..5369e944a2e81 100644
--- a/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
+++ b/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
@@ -74,7 +74,7 @@ set(ALL_UBSAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} 
${ARM64} ${RISCV64}
     ${MIPS32} ${MIPS64} ${PPC64} ${S390X} ${SPARC} ${SPARCV9} ${HEXAGON}
     ${LOONGARCH64})
 set(ALL_SAFESTACK_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM64} ${MIPS32} ${MIPS64}
-    ${HEXAGON} ${LOONGARCH64})
+    ${HEXAGON} ${LOONGARCH64} ${SPARC} ${SPARCV9})
 set(ALL_CFI_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${MIPS64}
     ${HEXAGON} ${LOONGARCH64})
 set(ALL_SCUDO_STANDALONE_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64}
diff --git a/compiler-rt/lib/safestack/CMakeLists.txt 
b/compiler-rt/lib/safestack/CMakeLists.txt
index 316ab69ecfdbe..730043eb87cab 100644
--- a/compiler-rt/lib/safestack/CMakeLists.txt
+++ b/compiler-rt/lib/safestack/CMakeLists.txt
@@ -14,6 +14,8 @@ foreach(arch ${SAFESTACK_SUPPORTED_ARCH})
     ARCHS ${arch}
     SOURCES ${SAFESTACK_SOURCES}
             $<TARGET_OBJECTS:RTInterception.${arch}>
+    OBJECT_LIBS RTSanitizerCommon
+                RTSanitizerCommonLibc
     CFLAGS ${SAFESTACK_CFLAGS}
     PARENT_TARGET safestack)
 endforeach()
diff --git a/compiler-rt/lib/safestack/safestack.cpp 
b/compiler-rt/lib/safestack/safestack.cpp
index 0751f3988b9c1..f8ef224f45494 100644
--- a/compiler-rt/lib/safestack/safestack.cpp
+++ b/compiler-rt/lib/safestack/safestack.cpp
@@ -224,6 +224,17 @@ INTERCEPTOR(int, pthread_create, pthread_t *thread,
     pthread_attr_destroy(&tmpattr);
   }
 
+#if SANITIZER_SOLARIS
+  // Solaris pthread_attr_init initializes stacksize to 0 (the default), so
+  // hardcode the actual values as documented in pthread_create(3C).
+  if (size == 0)
+#  if defined(_LP64)
+    size = 2 * 1024 * 1024;
+#  else
+    size = 1024 * 1024;
+#  endif
+#endif
+
   SFS_CHECK(size);
   size = RoundUpTo(size, kStackAlign);
 
diff --git a/compiler-rt/lib/safestack/safestack_platform.h 
b/compiler-rt/lib/safestack/safestack_platform.h
index d4b2e2ef7391c..77eeb9cda6e15 100644
--- a/compiler-rt/lib/safestack/safestack_platform.h
+++ b/compiler-rt/lib/safestack/safestack_platform.h
@@ -17,6 +17,7 @@
 #include "sanitizer_common/sanitizer_platform.h"
 
 #include <dlfcn.h>
+#include <errno.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -68,6 +69,24 @@ static void *GetRealLibcAddress(const char *symbol) {
   SFS_CHECK(real_##func);
 #endif
 
+#if SANITIZER_SOLARIS
+#  define _REAL(func) _##func
+#  define DEFINE__REAL(ret_type, func, ...) \
+    extern "C" ret_type _REAL(func)(__VA_ARGS__)
+
+#  if !defined(_LP64) && _FILE_OFFSET_BITS == 64
+#    define _REAL64(func) _##func##64
+#  else
+#    define _REAL64(func) _REAL(func)
+#  endif
+#  define DEFINE__REAL64(ret_type, func, ...) \
+    extern "C" ret_type _REAL64(func)(__VA_ARGS__)
+
+DEFINE__REAL64(void *, mmap, void *a, size_t b, int c, int d, int e, off_t f);
+DEFINE__REAL(int, munmap, void *a, size_t b);
+DEFINE__REAL(int, mprotect, void *a, size_t b, int c);
+#endif
+
 using ThreadId = uint64_t;
 
 inline ThreadId GetTid() {
@@ -91,11 +110,10 @@ inline int TgKill(pid_t pid, ThreadId tid, int sig) {
   (void)pid;
   return _REAL(_lwp_kill, tid, sig);
 #elif SANITIZER_SOLARIS
-#  ifdef SYS_lwp_kill
-  return syscall(SYS_lwp_kill, tid, sig);
-#  else
-  return -1;
-#  endif
+  (void)pid;
+  errno = thr_kill(tid, sig);
+  // TgKill is expected to return -1 on error, not an errno.
+  return errno != 0 ? -1 : 0;
 #elif SANITIZER_FREEBSD
   return syscall(SYS_thr_kill2, pid, tid, sig);
 #else
@@ -110,8 +128,7 @@ inline void *Mmap(void *addr, size_t length, int prot, int 
flags, int fd,
 #elif SANITIZER_FREEBSD && (defined(__aarch64__) || defined(__x86_64__))
   return (void *)__syscall(SYS_mmap, addr, length, prot, flags, fd, offset);
 #elif SANITIZER_SOLARIS
-  return (void *)(uintptr_t)syscall(SYS_mmap, addr, length, prot, flags, fd,
-                                    offset);
+  return _REAL64(mmap)(addr, length, prot, flags, fd, offset);
 #else
   return (void *)syscall(SYS_mmap, addr, length, prot, flags, fd, offset);
 #endif
@@ -121,6 +138,8 @@ inline int Munmap(void *addr, size_t length) {
 #if SANITIZER_NETBSD
   DEFINE__REAL(int, munmap, void *a, size_t b);
   return _REAL(munmap, addr, length);
+#elif SANITIZER_SOLARIS
+  return _REAL(munmap)(addr, length);
 #else
   return syscall(SYS_munmap, addr, length);
 #endif
@@ -130,6 +149,8 @@ inline int Mprotect(void *addr, size_t length, int prot) {
 #if SANITIZER_NETBSD
   DEFINE__REAL(int, mprotect, void *a, size_t b, int c);
   return _REAL(mprotect, addr, length, prot);
+#elif SANITIZER_SOLARIS
+  return _REAL(mprotect)(addr, length, prot);
 #else
   return syscall(SYS_mprotect, addr, length, prot);
 #endif
diff --git a/compiler-rt/test/safestack/lit.cfg.py 
b/compiler-rt/test/safestack/lit.cfg.py
index aadb8bf0d5c77..17dfae46a412b 100644
--- a/compiler-rt/test/safestack/lit.cfg.py
+++ b/compiler-rt/test/safestack/lit.cfg.py
@@ -33,5 +33,5 @@
         )
     )
 
-if config.host_os not in ["Linux", "FreeBSD", "NetBSD"]:
+if config.host_os not in ["Linux", "FreeBSD", "NetBSD", "SunOS"]:
     config.unsupported = True

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