[sanitizer] Add missing declarations for sigaltstack syscall wrappers.

[merge_guards_bot]

Unit tests: unknown.

clang-tidy: fail. clang-tidy found 0 errors and 7 warnings. 0 of them are added as review comments below (why?).

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[rupprecht]

compiler-rt/include/sanitizer/linux_syscall_hooks.h

3080–3081

LGTM with a change to longs:

void __sanitizer_syscall_pre_impl_sigaltstack(long ss, long oss);
void __sanitizer_syscall_post_impl_sigaltstack(long res, long ss, long oss);

[eugenis]

fix argument types + add a test

[merge_guards_bot]

Unit tests: unknown.

clang-tidy: fail. clang-tidy found 0 errors and 7 warnings. 0 of them are added as review comments below (why?).

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

compiler-rt/include/sanitizer/linux_syscall_hooks.h

 void __sanitizer_syscall_post_impl_vfork(long res);
 void __sanitizer_syscall_pre_impl_sigaction(long signum, long act, long oldact);
 void __sanitizer_syscall_post_impl_sigaction(long res, long signum, long act,
                                              long oldact);
 void __sanitizer_syscall_pre_impl_rt_sigaction(long signum, long act,
                                                long oldact, long sz);
 void __sanitizer_syscall_post_impl_rt_sigaction(long res, long signum, long act,
                                                 long oldact, long sz);
+void __sanitizer_syscall_pre_impl_sigaltstack(long ss, long oss);
+void __sanitizer_syscall_post_impl_sigaltstack(long res, long ss, long oss);
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // SANITIZER_LINUX_SYSCALL_HOOKS_H

compiler-rt/test/msan/Linux/syscalls.cpp

 // RUN: %clangxx_msan -O0 %s -o %t && %run %t 2>&1
 // RUN: %clangxx_msan -O3 %s -o %t && %run %t 2>&1
 
 #include <assert.h>
 #include <errno.h>
 #include <glob.h>
 #include <stdio.h>
 #include <string.h>
 
 #include <linux/aio_abi.h>
+#include <signal.h>
 #include <sys/ptrace.h>
 #include <sys/stat.h>
 #include <sys/uio.h>
 
 #include <sanitizer/linux_syscall_hooks.h>
 #include <sanitizer/msan_interface.h>
 
 /* Test the presence of __sanitizer_syscall_ in the tool runtime, and general
int main(int argc, char *argv[]) {
   __msan_poison(buf, sizeof(buf));
   __sanitizer_syscall_post_pipe2(0, (int *)buf, 0);
   assert(__msan_test_shadow(buf, sizeof(buf)) == 2 * sizeof(int));
 
   __msan_poison(buf, sizeof(buf));
   __sanitizer_syscall_post_socketpair(0, 0, 0, 0, (int *)buf);
   assert(__msan_test_shadow(buf, sizeof(buf)) == 2 * sizeof(int));
 
+  __msan_poison(buf, sizeof(buf));
+  __sanitizer_syscall_post_sigaltstack(0, nullptr, (stack_t *)buf);
+  assert(__msan_test_shadow(buf, sizeof(buf)) == sizeof(stack_t));
+
   return 0;
 }