[msan] Don't intercept LFS prlimit64/getrlimit64 on musl

[thesamesam]

Summary

These are aliases on musl and as of 1.2.4, aren't visible by default
(only with -D_LARGEFILE64_SOURCE), and will be removed entirely in a future
release.

This fixes a runtime failure with msan on musl-1.2.4:

$ echo 'int main(){}' | clang -x c - -fsanitize=memory -o /dev/null
/usr/bin/x86_64-gentoo-linux-musl-ld.bfd: /usr/lib/llvm/16/bin/../../../../lib/clang/16/lib/linux/libclang_rt.msan-x86_64.a(msan_interceptors.cpp.o): in function `__interceptor_getrlimit64':
[...]

Bug: https://bugs.gentoo.org/906603

[thesamesam]

I think we've had a similar set of changes like this before but I can't find them right now...

[MaskRay]

This is similar to D141186

compiler-rt/lib/msan/msan_interceptors.cpp

if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT_FSTAT MSAN_INTERCEPT_FUNC(fstat)
 #else
 #define MSAN_MAYBE_INTERCEPT_FSTAT
 #endif
 
-#if SANITIZER_STAT_LINUX
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, fstat64, int fd, void *buf) {
   ENSURE_MSAN_INITED();
   int res = REAL(fstat64)(fd, buf);
   if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT_FSTAT64 MSAN_INTERCEPT_FUNC(fstat64)
INTERCEPTOR(int, getrlimit, int resource, void *rlim) {
   INTERCEPTOR_GETRLIMIT_BODY(getrlimit, resource, rlim);
 }
 
 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
 INTERCEPTOR(int, __getrlimit, int resource, void *rlim) {
   INTERCEPTOR_GETRLIMIT_BODY(__getrlimit, resource, rlim);
 }
 
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, getrlimit64, int resource, void *rlim) {
   if (msan_init_is_running) return REAL(getrlimit64)(resource, rlim);
   ENSURE_MSAN_INITED();
   int res = REAL(getrlimit64)(resource, rlim);
   if (!res) __msan_unpoison(rlim, __sanitizer::struct_rlimit64_sz);
   return res;
 }
+#else
+#define MSAN_MAYBE_INTERCEPT_GETRLIMIT64 INTERCEPT_FUNCTION(getrlimit64)
+#endif
 
 INTERCEPTOR(int, prlimit, int pid, int resource, void *new_rlimit,
             void *old_rlimit) {
   if (msan_init_is_running)
     return REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
   ENSURE_MSAN_INITED();
   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit_sz);
   int res = REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit_sz);
   return res;
 }
 
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, prlimit64, int pid, int resource, void *new_rlimit,
             void *old_rlimit) {
   if (msan_init_is_running)
     return REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
   ENSURE_MSAN_INITED();
   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit64_sz);
   int res = REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit64_sz);
   return res;
 }
+#else
+#define MSAN_MAYBE_INTERCEPT_PRLIMIT64 INTERCEPT_FUNCTION(prlimit64)
+#endif
 
 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT INTERCEPT_FUNCTION(__getrlimit)
 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64 INTERCEPT_FUNCTION(getrlimit64)
 #define MSAN_MAYBE_INTERCEPT_PRLIMIT INTERCEPT_FUNCTION(prlimit)
 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64 INTERCEPT_FUNCTION(prlimit64)
 #else
 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT
 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64
#endif
   MSAN_MAYBE_INTERCEPT___FXSTAT64;
   MSAN_MAYBE_INTERCEPT___FXSTATAT64;
   INTERCEPT_FUNCTION(pipe);
   INTERCEPT_FUNCTION(pipe2);
   INTERCEPT_FUNCTION(socketpair);
   MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED;
   INTERCEPT_FUNCTION(getrlimit);
   MSAN_MAYBE_INTERCEPT___GETRLIMIT;
+#if SANITIZER_GLIBC
   MSAN_MAYBE_INTERCEPT_GETRLIMIT64;
+#endif
   MSAN_MAYBE_INTERCEPT_PRLIMIT;
+#if SANITIZER_GLIBC
   MSAN_MAYBE_INTERCEPT_PRLIMIT64;
+#endif
   INTERCEPT_FUNCTION(gethostname);
   MSAN_MAYBE_INTERCEPT_EPOLL_WAIT;
   MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT;
   INTERCEPT_FUNCTION(strsignal);
   INTERCEPT_FUNCTION(dladdr);
   INTERCEPT_FUNCTION(dlerror);
   INTERCEPT_FUNCTION(dl_iterate_phdr);
   INTERCEPT_FUNCTION(getrusage);