Add check for gnu/lib-names.h (#5727)

The header `<gnu/lib-names.h>` is not present on musl-libc based OSes.
Those names are not listed in any system header and this is deemed
irrelevant to have such a header in musl according to:
http://www.openwall.com/lists/musl/2013/11/09/1

3 files changed, 14 insertions, 2 deletions

diff --git a/src/pal/src/config.h.in b/src/pal/src/config.h.in
index fd0c4221e7..73a79b845b 100644
--- a/src/pal/src/config.h.in
+++ b/src/pal/src/config.h.in
@@ -19,6 +19,7 @@
 #cmakedefine01 HAVE_BSD_UUID_H
 #cmakedefine01 HAVE_RUNETYPE_H
 #cmakedefine01 HAVE_SYS_SYSCTL_H
+#cmakedefine01 HAVE_GNU_LIBNAMES_H
 
 #cmakedefine01 HAVE_KQUEUE
 #cmakedefine01 HAVE_GETPWUID_R
@@ -136,6 +137,7 @@
 #cmakedefine01 HAVE_FULLY_FEATURED_PTHREAD_MUTEXES
 #cmakedefine BSD_REGS_STYLE(reg, RR, rr) @BSD_REGS_STYLE@
 #cmakedefine FREEBSD_LIBC "@FREEBSD_LIBC@"
+#cmakedefine MUSL_LIBC_SO "@MUSL_LIBC_SO@"
 #cmakedefine01 HAVE_SCHED_OTHER_ASSIGNABLE
 
 #define CHECK_TRACE_SPECIFIERS 0
diff --git a/src/pal/src/configure.cmake b/src/pal/src/configure.cmake
index 3889d72133..7e95a776e7 100644
--- a/src/pal/src/configure.cmake
+++ b/src/pal/src/configure.cmake
@@ -36,6 +36,7 @@ check_include_files(runetype.h HAVE_RUNETYPE_H)
 check_include_files(lttng/tracepoint.h HAVE_LTTNG_TRACEPOINT_H)
 check_include_files(uuid/uuid.h HAVE_LIBUUID_H)
 check_include_files(sys/sysctl.h HAVE_SYS_SYSCTL_H)
+check_include_files(gnu/lib-names.h HAVE_GNU_LIBNAMES_H)
 
 check_function_exists(kqueue HAVE_KQUEUE)
 check_function_exists(getpwuid_r HAVE_GETPWUID_R)
@@ -1113,6 +1114,11 @@ else() # Anything else is Linux
     unset(HAVE_LIBUUID_H CACHE)
     message(FATAL_ERROR "Cannot find libuuid. Try installing uuid-dev or the appropriate packages for your platform")
   endif()
+  if(NOT HAVE_GNU_LIBNAMES_H)
+    if(EXISTS /lib/libc.musl-x86_64.so.1)
+      set(MUSL_LIBC_SO "/lib/libc.musl-x86_64.so.1")
+    endif()
+  endif()
   set(DEADLOCK_WHEN_THREAD_IS_SUSPENDED_WHILE_BLOCKED_ON_MUTEX 0)
   set(PAL_PTRACE "ptrace((cmd), (pid), (void*)(addr), (data))")
   set(PAL_PT_ATTACH PTRACE_ATTACH)
diff --git a/src/pal/src/loader/module.cpp b/src/pal/src/loader/module.cpp
index c7fe727c70..006d1bf933 100644
--- a/src/pal/src/loader/module.cpp
+++ b/src/pal/src/loader/module.cpp
@@ -54,7 +54,7 @@ Abstract:
 #include <sys/types.h>
 #include <sys/mman.h>
 
-#if defined(__linux__)
+#if HAVE_GNU_LIBNAMES_H
 #include <gnu/lib-names.h>
 #endif
 
@@ -1620,8 +1620,12 @@ static HMODULE LOADLoadLibrary(LPCSTR shortAsciiName, BOOL fDynamic)
         shortAsciiName = FREEBSD_LIBC;
 #elif defined(__NetBSD__)
         shortAsciiName = "libc.so";
-#else
+#elif defined(LIBC_SO)
         shortAsciiName = LIBC_SO;
+#elif defined(MUSL_LIBC_SO)
+        shortAsciiName = MUSL_LIBC_SO;
+#else
+#error Don't know how to get libc name on this platform
 #endif
     }