Changeset 8bb46d2 for libcfa

Timestamp:

Mar 2, 2023, 2:09:47 PM (2 years ago)

Author:

Peter A. Buhr <pabuhr@…>

Branches:

ADT, ast-experimental, master

Children:

1f951abd

Parents:

8603c10

Message:

fix errors on interpose code for libc and libpthread

Location:

libcfa/src

Files:

• interpose.cfa (modified) (4 diffs)
• interpose_thread.cfa (modified) (2 diffs)

libcfa/src/interpose.cfa ¶

@@ -10 +10 @@
 // Created On       : Wed Mar 29 16:10:31 2017
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Feb 24 15:31:03 2023
-// Update Count     : 185
+// Last Modified On : Thu Mar  2 13:56:26 2023
+// Update Count     : 191
 //
 
@@ -53 +53 @@
 
 static generic_fptr_t interpose_symbol( const char symbol[], const char version[] ) {
-        static void * library;
-        static void * pthread_library;
-
+        void * library;
+        #if defined( RTLD_NEXT )
+        library = RTLD_NEXT;
+        #else
+        library = dlopen( "libc.so.6", RTLD_LAZY );
         if ( ! library ) {
-                library = dlopen( "libc.so.6", RTLD_LAZY );
                 const char * error = dlerror();
                 if ( error ) {
@@ -63 +64 @@
                 } // if
         } // if
-        if ( ! pthread_library ) {
-                pthread_library = dlopen( "libpthread.so", RTLD_LAZY );
-                const char * error = dlerror();
-                if ( error ) {
-                        abort( "interpose_symbol : failed to open libpthread, %s\n", error );
-                } // if
-        } // if
+        #endif
 
         return do_interpose_symbol(library, symbol, version);
@@ -108 +103 @@
 
                 if(__cfathreadabi_interpose_startup) __cfathreadabi_interpose_startup( do_interpose_symbol );
+
+                // SKULLDUGGERY: In Ubuntu 22.04, someone augmented signal.h to allow SIGSTKSZ to be "sysconf(_SC_SIGSTKSZ)" in
+                // sigstksz.h, as well as 8192 in sigstack.h. HOWEVER, they forgot to provide a mechanism to tell signal.h to
+                // use sigstack.h rather than sigstksz.h. (I'm not happy.) By undefining _GNU_SOURCE before signal.h and
+                // redefining it afterwards, you can get 8192, but then nothing works correctly inside of signal.h without
+                // _GNU_SOURCE defined.  So what is needed is a way to get signal.h to use sigstack.h WITH _GNU_SOURCE defined.
+                // Basically something is wrong with features.h and its use in signal.h.
+
+                #undef SIGSTKSZ
+                #define SIGSTKSZ 8192
 
                 // As a precaution (and necessity), errors that result in termination are delivered on a separate stack because

libcfa/src/interpose_thread.cfa ¶

@@ -39 +39 @@
         const char version[]
 ) libcfa_public {
-        static void * library;
+        void * library;
+        #if defined( RTLD_NEXT )
+        library = RTLD_NEXT;
+        #else
+        // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
+        library = dlopen( "libthread_db.so", RTLD_LAZY );
         if ( ! library ) {
-                library = dlopen( "libpthread.so", RTLD_LAZY );
                 const char * error = dlerror();
                 if ( error ) {
@@ -47 +51 @@
                 }
         } // if
+        #endif // RTLD_NEXT
 
         return do_interpose_symbol(library, symbol, version);