Changeset 24d6572 for libcfa/src/interpose.cfa

Timestamp:

Jun 12, 2023, 2:45:32 PM (2 years ago)

Author:

Fangren Yu <f37yu@…>

Branches:

ast-experimental, master

Children:

62d62db

Parents:

34b4268 (diff), 251ce80 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' into ast-experimental

File:

• libcfa/src/interpose.cfa (modified) (5 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 Mar 13 17:35:37 2020
-// Update Count     : 178
-//
-
-#include <stdarg.h>                                                                             // va_start, va_end
+// Last Modified On : Mon Mar 27 21:09:03 2023
+// Update Count     : 196
+//
+
 #include <stdio.h>
-#include <string.h>                                                                             // strlen
 #include <unistd.h>                                                                             // _exit, getpid
-#define __USE_GNU
-#include <signal.h>
-#undef __USE_GNU
 extern "C" {
 #include <dlfcn.h>                                                                              // dlopen, dlsym
@@ -26 +21 @@
 }
 
-#include "bits/debug.hfa"
 #include "bits/defs.hfa"
 #include "bits/signal.hfa"                                                              // sigHandler_?
@@ -42 +36 @@
 
 typedef void (* generic_fptr_t)(void);
+
 static generic_fptr_t do_interpose_symbol( void * library, const char symbol[], const char version[] ) {
-        const char * error;
-
         union { generic_fptr_t fptr; void * ptr; } originalFunc;
 
         #if defined( _GNU_SOURCE )
-                if ( version ) {
-                        originalFunc.ptr = dlvsym( library, symbol, version );
-                } else {
-                        originalFunc.ptr = dlsym( library, symbol );
-                }
+        if ( version ) {
+                originalFunc.ptr = dlvsym( library, symbol, version );
+        } else {
+                originalFunc.ptr = dlsym( library, symbol );
+        } // if
         #else
-                originalFunc.ptr = dlsym( library, symbol );
+        originalFunc.ptr = dlsym( library, symbol );
         #endif // _GNU_SOURCE
 
-        error = dlerror();
-        if ( error ) abort( "interpose_symbol : internal error, %s\n", error );
-
+        if ( ! originalFunc.ptr ) {                                                     // == nullptr
+                abort( "interpose_symbol : internal error, %s\n", dlerror() );
+        } // if
         return originalFunc.fptr;
 }
 
 static generic_fptr_t interpose_symbol( const char symbol[], const char version[] ) {
-        const char * error;
-
-        static void * library;
-        static void * pthread_library;
-        if ( ! library ) {
-                #if defined( RTLD_NEXT )
-                        library = RTLD_NEXT;
-                #else
-                        // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
-                        library = dlopen( "libc.so.6", RTLD_LAZY );
-                        error = dlerror();
-                        if ( error ) {
-                                abort( "interpose_symbol : failed to open libc, %s\n", error );
-                        }
-                #endif
+        void * library;
+
+        #if defined( RTLD_NEXT )
+        library = RTLD_NEXT;
+        #else
+        // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
+        library = dlopen( "libc.so.6", RTLD_LAZY );
+        if ( ! library ) {                                                                      // == nullptr
+                abort( "interpose_symbol : failed to open libc, %s\n", dlerror() );
         } // if
-        if ( ! pthread_library ) {
-                #if defined( RTLD_NEXT )
-                        pthread_library = RTLD_NEXT;
-                #else
-                        // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
-                        pthread_library = dlopen( "libpthread.so", RTLD_LAZY );
-                        error = dlerror();
-                        if ( error ) {
-                                abort( "interpose_symbol : failed to open libpthread, %s\n", error );
-                        }
-                #endif
-        } // if
-
-        return do_interpose_symbol(library, symbol, version);
+        #endif // RTLD_NEXT
+
+        return do_interpose_symbol( library, symbol, version );
 }
 
@@ -123 +99 @@
                 preload_libgcc();
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
+                #pragma GCC diagnostic push
+                #pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
                 INTERPOSE_LIBC( abort, version );
                 INTERPOSE_LIBC( exit , version );
-#pragma GCC diagnostic pop
+                #pragma GCC diagnostic pop
 
                 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
@@ -295 +281 @@
         va_start( args, fmt );
         __abort( false, fmt, args );
-    // CONTROL NEVER REACHES HERE!
+        // CONTROL NEVER REACHES HERE!
         va_end( args );
 }
 
 void abort( bool signalAbort, const char fmt[], ... ) {
-    va_list args;
-    va_start( args, fmt );
-    __abort( signalAbort, fmt, args );
-    // CONTROL NEVER REACHES HERE!
-    va_end( args );
+        va_list args;
+        va_start( args, fmt );
+        __abort( signalAbort, fmt, args );
+        // CONTROL NEVER REACHES HERE!
+        va_end( args );
 }