Changeset b7d6a36 for libcfa/src/interpose.cfa

Timestamp:

Feb 20, 2020, 4:15:51 PM (6 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

6a490b2

Parents:

dca5802 (diff), 2cbfe92 (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 relaxed_ready

File:

• libcfa/src/interpose.cfa (modified) (11 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 : Sat Nov 30 07:09:42 2019
-// Update Count     : 119
+// Last Modified On : Mon Feb 17 10:18:53 2020
+// Update Count     : 166
 //
 
@@ -29 +29 @@
 #include "bits/signal.hfa"                                                              // sigHandler_?
 #include "startup.hfa"                                                                  // STARTUP_PRIORITY_CORE
+#include <assert.h>
 
 //=============================================================================================
@@ -40 +41 @@
 
 typedef void (* generic_fptr_t)(void);
-generic_fptr_t interpose_symbol( const char * symbol, const char * version ) {
+generic_fptr_t interpose_symbol( const char symbol[], const char version[] ) {
         const char * error;
 
@@ -95 +96 @@
         void __cfaabi_interpose_startup(void)  __attribute__(( constructor( STARTUP_PRIORITY_CORE ) ));
         void __cfaabi_interpose_startup( void ) {
-                const char *version = NULL;
+                const char *version = 0p;
 
                 preload_libgcc();
@@ -105 +106 @@
 #pragma GCC diagnostic pop
 
+                // As a precaution (and necessity), errors that result in termination are delivered on a separate stack because
+                // task stacks might be very small (4K) and the signal delivery corrupts memory to the point that a clean
+                // shutdown is impossible. Also, when a stack overflow encounters the non-accessible sentinel page (debug only)
+                // and generates a segment fault, the signal cannot be delivered on the sentinel page. Finally, calls to abort
+                // print a stack trace that uses substantial stack space.
+
+                #define MINSTKSZ SIGSTKSZ * 8
+                static char stack[MINSTKSZ] __attribute__(( aligned (16) ));
+                static stack_t ss;
+
+                ss.ss_sp = stack;
+                ss.ss_size = MINSTKSZ;
+                ss.ss_flags = 0;
+                if ( sigaltstack( &ss, 0p ) == -1 ) {
+                        abort( "__cfaabi_interpose_startup : internal error, sigaltstack error(%d) %s.", errno, strerror( errno ) );
+                } // if
+
                 // Failure handler
-                __cfaabi_sigaction( SIGSEGV, sigHandler_segv , SA_SIGINFO );
-                __cfaabi_sigaction( SIGBUS , sigHandler_segv , SA_SIGINFO );
-                __cfaabi_sigaction( SIGILL , sigHandler_ill  , SA_SIGINFO );
-                __cfaabi_sigaction( SIGFPE , sigHandler_fpe  , SA_SIGINFO );
-                __cfaabi_sigaction( SIGABRT, sigHandler_abrt, SA_SIGINFO | SA_RESETHAND);
-                __cfaabi_sigaction( SIGTERM, sigHandler_term , SA_SIGINFO );
-                __cfaabi_sigaction( SIGINT , sigHandler_term , SA_SIGINFO );
+                __cfaabi_sigaction( SIGSEGV, sigHandler_segv, SA_SIGINFO | SA_ONSTACK );
+                __cfaabi_sigaction( SIGBUS , sigHandler_segv, SA_SIGINFO | SA_ONSTACK );
+                __cfaabi_sigaction( SIGILL , sigHandler_ill , SA_SIGINFO | SA_ONSTACK );
+                __cfaabi_sigaction( SIGFPE , sigHandler_fpe , SA_SIGINFO | SA_ONSTACK );
+                __cfaabi_sigaction( SIGTERM, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // one shot handler, return to default
+                __cfaabi_sigaction( SIGINT , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND );
+                __cfaabi_sigaction( SIGABRT, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND );
+                __cfaabi_sigaction( SIGHUP , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // terminal hangup
         }
 }
@@ -123 +142 @@
 void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
 void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ ));
+void abort( bool signalAbort, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
 
 extern "C" {
         void abort( void ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
-                abort( NULL );
+                abort( false, "%s", "" );
         }
 
@@ -132 +152 @@
                 va_list argp;
                 va_start( argp, fmt );
-                abort( fmt, argp );
+                abort( false, fmt, argp );
                 va_end( argp );
         }
@@ -141 +161 @@
 }
 
-void * kernel_abort    ( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return NULL; }
-void   kernel_abort_msg( void * data, char * buffer, int size ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
+void * kernel_abort( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 0p; }
+void kernel_abort_msg( void * data, char buffer[], int size ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
+// See concurrency/kernel.cfa for strong definition used in multi-processor mode.
 int kernel_abort_lastframe( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 4; }
 
 enum { abort_text_size = 1024 };
 static char abort_text[ abort_text_size ];
-static int abort_lastframe;
-
-void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ )) {
-    va_list args;
-    va_start( args, fmt );
-    vfprintf( stderr, fmt, args );
-    va_end( args );
-        __cabi_libc.exit( status );
-}
-
-void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) {
-        void * kernel_data = kernel_abort();                    // must be done here to lock down kernel
-        int len;
-
-        abort_lastframe = kernel_abort_lastframe();
-        len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
-        __cfaabi_dbg_write( abort_text, len );
-
-        if ( fmt ) {
-                va_list args;
-                va_start( args, fmt );
-
-                len = vsnprintf( abort_text, abort_text_size, fmt, args );
-                va_end( args );
-                __cfaabi_dbg_write( abort_text, len );
-
-                if ( fmt[strlen( fmt ) - 1] != '\n' ) {         // add optional newline if missing at the end of the format text
-                        __cfaabi_dbg_write( "\n", 1 );
-                }
-        }
-
-        kernel_abort_msg( kernel_data, abort_text, abort_text_size );
-        __cabi_libc.abort();
-}
-
-static void __cfaabi_backtrace() {
-        enum {
-                Frames = 50,                                                                    // maximum number of stack frames
-                Start = 8,                                                                              // skip first N stack frames
-        };
+
+static void __cfaabi_backtrace( int start ) {
+        enum { Frames = 50, };                                                          // maximum number of stack frames
+        int last = kernel_abort_lastframe();                            // skip last N stack frames
 
         void * array[Frames];
         size_t size = backtrace( array, Frames );
-        char ** messages = backtrace_symbols( array, size );
-
-        // find executable name
-        *index( messages[0], '(' ) = '\0';
+        char ** messages = backtrace_symbols( array, size ); // does not demangle names
+
+        *index( messages[0], '(' ) = '\0';                                      // find executable name
         __cfaabi_bits_print_nolock( STDERR_FILENO, "Stack back trace for: %s\n", messages[0]);
 
-        for ( int i = Start; i < size - abort_lastframe && messages != 0p; i += 1 ) {
+        for ( unsigned int i = start; i < size - last && messages != 0p; i += 1 ) {
                 char * name = 0p, * offset_begin = 0p, * offset_end = 0p;
 
-                for ( char * p = messages[i]; *p; ++p ) {
+                for ( char * p = messages[i]; *p; p += 1 ) {    // find parantheses and +offset
                         //__cfaabi_bits_print_nolock( "X %s\n", p);
-                        // find parantheses and +offset
                         if ( *p == '(' ) {
                                 name = p;
@@ -212 +195 @@
                 }
 
-                // if line contains symbol print it
-                int frameNo = i - Start;
+                // if line contains symbol, print it
+                int frameNo = i - start;
                 if ( name && offset_begin && offset_end && name < offset_begin ) {
-                        // delimit strings
-                        *name++ = '\0';
+                        *name++ = '\0';                                                         // delimit strings
                         *offset_begin++ = '\0';
                         *offset_end++ = '\0';
@@ -228 +210 @@
 }
 
+void exit( int status, const char fmt[], ... ) {
+        va_list args;
+        va_start( args, fmt );
+        vfprintf( stderr, fmt, args );
+        va_end( args );
+        __cabi_libc.exit( status );
+}
+
+void abort( bool signalAbort, const char fmt[], ... ) {
+        void * kernel_data = kernel_abort();                            // must be done here to lock down kernel
+        int len;
+
+        signal( SIGABRT, SIG_DFL );                                                     // prevent final "real" abort from recursing to handler
+
+        len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
+        __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
+
+        assert( fmt );
+        va_list args;
+        va_start( args, fmt );
+
+        len = vsnprintf( abort_text, abort_text_size, fmt, args );
+        va_end( args );
+        __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
+
+        if ( fmt[strlen( fmt ) - 1] != '\n' ) {                         // add optional newline if missing at the end of the format text
+                __cfaabi_dbg_write( "\n", 1 );
+        } // if
+        kernel_abort_msg( kernel_data, abort_text, abort_text_size );
+
+        __cfaabi_backtrace( signalAbort ? 4 : 2 );
+
+        __cabi_libc.abort();                                                            // print stack trace in handler
+}
+
+void abort( const char fmt[], ... ) {
+        va_list args;
+        va_start( args, fmt );
+        abort( false, fmt, args );
+        va_end( args );
+}
+
 void sigHandler_segv( __CFA_SIGPARMS__ ) {
-        abort( "Addressing invalid memory at location %p\n"
-                        "Possible cause is reading outside the address space or writing to a protected area within the address space with an invalid pointer or subscript.\n",
-                        sfp->si_addr );
+                if ( sfp->si_addr == 0p ) {
+                        abort( true, "Null pointer (0p) dereference.\n" );
+                } else {
+                        abort( true, "%s at memory location %p.\n"
+                                   "Possible cause is reading outside the address space or writing to a protected area within the address space with an invalid pointer or subscript.\n",
+                                   (sig == SIGSEGV ? "Segment fault" : "Bus error"), sfp->si_addr );
+                }
 }
 
 void sigHandler_ill( __CFA_SIGPARMS__ ) {
-        abort( "Executing illegal instruction at location %p.\n"
+        abort( true, "Executing illegal instruction at location %p.\n"
                         "Possible cause is stack corruption.\n",
                         sfp->si_addr );
@@ -251 +279 @@
           default: msg = "unknown";
         } // choose
-        abort( "Computation error %s at location %p.\n", msg, sfp->si_addr );
-}
-
-void sigHandler_abrt( __CFA_SIGPARMS__ ) {
-        __cfaabi_backtrace();
-
-        // reset default signal handler
-        __cfaabi_sigdefault( SIGABRT );
-
-        raise( SIGABRT );
+        abort( true, "Computation error %s at location %p.\n", msg, sfp->si_addr );
 }
 
 void sigHandler_term( __CFA_SIGPARMS__ ) {
-        abort( "Application stopped by %s signal.", sig == SIGINT ? "an interrupt (SIGINT)" : "a terminate (SIGTERM)" );
+        abort( true, "Application interrupted by signal: %s.\n", strsignal( sig ) );
 }