source: libcfa/src/interpose.cfa@ 0a2e1c05

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 0a2e1c05 was 6791213, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago

fix abort to add newline if abort message does not end with one
  • Property mode set to 100644
File size: 10.5 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// interpose.c --
8//
9// Author : Thierry Delisle
10// Created On : Wed Mar 29 16:10:31 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Mar 13 17:35:37 2020
13// Update Count : 178
14//
15
16#include <stdarg.h> // va_start, va_end
17#include <string.h> // strlen
18#include <unistd.h> // _exit, getpid
19#define __USE_GNU
20#include <signal.h>
21#undef __USE_GNU
22extern "C" {
23#include <dlfcn.h> // dlopen, dlsym
24#include <execinfo.h> // backtrace, messages
25}
26
27#include "bits/debug.hfa"
28#include "bits/defs.hfa"
29#include "bits/signal.hfa" // sigHandler_?
30#include "startup.hfa" // STARTUP_PRIORITY_CORE
31#include <assert.h>
32
33//=============================================================================================
34// Interposing helpers
35//=============================================================================================
36
37void preload_libgcc(void) {
38 dlopen( "libgcc_s.so.1", RTLD_NOW );
39 if ( const char * error = dlerror() ) abort( "interpose_symbol : internal error pre-loading libgcc, %s\n", error );
40}
41
42typedef void (* generic_fptr_t)(void);
43generic_fptr_t interpose_symbol( const char symbol[], const char version[] ) {
44 const char * error;
45
46 static void * library;
47 if ( ! library ) {
48 #if defined( RTLD_NEXT )
49 library = RTLD_NEXT;
50 #else
51 // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
52 library = dlopen( "libc.so.6", RTLD_LAZY );
53 error = dlerror();
54 if ( error ) {
55 abort( "interpose_symbol : failed to open libc, %s\n", error );
56 }
57 #endif
58 } // if
59
60 union { generic_fptr_t fptr; void * ptr; } originalFunc;
61
62 #if defined( _GNU_SOURCE )
63 if ( version ) {
64 originalFunc.ptr = dlvsym( library, symbol, version );
65 } else {
66 originalFunc.ptr = dlsym( library, symbol );
67 }
68 #else
69 originalFunc.ptr = dlsym( library, symbol );
70 #endif // _GNU_SOURCE
71
72 error = dlerror();
73 if ( error ) abort( "interpose_symbol : internal error, %s\n", error );
74
75 return originalFunc.fptr;
76}
77
78#define INTERPOSE_LIBC( x, ver ) __cabi_libc.x = (typeof(__cabi_libc.x))interpose_symbol( #x, ver )
79
80//=============================================================================================
81// Interposition Startup logic
82//=============================================================================================
83
84void sigHandler_segv( __CFA_SIGPARMS__ );
85void sigHandler_ill ( __CFA_SIGPARMS__ );
86void sigHandler_fpe ( __CFA_SIGPARMS__ );
87void sigHandler_abrt( __CFA_SIGPARMS__ );
88void sigHandler_term( __CFA_SIGPARMS__ );
89
90struct {
91 void (* exit)( int ) __attribute__(( __noreturn__ ));
92 void (* abort)( void ) __attribute__(( __noreturn__ ));
93} __cabi_libc;
94
95extern "C" {
96 void __cfaabi_interpose_startup(void) __attribute__(( constructor( STARTUP_PRIORITY_CORE ) ));
97 void __cfaabi_interpose_startup( void ) {
98 const char *version = 0p;
99
100 preload_libgcc();
101
102#pragma GCC diagnostic push
103#pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
104 INTERPOSE_LIBC( abort, version );
105 INTERPOSE_LIBC( exit , version );
106#pragma GCC diagnostic pop
107
108 // As a precaution (and necessity), errors that result in termination are delivered on a separate stack because
109 // task stacks might be very small (4K) and the signal delivery corrupts memory to the point that a clean
110 // shutdown is impossible. Also, when a stack overflow encounters the non-accessible sentinel page (debug only)
111 // and generates a segment fault, the signal cannot be delivered on the sentinel page. Finally, calls to abort
112 // print a stack trace that uses substantial stack space.
113
114 #define MINSTKSZ SIGSTKSZ * 8
115 static char stack[MINSTKSZ] __attribute__(( aligned (16) ));
116 static stack_t ss;
117
118 ss.ss_sp = stack;
119 ss.ss_size = MINSTKSZ;
120 ss.ss_flags = 0;
121 if ( sigaltstack( &ss, 0p ) == -1 ) {
122 abort( "__cfaabi_interpose_startup : internal error, sigaltstack error(%d) %s.", errno, strerror( errno ) );
123 } // if
124
125 // Failure handler
126 __cfaabi_sigaction( SIGSEGV, sigHandler_segv, SA_SIGINFO | SA_ONSTACK );
127 __cfaabi_sigaction( SIGBUS , sigHandler_segv, SA_SIGINFO | SA_ONSTACK );
128 __cfaabi_sigaction( SIGILL , sigHandler_ill , SA_SIGINFO | SA_ONSTACK );
129 __cfaabi_sigaction( SIGFPE , sigHandler_fpe , SA_SIGINFO | SA_ONSTACK );
130 __cfaabi_sigaction( SIGTERM, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // one shot handler, return to default
131 __cfaabi_sigaction( SIGINT , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND );
132 __cfaabi_sigaction( SIGABRT, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND );
133 __cfaabi_sigaction( SIGHUP , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // terminal hangup
134 }
135}
136
137//=============================================================================================
138// Terminating Signals logic
139//=============================================================================================
140
141// Forward declare abort after the __typeof__ call to avoid ambiguities
142void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
143void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ ));
144void abort( bool signalAbort, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
145void __abort( bool signalAbort, const char fmt[], va_list args ) __attribute__(( __nothrow__, __leaf__, __noreturn__ ));
146
147extern "C" {
148 void abort( void ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
149 abort( false, "%s", "" );
150 }
151
152 void __cabi_abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) {
153 va_list argp;
154 va_start( argp, fmt );
155 __abort( false, fmt, argp );
156 va_end( argp );
157 }
158
159 void exit( int status ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
160 __cabi_libc.exit( status );
161 }
162}
163
164void * kernel_abort( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 0p; }
165void kernel_abort_msg( void * data, char buffer[], int size ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
166// See concurrency/kernel.cfa for strong definition used in multi-processor mode.
167int kernel_abort_lastframe( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 4; }
168
169enum { abort_text_size = 1024 };
170static char abort_text[ abort_text_size ];
171
172static void __cfaabi_backtrace( int start ) {
173 enum { Frames = 50, }; // maximum number of stack frames
174 int last = kernel_abort_lastframe(); // skip last N stack frames
175
176 void * array[Frames];
177 size_t size = backtrace( array, Frames );
178 char ** messages = backtrace_symbols( array, size ); // does not demangle names
179
180 *index( messages[0], '(' ) = '\0'; // find executable name
181 __cfaabi_bits_print_nolock( STDERR_FILENO, "Stack back trace for: %s\n", messages[0]);
182
183 for ( unsigned int i = start; i < size - last && messages != 0p; i += 1 ) {
184 char * name = 0p, * offset_begin = 0p, * offset_end = 0p;
185
186 for ( char * p = messages[i]; *p; p += 1 ) { // find parantheses and +offset
187 //__cfaabi_bits_print_nolock( "X %s\n", p);
188 if ( *p == '(' ) {
189 name = p;
190 } else if ( *p == '+' ) {
191 offset_begin = p;
192 } else if ( *p == ')' ) {
193 offset_end = p;
194 break;
195 }
196 }
197
198 // if line contains symbol, print it
199 int frameNo = i - start;
200 if ( name && offset_begin && offset_end && name < offset_begin ) {
201 *name++ = '\0'; // delimit strings
202 *offset_begin++ = '\0';
203 *offset_end++ = '\0';
204
205 __cfaabi_bits_print_nolock( STDERR_FILENO, "(%i) %s : %s + %s %s\n", frameNo, messages[i], name, offset_begin, offset_end);
206 } else { // otherwise, print the whole line
207 __cfaabi_bits_print_nolock( STDERR_FILENO, "(%i) %s\n", frameNo, messages[i] );
208 }
209 }
210 free( messages );
211}
212
213void exit( int status, const char fmt[], ... ) {
214 va_list args;
215 va_start( args, fmt );
216 vfprintf( stderr, fmt, args );
217 va_end( args );
218 __cabi_libc.exit( status );
219}
220
221// Cannot forward va_list.
222void __abort( bool signalAbort, const char fmt[], va_list args ) {
223 void * kernel_data = kernel_abort(); // must be done here to lock down kernel
224 int len;
225
226 signal( SIGABRT, SIG_DFL ); // prevent final "real" abort from recursing to handler
227
228 len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
229 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
230
231 assert( fmt );
232 len = vsnprintf( abort_text, abort_text_size, fmt, args );
233 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
234
235 if ( fmt[strlen( fmt ) - 1] != '\n' ) { // add optional newline if missing at the end of the format text
236 __cfaabi_bits_write( STDERR_FILENO, "\n", 1 );
237 } // if
238 kernel_abort_msg( kernel_data, abort_text, abort_text_size );
239
240 __cfaabi_backtrace( signalAbort ? 4 : 2 );
241
242 __cabi_libc.abort(); // print stack trace in handler
243}
244
245void abort( const char fmt[], ... ) {
246 va_list args;
247 va_start( args, fmt );
248 __abort( false, fmt, args );
249 // CONTROL NEVER REACHES HERE!
250 va_end( args );
251}
252
253void abort( bool signalAbort, const char fmt[], ... ) {
254 va_list args;
255 va_start( args, fmt );
256 __abort( signalAbort, fmt, args );
257 // CONTROL NEVER REACHES HERE!
258 va_end( args );
259}
260
261void sigHandler_segv( __CFA_SIGPARMS__ ) {
262 if ( sfp->si_addr == 0p ) {
263 abort( true, "Null pointer (0p) dereference.\n" );
264 } else {
265 abort( true, "%s at memory location %p.\n"
266 "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",
267 (sig == SIGSEGV ? "Segment fault" : "Bus error"), sfp->si_addr );
268 }
269}
270
271void sigHandler_ill( __CFA_SIGPARMS__ ) {
272 abort( true, "Executing illegal instruction at location %p.\n"
273 "Possible cause is stack corruption.\n",
274 sfp->si_addr );
275}
276
277void sigHandler_fpe( __CFA_SIGPARMS__ ) {
278 const char * msg;
279
280 choose( sfp->si_code ) {
281 case FPE_INTDIV, FPE_FLTDIV: msg = "divide by zero";
282 case FPE_FLTOVF: msg = "overflow";
283 case FPE_FLTUND: msg = "underflow";
284 case FPE_FLTRES: msg = "inexact result";
285 case FPE_FLTINV: msg = "invalid operation";
286 default: msg = "unknown";
287 } // choose
288 abort( true, "Computation error %s at location %p.\n", msg, sfp->si_addr );
289}
290
291void sigHandler_term( __CFA_SIGPARMS__ ) {
292 abort( true, "Application interrupted by signal: %s.\n", strsignal( sig ) );
293}
294
295// Local Variables: //
296// mode: c //
297// tab-width: 4 //
298// End: //
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