source: libcfa/src/interpose.cfa@ 6502a2b

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 6502a2b was 851fd92, checked in by Andrew Beach <ajbeach@…>, 5 years ago

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