source: libcfa/src/interpose.cfa@ bf20567

ADT ast-experimental
Last change on this file since bf20567 was ae267366, checked in by Peter A. Buhr <pabuhr@…>, 3 years ago

fix merge conflict

  • Property mode set to 100644
File size: 12.0 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 Feb 24 15:31:03 2023
13// Update Count : 185
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#include <signal.h>
21extern "C" {
22#include <dlfcn.h> // dlopen, dlsym
23#include <execinfo.h> // backtrace, messages
24}
25
26#include "bits/debug.hfa"
27#include "bits/defs.hfa"
28#include "bits/signal.hfa" // sigHandler_?
29#include "startup.hfa" // STARTUP_PRIORITY_CORE
30#include <assert.h>
31
32//=============================================================================================
33// Interposing helpers
34//=============================================================================================
35
36static void preload_libgcc(void) {
37 dlopen( "libgcc_s.so.1", RTLD_NOW );
38 if ( const char * error = dlerror() ) abort( "interpose_symbol : internal error pre-loading libgcc, %s\n", error );
39}
40
41typedef void (* generic_fptr_t)(void);
42static generic_fptr_t do_interpose_symbol( void * library, const char symbol[], const char version[] ) {
43 const char * error;
44
45 union { generic_fptr_t fptr; void * ptr; } originalFunc;
46
47 originalFunc.ptr = dlsym( library, symbol );
48 error = dlerror();
49 if ( error ) abort( "interpose_symbol : internal error, %s\n", error );
50
51 return originalFunc.fptr;
52}
53
54static generic_fptr_t interpose_symbol( const char symbol[], const char version[] ) {
55 static void * library;
56 static void * pthread_library;
57
58 if ( ! library ) {
59 library = dlopen( "libc.so.6", RTLD_LAZY );
60 const char * error = dlerror();
61 if ( error ) {
62 abort( "interpose_symbol : failed to open libc, %s\n", error );
63 } // if
64 } // if
65 if ( ! pthread_library ) {
66 pthread_library = dlopen( "libpthread.so", RTLD_LAZY );
67 const char * error = dlerror();
68 if ( error ) {
69 abort( "interpose_symbol : failed to open libpthread, %s\n", error );
70 } // if
71 } // if
72
73 return do_interpose_symbol(library, symbol, version);
74}
75
76#define INTERPOSE_LIBC( x, ver ) __cabi_libc.x = (typeof(__cabi_libc.x))interpose_symbol( #x, ver )
77
78//=============================================================================================
79// Interposition Startup logic
80//=============================================================================================
81
82static void sigHandler_segv( __CFA_SIGPARMS__ );
83static void sigHandler_ill ( __CFA_SIGPARMS__ );
84static void sigHandler_fpe ( __CFA_SIGPARMS__ );
85static void sigHandler_abrt( __CFA_SIGPARMS__ );
86static void sigHandler_term( __CFA_SIGPARMS__ );
87
88static struct {
89 void (* exit)( int ) __attribute__(( __noreturn__ ));
90 void (* abort)( void ) __attribute__(( __noreturn__ ));
91} __cabi_libc;
92
93libcfa_public int cfa_main_returned;
94
95extern "C" {
96 void __cfathreadabi_interpose_startup( generic_fptr_t (*do_interpose_symbol)( void * library, const char symbol[], const char version[] ) ) __attribute__((weak));
97 void __cfaabi_interpose_startup( void ) {
98 const char *version = 0p;
99 cfa_main_returned = 0;
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 if(__cfathreadabi_interpose_startup) __cfathreadabi_interpose_startup( do_interpose_symbol );
110
111 // As a precaution (and necessity), errors that result in termination are delivered on a separate stack because
112 // task stacks might be very small (4K) and the signal delivery corrupts memory to the point that a clean
113 // shutdown is impossible. Also, when a stack overflow encounters the non-accessible sentinel page (debug only)
114 // and generates a segment fault, the signal cannot be delivered on the sentinel page. Finally, calls to abort
115 // print a stack trace that uses substantial stack space.
116
117 #define MINSTKSZ SIGSTKSZ * 8
118 static char stack[MINSTKSZ] __attribute__(( aligned (16) ));
119 static stack_t ss;
120
121 ss.ss_sp = stack;
122 ss.ss_size = MINSTKSZ;
123 ss.ss_flags = 0;
124 if ( sigaltstack( &ss, 0p ) == -1 ) {
125 abort( "__cfaabi_interpose_startup : internal error, sigaltstack error(%d) %s.", errno, strerror( errno ) );
126 } // if
127
128 // Failure handler
129 // internal errors
130 __cfaabi_sigaction( SIGSEGV, sigHandler_segv, SA_SIGINFO | SA_ONSTACK ); // Invalid memory reference (default: Core)
131 __cfaabi_sigaction( SIGBUS , sigHandler_segv, SA_SIGINFO | SA_ONSTACK ); // Bus error, bad memory access (default: Core)
132 __cfaabi_sigaction( SIGILL , sigHandler_ill , SA_SIGINFO | SA_ONSTACK ); // Illegal Instruction (default: Core)
133 __cfaabi_sigaction( SIGFPE , sigHandler_fpe , SA_SIGINFO | SA_ONSTACK ); // Floating-point exception (default: Core)
134
135 // handlers to outside errors
136 // reset in-case they insist and send it over and over
137 __cfaabi_sigaction( SIGTERM, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Termination signal (default: Term)
138 __cfaabi_sigaction( SIGINT , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Interrupt from keyboard (default: Term)
139 __cfaabi_sigaction( SIGHUP , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Hangup detected on controlling terminal or death of controlling process (default: Term)
140 __cfaabi_sigaction( SIGQUIT, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Quit from keyboard (default: Core)
141 __cfaabi_sigaction( SIGABRT, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Abort signal from abort(3) (default: Core)
142 }
143}
144
145//=============================================================================================
146// Terminating Signals logic
147//=============================================================================================
148
149// Forward declare abort after the __typeof__ call to avoid ambiguities
150libcfa_public void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
151libcfa_public void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ ));
152libcfa_public void abort( bool signalAbort, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
153libcfa_public void __abort( bool signalAbort, const char fmt[], va_list args ) __attribute__(( __nothrow__, __leaf__, __noreturn__ ));
154
155extern "C" {
156 libcfa_public void abort( void ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
157 abort( false, "%s", "" );
158 }
159
160 libcfa_public void __cabi_abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) {
161 va_list argp;
162 va_start( argp, fmt );
163 __abort( false, fmt, argp );
164 va_end( argp );
165 }
166
167 libcfa_public void exit( int status ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
168 __cabi_libc.exit( status );
169 }
170}
171
172// See concurrency/kernel.cfa and concurrency/preemption.cfa for strong definition used in multi-processor mode.
173void __kernel_abort_lock( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
174void __kernel_abort_msg( char buffer[], int size ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
175int __kernel_abort_lastframe( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 4; }
176
177enum { abort_text_size = 1024 };
178static char abort_text[ abort_text_size ];
179
180static void __cfaabi_backtrace( int start ) {
181 enum { Frames = 50, }; // maximum number of stack frames
182 int last = __kernel_abort_lastframe(); // skip last N stack frames
183
184 void * array[Frames];
185 size_t size = backtrace( array, Frames );
186 char ** messages = backtrace_symbols( array, size ); // does not demangle names
187
188 *index( messages[0], '(' ) = '\0'; // find executable name
189 __cfaabi_bits_print_nolock( STDERR_FILENO, "Stack back trace for: %s\n", messages[0]);
190
191 for ( unsigned int i = start; i < size - last && messages != 0p; i += 1 ) {
192 char * name = 0p, * offset_begin = 0p, * offset_end = 0p;
193
194 for ( char * p = messages[i]; *p; p += 1 ) { // find parantheses and +offset
195 //__cfaabi_bits_print_nolock( "X %s\n", p);
196 if ( *p == '(' ) {
197 name = p;
198 } else if ( *p == '+' ) {
199 offset_begin = p;
200 } else if ( *p == ')' ) {
201 offset_end = p;
202 break;
203 }
204 }
205
206 // if line contains symbol, print it
207 int frameNo = i - start;
208 if ( name && offset_begin && offset_end && name < offset_begin ) {
209 *name++ = '\0'; // delimit strings
210 *offset_begin++ = '\0';
211 *offset_end++ = '\0';
212
213 __cfaabi_bits_print_nolock( STDERR_FILENO, "(%i) %s : %s + %s %s\n", frameNo, messages[i], name, offset_begin, offset_end);
214 } else { // otherwise, print the whole line
215 __cfaabi_bits_print_nolock( STDERR_FILENO, "(%i) %s\n", frameNo, messages[i] );
216 }
217 }
218 free( messages );
219}
220
221void exit( int status, const char fmt[], ... ) {
222 va_list args;
223 va_start( args, fmt );
224 vfprintf( stderr, fmt, args );
225 va_end( args );
226 __cabi_libc.exit( status );
227}
228
229static volatile bool __abort_first = 0;
230
231// Cannot forward va_list.
232void __abort( bool signalAbort, const char fmt[], va_list args ) {
233 // Multiple threads can come here from multiple paths
234 // To make sure this is safe any concurrent/subsequent call to abort is redirected to libc-abort
235 bool first = ! __atomic_test_and_set( &__abort_first, __ATOMIC_SEQ_CST);
236
237 // Prevent preemption from kicking-in and messing with the abort
238 __kernel_abort_lock();
239
240 // first to abort ?
241 if ( !first ) {
242 // We aren't the first to abort just let C handle it
243 signal( SIGABRT, SIG_DFL ); // restore default in case we came here through the function.
244 __cabi_libc.abort();
245 }
246
247 int len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
248 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
249
250 // print the cause of the error
251 assert( fmt );
252 len = vsnprintf( abort_text, abort_text_size, fmt, args );
253 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
254
255 // add optional newline if missing at the end of the format text
256 if ( fmt[strlen( fmt ) - 1] != '\n' ) {
257 __cfaabi_bits_write( STDERR_FILENO, "\n", 1 );
258 } // if
259
260 // Give the kernel the chance to add some data in here
261 __kernel_abort_msg( abort_text, abort_text_size );
262
263 // print stack trace in handler
264 __cfaabi_backtrace( signalAbort ? 4 : 2 );
265
266 // Finally call abort
267 __cabi_libc.abort();
268
269}
270
271void abort( const char fmt[], ... ) {
272 va_list args;
273 va_start( args, fmt );
274 __abort( false, fmt, args );
275 // CONTROL NEVER REACHES HERE!
276 va_end( args );
277}
278
279void abort( bool signalAbort, const char fmt[], ... ) {
280 va_list args;
281 va_start( args, fmt );
282 __abort( signalAbort, fmt, args );
283 // CONTROL NEVER REACHES HERE!
284 va_end( args );
285}
286
287void sigHandler_segv( __CFA_SIGPARMS__ ) {
288 if ( sfp->si_addr == 0p ) {
289 abort( true, "Null pointer (0p) dereference.\n" );
290 } else {
291 abort( true, "%s at memory location %p.\n"
292 "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",
293 (sig == SIGSEGV ? "Segment fault" : "Bus error"), sfp->si_addr );
294 }
295}
296
297void sigHandler_ill( __CFA_SIGPARMS__ ) {
298 abort( true, "Executing illegal instruction at location %p.\n"
299 "Possible cause is stack corruption.\n",
300 sfp->si_addr );
301}
302
303void sigHandler_fpe( __CFA_SIGPARMS__ ) {
304 const char * msg;
305
306 choose( sfp->si_code ) {
307 case FPE_INTDIV, FPE_FLTDIV: msg = "divide by zero";
308 case FPE_FLTOVF: msg = "overflow";
309 case FPE_FLTUND: msg = "underflow";
310 case FPE_FLTRES: msg = "inexact result";
311 case FPE_FLTINV: msg = "invalid operation";
312 default: msg = "unknown";
313 } // choose
314 abort( true, "Computation error %s at location %p.\n", msg, sfp->si_addr );
315}
316
317void sigHandler_term( __CFA_SIGPARMS__ ) {
318 abort( true, "Application interrupted by signal: %s.\n", strsignal( sig ) );
319}
320
321// Local Variables: //
322// mode: c //
323// tab-width: 4 //
324// End: //
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