source: libcfa/src/interpose.cfa@ e8b3717

Last change on this file since e8b3717 was a3f820b, checked in by Peter A. Buhr <pabuhr@…>, 20 months ago

interpose experiment to see if it is causing the build failure

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File size: 13.2 KB
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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 : Thu Jan 11 18:45:31 2024
13// Update Count : 218
14//
15
16#include <stdio.h>
17#include <unistd.h> // _exit, getpid
18extern "C" {
19#include <dlfcn.h> // dlopen, dlsym
20//#include <link.h> // dl_iterate_phdr
21struct dl_phdr_info;
22int dl_iterate_phdr( int (*)( struct dl_phdr_info *, size_t, void * ), void * );
23#include <execinfo.h> // backtrace, messages
24}
25
26#include "bits/defs.hfa"
27#include "bits/signal.hfa" // sigHandler_?
28#include "concurrency/kernel/fwd.hfa" // disable_interrupts, enable_interrupts
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);
42
43static generic_fptr_t do_interpose_symbol( void * library, const char symbol[], const char version[] ) {
44 union { generic_fptr_t fptr; void * ptr; } originalFunc;
45
46 #if defined( _GNU_SOURCE )
47 if ( version ) {
48 originalFunc.ptr = dlvsym( library, symbol, version );
49 } else {
50 originalFunc.ptr = dlsym( library, symbol );
51 } // if
52 #else
53 originalFunc.ptr = dlsym( library, symbol );
54 #endif // _GNU_SOURCE
55
56 if ( ! originalFunc.ptr ) { // == nullptr
57 abort( "interpose_symbol : internal error, %s\n", dlerror() );
58 } // if
59 return originalFunc.fptr;
60}
61
62static generic_fptr_t interpose_symbol( const char symbol[], const char version[] ) {
63 void * library;
64
65 #if defined( RTLD_NEXT )
66 library = RTLD_NEXT;
67 #else
68 // missing RTLD_NEXT => must hard-code library name, assuming libstdc++
69 library = dlopen( "libc.so.6", RTLD_LAZY );
70 if ( ! library ) { // == nullptr
71 abort( "interpose_symbol : failed to open libc, %s\n", dlerror() );
72 } // if
73 #endif // RTLD_NEXT
74
75 return do_interpose_symbol( library, symbol, version );
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
84static void sigHandler_segv( __CFA_SIGPARMS__ );
85static void sigHandler_ill ( __CFA_SIGPARMS__ );
86static void sigHandler_fpe ( __CFA_SIGPARMS__ );
87static void sigHandler_abrt( __CFA_SIGPARMS__ );
88static void sigHandler_term( __CFA_SIGPARMS__ );
89
90static struct {
91 void (* exit)( int ) __attribute__(( __noreturn__ ));
92 void (* abort)( void ) __attribute__(( __noreturn__ ));
93 int (* dl_iterate_phdr)( int (*)( struct dl_phdr_info *, size_t, void * ), void * );
94} __cabi_libc;
95
96libcfa_public int cfa_main_returned;
97
98extern "C" {
99 void __cfathreadabi_interpose_startup( generic_fptr_t (*do_interpose_symbol)( void * library, const char symbol[], const char version[] ) ) __attribute__((weak));
100 void __cfaabi_interpose_startup( void ) {
101 const char *version = 0p;
102 cfa_main_returned = 0;
103
104 preload_libgcc();
105
106 #pragma GCC diagnostic push
107 #pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
108 INTERPOSE_LIBC( abort, version );
109 INTERPOSE_LIBC( exit, version );
110 INTERPOSE_LIBC( dl_iterate_phdr, version );
111 #pragma GCC diagnostic pop
112
113 if(__cfathreadabi_interpose_startup) __cfathreadabi_interpose_startup( do_interpose_symbol );
114
115 // SKULLDUGGERY: In Ubuntu 22.04, someone augmented signal.h to allow SIGSTKSZ to be "sysconf(_SC_SIGSTKSZ)" in
116 // sigstksz.h, as well as 8192 in sigstack.h. HOWEVER, they forgot to provide a mechanism to tell signal.h to
117 // use sigstack.h rather than sigstksz.h. (I'm not happy.) By undefining _GNU_SOURCE before signal.h and
118 // redefining it afterwards, you can get 8192, but then nothing works correctly inside of signal.h without
119 // _GNU_SOURCE defined. So what is needed is a way to get signal.h to use sigstack.h WITH _GNU_SOURCE defined.
120 // Basically something is wrong with features.h and its use in signal.h.
121
122 #undef SIGSTKSZ
123 #define SIGSTKSZ 8192
124
125 // As a precaution (and necessity), errors that result in termination are delivered on a separate stack because
126 // task stacks might be very small (4K) and the signal delivery corrupts memory to the point that a clean
127 // shutdown is impossible. Also, when a stack overflow encounters the non-accessible sentinel page (debug only)
128 // and generates a segment fault, the signal cannot be delivered on the sentinel page. Finally, calls to abort
129 // print a stack trace that uses substantial stack space.
130
131 #define MINSTKSZ SIGSTKSZ * 8
132 static char stack[MINSTKSZ] __attribute__(( aligned (16) ));
133 static stack_t ss;
134
135 ss.ss_sp = stack;
136 ss.ss_size = MINSTKSZ;
137 ss.ss_flags = 0;
138 if ( sigaltstack( &ss, 0p ) == -1 ) {
139 abort( "__cfaabi_interpose_startup : internal error, sigaltstack error(%d) %s.", errno, strerror( errno ) );
140 } // if
141
142 // Failure handler
143 // internal errors
144 __cfaabi_sigaction( SIGSEGV, sigHandler_segv, SA_SIGINFO | SA_ONSTACK ); // Invalid memory reference (default: Core)
145 __cfaabi_sigaction( SIGBUS , sigHandler_segv, SA_SIGINFO | SA_ONSTACK ); // Bus error, bad memory access (default: Core)
146 __cfaabi_sigaction( SIGILL , sigHandler_ill , SA_SIGINFO | SA_ONSTACK ); // Illegal Instruction (default: Core)
147 __cfaabi_sigaction( SIGFPE , sigHandler_fpe , SA_SIGINFO | SA_ONSTACK ); // Floating-point exception (default: Core)
148
149 // handlers to outside errors
150 // reset in-case they insist and send it over and over
151 __cfaabi_sigaction( SIGTERM, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Termination signal (default: Term)
152 __cfaabi_sigaction( SIGINT , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Interrupt from keyboard (default: Term)
153 __cfaabi_sigaction( SIGHUP , sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Hangup detected on controlling terminal or death of controlling process (default: Term)
154 __cfaabi_sigaction( SIGQUIT, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Quit from keyboard (default: Core)
155 __cfaabi_sigaction( SIGABRT, sigHandler_term, SA_SIGINFO | SA_ONSTACK | SA_RESETHAND ); // Abort signal from abort(3) (default: Core)
156 }
157}
158
159extern "C" int dl_iterate_phdr( int (* callback)( struct dl_phdr_info *, size_t, void * ), void * data ) {
160 disable_interrupts();
161 int ret = __cabi_libc.dl_iterate_phdr( callback, data ); // call real routine
162 enable_interrupts( false );
163 return ret;
164} // dl_iterate_phdr
165
166//=============================================================================================
167// Terminating Signals logic
168//=============================================================================================
169
170// Forward declare abort after the __typeof__ call to avoid ambiguities
171libcfa_public void exit( int status, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
172libcfa_public void abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ ));
173libcfa_public void abort( bool signalAbort, const char fmt[], ... ) __attribute__(( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ ));
174libcfa_public void __abort( bool signalAbort, const char fmt[], va_list args ) __attribute__(( __nothrow__, __leaf__, __noreturn__ ));
175
176extern "C" {
177 libcfa_public void abort( void ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
178 abort( false, "%s", "" );
179 }
180
181 libcfa_public void __cabi_abort( const char fmt[], ... ) __attribute__(( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) {
182 va_list argp;
183 va_start( argp, fmt );
184 __abort( false, fmt, argp );
185 va_end( argp );
186 }
187
188 libcfa_public void exit( int status ) __attribute__(( __nothrow__, __leaf__, __noreturn__ )) {
189 __cabi_libc.exit( status );
190 }
191}
192
193// See concurrency/kernel.cfa and concurrency/preemption.cfa for strong definition used in multi-processor mode.
194void __kernel_abort_lock( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
195void __kernel_abort_msg( char buffer[], int size ) __attribute__(( __nothrow__, __leaf__, __weak__ )) {}
196int __kernel_abort_lastframe( void ) __attribute__(( __nothrow__, __leaf__, __weak__ )) { return 4; }
197
198enum { abort_text_size = 1024 };
199static char abort_text[ abort_text_size ];
200
201static void __cfaabi_backtrace( int start ) {
202 enum { Frames = 50, }; // maximum number of stack frames
203 int last = __kernel_abort_lastframe(); // skip last N stack frames
204
205 void * array[Frames];
206 size_t size = backtrace( array, Frames );
207 char ** messages = backtrace_symbols( array, size ); // does not demangle names
208
209 *index( messages[0], '(' ) = '\0'; // find executable name
210 __cfaabi_bits_print_nolock( STDERR_FILENO, "Stack back trace for: %s\n", messages[0]);
211
212 for ( unsigned int i = start; i < size - last && messages != 0p; i += 1 ) {
213 char * name = 0p, * offset_begin = 0p, * offset_end = 0p;
214
215 for ( char * p = messages[i]; *p; p += 1 ) { // find parantheses and +offset
216 //__cfaabi_bits_print_nolock( "X %s\n", p);
217 if ( *p == '(' ) {
218 name = p;
219 } else if ( *p == '+' ) {
220 offset_begin = p;
221 } else if ( *p == ')' ) {
222 offset_end = p;
223 break;
224 }
225 }
226
227 // if line contains symbol, print it
228 int frameNo = i - start;
229 if ( name && offset_begin && offset_end && name < offset_begin ) {
230 *name++ = '\0'; // delimit strings
231 *offset_begin++ = '\0';
232 *offset_end++ = '\0';
233
234 __cfaabi_bits_print_nolock( STDERR_FILENO, "(%i) %s : %s + %s %s\n", frameNo, messages[i], name, offset_begin, offset_end);
235 } else { // otherwise, print the whole line
236 __cfaabi_bits_print_nolock( STDERR_FILENO, "(%i) %s\n", frameNo, messages[i] );
237 }
238 }
239 free( messages );
240}
241
242void exit( int status, const char fmt[], ... ) {
243 va_list args;
244 va_start( args, fmt );
245 vfprintf( stderr, fmt, args );
246 va_end( args );
247 __cabi_libc.exit( status );
248}
249
250static volatile bool __abort_first = 0;
251
252// Cannot forward va_list.
253void __abort( bool signalAbort, const char fmt[], va_list args ) {
254 // Multiple threads can come here from multiple paths
255 // To make sure this is safe any concurrent/subsequent call to abort is redirected to libc-abort
256 bool first = ! __atomic_test_and_set( &__abort_first, __ATOMIC_SEQ_CST);
257
258 // Prevent preemption from kicking-in and messing with the abort
259 __kernel_abort_lock();
260
261 // first to abort ?
262 if ( !first ) {
263 // We aren't the first to abort just let C handle it
264 signal( SIGABRT, SIG_DFL ); // restore default in case we came here through the function.
265 __cabi_libc.abort();
266 }
267
268 int len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
269 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
270
271 // print the cause of the error
272 assert( fmt );
273 len = vsnprintf( abort_text, abort_text_size, fmt, args );
274 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
275
276 // add optional newline if missing at the end of the format text
277 if ( fmt[strlen( fmt ) - 1] != '\n' ) {
278 __cfaabi_bits_write( STDERR_FILENO, "\n", 1 );
279 } // if
280
281 // Give the kernel the chance to add some data in here
282 __kernel_abort_msg( abort_text, abort_text_size );
283
284 // print stack trace in handler
285 __cfaabi_backtrace( signalAbort ? 4 : 2 );
286
287 // Finally call abort
288 __cabi_libc.abort();
289
290}
291
292void abort( const char fmt[], ... ) {
293 va_list args;
294 va_start( args, fmt );
295 __abort( false, fmt, args );
296 // CONTROL NEVER REACHES HERE!
297 va_end( args );
298}
299
300void abort( bool signalAbort, const char fmt[], ... ) {
301 va_list args;
302 va_start( args, fmt );
303 __abort( signalAbort, fmt, args );
304 // CONTROL NEVER REACHES HERE!
305 va_end( args );
306}
307
308void sigHandler_segv( __CFA_SIGPARMS__ ) {
309 if ( sfp->si_addr == 0p ) {
310 abort( true, "Null pointer (0p) dereference.\n" );
311 } else {
312 abort( true, "%s at memory location %p.\n"
313 "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",
314 (sig == SIGSEGV ? "Segment fault" : "Bus error"), sfp->si_addr );
315 }
316}
317
318void sigHandler_ill( __CFA_SIGPARMS__ ) {
319 abort( true, "Executing illegal instruction at location %p.\n"
320 "Possible cause is stack corruption.\n",
321 sfp->si_addr );
322}
323
324void sigHandler_fpe( __CFA_SIGPARMS__ ) {
325 const char * msg;
326
327 choose( sfp->si_code ) {
328 case FPE_INTDIV, FPE_FLTDIV: msg = "divide by zero";
329 case FPE_FLTOVF: msg = "overflow";
330 case FPE_FLTUND: msg = "underflow";
331 case FPE_FLTRES: msg = "inexact result";
332 case FPE_FLTINV: msg = "invalid operation";
333 default: msg = "unknown";
334 } // choose
335 abort( true, "Computation error %s at location %p.\n", msg, sfp->si_addr );
336}
337
338void sigHandler_term( __CFA_SIGPARMS__ ) {
339 abort( true, "Application interrupted by signal: %s.\n", strsignal( sig ) );
340}
341
342// Local Variables: //
343// mode: c //
344// tab-width: 4 //
345// End: //
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