/**************************************************************************** * * * GNAT COMPILER COMPONENTS * * * * I N I T * * * * $Revision$ * * * C Implementation File * * * * Copyright (C) 1992-2002 Free Software Foundation, Inc. * * * * GNAT is free software; you can redistribute it and/or modify it under * * terms of the GNU General Public License as published by the Free Soft- * * ware Foundation; either version 2, or (at your option) any later ver- * * sion. GNAT is distributed in the hope that it will be useful, but WITH- * * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * * for more details. You should have received a copy of the GNU General * * Public License distributed with GNAT; see file COPYING. If not, write * * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, * * MA 02111-1307, USA. * * * * As a special exception, if you link this file with other files to * * produce an executable, this file does not by itself cause the resulting * * executable to be covered by the GNU General Public License. This except- * * ion does not however invalidate any other reasons why the executable * * file might be covered by the GNU Public License. * * * * GNAT was originally developed by the GNAT team at New York University. * * It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). * * * ****************************************************************************/ /* This unit contains initialization circuits that are system dependent. A major part of the functionality involved involves stack overflow checking. The GCC backend generates probe instructions to test for stack overflow. For details on the exact approach used to generate these probes, see the "Using and Porting GCC" manual, in particular the "Stack Checking" section and the subsection "Specifying How Stack Checking is Done". The handlers installed by this file are used to handle resulting signals that come from these probes failing (i.e. touching protected pages) */ /* The following include is here to meet the published VxWorks requirement that the __vxworks header appear before any other include. */ #ifdef __vxworks #include "vxWorks.h" #endif #ifdef IN_RTS #include "tconfig.h" #include "tsystem.h" #include /* We don't have libiberty, so us malloc. */ #define xmalloc(S) malloc (S) #else #include "config.h" #include "system.h" #endif #include "adaint.h" #include "raise.h" extern void __gnat_raise_program_error (const char *, int); /* Addresses of exception data blocks for predefined exceptions. */ extern struct Exception_Data constraint_error; extern struct Exception_Data numeric_error; extern struct Exception_Data program_error; extern struct Exception_Data storage_error; extern struct Exception_Data tasking_error; extern struct Exception_Data _abort_signal; #define Lock_Task system__soft_links__lock_task extern void (*Lock_Task) PARAMS ((void)); #define Unlock_Task system__soft_links__unlock_task extern void (*Unlock_Task) PARAMS ((void)); #define Get_Machine_State_Addr \ system__soft_links__get_machine_state_addr extern struct Machine_State *(*Get_Machine_State_Addr) PARAMS ((void)); #define Check_Abort_Status \ system__soft_links__check_abort_status extern int (*Check_Abort_Status) PARAMS ((void)); #define Raise_From_Signal_Handler \ ada__exceptions__raise_from_signal_handler extern void Raise_From_Signal_Handler PARAMS ((struct Exception_Data *, const char *)); #define Propagate_Signal_Exception \ __gnat_propagate_sig_exc extern void Propagate_Signal_Exception PARAMS ((struct Machine_State *, struct Exception_Data *, const char *)); /* Copies of global values computed by the binder */ int __gl_main_priority = -1; int __gl_time_slice_val = -1; char __gl_wc_encoding = 'n'; char __gl_locking_policy = ' '; char __gl_queuing_policy = ' '; char *__gl_restrictions = 0; char __gl_task_dispatching_policy = ' '; int __gl_unreserve_all_interrupts = 0; int __gl_exception_tracebacks = 0; int __gl_zero_cost_exceptions = 0; /* Indication of whether synchronous signal handler has already been installed by a previous call to adainit */ int __gnat_handler_installed = 0; /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float is defined. If this is not set them a void implementation will be defined at the end of this unit. */ #undef HAVE_GNAT_INIT_FLOAT /**********************/ /* __gnat_set_globals */ /**********************/ /* This routine is called from the binder generated main program. It copies the values for global quantities computed by the binder into the following global locations. The reason that we go through this copy, rather than just define the global locations in the binder generated file, is that they are referenced from the runtime, which may be in a shared library, and the binder file is not in the shared library. Global references across library boundaries like this are not handled correctly in all systems. */ void __gnat_set_globals (main_priority, time_slice_val, wc_encoding, locking_policy, queuing_policy, task_dispatching_policy, restrictions, unreserve_all_interrupts, exception_tracebacks, zero_cost_exceptions) int main_priority; int time_slice_val; char wc_encoding; char locking_policy, queuing_policy, task_dispatching_policy; char *restrictions; int unreserve_all_interrupts, exception_tracebacks, zero_cost_exceptions; { static int already_called = 0; /* If this procedure has been already called once, check that the arguments in this call are consistent with the ones in the previous calls. Otherwise, raise a Program_Error exception. We do not check for consistency of the wide character encoding method. This default affects only Wide_Text_IO where no explicit coding method is given, and there is no particular reason to let this default be affected by the source representation of a library in any case. The value of main_priority is meaningful only when we are invoked from the main program elaboration routine of an Ada application. Checking the consistency of this parameter should therefore not be done. Since it is assured that the main program elaboration will always invoke this procedure before any library elaboration routine, only the value of main_priority during the first call should be taken into account and all the subsequent ones should be ignored. Note that the case where the main program is not written in Ada is also properly handled, since the default value will then be used for this parameter. For identical reasons, the consistency of time_slice_val should not be checked. */ if (already_called) { if (__gl_locking_policy != locking_policy || __gl_queuing_policy != queuing_policy || __gl_task_dispatching_policy != task_dispatching_policy || __gl_unreserve_all_interrupts != unreserve_all_interrupts || __gl_exception_tracebacks != exception_tracebacks || __gl_zero_cost_exceptions != zero_cost_exceptions) __gnat_raise_program_error (__FILE__, __LINE__); return; } already_called = 1; __gl_main_priority = main_priority; __gl_time_slice_val = time_slice_val; __gl_wc_encoding = wc_encoding; __gl_locking_policy = locking_policy; __gl_queuing_policy = queuing_policy; __gl_restrictions = restrictions; __gl_task_dispatching_policy = task_dispatching_policy; __gl_unreserve_all_interrupts = unreserve_all_interrupts; __gl_exception_tracebacks = exception_tracebacks; /* ??? __gl_zero_cost_exceptions is new in 3.15 and is referenced from a-except.adb, which is also part of the compiler sources. Since the compiler is built with an older release of GNAT, the call generated by the old binder to this function does not provide any value for the corresponding argument, so the global has to be initialized in some reasonable other way. This could be removed as soon as the next major release is out. */ #ifdef IN_RTS __gl_zero_cost_exceptions = zero_cost_exceptions; #else __gl_zero_cost_exceptions = 0; /* We never build the compiler to run in ZCX mode currently anyway. */ #endif } /*********************/ /* __gnat_initialize */ /*********************/ /* __gnat_initialize is called at the start of execution of an Ada program (the call is generated by the binder). The standard routine does nothing at all; the intention is that this be replaced by system specific code where initialization is required. */ /***********************************/ /* __gnat_initialize (AIX version) */ /***********************************/ #if defined (_AIX) /* AiX doesn't have SA_NODEFER */ #define SA_NODEFER 0 #include /* AiX doesn't have nanosleep, but provides nsleep instead */ extern int nanosleep PARAMS ((struct timestruc_t *, struct timestruc_t *)); static void __gnat_error_handler PARAMS ((int)); int nanosleep (Rqtp, Rmtp) struct timestruc_t *Rqtp, *Rmtp; { return nsleep (Rqtp, Rmtp); } #include static void __gnat_error_handler (sig) int sig; { struct Exception_Data *exception; const char *msg; switch (sig) { case SIGSEGV: /* FIXME: we need to detect the case of a *real* SIGSEGV */ exception = &storage_error; msg = "stack overflow or erroneous memory access"; break; case SIGBUS: exception = &constraint_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Set up signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /****************************************/ /* __gnat_initialize (Dec Unix version) */ /****************************************/ #elif defined(__alpha__) && defined(__osf__) && ! defined(__alpha_vxworks) /* Note: it seems that __osf__ is defined for the Alpha VXWorks case. Not clear that this is reasonable, but in any case we have to be sure to exclude this case in the above test. */ #include #include static void __gnat_error_handler PARAMS ((int, siginfo_t *, struct sigcontext *)); extern char *__gnat_get_code_loc PARAMS ((struct sigcontext *)); extern void __gnat_enter_handler PARAMS ((struct sigcontext *, char *)); extern size_t __gnat_machine_state_length PARAMS ((void)); extern long exc_lookup_gp PARAMS ((char *)); extern void exc_resume PARAMS ((struct sigcontext *)); static void __gnat_error_handler (sig, sip, context) int sig; siginfo_t *sip; struct sigcontext *context; { struct Exception_Data *exception; static int recurse = 0; struct sigcontext *mstate; const char *msg; /* If this was an explicit signal from a "kill", just resignal it. */ if (SI_FROMUSER (sip)) { signal (sig, SIG_DFL); kill (getpid(), sig); } /* Otherwise, treat it as something we handle. */ switch (sig) { case SIGSEGV: /* If the problem was permissions, this is a constraint error. Likewise if the failing address isn't maximally aligned or if we've recursed. ??? Using a static variable here isn't task-safe, but it's much too hard to do anything else and we're just determining which exception to raise. */ if (sip->si_code == SEGV_ACCERR || (((long) sip->si_addr) & 3) != 0 || recurse) { exception = &constraint_error; msg = "SIGSEGV"; } else { /* See if the page before the faulting page is accessible. Do that by trying to access it. We'd like to simply try to access 4096 + the faulting address, but it's not guaranteed to be the actual address, just to be on the same page. */ recurse++; ((volatile char *) ((long) sip->si_addr & - getpagesize ()))[getpagesize ()]; msg = "stack overflow (or erroneous memory access)"; exception = &storage_error; } break; case SIGBUS: exception = &program_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } recurse = 0; mstate = (struct sigcontext *) (*Get_Machine_State_Addr) (); if (mstate != 0) *mstate = *context; Raise_From_Signal_Handler (exception, (char *) msg); } void __gnat_install_handler () { struct sigaction act; /* Setup signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = (void (*) PARAMS ((int))) __gnat_error_handler; act.sa_flags = SA_ONSTACK | SA_RESTART | SA_NODEFER | SA_SIGINFO; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /* Routines called by 5amastop.adb. */ #define SC_GP 29 char * __gnat_get_code_loc (context) struct sigcontext *context; { return (char *) context->sc_pc; } void __gnat_enter_handler (context, pc) struct sigcontext *context; char *pc; { context->sc_pc = (long) pc; context->sc_regs[SC_GP] = exc_lookup_gp (pc); exc_resume (context); } size_t __gnat_machine_state_length () { return sizeof (struct sigcontext); } /***********************************/ /* __gnat_initialize (HPUX version) */ /***********************************/ #elif defined (hpux) #include static void __gnat_error_handler PARAMS ((int)); static void __gnat_error_handler (sig) int sig; { struct Exception_Data *exception; char *msg; switch (sig) { case SIGSEGV: /* FIXME: we need to detect the case of a *real* SIGSEGV */ exception = &storage_error; msg = "stack overflow or erroneous memory access"; break; case SIGBUS: exception = &constraint_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Set up signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! Also setup an alternate stack region for the handler execution so that stack overflows can be handled properly, avoiding a SEGV generation from stack usage by the handler itself. */ static char handler_stack[SIGSTKSZ*2]; /* SIGSTKSZ appeared to be "short" for the needs in some contexts (e.g. experiments with GCC ZCX exceptions). */ stack_t stack; stack.ss_sp = handler_stack; stack.ss_size = sizeof (handler_stack); stack.ss_flags = 0; (void) sigaltstack (&stack, NULL); act.sa_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART | SA_ONSTACK; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /*************************************/ /* __gnat_initialize (GNU/Linux version) */ /*************************************/ #elif defined (linux) && defined (i386) && !defined (__RT__) #include #include /* GNU/Linux, which uses glibc, does not define NULL in included header files */ #if !defined (NULL) #define NULL ((void *) 0) #endif struct Machine_State { unsigned long eip; unsigned long ebx; unsigned long esp; unsigned long ebp; unsigned long esi; unsigned long edi; }; static void __gnat_error_handler PARAMS ((int)); static void __gnat_error_handler (sig) int sig; { struct Exception_Data *exception; const char *msg; static int recurse = 0; struct sigcontext *info = (struct sigcontext *) (((char *) &sig) + sizeof (int)); /* The Linux kernel does not document how to get the machine state in a signal handler, but in fact the necessary data is in a sigcontext_struct value that is on the stack immediately above the signal number parameter, and the above messing accesses this value on the stack. */ struct Machine_State *mstate; switch (sig) { case SIGSEGV: /* If the problem was permissions, this is a constraint error. Likewise if the failing address isn't maximally aligned or if we've recursed. ??? Using a static variable here isn't task-safe, but it's much too hard to do anything else and we're just determining which exception to raise. */ if (recurse) { exception = &constraint_error; msg = "SIGSEGV"; } else { /* Here we would like a discrimination test to see whether the page before the faulting address is accessible. Unfortunately Linux seems to have no way of giving us the faulting address. In versions of a-init.c before 1.95, we had a test of the page before the stack pointer using: recurse++; ((volatile char *) ((long) info->esp_at_signal & - getpagesize ()))[getpagesize ()]; but that's wrong, since it tests the stack pointer location, and the current stack probe code does not move the stack pointer until all probes succeed. For now we simply do not attempt any discrimination at all. Note that this is quite acceptable, since a "real" SIGSEGV can only occur as the result of an erroneous program */ msg = "stack overflow (or erroneous memory access)"; exception = &storage_error; } break; case SIGBUS: exception = &constraint_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } mstate = (*Get_Machine_State_Addr)(); if (mstate) { mstate->eip = info->eip; mstate->ebx = info->ebx; mstate->esp = info->esp_at_signal; mstate->ebp = info->ebp; mstate->esi = info->esi; mstate->edi = info->edi; } recurse = 0; Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Set up signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /******************************************/ /* __gnat_initialize (NT-mingw32 version) */ /******************************************/ #elif defined (__MINGW32__) #include static LONG __gnat_error_handler PARAMS ((PEXCEPTION_POINTERS)); /* __gnat_initialize (mingw32). */ static LONG __gnat_error_handler (info) PEXCEPTION_POINTERS info; { static int recurse; struct Exception_Data *exception; char *msg; switch (info->ExceptionRecord->ExceptionCode) { case EXCEPTION_ACCESS_VIOLATION: /* If the failing address isn't maximally-aligned or if we've recursed, this is a program error. */ if ((info->ExceptionRecord->ExceptionInformation[1] & 3) != 0 || recurse) { exception = &program_error; msg = "EXCEPTION_ACCESS_VIOLATION"; } else { /* See if the page before the faulting page is accessible. Do that by trying to access it. */ recurse++; * ((volatile char *) (info->ExceptionRecord->ExceptionInformation[1] + 4096)); exception = &storage_error; msg = "stack overflow (or erroneous memory access)"; } break; case EXCEPTION_ARRAY_BOUNDS_EXCEEDED: exception = &constraint_error; msg = "EXCEPTION_ARRAY_BOUNDS_EXCEEDED"; break; case EXCEPTION_DATATYPE_MISALIGNMENT: exception = &constraint_error; msg = "EXCEPTION_DATATYPE_MISALIGNMENT"; break; case EXCEPTION_FLT_DENORMAL_OPERAND: exception = &constraint_error; msg = "EXCEPTION_FLT_DENORMAL_OPERAND"; break; case EXCEPTION_FLT_DIVIDE_BY_ZERO: exception = &constraint_error; msg = "EXCEPTION_FLT_DENORMAL_OPERAND"; break; case EXCEPTION_FLT_INVALID_OPERATION: exception = &constraint_error; msg = "EXCEPTION_FLT_INVALID_OPERATION"; break; case EXCEPTION_FLT_OVERFLOW: exception = &constraint_error; msg = "EXCEPTION_FLT_OVERFLOW"; break; case EXCEPTION_FLT_STACK_CHECK: exception = &program_error; msg = "EXCEPTION_FLT_STACK_CHECK"; break; case EXCEPTION_FLT_UNDERFLOW: exception = &constraint_error; msg = "EXCEPTION_FLT_UNDERFLOW"; break; case EXCEPTION_INT_DIVIDE_BY_ZERO: exception = &constraint_error; msg = "EXCEPTION_INT_DIVIDE_BY_ZERO"; break; case EXCEPTION_INT_OVERFLOW: exception = &constraint_error; msg = "EXCEPTION_INT_OVERFLOW"; break; case EXCEPTION_INVALID_DISPOSITION: exception = &program_error; msg = "EXCEPTION_INVALID_DISPOSITION"; break; case EXCEPTION_NONCONTINUABLE_EXCEPTION: exception = &program_error; msg = "EXCEPTION_NONCONTINUABLE_EXCEPTION"; break; case EXCEPTION_PRIV_INSTRUCTION: exception = &program_error; msg = "EXCEPTION_PRIV_INSTRUCTION"; break; case EXCEPTION_SINGLE_STEP: exception = &program_error; msg = "EXCEPTION_SINGLE_STEP"; break; case EXCEPTION_STACK_OVERFLOW: exception = &storage_error; msg = "EXCEPTION_STACK_OVERFLOW"; break; default: exception = &program_error; msg = "unhandled signal"; } recurse = 0; Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { SetUnhandledExceptionFilter (__gnat_error_handler); __gnat_handler_installed = 1; } void __gnat_initialize () { /* Initialize floating-point coprocessor. This call is needed because the MS libraries default to 64-bit precision instead of 80-bit precision, and we require the full precision for proper operation, given that we have set Max_Digits etc with this in mind */ __gnat_init_float (); /* initialize a lock for a process handle list - see a-adaint.c for the implementation of __gnat_portable_no_block_spawn, __gnat_portable_wait */ __gnat_plist_init(); } /**************************************/ /* __gnat_initialize (Interix version) */ /**************************************/ #elif defined (__INTERIX) #include static void __gnat_error_handler PARAMS ((int)); static void __gnat_error_handler (sig) int sig; { struct Exception_Data *exception; char *msg; switch (sig) { case SIGSEGV: exception = &storage_error; msg = "stack overflow or erroneous memory access"; break; case SIGBUS: exception = &constraint_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Set up signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = 0; (void) sigemptyset (&act.sa_mask); /* Handlers for signals besides SIGSEGV cause c974013 to hang */ /* (void) sigaction (SIGILL, &act, NULL); */ /* (void) sigaction (SIGABRT, &act, NULL); */ /* (void) sigaction (SIGFPE, &act, NULL); */ /* (void) sigaction (SIGBUS, &act, NULL); */ (void) sigaction (SIGSEGV, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { __gnat_init_float (); } /**************************************/ /* __gnat_initialize (LynxOS version) */ /**************************************/ #elif defined (__Lynx__) void __gnat_initialize () { __gnat_init_float (); } /*********************************/ /* __gnat_install_handler (Lynx) */ /*********************************/ void __gnat_install_handler () { __gnat_handler_installed = 1; } /****************************/ /* __gnat_initialize (OS/2) */ /****************************/ #elif defined (__EMX__) /* OS/2 dependent initialization */ void __gnat_initialize () { } /*********************************/ /* __gnat_install_handler (OS/2) */ /*********************************/ void __gnat_install_handler () { __gnat_handler_installed = 1; } /***********************************/ /* __gnat_initialize (SGI version) */ /***********************************/ #elif defined (sgi) #include #include #ifndef NULL #define NULL 0 #endif #define SIGADAABORT 48 #define SIGNAL_STACK_SIZE 4096 #define SIGNAL_STACK_ALIGNMENT 64 struct Machine_State { sigcontext_t context; }; static void __gnat_error_handler PARAMS ((int, int, sigcontext_t *)); static void __gnat_error_handler (sig, code, sc) int sig; int code; sigcontext_t *sc; { struct Machine_State *mstate; struct Exception_Data *exception; char *msg; int i; switch (sig) { case SIGSEGV: if (code == EFAULT) { exception = &program_error; msg = "SIGSEGV: (Invalid virtual address)"; } else if (code == ENXIO) { exception = &program_error; msg = "SIGSEGV: (Read beyond mapped object)"; } else if (code == ENOSPC) { exception = &program_error; /* ??? storage_error ??? */ msg = "SIGSEGV: (Autogrow for file failed)"; } else if (code == EACCES) { /* ??? Re-add smarts to further verify that we launched the stack into a guard page, not an attempt to write to .text or something */ exception = &storage_error; msg = "SIGSEGV: (stack overflow or erroneous memory access)"; } else { /* Just in case the OS guys did it to us again. Sometimes they fail to document all of the valid codes that are passed to signal handlers, just in case someone depends on knowing all the codes */ exception = &program_error; msg = "SIGSEGV: (Undocumented reason)"; } break; case SIGBUS: /* Map all bus errors to Program_Error. */ exception = &program_error; msg = "SIGBUS"; break; case SIGFPE: /* Map all fpe errors to Constraint_Error. */ exception = &constraint_error; msg = "SIGFPE"; break; case SIGADAABORT: if ((*Check_Abort_Status) ()) { exception = &_abort_signal; msg = ""; } else return; break; default: /* Everything else is a Program_Error. */ exception = &program_error; msg = "unhandled signal"; } mstate = (*Get_Machine_State_Addr)(); if (mstate != 0) memcpy ((void *) mstate, (const void *) sc, sizeof (sigcontext_t)); Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { stack_t ss; struct sigaction act; /* Setup signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER + SA_RESTART; (void) sigfillset (&act.sa_mask); (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); (void) sigaction (SIGADAABORT, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /*************************************************/ /* __gnat_initialize (Solaris and SunOS version) */ /*************************************************/ #elif defined (sun) && defined (__SVR4) && !defined (__vxworks) #include #include static void __gnat_error_handler PARAMS ((int, siginfo_t *)); static void __gnat_error_handler (sig, sip) int sig; siginfo_t *sip; { struct Exception_Data *exception; static int recurse = 0; char *msg; /* If this was an explicit signal from a "kill", just resignal it. */ if (SI_FROMUSER (sip)) { signal (sig, SIG_DFL); kill (getpid(), sig); } /* Otherwise, treat it as something we handle. */ switch (sig) { case SIGSEGV: /* If the problem was permissions, this is a constraint error. Likewise if the failing address isn't maximally aligned or if we've recursed. ??? Using a static variable here isn't task-safe, but it's much too hard to do anything else and we're just determining which exception to raise. */ if (sip->si_code == SEGV_ACCERR || (((long) sip->si_addr) & 3) != 0 || recurse) { exception = &constraint_error; msg = "SIGSEGV"; } else { /* See if the page before the faulting page is accessible. Do that by trying to access it. We'd like to simply try to access 4096 + the faulting address, but it's not guaranteed to be the actual address, just to be on the same page. */ recurse++; ((volatile char *) ((long) sip->si_addr & - getpagesize ()))[getpagesize ()]; exception = &storage_error; msg = "stack overflow (or erroneous memory access)"; } break; case SIGBUS: exception = &program_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } recurse = 0; Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Set up signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /***********************************/ /* __gnat_initialize (SNI version) */ /***********************************/ #elif defined (__sni__) /* SNI needs special defines and includes */ #define _XOPEN_SOURCE #define _POSIX_SOURCE #include extern size_t __gnat_getpagesize PARAMS ((void)); static void __gnat_error_handler PARAMS ((int)); /* The run time needs this function which is a #define in SNI */ size_t __gnat_getpagesize () { return getpagesize (); } static void __gnat_error_handler (sig) int sig; { struct Exception_Data *exception; char *msg; switch (sig) { case SIGSEGV: /* FIXME: we need to detect the case of a *real* SIGSEGV */ exception = &storage_error; msg = "stack overflow or erroneous memory access"; break; case SIGBUS: exception = &constraint_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Set up signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGABRT, &act, NULL); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize () { } /***********************************/ /* __gnat_initialize (VMS version) */ /***********************************/ #elif defined (VMS) /* The prehandler actually gets control first on a condition. It swaps the stack pointer and calls the handler (__gnat_error_handler). */ extern long __gnat_error_prehandler (); extern char *__gnat_error_prehandler_stack; /* Alternate signal stack */ /* Conditions that don't have an Ada exception counterpart must raise Non_Ada_Error. Since this is defined in s-auxdec, it should only be referenced by user programs, not the compiler or tools. Hence the #ifdef IN_RTS. */ #ifdef IN_RTS #define Non_Ada_Error system__aux_dec__non_ada_error extern struct Exception_Data Non_Ada_Error; #define Coded_Exception system__vms_exception_table__coded_exception extern struct Exception_Data *Coded_Exception (int); #endif /* Define macro symbols for the VMS conditions that become Ada exceptions. Most of these are also defined in the header file ssdef.h which has not yet been converted to be recoginized by Gnu C. Some, which couldn't be located, are assigned names based on the DEC test suite tests which raise them. */ #define SS$_ACCVIO 12 #define SS$_DEBUG 1132 #define SS$_INTDIV 1156 #define SS$_HPARITH 1284 #define SS$_STKOVF 1364 #define SS$_RESIGNAL 2328 #define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */ #define SS$_CE24VRU 3253636 /* Write to unopened file */ #define SS$_C980VTE 3246436 /* AST requests time slice */ #define CMA$_EXIT_THREAD 4227492 #define CMA$_EXCCOPLOS 4228108 #define CMA$_ALERTED 4227460 struct descriptor_s {unsigned short len, mbz; char *adr; }; long __gnat_error_handler PARAMS ((int *, void *)); long __gnat_error_handler (sigargs, mechargs) int *sigargs; void *mechargs; { struct Exception_Data *exception = 0; char *msg = ""; char message[256]; long prvhnd; struct descriptor_s msgdesc; int msg_flag = 0x000f; /* 1 bit for each of the four message parts */ unsigned short outlen; char curr_icb[544]; long curr_invo_handle; long *mstate; /* Resignaled conditions aren't effected by by pragma Import_Exception */ switch (sigargs[1]) { case CMA$_EXIT_THREAD: return SS$_RESIGNAL; case SS$_DEBUG: /* Gdb attach, resignal to merge activate gdbstub. */ return SS$_RESIGNAL; case 1409786: /* Nickerson bug #33 ??? */ return SS$_RESIGNAL; case 1381050: /* Nickerson bug #33 ??? */ return SS$_RESIGNAL; case 11829410: /* Resignalled as Use_Error for CE10VRC */ return SS$_RESIGNAL; } #ifdef IN_RTS /* See if it's an imported exception. Mask off severity bits. */ exception = Coded_Exception (sigargs[1] & 0xfffffff8); if (exception) { msgdesc.len = 256; msgdesc.mbz = 0; msgdesc.adr = message; SYS$GETMSG (sigargs[1], &outlen, &msgdesc, msg_flag, 0); message[outlen] = 0; msg = message; exception->Name_Length = 19; /* The full name really should be get sys$getmsg returns. ??? */ exception->Full_Name = "IMPORTED_EXCEPTION"; exception->Import_Code = sigargs[1] & 0xfffffff8; } #endif if (exception == 0) switch (sigargs[1]) { case SS$_ACCVIO: if (sigargs[3] == 0) { exception = &constraint_error; msg = "access zero"; } else { exception = &storage_error; msg = "stack overflow (or erroneous memory access)"; } break; case SS$_STKOVF: exception = &storage_error; msg = "stack overflow"; break; case SS$_INTDIV: exception = &constraint_error; msg = "division by zero"; break; case SS$_HPARITH: #ifndef IN_RTS return SS$_RESIGNAL; /* toplev.c handles for compiler */ #else { exception = &constraint_error; msg = "arithmetic error"; } #endif break; case MTH$_FLOOVEMAT: exception = &constraint_error; msg = "floating overflow in math library"; break; case SS$_CE24VRU: exception = &constraint_error; msg = ""; break; case SS$_C980VTE: exception = &program_error; msg = ""; break; default: #ifndef IN_RTS exception = &program_error; #else /* User programs expect Non_Ada_Error to be raised, reference DEC Ada test CXCONDHAN. */ exception = &Non_Ada_Error; #endif msgdesc.len = 256; msgdesc.mbz = 0; msgdesc.adr = message; SYS$GETMSG (sigargs[1], &outlen, &msgdesc, msg_flag, 0); message[outlen] = 0; msg = message; break; } mstate = (long *) (*Get_Machine_State_Addr) (); if (mstate != 0) { LIB$GET_CURR_INVO_CONTEXT (&curr_icb); LIB$GET_PREV_INVO_CONTEXT (&curr_icb); LIB$GET_PREV_INVO_CONTEXT (&curr_icb); curr_invo_handle = LIB$GET_INVO_HANDLE (&curr_icb); *mstate = curr_invo_handle; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { long prvhnd; char *c; c = (char *) xmalloc (2049); __gnat_error_prehandler_stack = &c[2048]; /* __gnat_error_prehandler is an assembly function. */ SYS$SETEXV (1, __gnat_error_prehandler, 3, &prvhnd); __gnat_handler_installed = 1; } void __gnat_initialize() { } /***************************************/ /* __gnat_initialize (VXWorks version) */ /***************************************/ #elif defined(__vxworks) #include #include #include #include static void __gnat_init_handler PARAMS ((int)); extern int __gnat_inum_to_ivec PARAMS ((int)); static void __gnat_error_handler PARAMS ((int, int, struct sigcontext *)); static void __gnat_int_handler (interr) int interr; { /* Note that we should use something like Raise_From_Int_Handler here, but for now Raise_From_Signal_Handler will do the job. ??? */ Raise_From_Signal_Handler (&storage_error, "stack overflow"); } /* Used for stack-checking on VxWorks. Must be task-local in tasking programs */ void *__gnat_stack_limit = NULL; #ifndef __alpha_vxworks /* getpid is used by s-parint.adb, but is not defined by VxWorks, except on Alpha VxWorks */ extern long getpid PARAMS ((void)); long getpid () { return taskIdSelf (); } #endif /* This is needed by the GNAT run time to handle Vxworks interrupts */ int __gnat_inum_to_ivec (num) int num; { return INUM_TO_IVEC (num); } static void __gnat_error_handler (sig, code, sc) int sig; int code; struct sigcontext *sc; { struct Exception_Data *exception; sigset_t mask; int result; char *msg; /* VxWorks will always mask out the signal during the signal handler and will reenable it on a longjmp. GNAT does not generate a longjmp to return from a signal handler so the signal will still be masked unless we unmask it. */ (void) sigprocmask (SIG_SETMASK, NULL, &mask); sigdelset (&mask, sig); (void) sigprocmask (SIG_SETMASK, &mask, NULL); /* VxWorks will suspend the task when it gets a hardware exception. We take the liberty of resuming the task for the application. */ if (taskIsSuspended (taskIdSelf ()) != 0) (void) taskResume (taskIdSelf ()); switch (sig) { case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; case SIGILL: exception = &constraint_error; msg = "SIGILL"; break; case SIGSEGV: exception = &program_error; msg = "SIGSEGV"; break; case SIGBUS: exception = &program_error; msg = "SIGBUS"; break; default: exception = &program_error; msg = "unhandled signal"; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler () { struct sigaction act; /* Setup signal handler to map synchronous signals to appropriate exceptions. Make sure that the handler isn't interrupted by another signal that might cause a scheduling event! */ act.sa_handler = __gnat_error_handler; act.sa_flags = SA_SIGINFO | SA_ONSTACK; (void) sigemptyset (&act.sa_mask); (void) sigaction (SIGFPE, &act, NULL); (void) sigaction (SIGILL, &act, NULL); (void) sigaction (SIGSEGV, &act, NULL); (void) sigaction (SIGBUS, &act, NULL); __gnat_handler_installed = 1; } #define HAVE_GNAT_INIT_FLOAT void __gnat_init_float () { #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) /* Disable overflow/underflow exceptions on the PPC processor, this is needed to get correct Ada semantic */ asm ("mtfsb0 25"); asm ("mtfsb0 26"); #endif } void __gnat_initialize () { TASK_DESC pTaskDesc; if (taskInfoGet (taskIdSelf (), &pTaskDesc) != OK) printErr ("Cannot get task info"); __gnat_stack_limit = (void *) pTaskDesc.td_pStackLimit; __gnat_init_float (); #ifdef __mips_vxworks #if 0 /* For now remove this handler, since it is causing interferences with gdb */ /* Connect the overflow trap directly to the __gnat_int_handler routine as it is not converted to a signal by VxWorks. */ intConnect (INUM_TO_IVEC (IV_TRAP_VEC), &__gnat_int_handler, IV_TRAP_VEC); #endif #endif } #else /* For all other versions of GNAT, the initialize routine and handler installation do nothing */ /***************************************/ /* __gnat_initialize (default version) */ /***************************************/ void __gnat_initialize () { } /********************************************/ /* __gnat_install_handler (default version) */ /********************************************/ void __gnat_install_handler () { __gnat_handler_installed = 1; } #endif /*********************/ /* __gnat_init_float */ /*********************/ /* This routine is called as each process thread is created, for possible initialization of the FP processor. This version is used under INTERIX, WIN32 and could be used under OS/2 */ #if defined (_WIN32) || defined (__INTERIX) || defined (__EMX__) \ || defined (__Lynx__) #define HAVE_GNAT_INIT_FLOAT void __gnat_init_float () { #if defined (__i386__) || defined (i386) /* This is used to properly initialize the FPU on an x86 for each process thread. */ asm ("finit"); #endif /* Defined __i386__ */ } #endif #ifndef HAVE_GNAT_INIT_FLOAT /* All targets without a specific __gnat_init_float will use an empty one */ void __gnat_init_float () { } #endif