/****************************************************************************
* *
* GNAT COMPILER COMPONENTS *
* *
* I N I T *
* *
* C Implementation File *
* *
* Copyright (C) 1992-2012, 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 3, 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. *
* *
* As a special exception under Section 7 of GPL version 3, you are granted *
* additional permissions described in the GCC Runtime Library Exception, *
* version 3.1, as published by the Free Software Foundation. *
* *
* You should have received a copy of the GNU General Public License and *
* a copy of the GCC Runtime Library Exception along with this program; *
* see the files COPYING3 and COPYING.RUNTIME respectively. If not, see *
* . *
* *
* GNAT was originally developed by the GNAT team at New York University. *
* Extensive contributions were provided by Ada Core Technologies Inc. *
* *
****************************************************************************/
/* This unit contains initialization circuits that are system dependent.
A major part of the functionality 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 catch the resulting signals that come
from these probes failing (i.e. touching protected pages). */
#ifdef __cplusplus
extern "C" {
#endif
/* This file should be kept synchronized with 2sinit.ads, 2sinit.adb,
s-init-ae653-cert.adb and s-init-xi-sparc.adb. All these files implement
the required functionality for different targets. */
/* 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 use 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. Tasking_Error
is not used in this unit, and the abort signal is only used on IRIX. */
extern struct Exception_Data constraint_error;
extern struct Exception_Data numeric_error;
extern struct Exception_Data program_error;
extern struct Exception_Data storage_error;
/* For the Cert run time we use the regular raise exception routine because
Raise_From_Signal_Handler is not available. */
#ifdef CERT
#define Raise_From_Signal_Handler \
__gnat_raise_exception
extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
#else
#define Raise_From_Signal_Handler \
ada__exceptions__raise_from_signal_handler
extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
#endif
/* Global values computed by the binder. */
int __gl_main_priority = -1;
int __gl_main_cpu = -1;
int __gl_time_slice_val = -1;
char __gl_wc_encoding = 'n';
char __gl_locking_policy = ' ';
char __gl_queuing_policy = ' ';
char __gl_task_dispatching_policy = ' ';
char *__gl_priority_specific_dispatching = 0;
int __gl_num_specific_dispatching = 0;
char *__gl_interrupt_states = 0;
int __gl_num_interrupt_states = 0;
int __gl_unreserve_all_interrupts = 0;
int __gl_exception_tracebacks = 0;
int __gl_zero_cost_exceptions = 0;
int __gl_detect_blocking = 0;
int __gl_default_stack_size = -1;
int __gl_leap_seconds_support = 0;
int __gl_canonical_streams = 0;
/* Indication of whether synchronous signal handler has already been
installed by a previous call to adainit. */
int __gnat_handler_installed = 0;
#ifndef IN_RTS
int __gnat_inside_elab_final_code = 0;
/* ??? This variable is obsolete since 2001-08-29 but is kept to allow
bootstrap from old GNAT versions (< 3.15). */
#endif
/* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
is defined. If this is not set then a void implementation will be defined
at the end of this unit. */
#undef HAVE_GNAT_INIT_FLOAT
/******************************/
/* __gnat_get_interrupt_state */
/******************************/
char __gnat_get_interrupt_state (int);
/* This routine is called from the runtime as needed to determine the state
of an interrupt, as set by an Interrupt_State pragma appearing anywhere
in the current partition. The input argument is the interrupt number,
and the result is one of the following:
'n' this interrupt not set by any Interrupt_State pragma
'u' Interrupt_State pragma set state to User
'r' Interrupt_State pragma set state to Runtime
's' Interrupt_State pragma set state to System */
char
__gnat_get_interrupt_state (int intrup)
{
if (intrup >= __gl_num_interrupt_states)
return 'n';
else
return __gl_interrupt_states [intrup];
}
/***********************************/
/* __gnat_get_specific_dispatching */
/***********************************/
char __gnat_get_specific_dispatching (int);
/* This routine is called from the runtime as needed to determine the
priority specific dispatching policy, as set by a
Priority_Specific_Dispatching pragma appearing anywhere in the current
partition. The input argument is the priority number, and the result
is the upper case first character of the policy name, e.g. 'F' for
FIFO_Within_Priorities. A space ' ' is returned if no
Priority_Specific_Dispatching pragma is used in the partition. */
char
__gnat_get_specific_dispatching (int priority)
{
if (__gl_num_specific_dispatching == 0)
return ' ';
else if (priority >= __gl_num_specific_dispatching)
return 'F';
else
return __gl_priority_specific_dispatching [priority];
}
#ifndef IN_RTS
/**********************/
/* __gnat_set_globals */
/**********************/
/* This routine is kept for bootstrapping purposes, since the binder generated
file now sets the __gl_* variables directly. */
void
__gnat_set_globals (void)
{
}
#endif
/***************/
/* AIX Section */
/***************/
#if defined (_AIX)
#include
#include
/* Some versions of AIX don't define SA_NODEFER. */
#ifndef SA_NODEFER
#define SA_NODEFER 0
#endif /* SA_NODEFER */
/* Versions of AIX before 4.3 don't have nanosleep but provide
nsleep instead. */
#ifndef _AIXVERSION_430
extern int nanosleep (struct timestruc_t *, struct timestruc_t *);
int
nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp)
{
return nsleep (Rqtp, Rmtp);
}
#endif /* _AIXVERSION_430 */
/* Version of AIX before 5.3 don't have pthread_condattr_setclock:
* supply it as a weak symbol here so that if linking on a 5.3 or newer
* machine, we get the real one.
*/
#ifndef _AIXVERSION_530
#pragma weak pthread_condattr_setclock
int
pthread_condattr_setclock (pthread_condattr_t *attr, clockid_t cl) {
return 0;
}
#endif
static void
__gnat_error_handler (int sig,
siginfo_t *si ATTRIBUTE_UNUSED,
void *ucontext ATTRIBUTE_UNUSED)
{
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 (void)
{
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_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
act.sa_sigaction = __gnat_error_handler;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/*****************/
/* Tru64 section */
/*****************/
#elif defined(__alpha__) && defined(__osf__)
#include
#include
extern char *__gnat_get_code_loc (struct sigcontext *);
extern void __gnat_set_code_loc (struct sigcontext *, char *);
extern size_t __gnat_machine_state_length (void);
#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
void
__gnat_adjust_context_for_raise (int signo, void *ucontext)
{
struct sigcontext *sigcontext = (struct sigcontext *) ucontext;
/* The unwinder expects the signal context to contain the address of the
faulting instruction. For SIGFPE, this depends on the trap shadow
situation (see man ieee). We nonetheless always compensate for it,
considering that PC designates the instruction following the one that
trapped. This is not necessarily true but corresponds to what we have
always observed. */
if (signo == SIGFPE)
sigcontext->sc_pc--;
}
static void
__gnat_error_handler (int sig, siginfo_t *si, void *ucontext)
{
struct Exception_Data *exception;
static int recurse = 0;
const char *msg;
/* Adjusting is required for every fault context, so adjust for this one
now, before we possibly trigger a recursive fault below. */
__gnat_adjust_context_for_raise (sig, ucontext);
/* If this was an explicit signal from a "kill", just resignal it. */
if (SI_FROMUSER (si))
{
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 (si->si_code == SEGV_ACCERR
|| (long) si->si_addr == 0
|| (((long) si->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) si->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, CONST_CAST (char *, msg));
}
void
__gnat_install_handler (void)
{
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 (*) (int)) __gnat_error_handler;
act.sa_flags = SA_RESTART | SA_NODEFER | SA_SIGINFO;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/* Routines called by s-mastop-tru64.adb. */
#define SC_GP 29
char *
__gnat_get_code_loc (struct sigcontext *context)
{
return (char *) context->sc_pc;
}
void
__gnat_set_code_loc (struct sigcontext *context, char *pc)
{
context->sc_pc = (long) pc;
}
size_t
__gnat_machine_state_length (void)
{
return sizeof (struct sigcontext);
}
/*****************/
/* HP-UX section */
/*****************/
#elif defined (__hpux__)
#include
#include
static void
__gnat_error_handler (int sig,
siginfo_t *si ATTRIBUTE_UNUSED,
void *ucontext ATTRIBUTE_UNUSED)
{
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);
}
/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
#if defined (__hppa__)
char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
#else
char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */
#endif
void
__gnat_install_handler (void)
{
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. */
stack_t stack;
stack.ss_sp = __gnat_alternate_stack;
stack.ss_size = sizeof (__gnat_alternate_stack);
stack.ss_flags = 0;
sigaltstack (&stack, NULL);
act.sa_sigaction = __gnat_error_handler;
act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
act.sa_flags |= SA_ONSTACK;
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
__gnat_handler_installed = 1;
}
/*********************/
/* GNU/Linux Section */
/*********************/
#elif defined (linux)
#include
#define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
#include
/* GNU/Linux, which uses glibc, does not define NULL in included
header files. */
#if !defined (NULL)
#define NULL ((void *) 0)
#endif
#if defined (MaRTE)
/* MaRTE OS provides its own version of sigaction, sigfillset, and
sigemptyset (overriding these symbol names). We want to make sure that
the versions provided by the underlying C library are used here (these
versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
and fake_linux_sigemptyset, respectively). The MaRTE library will not
always be present (it will not be linked if no tasking constructs are
used), so we use the weak symbol mechanism to point always to the symbols
defined within the C library. */
#pragma weak linux_sigaction
int linux_sigaction (int signum, const struct sigaction *act,
struct sigaction *oldact) {
return sigaction (signum, act, oldact);
}
#define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)
#pragma weak fake_linux_sigfillset
void fake_linux_sigfillset (sigset_t *set) {
sigfillset (set);
}
#define sigfillset(set) fake_linux_sigfillset (set)
#pragma weak fake_linux_sigemptyset
void fake_linux_sigemptyset (sigset_t *set) {
sigemptyset (set);
}
#define sigemptyset(set) fake_linux_sigemptyset (set)
#endif
#if defined (i386) || defined (__x86_64__) || defined (__ia64__)
#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
{
mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
/* On the i386 and x86-64 architectures, stack checking is performed by
means of probes with moving stack pointer, that is to say the probed
address is always the value of the stack pointer. Upon hitting the
guard page, the stack pointer therefore points to an inaccessible
address and an alternate signal stack is needed to run the handler.
But there is an additional twist: on these architectures, the EH
return code writes the address of the handler at the target CFA's
value on the stack before doing the jump. As a consequence, if
there is an active handler in the frame whose stack has overflowed,
the stack pointer must nevertheless point to an accessible address
by the time the EH return is executed.
We therefore adjust the saved value of the stack pointer by the size
of one page + a small dope of 4 words, in order to make sure that it
points to an accessible address in case it's used as the target CFA.
The stack checking code guarantees that this address is unused by the
time this happens. */
#if defined (i386)
unsigned long *pc = (unsigned long *)mcontext->gregs[REG_EIP];
/* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
if (signo == SIGSEGV && pc && *pc == 0x00240c83)
mcontext->gregs[REG_ESP] += 4096 + 4 * sizeof (unsigned long);
#elif defined (__x86_64__)
unsigned long *pc = (unsigned long *)mcontext->gregs[REG_RIP];
/* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
if (signo == SIGSEGV && pc && (*pc & 0xffffffffff) == 0x00240c8348)
mcontext->gregs[REG_RSP] += 4096 + 4 * sizeof (unsigned long);
#elif defined (__ia64__)
/* ??? The IA-64 unwinder doesn't compensate for signals. */
mcontext->sc_ip++;
#endif
}
#endif
static void
__gnat_error_handler (int sig, siginfo_t *si ATTRIBUTE_UNUSED, void *ucontext)
{
struct Exception_Data *exception;
const char *msg;
/* Adjusting is required for every fault context, so adjust for this one
now, before we possibly trigger a recursive fault below. */
__gnat_adjust_context_for_raise (sig, ucontext);
switch (sig)
{
case SIGSEGV:
/* 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 old versions of init.c, we had a test of the page before the
stack pointer:
((volatile char *)
((long) si->esp_at_signal & - getpagesize ()))[getpagesize ()];
but that's wrong since it tests the stack pointer location and the
stack probing code may not move it 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. */
exception = &storage_error;
msg = "stack overflow or erroneous memory access";
break;
case SIGBUS:
exception = &storage_error;
msg = "SIGBUS: possible stack overflow";
break;
case SIGFPE:
exception = &constraint_error;
msg = "SIGFPE";
break;
default:
exception = &program_error;
msg = "unhandled signal";
}
Raise_From_Signal_Handler (exception, msg);
}
#if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
#endif
#ifdef __XENO__
#include
#include
RT_TASK main_task;
#endif
void
__gnat_install_handler (void)
{
struct sigaction act;
#ifdef __XENO__
int prio;
if (__gl_main_priority == -1)
prio = 49;
else
prio = __gl_main_priority;
/* Avoid memory swapping for this program */
mlockall (MCL_CURRENT|MCL_FUTURE);
/* Turn the current Linux task into a native Xenomai task */
rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
#endif
/* 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. */
#if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
stack_t stack;
stack.ss_sp = __gnat_alternate_stack;
stack.ss_size = sizeof (__gnat_alternate_stack);
stack.ss_flags = 0;
sigaltstack (&stack, NULL);
#endif
act.sa_sigaction = __gnat_error_handler;
act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
#if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
act.sa_flags |= SA_ONSTACK;
#endif
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
__gnat_handler_installed = 1;
}
/****************/
/* IRIX Section */
/****************/
#elif defined (sgi)
#include
#include
#ifndef NULL
#define NULL 0
#endif
#define SIGADAABORT 48
#define SIGNAL_STACK_SIZE 4096
#define SIGNAL_STACK_ALIGNMENT 64
#define Check_Abort_Status \
system__soft_links__check_abort_status
extern int (*Check_Abort_Status) (void);
extern struct Exception_Data _abort_signal;
/* We are not setting the SA_SIGINFO bit in the sigaction flags when
connecting that handler, with the effects described in the sigaction
man page:
SA_SIGINFO If set and the signal is caught, sig is passed as the
first argument to the signal-catching function. If the
second argument is not equal to NULL, it points to a
siginfo_t structure containing the reason why the
signal was generated [see siginfo(5)]; the third
argument points to a ucontext_t structure containing
the receiving process's context when the signal was
delivered [see ucontext(5)]. If cleared and the signal
is caught, the first argument is also the signal number
but the second argument is the signal code identifying
the cause of the signal. The third argument points to a
sigcontext_t structure containing the receiving
process's context when the signal was delivered. This
is the default behavior (see signal(5) for more
details). Additionally, when SA_SIGINFO is set for a
signal, multiple occurrences of that signal will be
queued for delivery in FIFO order (see sigqueue(3) for
a more detailed explanation of this concept), if those
occurrences of that signal were generated using
sigqueue(3). */
static void
__gnat_error_handler (int sig, siginfo_t *reason, void *uc ATTRIBUTE_UNUSED)
{
/* This handler is installed with SA_SIGINFO cleared, but there's no
prototype for the resulting alternative three-argument form, so we
have to hack around this by casting reason to the int actually
passed. */
int code = (int) reason;
struct Exception_Data *exception;
const char *msg;
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 || code == EEXIST)
{
/* ??? We handle stack overflows here, some of which do trigger
SIGSEGV + EEXIST on Irix 6.5 although EEXIST is not part of
the documented valid codes for SEGV in the signal(5) man
page. */
/* ??? 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";
}
Raise_From_Signal_Handler (exception, msg);
}
void
__gnat_install_handler (void)
{
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!
The handler is installed with SA_SIGINFO cleared, but there's no
C++ prototype for the three-argument form, so fake it by using
sa_sigaction and casting the arguments instead. */
act.sa_sigaction = __gnat_error_handler;
act.sa_flags = SA_NODEFER + SA_RESTART;
sigfillset (&act.sa_mask);
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
if (__gnat_get_interrupt_state (SIGADAABORT) != 's')
sigaction (SIGADAABORT, &act, NULL);
__gnat_handler_installed = 1;
}
/*******************/
/* LynxOS Section */
/*******************/
#elif defined (__Lynx__)
#include
#include
static void
__gnat_error_handler (int sig)
{
struct Exception_Data *exception;
const char *msg;
switch(sig)
{
case SIGFPE:
exception = &constraint_error;
msg = "SIGFPE";
break;
case SIGILL:
exception = &constraint_error;
msg = "SIGILL";
break;
case SIGSEGV:
exception = &storage_error;
msg = "stack overflow or erroneous memory access";
break;
case SIGBUS:
exception = &constraint_error;
msg = "SIGBUS";
break;
default:
exception = &program_error;
msg = "unhandled signal";
}
Raise_From_Signal_Handler(exception, msg);
}
void
__gnat_install_handler(void)
{
struct sigaction act;
act.sa_handler = __gnat_error_handler;
act.sa_flags = 0x0;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/*******************/
/* Solaris Section */
/*******************/
#elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
#include
#include
#include
#include
/* The code below is common to SPARC and x86. Beware of the delay slot
differences for signal context adjustments. */
#if defined (__sparc)
#define RETURN_ADDR_OFFSET 8
#else
#define RETURN_ADDR_OFFSET 0
#endif
static void
__gnat_error_handler (int sig, siginfo_t *si, void *ucontext ATTRIBUTE_UNUSED)
{
struct Exception_Data *exception;
static int recurse = 0;
const char *msg;
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 (si->si_code == SEGV_ACCERR
|| (long) si->si_addr == 0
|| (((long) si->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) si->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 (void)
{
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_sigaction = __gnat_error_handler;
act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/***************/
/* VMS Section */
/***************/
#elif defined (VMS)
/* Routine called from binder to override default feature values. */
void __gnat_set_features (void);
int __gnat_features_set = 0;
#ifdef __IA64
#define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
#define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
#define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
#else
#define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
#define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
#define lib_get_invo_handle LIB$GET_INVO_HANDLE
#endif
/* Define macro symbols for the VMS conditions that become Ada exceptions.
Most of these are also defined in the header file ssdef.h which has not
yet been converted to be recognized by GNU C. */
/* Defining these as macros, as opposed to external addresses, allows
them to be used in a case statement below. */
#define SS$_ACCVIO 12
#define SS$_HPARITH 1284
#define SS$_STKOVF 1364
#define SS$_RESIGNAL 2328
/* These codes are in standard message libraries. */
extern int C$_SIGKILL;
extern int SS$_DEBUG;
extern int LIB$_KEYNOTFOU;
extern int LIB$_ACTIMAGE;
#define CMA$_EXIT_THREAD 4227492
#define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */
#define SS$_INTDIV 1156
/* These codes are non standard, which is to say the author is
not sure if they are defined in the standard message libraries
so keep them as macros for now. */
#define RDB$_STREAM_EOF 20480426
#define FDL$_UNPRIKW 11829410
struct cond_except {
unsigned int cond;
const struct Exception_Data *except;
};
struct descriptor_s {
unsigned short len, mbz;
__char_ptr32 adr;
};
/* 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 Status_Error ada__io_exceptions__status_error
extern struct Exception_Data Status_Error;
#define Mode_Error ada__io_exceptions__mode_error
extern struct Exception_Data Mode_Error;
#define Name_Error ada__io_exceptions__name_error
extern struct Exception_Data Name_Error;
#define Use_Error ada__io_exceptions__use_error
extern struct Exception_Data Use_Error;
#define Device_Error ada__io_exceptions__device_error
extern struct Exception_Data Device_Error;
#define End_Error ada__io_exceptions__end_error
extern struct Exception_Data End_Error;
#define Data_Error ada__io_exceptions__data_error
extern struct Exception_Data Data_Error;
#define Layout_Error ada__io_exceptions__layout_error
extern struct Exception_Data Layout_Error;
#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 (Exception_Code);
#define Base_Code_In system__vms_exception_table__base_code_in
extern Exception_Code Base_Code_In (Exception_Code);
/* DEC Ada exceptions are not defined in a header file, so they
must be declared. */
#define ADA$_ALREADY_OPEN 0x0031a594
#define ADA$_CONSTRAINT_ERRO 0x00318324
#define ADA$_DATA_ERROR 0x003192c4
#define ADA$_DEVICE_ERROR 0x003195e4
#define ADA$_END_ERROR 0x00319904
#define ADA$_FAC_MODE_MISMAT 0x0031a8b3
#define ADA$_IOSYSFAILED 0x0031af04
#define ADA$_KEYSIZERR 0x0031aa3c
#define ADA$_KEY_MISMATCH 0x0031a8e3
#define ADA$_LAYOUT_ERROR 0x00319c24
#define ADA$_LINEXCMRS 0x0031a8f3
#define ADA$_MAXLINEXC 0x0031a8eb
#define ADA$_MODE_ERROR 0x00319f44
#define ADA$_MRN_MISMATCH 0x0031a8db
#define ADA$_MRS_MISMATCH 0x0031a8d3
#define ADA$_NAME_ERROR 0x0031a264
#define ADA$_NOT_OPEN 0x0031a58c
#define ADA$_ORG_MISMATCH 0x0031a8bb
#define ADA$_PROGRAM_ERROR 0x00318964
#define ADA$_RAT_MISMATCH 0x0031a8cb
#define ADA$_RFM_MISMATCH 0x0031a8c3
#define ADA$_STAOVF 0x00318cac
#define ADA$_STATUS_ERROR 0x0031a584
#define ADA$_STORAGE_ERROR 0x00318c84
#define ADA$_UNSUPPORTED 0x0031a8ab
#define ADA$_USE_ERROR 0x0031a8a4
/* DEC Ada specific conditions. */
static const struct cond_except dec_ada_cond_except_table [] = {
{ADA$_PROGRAM_ERROR, &program_error},
{ADA$_USE_ERROR, &Use_Error},
{ADA$_KEYSIZERR, &program_error},
{ADA$_STAOVF, &storage_error},
{ADA$_CONSTRAINT_ERRO, &constraint_error},
{ADA$_IOSYSFAILED, &Device_Error},
{ADA$_LAYOUT_ERROR, &Layout_Error},
{ADA$_STORAGE_ERROR, &storage_error},
{ADA$_DATA_ERROR, &Data_Error},
{ADA$_DEVICE_ERROR, &Device_Error},
{ADA$_END_ERROR, &End_Error},
{ADA$_MODE_ERROR, &Mode_Error},
{ADA$_NAME_ERROR, &Name_Error},
{ADA$_STATUS_ERROR, &Status_Error},
{ADA$_NOT_OPEN, &Use_Error},
{ADA$_ALREADY_OPEN, &Use_Error},
{ADA$_USE_ERROR, &Use_Error},
{ADA$_UNSUPPORTED, &Use_Error},
{ADA$_FAC_MODE_MISMAT, &Use_Error},
{ADA$_ORG_MISMATCH, &Use_Error},
{ADA$_RFM_MISMATCH, &Use_Error},
{ADA$_RAT_MISMATCH, &Use_Error},
{ADA$_MRS_MISMATCH, &Use_Error},
{ADA$_MRN_MISMATCH, &Use_Error},
{ADA$_KEY_MISMATCH, &Use_Error},
{ADA$_MAXLINEXC, &constraint_error},
{ADA$_LINEXCMRS, &constraint_error},
#if 0
/* Already handled by a pragma Import_Exception
in Aux_IO_Exceptions */
{ADA$_LOCK_ERROR, &Lock_Error},
{ADA$_EXISTENCE_ERROR, &Existence_Error},
{ADA$_KEY_ERROR, &Key_Error},
#endif
{0, 0}
};
#endif /* IN_RTS */
/* Non-DEC Ada specific conditions. We could probably also put
SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF. */
static const struct cond_except cond_except_table [] = {
{MTH$_FLOOVEMAT, &constraint_error},
{SS$_INTDIV, &constraint_error},
{0, 0}
};
/* To deal with VMS conditions and their mapping to Ada exceptions,
the __gnat_error_handler routine below is installed as an exception
vector having precedence over DEC frame handlers. Some conditions
still need to be handled by such handlers, however, in which case
__gnat_error_handler needs to return SS$_RESIGNAL. Consider for
instance the use of a third party library compiled with DECAda and
performing its own exception handling internally.
To allow some user-level flexibility, which conditions should be
resignaled is controlled by a predicate function, provided with the
condition value and returning a boolean indication stating whether
this condition should be resignaled or not.
That predicate function is called indirectly, via a function pointer,
by __gnat_error_handler, and changing that pointer is allowed to the
user code by way of the __gnat_set_resignal_predicate interface.
The user level function may then implement what it likes, including
for instance the maintenance of a dynamic data structure if the set
of to be resignalled conditions has to change over the program's
lifetime.
??? This is not a perfect solution to deal with the possible
interactions between the GNAT and the DECAda exception handling
models and better (more general) schemes are studied. This is so
just provided as a convenient workaround in the meantime, and
should be use with caution since the implementation has been kept
very simple. */
typedef int
resignal_predicate (int code);
static const int * const cond_resignal_table [] = {
&C$_SIGKILL,
(int *)CMA$_EXIT_THREAD,
&SS$_DEBUG,
&LIB$_KEYNOTFOU,
&LIB$_ACTIMAGE,
(int *) RDB$_STREAM_EOF,
(int *) FDL$_UNPRIKW,
0
};
static const int facility_resignal_table [] = {
0x1380000, /* RDB */
0x2220000, /* SQL */
0
};
/* Default GNAT predicate for resignaling conditions. */
static int
__gnat_default_resignal_p (int code)
{
int i, iexcept;
for (i = 0; facility_resignal_table [i]; i++)
if ((code & 0xfff0000) == facility_resignal_table [i])
return 1;
for (i = 0, iexcept = 0;
cond_resignal_table [i]
&& !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
i++);
return iexcept;
}
/* Static pointer to predicate that the __gnat_error_handler exception
vector invokes to determine if it should resignal a condition. */
static resignal_predicate *__gnat_resignal_p = __gnat_default_resignal_p;
/* User interface to change the predicate pointer to PREDICATE. Reset to
the default if PREDICATE is null. */
void
__gnat_set_resignal_predicate (resignal_predicate *predicate)
{
if (predicate == NULL)
__gnat_resignal_p = __gnat_default_resignal_p;
else
__gnat_resignal_p = predicate;
}
/* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
#define Default_Exception_Msg_Max_Length 512
/* Action routine for SYS$PUTMSG. There may be multiple
conditions, each with text to be appended to MESSAGE
and separated by line termination. */
static int
copy_msg (struct descriptor_s *msgdesc, char *message)
{
int len = strlen (message);
int copy_len;
/* Check for buffer overflow and skip. */
if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
{
strcat (message, "\r\n");
len += 2;
}
/* Check for buffer overflow and truncate if necessary. */
copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
msgdesc->len :
Default_Exception_Msg_Max_Length - 1 - len);
strncpy (&message [len], msgdesc->adr, copy_len);
message [len + copy_len] = 0;
return 0;
}
long
__gnat_handle_vms_condition (int *sigargs, void *mechargs)
{
struct Exception_Data *exception = 0;
Exception_Code base_code;
struct descriptor_s gnat_facility = {4, 0, "GNAT"};
char message [Default_Exception_Msg_Max_Length];
const char *msg = "";
/* Check for conditions to resignal which aren't effected by pragma
Import_Exception. */
if (__gnat_resignal_p (sigargs [1]))
return SS$_RESIGNAL;
#ifdef IN_RTS
/* See if it's an imported exception. Beware that registered exceptions
are bound to their base code, with the severity bits masked off. */
base_code = Base_Code_In ((Exception_Code) sigargs[1]);
exception = Coded_Exception (base_code);
if (exception)
{
message[0] = 0;
/* Subtract PC & PSL fields which messes with PUTMSG. */
sigargs[0] -= 2;
SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
sigargs[0] += 2;
msg = message;
exception->Name_Length = 19;
/* ??? The full name really should be get SYS$GETMSG returns. */
exception->Full_Name = "IMPORTED_EXCEPTION";
exception->Import_Code = base_code;
#ifdef __IA64
/* Do not adjust the program counter as already points to the next
instruction (just after the call to LIB$STOP). */
Raise_From_Signal_Handler (exception, msg);
#endif
}
#endif
if (exception == 0)
switch (sigargs[1])
{
case SS$_ACCVIO:
if (sigargs[3] == 0)
{
exception = &constraint_error;
msg = "access zero";
}
else
{
exception = &storage_error;
msg = "stack overflow or erroneous memory access";
}
__gnat_adjust_context_for_raise (SS$_ACCVIO, (void *)mechargs);
break;
case SS$_STKOVF:
exception = &storage_error;
msg = "stack overflow";
__gnat_adjust_context_for_raise (SS$_STKOVF, (void *)mechargs);
break;
case SS$_HPARITH:
#ifndef IN_RTS
return SS$_RESIGNAL; /* toplev.c handles for compiler */
#else
exception = &constraint_error;
msg = "arithmetic error";
__gnat_adjust_context_for_raise (SS$_HPARITH, (void *)mechargs);
#endif
break;
default:
#ifdef IN_RTS
{
int i;
/* Scan the DEC Ada exception condition table for a match and fetch
the associated GNAT exception pointer. */
for (i = 0;
dec_ada_cond_except_table [i].cond &&
!LIB$MATCH_COND (&sigargs [1],
&dec_ada_cond_except_table [i].cond);
i++);
exception = (struct Exception_Data *)
dec_ada_cond_except_table [i].except;
if (!exception)
{
/* Scan the VMS standard condition table for a match and fetch
the associated GNAT exception pointer. */
for (i = 0;
cond_except_table[i].cond &&
!LIB$MATCH_COND (&sigargs[1], &cond_except_table[i].cond);
i++);
exception = (struct Exception_Data *)
cond_except_table [i].except;
if (!exception)
/* User programs expect Non_Ada_Error to be raised, reference
DEC Ada test CXCONDHAN. */
exception = &Non_Ada_Error;
}
}
#else
exception = &program_error;
#endif
message[0] = 0;
/* Subtract PC & PSL fields which messes with PUTMSG. */
sigargs[0] -= 2;
SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
sigargs[0] += 2;
msg = message;
break;
}
Raise_From_Signal_Handler (exception, msg);
}
void
__gnat_install_handler (void)
{
long prvhnd ATTRIBUTE_UNUSED;
#if !defined (IN_RTS)
SYS$SETEXV (1, __gnat_handle_vms_condition, 3, &prvhnd);
#endif
__gnat_handler_installed = 1;
}
/* __gnat_adjust_context_for_raise for Alpha - see comments along with the
default version later in this file. */
#if defined (IN_RTS) && defined (__alpha__)
#include
#include
#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
{
if (signo == SS$_HPARITH)
{
/* Sub one to the address of the instruction signaling the condition,
located in the sigargs array. */
CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
CHF$SIGNAL_ARRAY * sigargs
= (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;
int vcount = sigargs->chf$is_sig_args;
int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];
(*pc_slot)--;
}
}
#endif
/* __gnat_adjust_context_for_raise for ia64. */
#if defined (IN_RTS) && defined (__IA64)
#include
#include
#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
typedef unsigned long long u64;
void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
{
/* Add one to the address of the instruction signaling the condition,
located in the 64bits sigargs array. */
CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
CHF64$SIGNAL_ARRAY *chfsig64
= (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;
u64 * post_sigarray
= (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;
u64 * ih_pc_loc = post_sigarray - 2;
(*ih_pc_loc) ++;
}
#endif
/* Easier interface for LIB$GET_LOGICAL: put the equivalence of NAME into BUF,
always NUL terminated. In case of error or if the result is longer than
LEN (length of BUF) an empty string is written info BUF. */
static void
__gnat_vms_get_logical (const char *name, char *buf, int len)
{
struct descriptor_s name_desc, result_desc;
int status;
unsigned short rlen;
/* Build the descriptor for NAME. */
name_desc.len = strlen (name);
name_desc.mbz = 0;
name_desc.adr = (char *)name;
/* Build the descriptor for the result. */
result_desc.len = len;
result_desc.mbz = 0;
result_desc.adr = buf;
status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);
if ((status & 1) == 1 && rlen < len)
buf[rlen] = 0;
else
buf[0] = 0;
}
/* Size of a page on ia64 and alpha VMS. */
#define VMS_PAGESIZE 8192
/* User mode. */
#define PSL__C_USER 3
/* No access. */
#define PRT__C_NA 0
/* Descending region. */
#define VA__M_DESCEND 1
/* Get by virtual address. */
#define VA___REGSUM_BY_VA 1
/* Memory region summary. */
struct regsum
{
unsigned long long q_region_id;
unsigned int l_flags;
unsigned int l_region_protection;
void *pq_start_va;
unsigned long long q_region_size;
void *pq_first_free_va;
};
extern int SYS$GET_REGION_INFO (unsigned int, unsigned long long *,
void *, void *, unsigned int,
void *, unsigned int *);
extern int SYS$EXPREG_64 (unsigned long long *, unsigned long long,
unsigned int, unsigned int, void **,
unsigned long long *);
extern int SYS$SETPRT_64 (void *, unsigned long long, unsigned int,
unsigned int, void **, unsigned long long *,
unsigned int *);
extern int SYS$PUTMSG (void *, int (*)(), void *, unsigned long long);
/* Add a guard page in the memory region containing ADDR at ADDR +/- SIZE.
(The sign depends on the kind of the memory region). */
static int
__gnat_set_stack_guard_page (void *addr, unsigned long size)
{
int status;
void *ret_va;
unsigned long long ret_len;
unsigned int ret_prot;
void *start_va;
unsigned long long length;
unsigned int retlen;
struct regsum buffer;
/* Get the region for ADDR. */
status = SYS$GET_REGION_INFO
(VA___REGSUM_BY_VA, NULL, addr, NULL, sizeof (buffer), &buffer, &retlen);
if ((status & 1) != 1)
return -1;
/* Extend the region. */
status = SYS$EXPREG_64 (&buffer.q_region_id,
size, 0, 0, &start_va, &length);
if ((status & 1) != 1)
return -1;
/* Create a guard page. */
if (!(buffer.l_flags & VA__M_DESCEND))
start_va = (void *)((unsigned long long)start_va + length - VMS_PAGESIZE);
status = SYS$SETPRT_64 (start_va, VMS_PAGESIZE, PSL__C_USER, PRT__C_NA,
&ret_va, &ret_len, &ret_prot);
if ((status & 1) != 1)
return -1;
return 0;
}
/* Read logicals to limit the stack(s) size. */
static void
__gnat_set_stack_limit (void)
{
#ifdef __ia64__
void *sp;
unsigned long size;
char value[16];
char *e;
/* The main stack. */
__gnat_vms_get_logical ("GNAT_STACK_SIZE", value, sizeof (value));
size = strtoul (value, &e, 0);
if (e > value && *e == 0)
{
asm ("mov %0=sp" : "=r" (sp));
__gnat_set_stack_guard_page (sp, size * 1024);
}
/* The register stack. */
__gnat_vms_get_logical ("GNAT_RBS_SIZE", value, sizeof (value));
size = strtoul (value, &e, 0);
if (e > value && *e == 0)
{
asm ("mov %0=ar.bsp" : "=r" (sp));
__gnat_set_stack_guard_page (sp, size * 1024);
}
#endif
}
/* Feature logical name and global variable address pair.
If we ever add another feature logical to this list, the
feature struct will need to be enhanced to take into account
possible values for *gl_addr. */
struct feature {
const char *name;
int *gl_addr;
};
/* Default values for GNAT features set by environment. */
int __gl_heap_size = 64;
/* Array feature logical names and global variable addresses. */
static const struct feature features[] = {
{"GNAT$NO_MALLOC_64", &__gl_heap_size},
{0, 0}
};
void
__gnat_set_features (void)
{
int i;
char buff[16];
/* Loop through features array and test name for enable/disable. */
for (i = 0; features[i].name; i++)
{
__gnat_vms_get_logical (features[i].name, buff, sizeof (buff));
if (strcmp (buff, "ENABLE") == 0
|| strcmp (buff, "TRUE") == 0
|| strcmp (buff, "1") == 0)
*features[i].gl_addr = 32;
else if (strcmp (buff, "DISABLE") == 0
|| strcmp (buff, "FALSE") == 0
|| strcmp (buff, "0") == 0)
*features[i].gl_addr = 64;
}
/* Features to artificially limit the stack size. */
__gnat_set_stack_limit ();
__gnat_features_set = 1;
}
/* Return true if the VMS version is 7.x. */
extern unsigned int LIB$GETSYI (int *, ...);
#define SYI$_VERSION 0x1000
int
__gnat_is_vms_v7 (void)
{
struct descriptor_s desc;
char version[8];
int status;
int code = SYI$_VERSION;
desc.len = sizeof (version);
desc.mbz = 0;
desc.adr = version;
status = LIB$GETSYI (&code, 0, &desc);
if ((status & 1) == 1 && version[1] == '7' && version[2] == '.')
return 1;
else
return 0;
}
/*******************/
/* FreeBSD Section */
/*******************/
#elif defined (__FreeBSD__)
#include
#include
#include
static void
__gnat_error_handler (int sig,
siginfo_t *si ATTRIBUTE_UNUSED,
void *ucontext ATTRIBUTE_UNUSED)
{
struct Exception_Data *exception;
const char *msg;
switch (sig)
{
case SIGFPE:
exception = &constraint_error;
msg = "SIGFPE";
break;
case SIGILL:
exception = &constraint_error;
msg = "SIGILL";
break;
case SIGSEGV:
exception = &storage_error;
msg = "stack overflow or erroneous memory access";
break;
case SIGBUS:
exception = &storage_error;
msg = "SIGBUS: possible stack overflow";
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_sigaction
= (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
(void) sigemptyset (&act.sa_mask);
(void) sigaction (SIGILL, &act, NULL);
(void) sigaction (SIGFPE, &act, NULL);
(void) sigaction (SIGSEGV, &act, NULL);
(void) sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/*******************/
/* VxWorks Section */
/*******************/
#elif defined(__vxworks)
#include
#include
#ifndef __RTP__
#include
#include
#endif
#ifdef VTHREADS
#include "private/vThreadsP.h"
#endif
void __gnat_error_handler (int, void *, struct sigcontext *);
#ifndef __RTP__
/* Directly vectored Interrupt routines are not supported when using RTPs. */
extern int __gnat_inum_to_ivec (int);
/* This is needed by the GNAT run time to handle Vxworks interrupts. */
int
__gnat_inum_to_ivec (int num)
{
return INUM_TO_IVEC (num);
}
#endif
#if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
/* getpid is used by s-parint.adb, but is not defined by VxWorks, except
on Alpha VxWorks and VxWorks 6.x (including RTPs). */
extern long getpid (void);
long
getpid (void)
{
return taskIdSelf ();
}
#endif
/* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is.
handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp
doesn't. */
void
__gnat_clear_exception_count (void)
{
#ifdef VTHREADS
WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();
currentTask->vThreads.excCnt = 0;
#endif
}
/* Handle different SIGnal to exception mappings in different VxWorks
versions. */
static void
__gnat_map_signal (int sig, void *si ATTRIBUTE_UNUSED,
struct sigcontext *sc ATTRIBUTE_UNUSED)
{
struct Exception_Data *exception;
const char *msg;
switch (sig)
{
case SIGFPE:
exception = &constraint_error;
msg = "SIGFPE";
break;
#ifdef VTHREADS
#ifdef __VXWORKSMILS__
case SIGILL:
exception = &storage_error;
msg = "SIGILL: possible stack overflow";
break;
case SIGSEGV:
exception = &storage_error;
msg = "SIGSEGV";
break;
case SIGBUS:
exception = &program_error;
msg = "SIGBUS";
break;
#else
case SIGILL:
exception = &constraint_error;
msg = "Floating point exception or SIGILL";
break;
case SIGSEGV:
exception = &storage_error;
msg = "SIGSEGV";
break;
case SIGBUS:
exception = &storage_error;
msg = "SIGBUS: possible stack overflow";
break;
#endif
#elif (_WRS_VXWORKS_MAJOR == 6)
case SIGILL:
exception = &constraint_error;
msg = "SIGILL";
break;
#ifdef __RTP__
/* In RTP mode a SIGSEGV is most likely due to a stack overflow,
since stack checking uses the probing mechanism. */
case SIGSEGV:
exception = &storage_error;
msg = "SIGSEGV: possible stack overflow";
break;
case SIGBUS:
exception = &program_error;
msg = "SIGBUS";
break;
#else
/* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */
case SIGSEGV:
exception = &storage_error;
msg = "SIGSEGV";
break;
case SIGBUS:
exception = &storage_error;
msg = "SIGBUS: possible stack overflow";
break;
#endif
#else
/* VxWorks 5: a SIGILL is most likely due to a stack overflow,
since stack checking uses the stack limit mechanism. */
case SIGILL:
exception = &storage_error;
msg = "SIGILL: possible stack overflow";
break;
case SIGSEGV:
exception = &storage_error;
msg = "SIGSEGV";
break;
case SIGBUS:
exception = &program_error;
msg = "SIGBUS";
break;
#endif
default:
exception = &program_error;
msg = "unhandled signal";
}
__gnat_clear_exception_count ();
Raise_From_Signal_Handler (exception, msg);
}
/* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
propagation after the required low level adjustments. */
void
__gnat_error_handler (int sig, void *si, struct sigcontext *sc)
{
sigset_t mask;
/* 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. */
sigprocmask (SIG_SETMASK, NULL, &mask);
sigdelset (&mask, sig);
sigprocmask (SIG_SETMASK, &mask, NULL);
#if defined (__PPC__) && defined(_WRS_KERNEL)
/* On PowerPC, kernel mode, we process signals through a Call Frame Info
trampoline, voiding the need for myriads of fallback_frame_state
variants in the ZCX runtime. We have no simple way to distinguish ZCX
from SJLJ here, so we do this for SJLJ as well even though this is not
necessary. This only incurs a few extra instructions and a tiny
amount of extra stack usage. */
#include "sigtramp.h"
__gnat_sigtramp (sig, (void *)si, (void *)sc,
(sighandler_t *)&__gnat_map_signal);
#else
__gnat_map_signal (sig, si, sc);
#endif
}
void
__gnat_install_handler (void)
{
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;
sigemptyset (&act.sa_mask);
/* For VxWorks, install all signal handlers, since pragma Interrupt_State
applies to vectored hardware interrupts, not signals. */
sigaction (SIGFPE, &act, NULL);
sigaction (SIGILL, &act, NULL);
sigaction (SIGSEGV, &act, NULL);
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
#define HAVE_GNAT_INIT_FLOAT
void
__gnat_init_float (void)
{
/* Disable overflow/underflow exceptions on the PPC processor, needed
to get correct Ada semantics. Note that for AE653 vThreads, the HW
overflow settings are an OS configuration issue. The instructions
below have no effect. */
#if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && (!defined (VTHREADS) || defined (__VXWORKSMILS__))
#if defined (__SPE__)
{
const unsigned long spefscr_mask = 0xfffffff3;
unsigned long spefscr;
asm ("mfspr %0, 512" : "=r" (spefscr));
spefscr = spefscr & spefscr_mask;
asm ("mtspr 512, %0\n\tisync" : : "r" (spefscr));
}
#else
asm ("mtfsb0 25");
asm ("mtfsb0 26");
#endif
#endif
#if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
/* This is used to properly initialize the FPU on an x86 for each
process thread. */
asm ("finit");
#endif
/* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
field of the Floating-point Status Register (see the SPARC Architecture
Manual Version 9, p 48). */
#if defined (sparc64)
#define FSR_TEM_NVM (1 << 27) /* Invalid operand */
#define FSR_TEM_OFM (1 << 26) /* Overflow */
#define FSR_TEM_UFM (1 << 25) /* Underflow */
#define FSR_TEM_DZM (1 << 24) /* Division by Zero */
#define FSR_TEM_NXM (1 << 23) /* Inexact result */
{
unsigned int fsr;
__asm__("st %%fsr, %0" : "=m" (fsr));
fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
__asm__("ld %0, %%fsr" : : "m" (fsr));
}
#endif
}
/* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
(if not null) when a new task is created. It is initialized by
System.Stack_Checking.Operations.Initialize_Stack_Limit.
The use of a hook avoids to drag stack checking subprograms if stack
checking is not used. */
void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0;
/******************/
/* NetBSD Section */
/******************/
#elif defined(__NetBSD__)
#include
#include
static void
__gnat_error_handler (int sig)
{
struct Exception_Data *exception;
const char *msg;
switch(sig)
{
case SIGFPE:
exception = &constraint_error;
msg = "SIGFPE";
break;
case SIGILL:
exception = &constraint_error;
msg = "SIGILL";
break;
case SIGSEGV:
exception = &storage_error;
msg = "stack overflow or erroneous memory access";
break;
case SIGBUS:
exception = &constraint_error;
msg = "SIGBUS";
break;
default:
exception = &program_error;
msg = "unhandled signal";
}
Raise_From_Signal_Handler(exception, msg);
}
void
__gnat_install_handler(void)
{
struct sigaction act;
act.sa_handler = __gnat_error_handler;
act.sa_flags = SA_NODEFER | SA_RESTART;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/*******************/
/* OpenBSD Section */
/*******************/
#elif defined(__OpenBSD__)
#include
#include
static void
__gnat_error_handler (int sig)
{
struct Exception_Data *exception;
const char *msg;
switch(sig)
{
case SIGFPE:
exception = &constraint_error;
msg = "SIGFPE";
break;
case SIGILL:
exception = &constraint_error;
msg = "SIGILL";
break;
case SIGSEGV:
exception = &storage_error;
msg = "stack overflow or erroneous memory access";
break;
case SIGBUS:
exception = &constraint_error;
msg = "SIGBUS";
break;
default:
exception = &program_error;
msg = "unhandled signal";
}
Raise_From_Signal_Handler(exception, msg);
}
void
__gnat_install_handler(void)
{
struct sigaction act;
act.sa_handler = __gnat_error_handler;
act.sa_flags = SA_NODEFER | SA_RESTART;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System" */
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
/******************/
/* Darwin Section */
/******************/
#elif defined(__APPLE__)
#include
#include
#include
#include
#include
/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
char __gnat_alternate_stack[32 * 1024]; /* 1 * MINSIGSTKSZ */
/* Defined in xnu unix_signal.c.
Tell the kernel to re-use alt stack when delivering a signal. */
#define UC_RESET_ALT_STACK 0x80000000
/* Return true if ADDR is within a stack guard area. */
static int
__gnat_is_stack_guard (mach_vm_address_t addr)
{
kern_return_t kret;
vm_region_submap_info_data_64_t info;
mach_vm_address_t start;
mach_vm_size_t size;
natural_t depth;
mach_msg_type_number_t count;
count = VM_REGION_SUBMAP_INFO_COUNT_64;
start = addr;
size = -1;
depth = 9999;
kret = mach_vm_region_recurse (mach_task_self (), &start, &size, &depth,
(vm_region_recurse_info_t) &info, &count);
if (kret == KERN_SUCCESS
&& addr >= start && addr < (start + size)
&& info.protection == VM_PROT_NONE
&& info.user_tag == VM_MEMORY_STACK)
return 1;
return 0;
}
#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
void *ucontext ATTRIBUTE_UNUSED)
{
#if defined (__x86_64__)
/* Work around radar #10302855/pr50678, where the unwinders (libunwind or
libgcc_s depending on the system revision) and the DWARF unwind data for
the sigtramp have different ideas about register numbering (causing rbx
and rdx to be transposed).. */
ucontext_t *uc = (ucontext_t *)ucontext ;
unsigned long t = uc->uc_mcontext->__ss.__rbx;
uc->uc_mcontext->__ss.__rbx = uc->uc_mcontext->__ss.__rdx;
uc->uc_mcontext->__ss.__rdx = t;
#endif
}
static void
__gnat_error_handler (int sig, siginfo_t *si, void *ucontext)
{
struct Exception_Data *exception;
const char *msg;
__gnat_adjust_context_for_raise (sig, ucontext);
switch (sig)
{
case SIGSEGV:
case SIGBUS:
if (__gnat_is_stack_guard ((unsigned long)si->si_addr))
{
exception = &storage_error;
msg = "stack overflow";
}
else
{
exception = &constraint_error;
msg = "erroneous memory access";
}
/* Reset the use of alt stack, so that the alt stack will be used
for the next signal delivery.
The stack can't be used in case of stack checking. */
syscall (SYS_sigreturn, NULL, UC_RESET_ALT_STACK);
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 (void)
{
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 (and it is required by Darwin). */
stack_t stack;
stack.ss_sp = __gnat_alternate_stack;
stack.ss_size = sizeof (__gnat_alternate_stack);
stack.ss_flags = 0;
sigaltstack (&stack, NULL);
act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
act.sa_sigaction = __gnat_error_handler;
sigemptyset (&act.sa_mask);
/* Do not install handlers if interrupt state is "System". */
if (__gnat_get_interrupt_state (SIGABRT) != 's')
sigaction (SIGABRT, &act, NULL);
if (__gnat_get_interrupt_state (SIGFPE) != 's')
sigaction (SIGFPE, &act, NULL);
if (__gnat_get_interrupt_state (SIGILL) != 's')
sigaction (SIGILL, &act, NULL);
act.sa_flags |= SA_ONSTACK;
if (__gnat_get_interrupt_state (SIGSEGV) != 's')
sigaction (SIGSEGV, &act, NULL);
if (__gnat_get_interrupt_state (SIGBUS) != 's')
sigaction (SIGBUS, &act, NULL);
__gnat_handler_installed = 1;
}
#else
/* For all other versions of GNAT, the handler does nothing. */
/*******************/
/* Default Section */
/*******************/
void
__gnat_install_handler (void)
{
__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
and WIN32. */
#if defined (_WIN32) || defined (__INTERIX) \
|| defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
|| defined (__OpenBSD__)
#define HAVE_GNAT_INIT_FLOAT
void
__gnat_init_float (void)
{
#if defined (__i386__) || defined (i386) || defined (__x86_64)
/* 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 (void)
{
}
#endif
/***********************************/
/* __gnat_adjust_context_for_raise */
/***********************************/
#ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
/* All targets without a specific version will use an empty one. */
/* Given UCONTEXT a pointer to a context structure received by a signal
handler for SIGNO, perform the necessary adjustments to let the handler
raise an exception. Calls to this routine are not conditioned by the
propagation scheme in use. */
void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
void *ucontext ATTRIBUTE_UNUSED)
{
/* We used to compensate here for the raised from call vs raised from signal
exception discrepancy with the GCC ZCX scheme, but this now can be dealt
with generically in the unwinder (see GCC PR other/26208). This however
requires the use of the _Unwind_GetIPInfo routine in raise-gcc.c, which
is predicated on the definition of HAVE_GETIPINFO at compile time. Only
the VMS ports still do the compensation described in the few lines below.
*** Call vs signal exception discrepancy with GCC ZCX scheme ***
The GCC unwinder expects to be dealing with call return addresses, since
this is the "nominal" case of what we retrieve while unwinding a regular
call chain.
To evaluate if a handler applies at some point identified by a return
address, the propagation engine needs to determine what region the
corresponding call instruction pertains to. Because the return address
may not be attached to the same region as the call, the unwinder always
subtracts "some" amount from a return address to search the region
tables, amount chosen to ensure that the resulting address is inside the
call instruction.
When we raise an exception from a signal handler, e.g. to transform a
SIGSEGV into Storage_Error, things need to appear as if the signal
handler had been "called" by the instruction which triggered the signal,
so that exception handlers that apply there are considered. What the
unwinder will retrieve as the return address from the signal handler is
what it will find as the faulting instruction address in the signal
context pushed by the kernel. Leaving this address untouched looses, if
the triggering instruction happens to be the very first of a region, as
the later adjustments performed by the unwinder would yield an address
outside that region. We need to compensate for the unwinder adjustments
at some point, and this is what this routine is expected to do.
signo is passed because on some targets for some signals the PC in
context points to the instruction after the faulting one, in which case
the unwinder adjustment is still desired. */
}
#endif
#ifdef __cplusplus
}
#endif