diff options
Diffstat (limited to 'gcc/ada/init.c')
| -rw-r--r-- | gcc/ada/init.c | 64 |
1 files changed, 56 insertions, 8 deletions
diff --git a/gcc/ada/init.c b/gcc/ada/init.c index c8de26b..d7653c7 100644 --- a/gcc/ada/init.c +++ b/gcc/ada/init.c @@ -1665,8 +1665,6 @@ __gnat_install_handler () #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. */ @@ -1677,7 +1675,7 @@ extern int __gnat_inum_to_ivec (int); int __gnat_inum_to_ivec (int num) { - return INUM_TO_IVEC (num); + return (int) INUM_TO_IVEC (num); } #endif @@ -1711,8 +1709,8 @@ __gnat_clear_exception_count (void) /* 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) +__gnat_map_signal (int sig, siginfo_t *si ATTRIBUTE_UNUSED, + void *sc ATTRIBUTE_UNUSED) { struct Exception_Data *exception; const char *msg; @@ -1799,6 +1797,56 @@ __gnat_map_signal (int sig, void *si ATTRIBUTE_UNUSED, msg = "unhandled signal"; } + /* On ARM VxWorks 6.x, the guard page is left in a RWX state by the kernel + after being violated, so subsequent violations aren't detected. Even if + this defect is fixed, it seems dubious to rely on the signal value alone, + so we retrieve the address of the guard page from the TCB and compare it + with the page that is violated (pREG 12 in the context) and re-arm that + page if there's a match. Additionally we're are assured this is a + genuine stack overflow condition and and set the message and exception + to that effect. */ +#if defined (ARMEL) && (_WRS_VXWORKS_MAJOR == 6) + + /* We re-arm the guard page by re-setting it's attributes, however the + protection bits are just the low order seven (0x3f). + 0x00040 is the Valid Mask + 0x00f00 are Cache attributes + 0xff000 are Special attributes + We don't meddle with the 0xfff40 attributes. */ + +#define PAGE_SIZE 4096 +#define MMU_ATTR_PROT_MSK 0x0000003f /* Protection Mask. */ +#define GUARD_PAGE_PROT 0x8101 /* Found by experiment. */ + + if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL) + { + TASK_ID tid = taskIdSelf (); + WIND_TCB *pTcb = taskTcb (tid); + unsigned long Violated_Page + = ((struct sigcontext *) sc)->sc_pregs->r[12] & ~(PAGE_SIZE - 1); + + if ((unsigned long) (pTcb->pStackEnd - PAGE_SIZE) == Violated_Page) + { + vmStateSet (NULL, Violated_Page, + PAGE_SIZE, MMU_ATTR_PROT_MSK, GUARD_PAGE_PROT); + exception = &storage_error; + + switch (sig) + { + case SIGSEGV: + msg = "SIGSEGV: stack overflow"; + break; + case SIGBUS: + msg = "SIGBUS: stack overflow"; + break; + case SIGILL: + msg = "SIGILL: stack overflow"; + break; + } + } + } +#endif /* defined (ARMEL) && (_WRS_VXWORKS_MAJOR == 6) */ + __gnat_clear_exception_count (); Raise_From_Signal_Handler (exception, msg); } @@ -1806,8 +1854,8 @@ __gnat_map_signal (int sig, void *si ATTRIBUTE_UNUSED, /* 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) +static void +__gnat_error_handler (int sig, siginfo_t *si, void *sc) { sigset_t mask; @@ -1865,7 +1913,7 @@ __gnat_install_handler (void) 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_sigaction = __gnat_error_handler; act.sa_flags = SA_SIGINFO | SA_ONSTACK; sigemptyset (&act.sa_mask); |