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#ifdef NEED_TRAP
#include <stdio.h>
#include "lutil.h"
#include "trap.h"
#ifdef TESTING
#define logerr printf
#else
#include "lutil.h"
#endif
#if defined(linux)
# ifndef __GLIBC__
# define ASC_LINUX_VERSION(V, P, S) (((V) * 65536) + ((P) * 256) + (S))
# include <linux/version.h>
# if LINUX_VERSION_CODE < ASC_LINUX_VERSION(2,1,0)
# define sigcontext sigcontext_struct
# endif
# define __KERNEL__
# include <linux/signal.h>
# undef __KERNEL__
# endif /* __GLIBC__ */
# ifdef __i386__
# define iBCS2
# else
# define SUNSTYLE
# endif /* __i386__ */
#elif defined(sun)
#define SUNSTYLE
#elif defined(SVR4)
#define SVR4STYLE
#endif
#include <signal.h>
#ifdef HAS_SYSLOG
#include <sys/types.h>
#include <unistd.h>
#include <syslog.h>
#endif
static char *nm="";
static struct _signames {
int sig;
char *name;
} signames[] =
{
#ifdef SIGSEGV
{SIGSEGV,"SIGSEGV"},
#endif
#ifdef SIGBUS
{SIGBUS,"SIGBUS"},
#endif
#ifdef SIGFPE
{SIGFPE,"SIGFPE"},
#endif
#ifdef SIGSTKFLT
{SIGSTKFLT,"SIGSTKFLT"},
#endif
{0,NULL}
};
static char *signame(sig)
int sig;
{
int i;
static char buf[8];
for (i=0;signames[i].name;i++)
if (signames[i].sig == sig) break;
if (signames[i].name) return signames[i].name;
sprintf(buf,"%d",sig);
return buf;
}
#if defined(iBCS2)
static void trap(sig,context)
int sig;
struct sigcontext context;
#elif defined(SVR4STYLE)
static void trap(sig,context)
int sig;
siginfo_t *si;
#elif defined(SUNSTYLE)
static void trap(sig,code,context,addr)
int sig;
int code;
struct sigcontext *context;
char *addr;
#else
static void trap(sig)
int sig;
#endif
{
#if defined(iBCS2)
long *stack;
#ifdef TESTING
int i;
printf("conext.gs=%04hx,%04hx\n",context.__gsh,context.gs);
printf("conext.fs=%04hx,%04hx\n",context.__fsh,context.fs);
printf("conext.es=%04hx,%04hx\n",context.__esh,context.es);
printf("conext.ds=%04hx,%04hx\n",context.__dsh,context.ds);
printf("conext.edi=%08lx\n",context.edi);
printf("conext.esi=%08lx\n",context.esi);
printf("conext.ebp=%08lx\n",context.ebp);
printf("conext.esp=%08lx\n",context.esp);
printf("conext.ebx=%08lx\n",context.ebx);
printf("conext.edx=%08lx\n",context.edx);
printf("conext.ecx=%08lx\n",context.ecx);
printf("conext.eax=%08lx\n",context.eax);
printf("conext.trapno=%08lx\n",context.trapno);
printf("conext.err=%08lx\n",context.err);
printf("conext.eip=%08lx\n",context.eip);
printf("conext.cs=%04hx,%04hx\n",context.__csh,context.cs);
printf("conext.eflags=%08lx\n",context.eflags);
printf("conext.esp_at_signal=%08lx\n",context.esp_at_signal);
printf("conext.ss=%04hx,%04hx\n",context.__ssh,context.ss);
printf("conext.i387=%08lx\n",context.i387);
printf("conext.oldmask=%08lx\n",context.oldmask);
printf("conext.cr2=%08lx\n",context.cr2);
stack=(long *)context.esp_at_signal;
for (i=-2;i<10;i++)
printf("stack %2d: 0x%08lx: 0x%08lx\n",i,(long)&(stack[i]),stack[i]);
#endif
signal(sig,SIG_DFL); /* for BSD compatibility, won't harm SysV */
logerr("caught %s at offset 0x%08lx",signame(sig),context.eip);
/*
Follows an awful, nasty kludge. The problem is that when
interrupt occurs in a function compiled with
-fomit-frame-pointer, there is no way (or at least I don't know
one) to catch the beginning of the stack frame chain. So, the
only thing I could think of is to scan the stack in search of a
value the _looks_like_ a frame chain pointer. Generally, this
approach may cause all kind of problems: from false backtrace
information to segfault inside the handler. If you know a
better way, _please_ make me know!
*/
for (stack=(long *)context.esp_at_signal;
stack && ((unsigned)((long *)stack[0]-stack) > 20);
stack++);
for (;stack && stack[1];stack=(long*)stack[0])
{
#ifdef TESTING
printf("\n[0x%08lx] next 0x%08lx, ret 0x%08lx ",(long)stack,
stack[0],stack[1]);
#endif
logerr("called from 0x%08lx",stack[1]);
}
#elif defined(SVR4STYLE)
if (context) psiginfo(si,nm);
else psignal(sig,nm);
#elif defined(SUNSTYLE)
logerr("caught %s at offset 0x%08lx",signame(sig),addr);
#else
#warning Cannot provide detailed info on this architecture
logerr("caught %s",signame(sig));
psignal(sig,nm);
#endif
#ifdef HAS_SYSLOG
debug(2,"closing syslog");
closelog();
#endif
#ifdef TESTING
printf("\n");
#else
abort(); /* stupid, but BSD will cycle otherwise */
#endif
return;
}
void catch(name)
char *name;
{
int i=0;
nm=name;
for (i=0;signames[i].name;i++)
debug(2,"catch: signal(%d) return %d",
signames[i].sig,signal(signames[i].sig,trap));
return;
}
#ifdef TESTING
void faulty(s)
int *s;
{
int w=1234;
memcpy(s,&w,sizeof(int));
*s=1234;
return;
}
int good(s)
int *s;
{
faulty(s);
return 0;
}
int main()
{
int *s=NULL;
int i;
catch("trap test");
printf("\nbefore fault\n");
i=good(s);
printf("\nafter fault\n");
return 0;
}
#endif /* TESTING */
#endif /* NEED_TRAP */
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