fault.c File Reference

#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <atalk/logger.h>
#include <atalk/util.h>

Macros
#define	SIGNAL_CAST   (void (*)(int))
#define	SAFE_FREE(x)   do { if ((x) != NULL) {free(x); x=NULL;} } while(0)
#define	BACKTRACE_STACK_SIZE   64
#define	FAULT_ALTSTACK_SIZE   (64 * 1024)

Functions
static void	log_backtrace (void *uctx)
static void	panic_report (const char *why, void *uctx)
void	netatalk_panic (const char *why)
static void	fault_report (int sig, siginfo_t *info, void *uctx)
static void	sig_fault (int sig, siginfo_t *info, void *ctx)
static void	catch_fault_signal (int signum)
void	fault_setup_thread (void)
void	fault_setup (void(*fn)(void *))

Variables
static void(*	cont_fn )(void *)
static void(*)(int)	CatchSignal (int signum, void(*handler)(int))

Macro Definition Documentation

BACKTRACE_STACK_SIZE

#define BACKTRACE_STACK_SIZE   64

FAULT_ALTSTACK_SIZE

#define FAULT_ALTSTACK_SIZE   (64 * 1024)

SAFE_FREE

#define SAFE_FREE

(

x

)

do { if ((x) != NULL) {free(x); x=NULL;} } while(0)

SIGNAL_CAST

#define SIGNAL_CAST   (void (*)(int))

Function Documentation

catch_fault_signal()

static void catch_fault_signal ( int  signum )

static

Install sig_fault for a fault signal, on the alternate stack

SA_ONSTACK is required to report stack exhaustion: the guard page leaves no room for a signal frame, so without it the kernel cannot run the handler and kills the process with no diagnostic.

fault_report()

static void fault_report ( int  sig, siginfo_t *  info, void *  uctx  )

static

report a fault

fault_setup()

void fault_setup

(

void(*)(void *)

fn

)

setup our fault handlers

fault_setup_thread()

void fault_setup_thread

(

void

)

Give the calling thread its own alternate signal stack

sigaltstack() is per-thread and survives fork() but not pthread_create(), so a thread that exhausts its stack dies unreported unless it installs one.

log_backtrace()

static void log_backtrace ( void *  uctx )

static

Log a backtrace of the calling thread

libunwind names frames on musl, which ships no execinfo; the execinfo path stays for platforms that do. Deep runs of one frame are the signature of runaway recursion, so log enough of them to see it.

netatalk_panic()

void netatalk_panic

(

const char *

why

)

panic_report()

static void panic_report ( const char *  why, void *  uctx  )

static

Something really nasty happened - panic !

sig_fault()

static void sig_fault ( int  sig, siginfo_t *  info, void *  ctx  )

static

catch serious errors

Variable Documentation

CatchSignal

void(*)(int) CatchSignal(int signum, void(*handler)(int)) ( int  signum, void(*)(int)  handler  )

static

Catch a signal. This should implement the following semantics:

1. The handler remains installed after being called.
2. The signal should be blocked during handler execution.

cont_fn

void(* cont_fn) (void *) ( void *  )

static