fpm_trace_ptrace.c

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    /* (c) 2007,2008 Andrei Nigmatulin */
 
#include "fpm_config.h"
 
#include <sys/wait.h>
#include <sys/ptrace.h>
#include <unistd.h>
#include <errno.h>
 
#if defined(PT_ATTACH) && !defined(PTRACE_ATTACH)
#define PTRACE_ATTACH PT_ATTACH
#endif
 
#if defined(PT_DETACH) && !defined(PTRACE_DETACH)
#define PTRACE_DETACH PT_DETACH
#endif
 
#if defined(PT_READ_D) && !defined(PTRACE_PEEKDATA)
#define PTRACE_PEEKDATA PT_READ_D
#endif
 
#include "fpm_trace.h"
#include "zlog.h"
 
static pid_t traced_pid;
 
int fpm_trace_signal(pid_t pid) /* {{{ */
{
    if (0 > ptrace(PTRACE_ATTACH, pid, 0, 0)) {
        zlog(ZLOG_SYSERROR, "failed to ptrace(ATTACH) child %d", pid);
        return -1;
    }
    return 0;
}
/* }}} */
 
int fpm_trace_ready(pid_t pid) /* {{{ */
{
    traced_pid = pid;
    return 0;
}
/* }}} */
 
int fpm_trace_close(pid_t pid) /* {{{ */
{
    if (0 > ptrace(PTRACE_DETACH, pid, (void *) 1, 0)) {
        zlog(ZLOG_SYSERROR, "failed to ptrace(DETACH) child %d", pid);
        return -1;
    }
    traced_pid = 0;
    return 0;
}
/* }}} */
 
int fpm_trace_get_long(long addr, long *data) /* {{{ */
{
#ifdef PT_IO
    struct ptrace_io_desc ptio = {
        .piod_op = PIOD_READ_D,
        .piod_offs = (void *) addr,
        .piod_addr = (void *) data,
        .piod_len = sizeof(long)
    };
 
    if (0 > ptrace(PT_IO, traced_pid, (void *) &ptio, 0)) {
        zlog(ZLOG_SYSERROR, "failed to ptrace(PT_IO) pid %d", traced_pid);
        return -1;
    }
#else
    errno = 0;
    *data = ptrace(PTRACE_PEEKDATA, traced_pid, (void *) addr, 0);
    if (errno) {
        zlog(ZLOG_SYSERROR, "failed to ptrace(PEEKDATA) pid %d", traced_pid);
        return -1;
    }
#endif
    return 0;
}
/* }}} */