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#include "config.h"
#define _GNU_SOURCE 1
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/ptrace.h>
#include "common.h"
static Event event;
Event *
next_event(void) {
pid_t pid;
int status;
int tmp;
int stop_signal;
debug(DEBUG_FUNCTION, "next_event()");
if (!list_of_processes) {
debug(DEBUG_EVENT, "event: No more traced programs: exiting");
exit(0);
}
pid = waitpid(-1, &status, __WALL);
if (pid == -1) {
if (errno == ECHILD) {
debug(DEBUG_EVENT, "event: No more traced programs: exiting");
exit(0);
} else if (errno == EINTR) {
debug(DEBUG_EVENT, "event: none (wait received EINTR?)");
event.type = EVENT_NONE;
return &event;
}
perror("wait");
exit(1);
}
event.proc = pid2proc(pid);
if (!event.proc || event.proc->state == STATE_BEING_CREATED) {
event.type = EVENT_NEW;
event.e_un.newpid = pid;
debug(DEBUG_EVENT, "event: NEW: pid=%d", pid);
return &event;
}
get_arch_dep(event.proc);
event.proc->instruction_pointer = NULL;
debug(3, "event from pid %u", pid);
if (event.proc->breakpoints_enabled == -1) {
enable_all_breakpoints(event.proc);
event.type = EVENT_NONE;
trace_set_options(event.proc, event.proc->pid);
continue_process(event.proc->pid);
debug(DEBUG_EVENT, "event: NONE: pid=%d (enabling breakpoints)", pid);
return &event;
}
if (opt_i) {
event.proc->instruction_pointer =
get_instruction_pointer(event.proc);
}
switch (syscall_p(event.proc, status, &tmp)) {
case 1:
event.type = EVENT_SYSCALL;
event.e_un.sysnum = tmp;
debug(DEBUG_EVENT, "event: SYSCALL: pid=%d, sysnum=%d", pid, tmp);
return &event;
case 2:
event.type = EVENT_SYSRET;
event.e_un.sysnum = tmp;
debug(DEBUG_EVENT, "event: SYSRET: pid=%d, sysnum=%d", pid, tmp);
return &event;
case 3:
event.type = EVENT_ARCH_SYSCALL;
event.e_un.sysnum = tmp;
debug(DEBUG_EVENT, "event: ARCH_SYSCALL: pid=%d, sysnum=%d", pid, tmp);
return &event;
case 4:
event.type = EVENT_ARCH_SYSRET;
event.e_un.sysnum = tmp;
debug(DEBUG_EVENT, "event: ARCH_SYSRET: pid=%d, sysnum=%d", pid, tmp);
return &event;
case -1:
event.type = EVENT_NONE;
continue_process(event.proc->pid);
debug(DEBUG_EVENT, "event: NONE: pid=%d (syscall_p returned -1)", pid);
return &event;
}
if (WIFSTOPPED(status) && ((status>>16 == PTRACE_EVENT_FORK) || (status>>16 == PTRACE_EVENT_VFORK) || (status>>16 == PTRACE_EVENT_CLONE))) {
unsigned long data;
ptrace(PTRACE_GETEVENTMSG, pid, NULL, &data);
event.type = EVENT_CLONE;
event.e_un.newpid = data;
debug(DEBUG_EVENT, "event: CLONE: pid=%d, newpid=%d", pid, (int)data);
return &event;
}
if (WIFSTOPPED(status) && (status>>16 == PTRACE_EVENT_EXEC)) {
event.type = EVENT_EXEC;
debug(DEBUG_EVENT, "event: EXEC: pid=%d", pid);
return &event;
}
if (WIFEXITED(status)) {
event.type = EVENT_EXIT;
event.e_un.ret_val = WEXITSTATUS(status);
debug(DEBUG_EVENT, "event: EXIT: pid=%d, status=%d", pid, event.e_un.ret_val);
return &event;
}
if (WIFSIGNALED(status)) {
event.type = EVENT_EXIT_SIGNAL;
event.e_un.signum = WTERMSIG(status);
debug(DEBUG_EVENT, "event: EXIT_SIGNAL: pid=%d, signum=%d", pid, event.e_un.signum);
return &event;
}
if (!WIFSTOPPED(status)) {
/* should never happen */
event.type = EVENT_NONE;
debug(DEBUG_EVENT, "event: NONE: pid=%d (wait error?)", pid);
return &event;
}
stop_signal = WSTOPSIG(status);
/* On some targets, breakpoints are signalled not using
SIGTRAP, but also with SIGILL, SIGSEGV or SIGEMT. Check
for these. (TODO: is this true?) */
if (stop_signal == SIGSEGV
|| stop_signal == SIGILL
#ifdef SIGEMT
|| stop_signal == SIGEMT
#endif
) {
if (!event.proc->instruction_pointer) {
event.proc->instruction_pointer =
get_instruction_pointer(event.proc);
}
if (address2bpstruct(event.proc, event.proc->instruction_pointer))
stop_signal = SIGTRAP;
}
if (stop_signal != (SIGTRAP | event.proc->tracesysgood)
&& stop_signal != SIGTRAP) {
event.type = EVENT_SIGNAL;
event.e_un.signum = stop_signal;
debug(DEBUG_EVENT, "event: SIGNAL: pid=%d, signum=%d", pid, stop_signal);
return &event;
}
/* last case [by exhaustion] */
event.type = EVENT_BREAKPOINT;
if (!event.proc->instruction_pointer) {
event.proc->instruction_pointer =
get_instruction_pointer(event.proc);
}
event.e_un.brk_addr =
event.proc->instruction_pointer - DECR_PC_AFTER_BREAK;
debug(DEBUG_EVENT, "event: BREAKPOINT: pid=%d, addr=%p", pid, event.e_un.brk_addr);
return &event;
}
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