114 lines
2.9 KiB
C
Executable file
114 lines
2.9 KiB
C
Executable file
/*
|
|
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/sched.h>
|
|
#include <asm/siginfo.h>
|
|
#include <asm/signal.h>
|
|
#include <asm/unistd.h>
|
|
#include <frame_kern.h>
|
|
#include <kern_util.h>
|
|
|
|
EXPORT_SYMBOL(block_signals);
|
|
EXPORT_SYMBOL(unblock_signals);
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
sigset_t *oldset = sigmask_to_save();
|
|
int singlestep = 0;
|
|
unsigned long sp;
|
|
int err;
|
|
|
|
if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
|
|
singlestep = 1;
|
|
|
|
/* Did we come from a system call? */
|
|
if (PT_REGS_SYSCALL_NR(regs) >= 0) {
|
|
/* If so, check system call restarting.. */
|
|
switch (PT_REGS_SYSCALL_RET(regs)) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
PT_REGS_SYSCALL_RET(regs) = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
|
|
PT_REGS_SYSCALL_RET(regs) = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
|
|
break;
|
|
}
|
|
}
|
|
|
|
sp = PT_REGS_SP(regs);
|
|
if ((ksig->ka.sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
|
|
sp = current->sas_ss_sp + current->sas_ss_size;
|
|
|
|
#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
|
|
if (!(ksig->ka.sa.sa_flags & SA_SIGINFO))
|
|
err = setup_signal_stack_sc(sp, ksig, regs, oldset);
|
|
else
|
|
#endif
|
|
err = setup_signal_stack_si(sp, ksig, regs, oldset);
|
|
|
|
signal_setup_done(err, ksig, singlestep);
|
|
}
|
|
|
|
void do_signal(struct pt_regs *regs)
|
|
{
|
|
struct ksignal ksig;
|
|
int handled_sig = 0;
|
|
|
|
while (get_signal(&ksig)) {
|
|
handled_sig = 1;
|
|
/* Whee! Actually deliver the signal. */
|
|
handle_signal(&ksig, regs);
|
|
}
|
|
|
|
/* Did we come from a system call? */
|
|
if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
|
|
/* Restart the system call - no handlers present */
|
|
switch (PT_REGS_SYSCALL_RET(regs)) {
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
break;
|
|
case -ERESTART_RESTARTBLOCK:
|
|
PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This closes a way to execute a system call on the host. If
|
|
* you set a breakpoint on a system call instruction and singlestep
|
|
* from it, the tracing thread used to PTRACE_SINGLESTEP the process
|
|
* rather than PTRACE_SYSCALL it, allowing the system call to execute
|
|
* on the host. The tracing thread will check this flag and
|
|
* PTRACE_SYSCALL if necessary.
|
|
*/
|
|
if (current->ptrace & PT_DTRACE)
|
|
current->thread.singlestep_syscall =
|
|
is_syscall(PT_REGS_IP(¤t->thread.regs));
|
|
|
|
/*
|
|
* if there's no signal to deliver, we just put the saved sigmask
|
|
* back
|
|
*/
|
|
if (!handled_sig)
|
|
restore_saved_sigmask();
|
|
}
|