Commit 4cd2e0e7 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

signal: Introduce copy_siginfo_from_user and use it's return value 



In preparation for using a smaller version of siginfo in the kernel
introduce copy_siginfo_from_user and use it when siginfo is copied from
userspace.

Make the pattern for using copy_siginfo_from_user and
copy_siginfo_from_user32 to capture the return value and return that
value on error.

This is a necessary prerequisite for using a smaller siginfo
in the kernel than the kernel exports to userspace.

Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent f2838018

include/linux/signal.h

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ static inline void clear_siginfo(struct siginfo *info) 
}



int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from);

int copy_siginfo_from_user(struct siginfo *to, const struct siginfo __user *from);



enum siginfo_layout {

	SIL_KILL,

kernel/ptrace.c

+5 −7
Original line number Diff line number Diff line
@@ -919,9 +919,8 @@ int ptrace_request(struct task_struct *child, long request, 
		break;



	case PTRACE_SETSIGINFO:

		if (copy_from_user(&siginfo, datavp, sizeof siginfo))

			ret = -EFAULT;

		else

		ret = copy_siginfo_from_user(&siginfo, datavp);

		if (!ret)

			ret = ptrace_setsiginfo(child, &siginfo);

		break;
@@ -1215,10 +1214,9 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, 
		break;



	case PTRACE_SETSIGINFO:

		if (copy_siginfo_from_user32(

			    &siginfo, (struct compat_siginfo __user *) datap))

			ret = -EFAULT;

		else

		ret = copy_siginfo_from_user32(

			&siginfo, (struct compat_siginfo __user *) datap);

		if (!ret)

			ret = ptrace_setsiginfo(child, &siginfo);

		break;

#ifdef CONFIG_HAVE_ARCH_TRACEHOOK

kernel/signal.c

+16 −9
Original line number Diff line number Diff line
@@ -2896,6 +2896,13 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) 
	return 0;

}



int copy_siginfo_from_user(siginfo_t *to, const siginfo_t __user *from)

{

	if (copy_from_user(to, from, sizeof(struct siginfo)))

		return -EFAULT;

	return 0;

}



#ifdef CONFIG_COMPAT

int copy_siginfo_to_user32(struct compat_siginfo __user *to,

			   const struct siginfo *from)
@@ -3323,8 +3330,9 @@ SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, 
		siginfo_t __user *, uinfo)

{

	siginfo_t info;

	if (copy_from_user(&info, uinfo, sizeof(siginfo_t)))

		return -EFAULT;

	int ret = copy_siginfo_from_user(&info, uinfo);

	if (unlikely(ret))

		return ret;

	return do_rt_sigqueueinfo(pid, sig, &info);

}
@@ -3365,10 +3373,9 @@ SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, 
		siginfo_t __user *, uinfo)

{

	siginfo_t info;



	if (copy_from_user(&info, uinfo, sizeof(siginfo_t)))

		return -EFAULT;



	int ret = copy_siginfo_from_user(&info, uinfo);

	if (unlikely(ret))

		return ret;

	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);

}
@@ -3380,9 +3387,9 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, 
			struct compat_siginfo __user *, uinfo)

{

	siginfo_t info;



	if (copy_siginfo_from_user32(&info, uinfo))

		return -EFAULT;

	int ret = copy_siginfo_from_user32(&info, uinfo);

	if (unlikely(ret))

		return ret;

	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);

}

#endif

CRA Git | Maintained and supported by SUSTech CRA and CCSE