[PATCH 5/5] y2038: signal: Add compat_sys_rt_sigtimedwait_time64

From: Arnd Bergmann
Date: Fri Dec 07 2018 - 16:18:27 EST


Now that 32-bit architectures have two variants of sys_rt_sigtimedwaid()
for 32-bit and 64-bit time_t, we also need to have a second compat system
call entry point on the corresponding 64-bit architectures.

The traditional system call keeps getting handled
by compat_sys_rt_sigtimedwait(), and this adds a new
compat_sys_rt_sigtimedwait_time64() that differs only in the timeout
argument type.

The naming remains a bit asymmetric for the moment. Ideally we would
want to have compat_sys_rt_sigtimedwait_time32() for the old version
and compat_sys_rt_sigtimedwait() for the new one to mirror the names
of the native entry points, but renaming the existing system call
tables causes unnecessary churn. I would suggest renaming all such
system calls together at a later point.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
include/linux/compat.h | 3 +++
kernel/signal.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 72969d303434..3bc5f218efd8 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -788,6 +788,9 @@ asmlinkage long compat_sys_rt_sigpending(compat_sigset_t __user *uset,
asmlinkage long compat_sys_rt_sigtimedwait(compat_sigset_t __user *uthese,
struct compat_siginfo __user *uinfo,
struct old_timespec32 __user *uts, compat_size_t sigsetsize);
+asmlinkage long compat_sys_rt_sigtimedwait_time64(compat_sigset_t __user *uthese,
+ struct compat_siginfo __user *uinfo,
+ struct __kernel_timespec __user *uts, compat_size_t sigsetsize);
asmlinkage long compat_sys_rt_sigqueueinfo(compat_pid_t pid, int sig,
struct compat_siginfo __user *uinfo);
/* No generic prototype for rt_sigreturn */
diff --git a/kernel/signal.c b/kernel/signal.c
index be6744cd0a11..53e07d97ffe0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3366,6 +3366,37 @@ SYSCALL_DEFINE4(rt_sigtimedwait_time32, const sigset_t __user *, uthese,
#endif

#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time64, compat_sigset_t __user *, uthese,
+ struct compat_siginfo __user *, uinfo,
+ struct __kernel_timespec __user *, uts, compat_size_t, sigsetsize)
+{
+ sigset_t s;
+ struct timespec64 t;
+ kernel_siginfo_t info;
+ long ret;
+
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+
+ if (get_compat_sigset(&s, uthese))
+ return -EFAULT;
+
+ if (uts) {
+ if (get_timespec64(&t, uts))
+ return -EFAULT;
+ }
+
+ ret = do_sigtimedwait(&s, &info, uts ? &t : NULL);
+
+ if (ret > 0 && uinfo) {
+ if (copy_siginfo_to_user32(uinfo, &info))
+ ret = -EFAULT;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
struct compat_siginfo __user *, uinfo,
struct old_timespec32 __user *, uts, compat_size_t, sigsetsize)
@@ -3396,6 +3427,7 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
return ret;
}
#endif
+#endif

/**
* sys_kill - send a signal to a process
--
2.18.0