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[PATCH v2 16/17] y2038: Make compat_sys_rt_sigtimedwait usable on 32-bit
- From: Arnd Bergmann <arnd at arndb dot de>
- To: tglx at linutronix dot de
- Cc: y2038 at lists dot linaro dot org, hch at infradead dot org, linux-api at vger dot kernel dot org, linux-arch at vger dot kernel dot org, libc-alpha at sourceware dot org, albert dot aribaud at 3adev dot fr, netdev at vger dot kernel dot org, viro at zeniv dot linux dot org dot uk, peterz at infradead dot org, dvhart at infradead dot org, ebiederm at xmission dot com, linux at dominikbrodowski dot net, Arnd Bergmann <arnd at arndb dot de>
- Date: Mon, 16 Jul 2018 18:11:02 +0200
- Subject: [PATCH v2 16/17] y2038: Make compat_sys_rt_sigtimedwait usable on 32-bit
- References: <20180716161103.16239-1-arnd@arndb.de>
Once sys_rt_sigtimedwait() gets changed to a 64-bit time_t, we have
to provide compatibility support for existing binaries. Using the
compat_sys_rt_sigtimedwait() entry point is convenient because it allows
to share the implementation with 64-bit architectures.
Unfortunately, the get_compat_sigset() and copy_siginfo_to_user32()
functions are used in that function, but we can replace them with
trivial helpers that do the same thing as before.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
kernel/signal.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/kernel/signal.c b/kernel/signal.c
index 0418a499b9f3..8d4382d5182f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3027,7 +3027,22 @@ int copy_siginfo_from_user32(struct siginfo *to,
}
return 0;
}
-#endif /* CONFIG_COMPAT */
+
+#else /* !CONFIG_COMPAT */
+
+/* 32-bit architectures only need to convert compat_time_t, not siginfo or sigset_t */
+
+#define compat_siginfo siginfo
+#define compat_sigset_t sigset_t
+#define copy_siginfo_to_user32 copy_siginfo_to_user
+static inline int get_compat_sigset(sigset_t *set, const sigset_t __user *compat)
+{
+ if (copy_from_user(set, compat, sizeof *set))
+ return -EFAULT;
+
+ return 0;
+}
+#endif /* !CONFIG_COMPAT */
/**
* do_sigtimedwait - wait for queued signals specified in @which
@@ -3125,7 +3140,7 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
return ret;
}
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_32BIT_TIME
COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
struct compat_siginfo __user *, uinfo,
struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
--
2.9.0