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From: Arnd Bergmann <arnd@arndb.de>
To: y2038@lists.linaro.org, linux-kernel@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>,
	linux-api@vger.kernel.org, linux-arch@vger.kernel.org,
	libc-alpha@sourceware.org, tglx@linutronix.de,
	netdev@vger.kernel.org, deepa.kernel@gmail.com,
	viro@zeniv.linux.org.uk, albert.aribaud@3adev.fr,
	Peter Zijlstra <peterz@infradead.org>,
	Darren Hart <dvhart@infradead.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Dominik Brodowski <linux@dominikbrodowski.net>
Subject: [PATCH 16/17] y2038: Make compat_sys_rt_sigtimedwait usable on 32-bit
Date: Wed, 25 Apr 2018 18:03:10 +0200	[thread overview]
Message-ID: <20180425160311.2718314-17-arnd@arndb.de> (raw)
In-Reply-To: <20180425160311.2718314-1-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 d8d68a9556ae..72609c6835fd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3104,7 +3104,22 @@ 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
@@ -3202,7 +3217,7 @@ 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

  parent reply	other threads:[~2018-04-25 16:03 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-25 16:02 [PATCH 00/17] y2038: system calls, part 3 Arnd Bergmann
2018-04-25 16:02 ` [PATCH 01/17] y2038: compat: Move common compat types to asm-generic/compat.h Arnd Bergmann
2018-04-25 16:02 ` [PATCH 02/17] y2038: Remove newstat family from default syscall set Arnd Bergmann
2018-04-25 18:36   ` Geert Uytterhoeven
2018-04-25 16:02 ` [PATCH 03/17] y2038: Remove stat64 " Arnd Bergmann
2018-04-25 16:02 ` [PATCH 04/17] asm-generic: Remove unneeded __ARCH_WANT_SYS_LLSEEK macro Arnd Bergmann
2018-04-25 18:36   ` Geert Uytterhoeven
2018-04-25 16:02 ` [PATCH 05/17] asm-generic: Remove empty asm/unistd.h Arnd Bergmann
2018-04-25 16:03 ` [PATCH 06/17] y2038: Change sys_utimensat() to use __kernel_timespec Arnd Bergmann
2018-04-25 16:03 ` [PATCH 07/17] y2038: Compile utimes()/futimesat() conditionally Arnd Bergmann
2018-04-25 16:03 ` [PATCH 08/17] y2038: utimes: Rework #ifdef guards for compat syscalls Arnd Bergmann
2018-04-25 16:03 ` [PATCH 09/17] y2038: futex: Move compat implementation into futex.c Arnd Bergmann
2018-04-25 16:03 ` [PATCH 10/17] y2038: futex: Add support for __kernel_timespec Arnd Bergmann
2018-04-25 16:03 ` [PATCH 11/17] y2038: Prepare sched_rr_get_interval " Arnd Bergmann
2018-04-25 16:03 ` [PATCH 12/17] y2038: aio: Prepare sys_io_getevents " Arnd Bergmann
2018-04-25 16:03 ` [PATCH 13/17] y2038: socket: Convert recvmmsg to __kernel_timespec Arnd Bergmann
2018-04-25 16:03 ` [PATCH 14/17] y2038: socket: Add compat_sys_recvmmsg_time64 Arnd Bergmann
2018-04-25 16:03 ` [PATCH 15/17] y2038: signal: Change rt_sigtimedwait to use __kernel_timespec Arnd Bergmann
2018-04-25 16:03 ` Arnd Bergmann [this message]
2018-04-25 16:03 ` [PATCH 17/17] y2038: signal: Add compat_sys_rt_sigtimedwait_time64 Arnd Bergmann

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