From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH 16/17] y2038: Make compat_sys_rt_sigtimedwait usable on 32-bit Date: Wed, 25 Apr 2018 18:03:10 +0200 Message-ID: <20180425160311.2718314-17-arnd@arndb.de> References: <20180425160311.2718314-1-arnd@arndb.de> Cc: Arnd Bergmann , 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 , Darren Hart , "Eric W. Biederman" , Dominik Brodowski To: y2038@lists.linaro.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <20180425160311.2718314-1-arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- 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