[PATCH 16/17] y2038: Make compat_sys_rt_sigtimedwait usable on 32-bit
From: Arnd Bergmann <arnd@arndb.de>
Date: 2018-04-25 16:05:19
Also in:
linux-arch, lkml, netdev
Subsystem:
the rest · Maintainer:
Linus Torvalds
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)
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2.9.0