diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2009-04-03 00:36:27 -0700 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2009-11-06 03:52:55 -0800 |
| commit | da3f6f9b3e0d1e73975ca81ae124406bf1587d40 (patch) | |
| tree | ab2e5bb6366b0bdc00ec1bc5c02e610c1c77195d /kernel | |
| parent | 2830b68361a9f58354ad043c6d85043ea917f907 (diff) | |
sysctl: Introduce a generic compat sysctl sysctl
This uses compat_alloc_userspace to remove the various
hacks to allow do_sysctl to write to throuh oldlenp.
The rest of our mature compat syscall helper facitilies
are used as well to ensure we have a nice clean maintainable
compat syscall that can be used on all architectures.
The motiviation for a generic compat sysctl (besides the
obvious hack removal) is to reduce the number of compat
sysctl defintions out there so I can refactor the
binary sysctl implementation.
ppc already used the name compat_sys_sysctl so I remove the
ppcs version here.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sysctl_binary.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c index 930a31cd708..775cc49da62 100644 --- a/kernel/sysctl_binary.c +++ b/kernel/sysctl_binary.c @@ -176,3 +176,53 @@ SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args) return error; } + +#ifdef CONFIG_COMPAT +#include <asm/compat.h> + +struct compat_sysctl_args { + compat_uptr_t name; + int nlen; + compat_uptr_t oldval; + compat_uptr_t oldlenp; + compat_uptr_t newval; + compat_size_t newlen; + compat_ulong_t __unused[4]; +}; + +asmlinkage long compat_sys_sysctl(struct compat_sysctl_args __user *args) +{ + struct compat_sysctl_args tmp; + compat_size_t __user *compat_oldlenp; + size_t __user *oldlenp = NULL; + size_t oldlen = 0; + ssize_t result; + + if (copy_from_user(&tmp, args, sizeof(tmp))) + return -EFAULT; + + compat_oldlenp = compat_ptr(tmp.oldlenp); + if (compat_oldlenp) { + oldlenp = compat_alloc_user_space(sizeof(*compat_oldlenp)); + + if (get_user(oldlen, compat_oldlenp) || + put_user(oldlen, oldlenp)) + return -EFAULT; + } + + lock_kernel(); + result = do_sysctl(compat_ptr(tmp.name), tmp.nlen, + compat_ptr(tmp.oldval), oldlenp, + compat_ptr(tmp.newval), tmp.newlen); + unlock_kernel(); + + if (oldlenp && !result) { + if (get_user(oldlen, oldlenp) || + put_user(oldlen, compat_oldlenp)) + return -EFAULT; + } + + return result; +} + +#endif /* CONFIG_COMPAT */ |