On Thu, Jan 2, 2020 at 10:16 AM Arnd Bergmann arnd@arndb.de wrote:
On Tue, Dec 24, 2019 at 9:45 AM Christoph Hellwig hch@infradead.org wrote:
On Wed, Dec 18, 2019 at 05:39:29PM +0100, Arnd Bergmann wrote:
+/* disallow y2038-unsafe ioctls with CONFIG_COMPAT_32BIT_TIME=n */ +static bool xfs_have_compat_bstat_time32(unsigned int cmd) +{
if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))return true;if (IS_ENABLED(CONFIG_64BIT) && !in_compat_syscall())return true;if (cmd == XFS_IOC_FSBULKSTAT_SINGLE ||cmd == XFS_IOC_FSBULKSTAT ||cmd == XFS_IOC_SWAPEXT)return false;return true;I think the check for the individual command belongs into the callers, which laves us with:
static inline bool have_time32(void) { return IS_ENABLED(CONFIG_COMPAT_32BIT_TIME) || (IS_ENABLED(CONFIG_64BIT) && !in_compat_syscall()); }
and that looks like it should be in a generic helper somewhere.
Yes, makes sense.
I was going for something XFS specific here because XFS is unique in the kernel in completely deprecating a set of ioctl commands (replacing the old interface with a v5) rather than allowing the user space to be compiled with 64-bit time_t.
I tried adding the helper now but ran into a stupid problem: the best place to put it would be linux/time32.h, but then I have to include linux/compat.h from there, which in turn pulls in tons of other headers in any file using linux/time.h.
I considered making it a macro instead, but that's also really ugly.
I now think we should just defer this change until after v5.6, once I have separated linux/time.h from linux/time32.h. In the meantime I'll resend the other two patches that I know we need in v5.6 in order to get there, so Darrick can apply them to his tree.
Arnd