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| author | Arnd Bergmann <arnd@arndb.de> | 2019-03-14 19:45:18 +0300 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2019-10-23 18:23:46 +0300 |
| commit | 98aaaec4a150c39219a8aaa68c3adc6eed443ea8 (patch) | |
| tree | 6d5f1f117ca3148888987d154411b07d51b837d7 /lib/iov_iter.c | |
| parent | b6dfb2477fb0bf48e31999d306d2552144891f6e (diff) | |
| download | linux-98aaaec4a150c39219a8aaa68c3adc6eed443ea8.tar.xz | |
compat_ioctl: reimplement SG_IO handling
There are two code locations that implement the SG_IO ioctl: the old
sg.c driver, and the generic scsi_ioctl helper that is in turn used by
multiple drivers.
To eradicate the old compat_ioctl conversion handler for the SG_IO
command, I implement a readable pair of put_sg_io_hdr() /get_sg_io_hdr()
helper functions that can be used for both compat and native mode,
and then I call this from both drivers.
For the iovec handling, there is already a compat_import_iovec() function
that can simply be called in place of import_iovec().
To avoid having to pass the compat/native state through multiple
indirections, I mark the SG_IO command itself as compatible in
fs/compat_ioctl.c and use in_compat_syscall() to figure out where
we are called from.
As a side-effect of this, the sg.c driver now also accepts the 32-bit
sg_io_hdr format in compat mode using the read/write interface, not
just ioctl. This should improve compatiblity with old 32-bit binaries,
but it would break if any application intentionally passes the 64-bit
data structure in compat mode here.
Steffen Maier helped debug an issue in an earlier version of this patch.
Cc: Steffen Maier <maier@linux.ibm.com>
Cc: linux-scsi@vger.kernel.org
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 639d5e7014c1..ffb52f2c0ef4 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1678,6 +1678,7 @@ ssize_t compat_import_iovec(int type, *iov = p == *iov ? NULL : p; return n; } +EXPORT_SYMBOL(compat_import_iovec); #endif int import_single_range(int rw, void __user *buf, size_t len, |