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authorOleg Drokin <green@linuxhacker.ru>2017-05-26 23:40:33 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-14 12:54:18 +0200
commit1bd1abfad7a72826ed56e75385b87f3518eb2351 (patch)
tree3e6b036cee90a65e240043e6c8d64e5a3b5bc4cc
parent0d335f5b5194d931d52fd3b9633375c5aa183316 (diff)
staging/lustre/lov: remove set_fs() call from lov_getstripe()
commit 0a33252e060e97ed3fbdcec9517672f1e91aaef3 upstream. lov_getstripe() calls set_fs(KERNEL_DS) so that it can handle a struct lov_user_md pointer from user- or kernel-space. This changes the behavior of copy_from_user() on SPARC and may result in a misaligned access exception which in turn oopses the kernel. In fact the relevant argument to lov_getstripe() is never called with a kernel-space pointer and so changing the address limits is unnecessary and so we remove the calls to save, set, and restore the address limits. Signed-off-by: John L. Hammond <john.hammond@intel.com> Reviewed-on: http://review.whamcloud.com/6150 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3221 Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Reviewed-by: Li Wei <wei.g.li@intel.com> Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/staging/lustre/lustre/lov/lov_pack.c9
1 files changed, 0 insertions, 9 deletions
diff --git a/drivers/staging/lustre/lustre/lov/lov_pack.c b/drivers/staging/lustre/lustre/lov/lov_pack.c
index 5edd6a3a9c54..6826d705342a 100644
--- a/drivers/staging/lustre/lustre/lov/lov_pack.c
+++ b/drivers/staging/lustre/lustre/lov/lov_pack.c
@@ -420,18 +420,10 @@ int lov_getstripe(struct obd_export *exp, struct lov_stripe_md *lsm,
struct lov_mds_md *lmmk = NULL;
int rc, lmm_size;
int lum_size;
- mm_segment_t seg;
if (!lsm)
return -ENODATA;
- /*
- * "Switch to kernel segment" to allow copying from kernel space by
- * copy_{to,from}_user().
- */
- seg = get_fs();
- set_fs(KERNEL_DS);
-
/* we only need the header part from user space to get lmm_magic and
* lmm_stripe_count, (the header part is common to v1 and v3) */
lum_size = sizeof(struct lov_user_md_v1);
@@ -507,6 +499,5 @@ int lov_getstripe(struct obd_export *exp, struct lov_stripe_md *lsm,
obd_free_diskmd(exp, &lmmk);
out_set:
- set_fs(seg);
return rc;
}