Merge branch 'uverbs_dev_cleanups' into rdma.git for-next

For dependencies, branch based on rdma.git 'for-rc' of
https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/

Pull 'uverbs_dev_cleanups' from Leon Romanovsky:

====================
Reuse the char device code interfaces to simplify ib_uverbs_device
creation and destruction. As part of this series, we are sending fix to
cleanup path, which was discovered during internal review,

The fix definitely can go to -rc, but it means that this series will be
dependent on rdma-rc.
====================

* branch 'uverbs_dev_cleanups':
  RDMA/uverbs: Use device.groups to initialize device attributes
  RDMA/uverbs: Use cdev_device_add() instead of cdev_add()
  RDMA/core: Depend on device_add() to add device attributes
  RDMA/uverbs: Fix error cleanup path of ib_uverbs_add_one()

Resolved conflict in ib_device_unregister_sysfs()

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 8d6c34fe49be..51a5a69ecac9 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1420,6 +1420,29 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
         return 0;
 }
 
+/*
+ * Machine check recovery code needs to change cache mode of poisoned
+ * pages to UC to avoid speculative access logging another error. But
+ * passing the address of the 1:1 mapping to set_memory_uc() is a fine
+ * way to encourage a speculative access. So we cheat and flip the top
+ * bit of the address. This works fine for the code that updates the
+ * page tables. But at the end of the process we need to flush the cache
+ * and the non-canonical address causes a #GP fault when used by the
+ * CLFLUSH instruction.
+ *
+ * But in the common case we already have a canonical address. This code
+ * will fix the top bit if needed and is a no-op otherwise.
+ */
+static inline unsigned long make_addr_canonical_again(unsigned long addr)
+{
+#ifdef CONFIG_X86_64
+        return (long)(addr << 1) >> 1;
+#else
+        return addr;
+#endif
+}
+
+
 static int change_page_attr_set_clr(unsigned long *addr, int numpages,
                                     pgprot_t mask_set, pgprot_t mask_clr,
                                     int force_split, int in_flag,
@@ -1465,7 +1488,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
                  * Save address for cache flush. *addr is modified in the call
                  * to __change_page_attr_set_clr() below.
                  */
-                baddr = *addr;
+                baddr = make_addr_canonical_again(*addr);
         }
 
         /* Must avoid aliasing mappings in the highmem code */