Merge tag 'powerpc-5.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Three non-regression fixes.

   - Our optimised memcmp could read past the end of one of the buffers
     and potentially trigger a page fault leading to an oops.

   - Some of our code to read energy management data on PowerVM had an
     endian bug leading to bogus results.

   - When reporting a machine check exception we incorrectly reported
     TLB multihits as D-Cache multhits due to a missing entry in the
     array of causes.

  Thanks to: Chandan Rajendra, Gautham R. Shenoy, Mahesh Salgaonkar,
  Segher Boessenkool, Vaidyanathan Srinivasan"

* tag 'powerpc-5.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/mce: Fix misleading print for TLB mutlihit
  powerpc/pseries/energy: Use OF accessor functions to read ibm,drc-indexes
  powerpc/64: Fix memcmp reading past the end of src/dest

3 files changed, 32 insertions, 13 deletions

diff --git a/arch/powerpc/lib/memcmp_64.S b/arch/powerpc/lib/memcmp_64.S
index 844d8e774492..b7f6f6e0b6e8 100644
--- a/arch/powerpc/lib/memcmp_64.S
+++ b/arch/powerpc/lib/memcmp_64.S
@@ -215,11 +215,20 @@ _GLOBAL_TOC(memcmp)
         beq     .Lzero
 
 .Lcmp_rest_lt8bytes:
-        /* Here we have only less than 8 bytes to compare with. at least s1
-         * Address is aligned with 8 bytes.
-         * The next double words are load and shift right with appropriate
-         * bits.
+        /*
+         * Here we have less than 8 bytes to compare. At least s1 is aligned to
+         * 8 bytes, but s2 may not be. We must make sure s2 + 7 doesn't cross a
+         * page boundary, otherwise we might read past the end of the buffer and
+         * trigger a page fault. We use 4K as the conservative minimum page
+         * size. If we detect that case we go to the byte-by-byte loop.
+         *
+         * Otherwise the next double word is loaded from s1 and s2, and shifted
+         * right to compare the appropriate bits.
          */
+        clrldi  r6,r4,(64-12)   // r6 = r4 & 0xfff
+        cmpdi   r6,0xff8
+        bgt     .Lshort
+
         subfic  r6,r5,8
         slwi    r6,r6,3
         LD      rA,0,r3
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index 6ed22127391b..921f12182f3e 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -77,18 +77,27 @@ static u32 cpu_to_drc_index(int cpu)
 
                 ret = drc.drc_index_start + (thread_index * drc.sequential_inc);
         } else {
-                const __be32 *indexes;
-
-                indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
-                if (indexes == NULL)
-                        goto err_of_node_put;
+                u32 nr_drc_indexes, thread_drc_index;
 
                 /*
-                 * The first element indexes[0] is the number of drc_indexes
-                 * returned in the list.  Hence thread_index+1 will get the
-                 * drc_index corresponding to core number thread_index.
+                 * The first element of ibm,drc-indexes array is the
+                 * number of drc_indexes returned in the list.  Hence
+                 * thread_index+1 will get the drc_index corresponding
+                 * to core number thread_index.
                  */
-                ret = indexes[thread_index + 1];
+                rc = of_property_read_u32_index(dn, "ibm,drc-indexes",
+                                                0, &nr_drc_indexes);
+                if (rc)
+                        goto err_of_node_put;
+
+                WARN_ON_ONCE(thread_index > nr_drc_indexes);
+                rc = of_property_read_u32_index(dn, "ibm,drc-indexes",
+                                                thread_index + 1,
+                                                &thread_drc_index);
+                if (rc)
+                        goto err_of_node_put;
+
+                ret = thread_drc_index;
         }
 
         rc = 0;
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index d97d52772789..452dcfd7e5dd 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -550,6 +550,7 @@ static void pseries_print_mce_info(struct pt_regs *regs,
                 "UE",
                 "SLB",
                 "ERAT",
+                "Unknown",
                 "TLB",
                 "D-Cache",
                 "Unknown",