Merge tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Michael writes:
  "powerpc fixes for 4.19 #4

   Four regression fixes.

   A fix for a change to lib/xz which broke our zImage loader when
   building with XZ compression. OK'ed by Herbert who merged the
   original patch.

   The recent fix we did to avoid patching __init text broke some 32-bit
   machines, fix that.

   Our show_user_instructions() could be tricked into printing kernel
   memory, add a check to avoid that.

   And a fix for a change to our NUMA initialisation logic, which causes
   crashes in some kdump configurations.

   Thanks to:
     Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis
     Roos, Murilo Opsfelder Araujo, Srikar Dronamraju."

* tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/numa: Skip onlining a offline node in kdump path
  powerpc: Don't print kernel instructions in show_user_instructions()
  powerpc/lib: fix book3s/32 boot failure due to code patching
  lib/xz: Put CRC32_POLY_LE in xz_private.h

5 files changed, 29 insertions, 11 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 913c5725cdb2..bb6ac471a784 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1306,6 +1306,16 @@ void show_user_instructions(struct pt_regs *regs)
 
         pc = regs->nip - (instructions_to_print * 3 / 4 * sizeof(int));
 
+        /*
+         * Make sure the NIP points at userspace, not kernel text/data or
+         * elsewhere.
+         */
+        if (!__access_ok(pc, instructions_to_print * sizeof(int), USER_DS)) {
+                pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
+                        current->comm, current->pid);
+                return;
+        }
+
         pr_info("%s[%d]: code: ", current->comm, current->pid);
 
         for (i = 0; i < instructions_to_print; i++) {
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 6ae2777c220d..5ffee298745f 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -28,12 +28,6 @@ static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
 {
         int err;
 
-        /* Make sure we aren't patching a freed init section */
-        if (init_mem_is_free && init_section_contains(exec_addr, 4)) {
-                pr_debug("Skipping init section patching addr: 0x%px\n", exec_addr);
-                return 0;
-        }
-
         __put_user_size(instr, patch_addr, 4, err);
         if (err)
                 return err;
@@ -148,7 +142,7 @@ static inline int unmap_patch_area(unsigned long addr)
         return 0;
 }
 
-int patch_instruction(unsigned int *addr, unsigned int instr)
+static int do_patch_instruction(unsigned int *addr, unsigned int instr)
 {
         int err;
         unsigned int *patch_addr = NULL;
@@ -188,12 +182,22 @@ out:
 }
 #else /* !CONFIG_STRICT_KERNEL_RWX */
 
-int patch_instruction(unsigned int *addr, unsigned int instr)
+static int do_patch_instruction(unsigned int *addr, unsigned int instr)
 {
         return raw_patch_instruction(addr, instr);
 }
 
 #endif /* CONFIG_STRICT_KERNEL_RWX */
+
+int patch_instruction(unsigned int *addr, unsigned int instr)
+{
+        /* Make sure we aren't patching a freed init section */
+        if (init_mem_is_free && init_section_contains(addr, 4)) {
+                pr_debug("Skipping init section patching addr: 0x%px\n", addr);
+                return 0;
+        }
+        return do_patch_instruction(addr, instr);
+}
 NOKPROBE_SYMBOL(patch_instruction);
 
 int patch_branch(unsigned int *addr, unsigned long target, int flags)
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 59d07bd5374a..055b211b7126 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1217,9 +1217,10 @@ int find_and_online_cpu_nid(int cpu)
                  * Need to ensure that NODE_DATA is initialized for a node from
                  * available memory (see memblock_alloc_try_nid). If unable to
                  * init the node, then default to nearest node that has memory
-                 * installed.
+                 * installed. Skip onlining a node if the subsystems are not
+                 * yet initialized.
                  */
-                if (try_online_node(new_nid))
+                if (!topology_inited || try_online_node(new_nid))
                         new_nid = first_online_node;
 #else
                 /*
diff --git a/lib/xz/xz_crc32.c b/lib/xz/xz_crc32.c
index 25a5d87e2e4c..912aae5fa09e 100644
--- a/lib/xz/xz_crc32.c
+++ b/lib/xz/xz_crc32.c
@@ -15,7 +15,6 @@
  * but they are bigger and use more memory for the lookup table.
  */
 
-#include <linux/crc32poly.h>
 #include "xz_private.h"
 
 /*
diff --git a/lib/xz/xz_private.h b/lib/xz/xz_private.h
index 482b90f363fe..09360ebb510e 100644
--- a/lib/xz/xz_private.h
+++ b/lib/xz/xz_private.h
@@ -102,6 +102,10 @@
 #       endif
 #endif
 
+#ifndef CRC32_POLY_LE
+#define CRC32_POLY_LE 0xedb88320
+#endif
+
 /*
  * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
  * before calling xz_dec_lzma2_run().