4 files changed, 61 insertions, 4 deletions

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 2db42b18f53f..8517c3c3eb33 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -436,7 +436,7 @@ __und_usr:
         usr_entry
 
         tst     r3, #PSR_T_BIT                  @ Thumb mode?
-        bne     fpundefinstr                    @ ignore FP
+        bne     __und_usr_unknown               @ ignore FP
         sub     r4, r2, #4
 
         @
@@ -448,7 +448,7 @@ __und_usr:
         @
 1:      ldrt    r0, [r4]
         adr     r9, ret_from_exception
-        adr     lr, fpundefinstr
+        adr     lr, __und_usr_unknown
         @
         @ fallthrough to call_fpe
         @
@@ -476,7 +476,9 @@ __und_usr:
  * Emulators may wish to make use of the following registers:
  *  r0  = instruction opcode.
  *  r2  = PC+4
+ *  r9  = normal "successful" return address
  *  r10 = this threads thread_info structure.
+ *  lr  = unrecognised instruction return address
  */
 call_fpe:
         tst     r0, #0x08000000                 @ only CDP/CPRT/LDC/STC have bit 27
@@ -545,10 +547,12 @@ do_fpe:
 
         .data
 ENTRY(fp_enter)
-        .word   fpundefinstr
+        .word   no_fp
         .text
 
-fpundefinstr:
+no_fp:  mov     pc, lr
+
+__und_usr_unknown:
         mov     r0, sp
         adr     lr, ret_from_exception
         b       do_undefinstr
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index 6ff5e3ff6cb5..3c8cdcfe8d4a 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -29,6 +29,8 @@
 #include <linux/timer.h>
 #include <linux/irq.h>
 
+#include <linux/mc146818rtc.h>
+
 #include <asm/leds.h>
 #include <asm/thread_info.h>
 #include <asm/mach/time.h>
@@ -85,6 +87,17 @@ unsigned long long __attribute__((weak)) sched_clock(void)
         return (unsigned long long)jiffies * (1000000000 / HZ);
 }
 
+/*
+ * An implementation of printk_clock() independent from
+ * sched_clock().  This avoids non-bootable kernels when
+ * printk_clock is enabled.
+ */
+unsigned long long printk_clock(void)
+{
+        return (unsigned long long)(jiffies - INITIAL_JIFFIES) *
+                        (1000000000 / HZ);
+}
+
 static unsigned long next_rtc_update;
 
 /*
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 042a12982e98..908915675edc 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -27,6 +27,7 @@
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/traps.h>
+#include <asm/io.h>
 
 #include "ptrace.h"
 #include "signal.h"
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 628348c9f6c5..9df507d36e0b 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -202,3 +202,42 @@ void flush_dcache_page(struct page *page)
         }
 }
 EXPORT_SYMBOL(flush_dcache_page);
+
+/*
+ * Flush an anonymous page so that users of get_user_pages()
+ * can safely access the data.  The expected sequence is:
+ *
+ *  get_user_pages()
+ *    -> flush_anon_page
+ *  memcpy() to/from page
+ *  if written to page, flush_dcache_page()
+ */
+void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
+{
+        unsigned long pfn;
+
+        /* VIPT non-aliasing caches need do nothing */
+        if (cache_is_vipt_nonaliasing())
+                return;
+
+        /*
+         * Write back and invalidate userspace mapping.
+         */
+        pfn = page_to_pfn(page);
+        if (cache_is_vivt()) {
+                flush_cache_page(vma, vmaddr, pfn);
+        } else {
+                /*
+                 * For aliasing VIPT, we can flush an alias of the
+                 * userspace address only.
+                 */
+                flush_pfn_alias(pfn, vmaddr);
+        }
+
+        /*
+         * Invalidate kernel mapping.  No data should be contained
+         * in this mapping of the page.  FIXME: this is overkill
+         * since we actually ask for a write-back and invalidate.
+         */
+        __cpuc_flush_dcache_page(page_address(page));
+}