arm64: cpuinfo: add system serial support

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / sys_compat.c

diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index dc47e53e9e28c15da99e62976a9ca29f71da8bc4..28c511b06edfc05d9ac95e8c4ddf7bf11d62df05 100644 (file)
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -28,29 +28,39 @@
 #include <asm/cacheflush.h>
 #include <asm/unistd.h>
 
-static inline void
-do_compat_cache_op(unsigned long start, unsigned long end, int flags)
+static long
+__do_compat_cache_op(unsigned long start, unsigned long end)
 {
-       struct mm_struct *mm = current->active_mm;
-       struct vm_area_struct *vma;
+       long ret;
 
-       if (end < start || flags)
-               return;
+       do {
+               unsigned long chunk = min(PAGE_SIZE, end - start);
 
-       down_read(&mm->mmap_sem);
-       vma = find_vma(mm, start);
-       if (vma && vma->vm_start < end) {
-               if (start < vma->vm_start)
-                       start = vma->vm_start;
-               if (end > vma->vm_end)
-                       end = vma->vm_end;
-               up_read(&mm->mmap_sem);
-               __flush_cache_user_range(start & PAGE_MASK, PAGE_ALIGN(end));
-               return;
-       }
-       up_read(&mm->mmap_sem);
+               if (fatal_signal_pending(current))
+                       return 0;
+
+               ret = __flush_cache_user_range(start, start + chunk);
+               if (ret)
+                       return ret;
+
+               cond_resched();
+               start += chunk;
+       } while (start < end);
+
+       return 0;
 }
 
+static inline long
+do_compat_cache_op(unsigned long start, unsigned long end, int flags)
+{
+       if (end < start || flags)
+               return -EINVAL;
+
+       if (!access_ok(VERIFY_READ, start, end - start))
+               return -EFAULT;
+
+       return __do_compat_cache_op(start, end);
+}
 /*
  * Handle all unrecognised system calls.
  */
@@ -74,8 +84,7 @@ long compat_arm_syscall(struct pt_regs *regs)
         * the specified region).
         */
        case __ARM_NR_compat_cacheflush:
-               do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);
-               return 0;
+               return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);
 
        case __ARM_NR_compat_set_tls:
                current->thread.tp_value = regs->regs[0];