Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes:

   - Prevent potential NULL pointer dereferences in the HPET and HyperV
     code

   - Exclude the GART aperture from /proc/kcore to prevent kernel
     crashes on access

   - Use the correct macros for Cyrix I/O on Geode processors

   - Remove yet another kernel address printk leak

   - Announce microcode reload completion as requested by quite some
     people. Microcode loading has become popular recently.

   - Some 'Make Clang' happy fixlets

   - A few cleanups for recently added code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/gart: Exclude GART aperture from kcore
  x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error
  x86/mm/pti: Make local symbols static
  x86/cpu/cyrix: Remove {get,set}Cx86_old macros used for Cyrix processors
  x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors
  x86/microcode: Announce reload operation's completion
  x86/hyperv: Prevent potential NULL pointer dereference
  x86/hpet: Prevent potential NULL pointer dereference
  x86/lib: Fix indentation issue, remove extra tab
  x86/boot: Restrict header scope to make Clang happy
  x86/mm: Don't leak kernel addresses
  x86/cpufeature: Fix various quality problems in the <asm/cpu_device_hd.h> header

1 files changed, 27 insertions, 0 deletions

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index bbcc185062bb..d29d869abec1 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -54,6 +54,28 @@ static LIST_HEAD(kclist_head);
 static DECLARE_RWSEM(kclist_lock);
 static int kcore_need_update = 1;
 
+/*
+ * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
+ * Same as oldmem_pfn_is_ram in vmcore
+ */
+static int (*mem_pfn_is_ram)(unsigned long pfn);
+
+int __init register_mem_pfn_is_ram(int (*fn)(unsigned long pfn))
+{
+	if (mem_pfn_is_ram)
+		return -EBUSY;
+	mem_pfn_is_ram = fn;
+	return 0;
+}
+
+static int pfn_is_ram(unsigned long pfn)
+{
+	if (mem_pfn_is_ram)
+		return mem_pfn_is_ram(pfn);
+	else
+		return 1;
+}
+
 /* This doesn't grab kclist_lock, so it should only be used at init time. */
 void __init kclist_add(struct kcore_list *new, void *addr, size_t size,
 		       int type)
@@ -465,6 +487,11 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
 				goto out;
 			}
 			m = NULL;	/* skip the list anchor */
+		} else if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) {
+			if (clear_user(buffer, tsz)) {
+				ret = -EFAULT;
+				goto out;
+			}
 		} else if (m->type == KCORE_VMALLOC) {
 			vread(buf, (char *)start, tsz);
 			/* we have to zero-fill user buffer even if no read */