From: Laura Abbott <labbott@redhat.com>
Date: Mon, 8 May 2017 21:23:16 +0000 (-0700)
Subject: x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~1^2~50
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=93d022e25642036406983d9608852c605bfd5227;p=firefly-linux-kernel-4.4.55.git

x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()

commit 861ce4a3244c21b0af64f880d5bfe5e6e2fb9e4a upstream.

'__vmalloc_start_set' currently only gets set in initmem_init() when
!CONFIG_NEED_MULTIPLE_NODES. This breaks detection of vmalloc address
with virt_addr_valid() with CONFIG_NEED_MULTIPLE_NODES=y, causing
a kernel crash:

  [mm/usercopy] 517e1fbeb6: kernel BUG at arch/x86/mm/physaddr.c:78!

Set '__vmalloc_start_set' appropriately for that case as well.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dc16ecf7fd1f ("x86-32: use specific __vmalloc_start_set flag in __virt_addr_valid")
Link: http://lkml.kernel.org/r/1494278596-30373-1-git-send-email-labbott@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/mm/numa_32.c b/arch/x86/mm/numa_32.c
index 47b6436e41c2..3686a1db25b2 100644
--- a/arch/x86/mm/numa_32.c
+++ b/arch/x86/mm/numa_32.c
@@ -100,5 +100,6 @@ void __init initmem_init(void)
 	printk(KERN_DEBUG "High memory starts at vaddr %08lx\n",
 			(ulong) pfn_to_kaddr(highstart_pfn));
 
+	__vmalloc_start_set = true;
 	setup_bootmem_allocator();
 }