[GIT PULL] x86/vdso tree change for v3.18

[GIT PULL] x86/vdso tree change for v3.18

[Ingo Molnar]

Linus,

Please pull the latest x86-vdso-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-vdso-for-linus

   # HEAD: f12c1f9002d27374fd205f6e692891116ca22272 x86/vdso: Fix vdso2c's special_pages[] error checking

Includes a single fix to vdso error checking.

 Thanks,

	Ingo

------------------>
Andy Lutomirski (1):
      x86/vdso: Fix vdso2c's special_pages[] error checking


 arch/x86/vdso/vdso2c.h | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index fd57829b30d8..0224987556ce 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -109,16 +109,18 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len,
 
 	/* Validate mapping addresses. */
 	for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
-		if (!syms[i])
+		INT_BITS symval = syms[special_pages[i]];
+
+		if (!symval)
 			continue;  /* The mapping isn't used; ignore it. */
 
-		if (syms[i] % 4096)
+		if (symval % 4096)
 			fail("%s must be a multiple of 4096\n",
 			     required_syms[i].name);
-		if (syms[sym_vvar_start] > syms[i] + 4096)
-			fail("%s underruns begin_vvar\n",
+		if (symval + 4096 < syms[sym_vvar_start])
+			fail("%s underruns vvar_start\n",
 			     required_syms[i].name);
-		if (syms[i] + 4096 > 0)
+		if (symval + 4096 > 0)
 			fail("%s is on the wrong side of the vdso text\n",
 			     required_syms[i].name);
 	}