From: Wufei <fei.wu@windriver.com>
Date: Wed, 28 Apr 2010 21:42:32 +0000 (-0400)
Subject: kgdb: don't needlessly skip PAGE_USER test for Fsl booke
X-Git-Tag: firefly_0821_release~10186^2~1650
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=150d8a1fe2e89b124bc5bc3628095b8db2435272;p=firefly-linux-kernel-4.4.55.git

kgdb: don't needlessly skip PAGE_USER test for Fsl booke

commit 56151e753468e34aeb322af4b0309ab727c97d2e upstream.

The bypassing of this test is a leftover from 2.4 vintage
kernels, and is no longer appropriate, or even used by KGDB.
Currently KGDB uses probe_kernel_write() for all access to
memory via the KGDB core, so it can simply be deleted.

This fixes CVE-2010-1446.

CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Wufei <fei.wu@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index dc93e95b256e..45f4e61b2632 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -131,15 +131,10 @@ void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 	TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;
 	TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 
-#ifndef CONFIG_KGDB /* want user access for breakpoints */
 	if (flags & _PAGE_USER) {
 	   TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 	   TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 	}
-#else
-	TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
-	TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
-#endif
 
 	tlbcam_addrs[index].start = virt;
 	tlbcam_addrs[index].limit = virt + size - 1;