From: Helge Deller <deller@gmx.de>
Date: Fri, 12 Oct 2018 20:37:46 +0000 (+0200)
Subject: parisc: Fix map_pages() to not overwrite existing pte entries
X-Git-Tag: rel_imx_4.19.35_1.1.0~9041
X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=72f6b9c076c93a79508d2f653f213be333096a97;p=linux.git

parisc: Fix map_pages() to not overwrite existing pte entries

commit 3c229b3f2dd8133f61bb81d3cb018be92f4bba39 upstream.

Fix a long-existing small nasty bug in the map_pages() implementation which
leads to overwriting already written pte entries with zero, *if* map_pages() is
called a second time with an end address which isn't aligned on a pmd boundry.
This happens for example if we want to remap only the text segment read/write
in order to run alternative patching on the code. Exiting the loop when we
reach the end address fixes this.

Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 74842d28a7a1..aae9b0d71c1e 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -494,12 +494,8 @@ static void __init map_pages(unsigned long start_vaddr,
 						pte = pte_mkhuge(pte);
 				}
 
-				if (address >= end_paddr) {
-					if (force)
-						break;
-					else
-						pte_val(pte) = 0;
-				}
+				if (address >= end_paddr)
+					break;
 
 				set_pte(pg_table, pte);