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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Helge Deller <deller@gmx.de>
Subject: [PATCH 4.20 143/145] parisc: Remap hugepage-aligned pages in set_kernel_text_rw()
Date:   Mon,  7 Jan 2019 13:33:00 +0100
Message-Id: <20190107104455.846950033@linuxfoundation.org>
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4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Helge Deller <deller@gmx.de>

commit dfbaecb2b707cfdc5276b548d52b437384bd6483 upstream.

The alternative coding patch for parisc in kernel 4.20 broke booting
machines with PA8500-PA8700 CPUs. The problem is, that for such machines
the parisc kernel automatically utilizes huge pages to access kernel
text code, but the set_kernel_text_rw() function, which is used shortly
before applying any alternative patches, didn't used the correctly
hugepage-aligned addresses to remap the kernel text read-writeable.

Fixes: 3847dab77421 ("parisc: Add alternative coding infrastructure")
Cc: <stable@vger.kernel.org>	[4.20]
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/parisc/mm/init.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -512,8 +512,8 @@ static void __init map_pages(unsigned lo
 
 void __init set_kernel_text_rw(int enable_read_write)
 {
-	unsigned long start = (unsigned long)__init_begin;
-	unsigned long end   = (unsigned long)_etext;
+	unsigned long start = (unsigned long) _text;
+	unsigned long end   = (unsigned long) &data_start;
 
 	map_pages(start, __pa(start), end-start,
 		PAGE_KERNEL_RWX, enable_read_write ? 1:0);