From: Stefan Roese <sr@denx.de>
Date: Thu, 14 Apr 2011 23:49:53 +0000 (+0000)
Subject: powerpc: Don't write protect kernel text with CONFIG_DYNAMIC_FTRACE enabled
X-Git-Tag: v2.6.39-rc4~4^2~2
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=09597cfe93d3cc2c6e064a3ead5956b882511560;p=~emulex%2Finfiniband.git

powerpc: Don't write protect kernel text with CONFIG_DYNAMIC_FTRACE enabled

This problem was noticed on an MPC855T platform. Ftrace did oops
when trying to write to the kernel text segment.

Many thanks to Joakim for finding the root cause of this problem.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index 811f04ac366..8d1569c2904 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -162,7 +162,7 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
  * on platforms where such control is possible.
  */
 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
-	defined(CONFIG_KPROBES)
+	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
 #else
 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX