This is a note to let you know that I've just added the patch titled
ARM: OMAP: Fix SRAM W+X mapping
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-omap-fix-sram-w-x-mapping.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From eb85a355c3afd9379f5953cfe2df73632d14c884 Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@xxxxxxxxxxx>
Date: Wed, 21 Mar 2018 08:16:29 -0700
Subject: ARM: OMAP: Fix SRAM W+X mapping
From: Tony Lindgren <tony@xxxxxxxxxxx>
commit eb85a355c3afd9379f5953cfe2df73632d14c884 upstream.
We are still using custom SRAM code for some SoCs and are not marking
the PM code mapped to SRAM as read-only and executable after we're
done. With CONFIG_DEBUG_WX=y, we will get "Found insecure W+X mapping
at address" warning.
Let's fix this issue the same way as commit 728bbe75c82f ("misc: sram:
Introduce support code for protect-exec sram type") is doing for
drivers/misc/sram-exec.c.
On omap3, we need to restore SRAM when returning from off mode after
idle, so init time configuration is not enough.
And as we no longer have users for omap_sram_push_address() we can
make it static while at it.
Note that eventually we should be using sram-exec.c for all SoCs.
Cc: stable@xxxxxxxxxxxxxxx # v4.12+
Cc: Dave Gerlach <d-gerlach@xxxxxx>
Reported-by: Pavel Machek <pavel@xxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/plat-omap/include/plat/sram.h | 11 ----------
arch/arm/plat-omap/sram.c | 36 ++++++++++++++++++++++++++++++++-
2 files changed, 36 insertions(+), 11 deletions(-)
--- a/arch/arm/plat-omap/include/plat/sram.h
+++ b/arch/arm/plat-omap/include/plat/sram.h
@@ -5,13 +5,4 @@ void omap_map_sram(unsigned long start,
unsigned long skip, int cached);
void omap_sram_reset(void);
-extern void *omap_sram_push_address(unsigned long size);
-
-/* Macro to push a function to the internal SRAM, using the fncpy API */
-#define omap_sram_push(funcp, size) ({ \
- typeof(&(funcp)) _res = NULL; \
- void *_sram_address = omap_sram_push_address(size); \
- if (_sram_address) \
- _res = fncpy(_sram_address, &(funcp), size); \
- _res; \
-})
+extern void *omap_sram_push(void *funcp, unsigned long size);
--- a/arch/arm/plat-omap/sram.c
+++ b/arch/arm/plat-omap/sram.c
@@ -23,6 +23,7 @@
#include <asm/fncpy.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
+#include <asm/set_memory.h>
#include <asm/mach/map.h>
@@ -42,7 +43,7 @@ static void __iomem *omap_sram_ceil;
* Note that fncpy requires the returned address to be aligned
* to an 8-byte boundary.
*/
-void *omap_sram_push_address(unsigned long size)
+static void *omap_sram_push_address(unsigned long size)
{
unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
@@ -60,6 +61,30 @@ void *omap_sram_push_address(unsigned lo
return (void *)omap_sram_ceil;
}
+void *omap_sram_push(void *funcp, unsigned long size)
+{
+ void *sram;
+ unsigned long base;
+ int pages;
+ void *dst = NULL;
+
+ sram = omap_sram_push_address(size);
+ if (!sram)
+ return NULL;
+
+ base = (unsigned long)sram & PAGE_MASK;
+ pages = PAGE_ALIGN(size) / PAGE_SIZE;
+
+ set_memory_rw(base, pages);
+
+ dst = fncpy(sram, funcp, size);
+
+ set_memory_ro(base, pages);
+ set_memory_x(base, pages);
+
+ return dst;
+}
+
/*
* The SRAM context is lost during off-idle and stack
* needs to be reset.
@@ -75,6 +100,9 @@ void omap_sram_reset(void)
void __init omap_map_sram(unsigned long start, unsigned long size,
unsigned long skip, int cached)
{
+ unsigned long base;
+ int pages;
+
if (size == 0)
return;
@@ -95,4 +123,10 @@ void __init omap_map_sram(unsigned long
*/
memset_io(omap_sram_base + omap_sram_skip, 0,
omap_sram_size - omap_sram_skip);
+
+ base = (unsigned long)omap_sram_base;
+ pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
+
+ set_memory_ro(base, pages);
+ set_memory_x(base, pages);
}
Patches currently in stable-queue which might be from tony@xxxxxxxxxxx are
queue-4.14/arm-omap-fix-sram-w-x-mapping.patch