From eb85a355c3afd9379f5953cfe2df73632d14c884 Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Wed, 21 Mar 2018 08:16:29 -0700 Subject: [PATCH] ARM: OMAP: Fix SRAM W+X mapping 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@vger.kernel.org # v4.12+ Cc: Dave Gerlach Reported-by: Pavel Machek Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/include/plat/sram.h | 11 +------- arch/arm/plat-omap/sram.c | 36 +++++++++++++++++++++++++- 2 files changed, 36 insertions(+), 11 deletions(-) diff --git a/arch/arm/plat-omap/include/plat/sram.h b/arch/arm/plat-omap/include/plat/sram.h index fb061cf0d736..30a07730807a 100644 --- 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 size, 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); diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c index a5bc92d7e476..921840acf65c 100644 --- a/arch/arm/plat-omap/sram.c +++ b/arch/arm/plat-omap/sram.c @@ -23,6 +23,7 @@ #include #include #include +#include #include @@ -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 long size) 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 start, unsigned long size, */ 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); }