All of lore.kernel.org
 help / color / mirror / Atom feed
* [U-Boot] [PATCH 1/2] arm: Set TTB XN bit in case DCACHE_OFF for LPAE mode
@ 2016-10-28  6:31 Keerthy
  2016-10-28  6:31 ` [U-Boot] [PATCH 2/2] arm: cpu: armv7: omap-common: Clear XN bit in the ARMV7_DCACHE_POLICY Keerthy
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Keerthy @ 2016-10-28  6:31 UTC (permalink / raw)
  To: u-boot

While we setup the mmu initially we mark set_section_dcache with
DCACHE_OFF flag. In case of non-LPAE mode the DCACHE_OFF macro
is rightly defined with TTB_SECT_XN_MASK set so as to mark all the
4GB XN. In case of LPAE mode  XN(Execute-never) bit is not set with
DCACHE_OFF. Hence XN bit is not set by default for DCACHE_OFF which
keeps all the regions execute okay and this leads to random speculative
fetches in random memory regions which was eventually caught by kernel
omap-l3-noc driver.

Fix this to mark the regions as XN by default.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 arch/arm/include/asm/system.h | 2 +-
 arch/arm/lib/cache-cp15.c     | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index b928bd8..2f430ad 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -329,7 +329,7 @@ static inline void set_dacr(unsigned int val)
 
 /* options available for data cache on each page */
 enum dcache_option {
-	DCACHE_OFF = TTB_SECT | TTB_SECT_MAIR(0),
+	DCACHE_OFF = TTB_SECT | TTB_SECT_MAIR(0) | TTB_SECT_XN_MASK,
 	DCACHE_WRITETHROUGH = TTB_SECT | TTB_SECT_MAIR(1),
 	DCACHE_WRITEBACK = TTB_SECT | TTB_SECT_MAIR(2),
 	DCACHE_WRITEALLOC = TTB_SECT | TTB_SECT_MAIR(3),
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
index 70e94f0..4d9903e 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/arch/arm/lib/cache-cp15.c
@@ -71,8 +71,13 @@ void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
 
 	end = ALIGN(start + size, MMU_SECTION_SIZE) >> MMU_SECTION_SHIFT;
 	start = start >> MMU_SECTION_SHIFT;
+#ifdef CONFIG_ARMV7_LPAE
+	debug("%s: start=%pa, size=%zu, option=%llu\n", __func__, &start, size,
+	      option);
+#else
 	debug("%s: start=%pa, size=%zu, option=%d\n", __func__, &start, size,
 	      option);
+#endif
 	for (upto = start; upto < end; upto++)
 		set_section_dcache(upto, option);
 
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2016-10-29  9:48 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-10-28  6:31 [U-Boot] [PATCH 1/2] arm: Set TTB XN bit in case DCACHE_OFF for LPAE mode Keerthy
2016-10-28  6:31 ` [U-Boot] [PATCH 2/2] arm: cpu: armv7: omap-common: Clear XN bit in the ARMV7_DCACHE_POLICY Keerthy
2016-10-28  7:26   ` Alexander Graf
2016-10-28  7:40     ` Keerthy
2016-10-28 13:12   ` Tom Rini
2016-10-28  7:24 ` [U-Boot] [PATCH 1/2] arm: Set TTB XN bit in case DCACHE_OFF for LPAE mode Alexander Graf
2016-10-28 13:12 ` Tom Rini
2016-10-29  9:48   ` Keerthy

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.