[PATCH v5] x86, tboot: iomem fixes

From: Qiaowei Ren
Date: Sat Jul 20 2013 - 12:37:54 EST


Current code doesn't use specific interface to access I/O space.
So some potential bugs can be caused. We can fix this by using
specific API.

Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
---
arch/x86/kernel/tboot.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 3ff42d2..4e149c7 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -468,7 +468,8 @@ struct sinit_mle_data {

struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
{
- void *heap_base, *heap_ptr, *config;
+ void __iomem *heap_base, *heap_ptr, *config;
+ u32 dmar_tbl_off;

if (!tboot_enabled())
return dmar_tbl;
@@ -485,25 +486,26 @@ struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tb
return NULL;

/* now map TXT heap */
- heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
- *(u64 *)(config + TXTCR_HEAP_SIZE));
+ heap_base = ioremap(readl(config + TXTCR_HEAP_BASE),
+ readl(config + TXTCR_HEAP_SIZE));
iounmap(config);
if (!heap_base)
return NULL;

/* walk heap to SinitMleData */
/* skip BiosData */
- heap_ptr = heap_base + *(u64 *)heap_base;
+ heap_ptr = heap_base + readq(heap_base);
/* skip OsMleData */
- heap_ptr += *(u64 *)heap_ptr;
+ heap_ptr += readq(heap_ptr);
/* skip OsSinitData */
- heap_ptr += *(u64 *)heap_ptr;
+ heap_ptr += readq(heap_ptr);
/* now points to SinitMleDataSize; set to SinitMleData */
heap_ptr += sizeof(u64);
/* get addr of DMAR table */
+ dmar_tbl_off = readl(heap_ptr +
+ offsetof(struct sinit_mle_data, vtd_dmars_off));
dmar_tbl = (struct acpi_table_header *)(heap_ptr +
- ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
- sizeof(u64));
+ dmar_tbl_off - sizeof(u64));

/* don't unmap heap because dmar.c needs access to this */

--
1.7.9.5

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