Re: [PATCH v5] x86, tboot: iomem fixes

From: Ingo Molnar
Date: Mon Jul 22 2013 - 04:50:48 EST



* Qiaowei Ren <qiaowei.ren@xxxxxxxxx> wrote:

> 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);

tboot.c is build on 32-bit kernel as well, but readq() is only available
on 64-bit systems.

Thanks,

Ingo
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