2013-07-18 08:18:54

by Ren Qiaowei

Subject: [PATCH v3] x86, tboot: iomem fixes

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 <[email protected]>
---
arch/x86/kernel/tboot.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 3ff42d2..afe8cf8 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -466,9 +466,12 @@ struct sinit_mle_data {
u32 vtd_dmars_off;
} __packed;

+#define SINIT_MLE_DATA_VTD_DMAR_OFF 140
+
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 +488,25 @@ 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 = (struct acpi_table_header *)(heap_ptr +
- ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
- sizeof(u64));
+ dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
+ memcpy_fromio(dmar_tbl, heap_ptr + dmar_tbl_off - sizeof(u64),
+ sizeof(struct acpi_table_header));

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

--
1.7.9.5

2013-07-18 10:42:29

by Ingo Molnar

Subject: Re: [PATCH v3] x86, tboot: iomem fixes

* Qiaowei Ren <[email protected]> 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.

This is still very vague.

>
> Signed-off-by: Qiaowei Ren <[email protected]>
> ---
> arch/x86/kernel/tboot.c | 21 ++++++++++++---------
> 1 file changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
> index 3ff42d2..afe8cf8 100644
> --- a/arch/x86/kernel/tboot.c
> +++ b/arch/x86/kernel/tboot.c
> @@ -466,9 +466,12 @@ struct sinit_mle_data {
> u32 vtd_dmars_off;
> } __packed;
>
> +#define SINIT_MLE_DATA_VTD_DMAR_OFF 140
> +
> 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 +488,25 @@ 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 = (struct acpi_table_header *)(heap_ptr +
> - ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
> - sizeof(u64));
> + dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
> + memcpy_fromio(dmar_tbl, heap_ptr + dmar_tbl_off - sizeof(u64),
> + sizeof(struct acpi_table_header));

That memcpy (or an equivalent of it) was not in the code before, AFAICS.

How can this be an 'interface fix'? It adds in new code...

Thanks,

Ingo

2013-07-18 12:42:06

by Ren Qiaowei

Subject: RE: [PATCH v3] x86, tboot: iomem fixes

On 2013-07-18, Ingo Molnar wrote:
>
> * Qiaowei Ren <[email protected]> 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.
>
> This is still very vague.
>
>>
>> Signed-off-by: Qiaowei Ren <[email protected]>
>> ---
>> arch/x86/kernel/tboot.c | 21 ++++++++++++---------
>> 1 file changed, 12 insertions(+), 9 deletions(-)
>> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index
>> 3ff42d2..afe8cf8 100644
>> --- a/arch/x86/kernel/tboot.c
>> +++ b/arch/x86/kernel/tboot.c
>> @@ -466,9 +466,12 @@ struct sinit_mle_data {
>> u32 vtd_dmars_off;
>> } __packed;
>> +#define SINIT_MLE_DATA_VTD_DMAR_OFF 140
>> +
>> 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 +488,25 @@ 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 = (struct acpi_table_header *)(heap_ptr +
>> - ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
>> - sizeof(u64));
>> + dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
>> + memcpy_fromio(dmar_tbl, heap_ptr + dmar_tbl_off - sizeof(u64),
>> + sizeof(struct acpi_table_header));
>
> That memcpy (or an equivalent of it) was not in the code before, AFAICS.
>
> How can this be an 'interface fix'? It adds in new code...
>
Sorry, current code only need to get addr of DMAR table, so memcpy_fromio may be removed, even though this will also work.
So "memcpy_fromio" line will be changed to
dmar_tbl = (struct acpi_table_header *)(heap_ptr + dmar_tbl_off + - sizeof(u64));
If so, no new interface will be added, and the changelog at the beginning of this patch is engouch?

Thanks,
Qiaowei

2013-07-19 07:59:56

by Ingo Molnar

Subject: Re: [PATCH v3] x86, tboot: iomem fixes

* Ren, Qiaowei <[email protected]> wrote:

> On 2013-07-18, Ingo Molnar wrote:
> >
> > * Qiaowei Ren <[email protected]> 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.
> >
> > This is still very vague.
> >
> >>
> >> Signed-off-by: Qiaowei Ren <[email protected]>
> >> ---
> >> arch/x86/kernel/tboot.c | 21 ++++++++++++---------
> >> 1 file changed, 12 insertions(+), 9 deletions(-)
> >> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index
> >> 3ff42d2..afe8cf8 100644
> >> --- a/arch/x86/kernel/tboot.c
> >> +++ b/arch/x86/kernel/tboot.c
> >> @@ -466,9 +466,12 @@ struct sinit_mle_data {
> >> u32 vtd_dmars_off;
> >> } __packed;
> >> +#define SINIT_MLE_DATA_VTD_DMAR_OFF 140
> >> +
> >> 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 +488,25 @@ 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 = (struct acpi_table_header *)(heap_ptr +
> >> - ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
> >> - sizeof(u64));
> >> + dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
> >> + memcpy_fromio(dmar_tbl, heap_ptr + dmar_tbl_off - sizeof(u64),
> >> + sizeof(struct acpi_table_header));
> >
> > That memcpy (or an equivalent of it) was not in the code before, AFAICS.
> >
> > How can this be an 'interface fix'? It adds in new code...
> >
> Sorry, current code only need to get addr of DMAR table, so memcpy_fromio may be removed, even though this will also work.
> So "memcpy_fromio" line will be changed to
> dmar_tbl = (struct acpi_table_header *)(heap_ptr + dmar_tbl_off + - sizeof(u64));
> If so, no new interface will be added, and the changelog at the beginning of this patch is engouch?

Please resubmit the fixed patch so I can have a fresh look.

Thanks,

Ingo