Messages in this thread | | | Date | Thu, 18 Jul 2013 12:42:23 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v3] x86, tboot: iomem fixes |
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* Qiaowei Ren <qiaowei.ren@intel.com> 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 <qiaowei.ren@intel.com> > --- > 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
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