Re: [RFC PATCH v2 19/20] x86: Access the setup data through debugfs un-encrypted
From: Borislav Petkov <hidden>
Date: 2016-09-12 16:59:52
Also in:
kvm, linux-arch, linux-iommu, linux-mm, lkml
On Mon, Aug 22, 2016 at 05:38:59PM -0500, Tom Lendacky wrote:
quoted hunk ↗ jump to hunk
Since the setup data is in memory in the clear, it must be accessed as un-encrypted. Always use ioremap (similar to sysfs setup data support) to map the data. Signed-off-by: Tom Lendacky <redacted> --- arch/x86/kernel/kdebugfs.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-)diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c index bdb83e4..a58a82e 100644 --- a/arch/x86/kernel/kdebugfs.c +++ b/arch/x86/kernel/kdebugfs.c@@ -48,17 +48,13 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf, pa = node->paddr + sizeof(struct setup_data) + pos; pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT); - if (PageHighMem(pg)) {
Why is it ok to get rid of the PageHighMem() check?
Btw, we did talk earlier in the thread about making __va() clear the SME
mask and then you won't really need to change stuff here. Or?
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.