diff mbox series

[v29,14/20] x86/sgx: ptrace() support for the SGX driver

Message ID 20200421215316.56503-15-jarkko.sakkinen@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Intel SGX foundations | expand

Commit Message

Jarkko Sakkinen April 21, 2020, 9:53 p.m. UTC 
Add VMA callbacks for ptrace() that can be used with debug enclaves.
With debug enclaves data can be read and write the memory word at a time
by using ENCLS(EDBGRD) and ENCLS(EDBGWR) leaf instructions.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/kernel/cpu/sgx/encl.c | 88 ++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

Comments

Sean Christopherson May 6, 2020, 9:50 p.m. UTC | #1 
On Wed, Apr 22, 2020 at 12:53:10AM +0300, Jarkko Sakkinen wrote:
> Add VMA callbacks for ptrace() that can be used with debug enclaves.
> With debug enclaves data can be read and write the memory word at a time
> by using ENCLS(EDBGRD) and ENCLS(EDBGWR) leaf instructions.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  arch/x86/kernel/cpu/sgx/encl.c | 88 ++++++++++++++++++++++++++++++++++
>  1 file changed, 88 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index fe7dbca40bb4..0c5ea2968868 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -326,6 +326,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
>  	return 0;
>  }
>  
> +

Unnecessary whitespace change.

>  static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start,
>  			    unsigned long end, unsigned long prot)
>  {
Jarkko Sakkinen May 13, 2020, 9:40 p.m. UTC | #2 
On Wed, May 06, 2020 at 02:50:48PM -0700, Sean Christopherson wrote:
> On Wed, Apr 22, 2020 at 12:53:10AM +0300, Jarkko Sakkinen wrote:
> > Add VMA callbacks for ptrace() that can be used with debug enclaves.
> > With debug enclaves data can be read and write the memory word at a time
> > by using ENCLS(EDBGRD) and ENCLS(EDBGWR) leaf instructions.
> > 
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > ---
> >  arch/x86/kernel/cpu/sgx/encl.c | 88 ++++++++++++++++++++++++++++++++++
> >  1 file changed, 88 insertions(+)
> > 
> > diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> > index fe7dbca40bb4..0c5ea2968868 100644
> > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > @@ -326,6 +326,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
> >  	return 0;
> >  }
> >  
> > +
> 
> Unnecessary whitespace change.

Would not update series just for this. If something else, will fix this
one.

/Jarkko
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index fe7dbca40bb4..0c5ea2968868 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -326,6 +326,7 @@  int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
 	return 0;
 }
 
+
 static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start,
 			    unsigned long end, unsigned long prot)
 {
@@ -333,10 +334,97 @@  static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start,
 				calc_vm_prot_bits(prot, 0));
 }
 
+static int sgx_edbgrd(struct sgx_encl *encl, struct sgx_encl_page *page,
+		      unsigned long addr, void *data)
+{
+	unsigned long offset = addr & ~PAGE_MASK;
+	int ret;
+
+
+	ret = __edbgrd(sgx_epc_addr(page->epc_page) + offset, data);
+	if (ret)
+		return -EIO;
+
+	return 0;
+}
+
+static int sgx_edbgwr(struct sgx_encl *encl, struct sgx_encl_page *page,
+		      unsigned long addr, void *data)
+{
+	unsigned long offset = addr & ~PAGE_MASK;
+	int ret;
+
+	ret = __edbgwr(sgx_epc_addr(page->epc_page) + offset, data);
+	if (ret)
+		return -EIO;
+
+	return 0;
+}
+
+static int sgx_vma_access(struct vm_area_struct *vma, unsigned long addr,
+			  void *buf, int len, int write)
+{
+	struct sgx_encl *encl = vma->vm_private_data;
+	struct sgx_encl_page *entry = NULL;
+	char data[sizeof(unsigned long)];
+	unsigned long align;
+	unsigned int flags;
+	int offset;
+	int cnt;
+	int ret = 0;
+	int i;
+
+	/* If process was forked, VMA is still there but vm_private_data is set
+	 * to NULL.
+	 */
+	if (!encl)
+		return -EFAULT;
+
+	flags = atomic_read(&encl->flags);
+
+	if (!(flags & SGX_ENCL_DEBUG) || !(flags & SGX_ENCL_INITIALIZED) ||
+	    (flags & SGX_ENCL_DEAD))
+		return -EFAULT;
+
+	for (i = 0; i < len; i += cnt) {
+		entry = sgx_encl_reserve_page(encl, (addr + i) & PAGE_MASK);
+		if (IS_ERR(entry)) {
+			ret = PTR_ERR(entry);
+			break;
+		}
+
+		align = ALIGN_DOWN(addr + i, sizeof(unsigned long));
+		offset = (addr + i) & (sizeof(unsigned long) - 1);
+		cnt = sizeof(unsigned long) - offset;
+		cnt = min(cnt, len - i);
+
+		ret = sgx_edbgrd(encl, entry, align, data);
+		if (ret)
+			goto out;
+
+		if (write) {
+			memcpy(data + offset, buf + i, cnt);
+			ret = sgx_edbgwr(encl, entry, align, data);
+			if (ret)
+				goto out;
+		} else
+			memcpy(buf + i, data + offset, cnt);
+
+out:
+		mutex_unlock(&encl->lock);
+
+		if (ret)
+			break;
+	}
+
+	return ret < 0 ? ret : i;
+}
+
 const struct vm_operations_struct sgx_vm_ops = {
 	.open = sgx_vma_open,
 	.fault = sgx_vma_fault,
 	.may_mprotect = sgx_vma_mprotect,
+	.access = sgx_vma_access,
 };
 
 /**