diff mbox series

[v3,08/24] powerpc/secvar: Allow backend to populate static list of variable names

Message ID 20230118061049.1006141-9-ajd@linux.ibm.com
State New
Headers
Series pSeries dynamic secure boot secvar interface + platform keyring loading |

Commit Message

Andrew Donnellan Jan. 18, 2023, 6:10 a.m. UTC 
  Currently, the list of variables is populated by calling
secvar_ops->get_next() repeatedly, which is explicitly modelled on the
OPAL API (including the keylen parameter).

For the upcoming PLPKS backend, we have a static list of variable names.
It is messy to fit that into get_next(), so instead, let the backend put
a NULL-terminated array of variable names into secvar_ops->var_names,
which will be used if get_next() is undefined.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>

---

v3: New patch (ajd/mpe)
---
 arch/powerpc/include/asm/secvar.h  |  4 ++
 arch/powerpc/kernel/secvar-sysfs.c | 67 ++++++++++++++++++++----------
 2 files changed, 50 insertions(+), 21 deletions(-)

Comments

Nicholas Piggin Jan. 19, 2023, 1:10 a.m. UTC | #1 
On Wed Jan 18, 2023 at 4:10 PM AEST, Andrew Donnellan wrote:
> Currently, the list of variables is populated by calling
> secvar_ops->get_next() repeatedly, which is explicitly modelled on the
> OPAL API (including the keylen parameter).
>
> For the upcoming PLPKS backend, we have a static list of variable names.
> It is messy to fit that into get_next(), so instead, let the backend put
> a NULL-terminated array of variable names into secvar_ops->var_names,
> which will be used if get_next() is undefined.
>
> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Russell Currey <ruscur@russell.cc>
>
> ---
>
> v3: New patch (ajd/mpe)
> ---
>  arch/powerpc/include/asm/secvar.h  |  4 ++
>  arch/powerpc/kernel/secvar-sysfs.c | 67 ++++++++++++++++++++----------
>  2 files changed, 50 insertions(+), 21 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h
> index ebf95386d720..c8bee1834b54 100644
> --- a/arch/powerpc/include/asm/secvar.h
> +++ b/arch/powerpc/include/asm/secvar.h
> @@ -23,6 +23,10 @@ struct secvar_operations {
>  	ssize_t (*format)(char *buf);
>  	int (*max_size)(u64 *max_size);
>  	const struct attribute **config_attrs;
> +
> +	// NULL-terminated array of fixed variable names
> +	// Only used if get_next() isn't provided
> +	const char * const *var_names;

The other way you could go is provide a sysfs_init() ops call here,
and export the add_var as a library function that backends can use.

Thanks,
Nick
Andrew Donnellan Jan. 20, 2023, 6:20 a.m. UTC | #2 
On Thu, 2023-01-19 at 11:10 +1000, Nicholas Piggin wrote:
> > diff --git a/arch/powerpc/include/asm/secvar.h
> > b/arch/powerpc/include/asm/secvar.h
> > index ebf95386d720..c8bee1834b54 100644
> > --- a/arch/powerpc/include/asm/secvar.h
> > +++ b/arch/powerpc/include/asm/secvar.h
> > @@ -23,6 +23,10 @@ struct secvar_operations {
> >         ssize_t (*format)(char *buf);
> >         int (*max_size)(u64 *max_size);
> >         const struct attribute **config_attrs;
> > +
> > +       // NULL-terminated array of fixed variable names
> > +       // Only used if get_next() isn't provided
> > +       const char * const *var_names;
> 
> The other way you could go is provide a sysfs_init() ops call here,
> and export the add_var as a library function that backends can use.

True, I think I'll keep it as is for now but I'll have a think about
whether to do that in a later patch.
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h
index ebf95386d720..c8bee1834b54 100644
--- a/arch/powerpc/include/asm/secvar.h
+++ b/arch/powerpc/include/asm/secvar.h
@@ -23,6 +23,10 @@  struct secvar_operations {
 	ssize_t (*format)(char *buf);
 	int (*max_size)(u64 *max_size);
 	const struct attribute **config_attrs;
+
+	// NULL-terminated array of fixed variable names
+	// Only used if get_next() isn't provided
+	const char * const *var_names;
 };
 
 #ifdef CONFIG_PPC_SECURE_BOOT
diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c
index b82e95a2e415..d9352d4be87b 100644
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -153,9 +153,31 @@  static int secvar_sysfs_config(struct kobject *kobj)
 	return 0;
 }
 
-static int secvar_sysfs_load(void)
+static int add_var(const char *name)
 {
 	struct kobject *kobj;
+	int rc;
+
+	kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
+	if (!kobj)
+		return -ENOMEM;
+
+	kobject_init(kobj, &secvar_ktype);
+
+	rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name);
+	if (rc) {
+		pr_warn("kobject_add error %d for attribute: %s\n", rc,
+			name);
+		kobject_put(kobj);
+		return rc;
+	}
+
+	kobject_uevent(kobj, KOBJ_ADD);
+	return 0;
+}
+
+static int secvar_sysfs_load(void)
+{
 	u64 namesize = 0;
 	char *name;
 	int rc;
@@ -173,31 +195,26 @@  static int secvar_sysfs_load(void)
 			break;
 		}
 
-		kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
-		if (!kobj) {
-			rc = -ENOMEM;
-			break;
-		}
-
-		kobject_init(kobj, &secvar_ktype);
-
-		rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name);
-		if (rc) {
-			pr_warn("kobject_add error %d for attribute: %s\n", rc,
-				name);
-			kobject_put(kobj);
-			kobj = NULL;
-		}
-
-		if (kobj)
-			kobject_uevent(kobj, KOBJ_ADD);
-
+		rc = add_var(name);
 	} while (!rc);
 
 	kfree(name);
 	return rc;
 }
 
+static int secvar_sysfs_load_static(void)
+{
+	const char * const *name_ptr = secvar_ops->var_names;
+	int rc;
+	while (*name_ptr) {
+		rc = add_var(*name_ptr);
+		if (rc)
+			return rc;
+		name_ptr++;
+	}
+	return 0;
+}
+
 static int secvar_sysfs_init(void)
 {
 	int rc;
@@ -239,7 +256,15 @@  static int secvar_sysfs_init(void)
 		goto err;
 	}
 
-	secvar_sysfs_load();
+	if (secvar_ops->get_next)
+		rc = secvar_sysfs_load();
+	else
+		rc = secvar_sysfs_load_static();
+
+	if (rc) {
+		pr_err("Failed to create variable attributes\n");
+		goto err;
+	}
 
 	return 0;
 err: