Message-Id: <1460728216-19563-2-git-send-email-stefanb@linux.vnet.ibm.com>
Date:	Fri, 15 Apr 2016 09:50:12 -0400
From:	Stefan Berger <stefanb@...ux.vnet.ibm.com>
To:	tpmdd-devel@...ts.sourceforge.net
Cc:	jarkko.sakkinen@...ux.intel.com, jgunthorpe@...idianresearch.com,
	linux-security-module@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Stefan Berger <stefanb@...ux.vnet.ibm.com>
Subject: [PATCH v10 1/5] tpm: Remove all uses of drvdata from the TPM Core

From: Jason Gunthorpe <jgunthorpe@...idianresearch.com>

The final thing preventing this was the way the sysfs files were
attached to the pdev. Follow the approach developed for ppi and move
the sysfs files to the chip->dev with symlinks from the pdev
for compatibility. Everything in the core now sanely uses container_of
to get the chip.

Signed-off-by: Jason Gunthorpe <jgunthorpe@...idianresearch.com>
Signed-off-by: Stefan Berger <stefanb@...ux.vnet.ibm.com>
---
 drivers/char/tpm/tpm-chip.c      | 73 ++++++++++++++++++++++++++++------------
 drivers/char/tpm/tpm-interface.c |  7 ++--
 drivers/char/tpm/tpm-sysfs.c     | 61 ++++++++++++++-------------------
 drivers/char/tpm/tpm.h           | 10 +++---
 4 files changed, 84 insertions(+), 67 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 5bc530c..7e2c9cf 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -170,9 +170,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *dev,
 	chip->dev.class = tpm_class;
 	chip->dev.release = tpm_dev_release;
 	chip->dev.parent = dev;
-#ifdef CONFIG_ACPI
 	chip->dev.groups = chip->groups;
-#endif
 
 	if (chip->dev_num == 0)
 		chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
@@ -276,14 +274,10 @@ static void tpm_del_char_device(struct tpm_chip *chip)
 
 static int tpm1_chip_register(struct tpm_chip *chip)
 {
-	int rc;
-
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		return 0;
 
-	rc = tpm_sysfs_add_device(chip);
-	if (rc)
-		return rc;
+	tpm_sysfs_add_device(chip);
 
 	chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));
 
@@ -297,10 +291,50 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
 
 	if (chip->bios_dir)
 		tpm_bios_log_teardown(chip->bios_dir);
+}
+
+static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
+{
+	struct attribute **i;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		return;
 
-	tpm_sysfs_del_device(chip);
+	sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
+
+	for (i = chip->groups[0]->attrs; *i != NULL; ++i)
+		sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
 }
 
+/* For compatibility with legacy sysfs paths we provide symlinks from the
+ * parent dev directory to selected names within the tpm chip directory. Old
+ * kernel versions created these files directly under the parent.
+ */
+static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
+{
+	struct attribute **i;
+	int rc;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		return 0;
+
+	rc = __compat_only_sysfs_link_entry_to_kobj(
+		    &chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
+	if (rc && rc != -ENOENT)
+		return rc;
+
+	/* All the names from tpm-sysfs */
+	for (i = chip->groups[0]->attrs; *i != NULL; ++i) {
+		rc = __compat_only_sysfs_link_entry_to_kobj(
+		    &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name);
+		if (rc) {
+			tpm_del_legacy_sysfs(chip);
+			return rc;
+		}
+	}
+
+	return 0;
+}
 /*
  * tpm_chip_register() - create a character device for the TPM chip
  * @chip: TPM chip to use.
@@ -323,24 +357,20 @@ int tpm_chip_register(struct tpm_chip *chip)
 	tpm_add_ppi(chip);
 
 	rc = tpm_add_char_device(chip);
-	if (rc)
-		goto out_err;
+	if (rc) {
+		tpm1_chip_unregister(chip);
+		return rc;
+	}
 
 	chip->flags |= TPM_CHIP_FLAG_REGISTERED;
 
-	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
-		rc = __compat_only_sysfs_link_entry_to_kobj(
-		    &chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
-		if (rc && rc != -ENOENT) {
-			tpm_chip_unregister(chip);
-			return rc;
-		}
+	rc = tpm_add_legacy_sysfs(chip);
+	if (rc) {
+		tpm_chip_unregister(chip);
+		return rc;
 	}
 
 	return 0;
-out_err:
-	tpm1_chip_unregister(chip);
-	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_chip_register);
 
@@ -362,8 +392,7 @@ void tpm_chip_unregister(struct tpm_chip *chip)
 	if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))
 		return;
 
-	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
-		sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
+	tpm_del_legacy_sysfs(chip);
 
 	tpm1_chip_unregister(chip);
 	tpm_del_char_device(chip);
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 7cba092..080dade 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -432,12 +432,11 @@ static const struct tpm_input_header tpm_getcap_header = {
 	.ordinal = TPM_ORD_GET_CAP
 };
 
-ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
+ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
 		   const char *desc)
 {
 	struct tpm_cmd_t tpm_cmd;
 	int rc;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
 
 	tpm_cmd.header.in = tpm_getcap_header;
 	if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
@@ -935,7 +934,7 @@ static struct tpm_input_header savestate_header = {
  */
 int tpm_pm_suspend(struct device *dev)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 	struct tpm_cmd_t cmd;
 	int rc, try;
 
@@ -996,7 +995,7 @@ EXPORT_SYMBOL_GPL(tpm_pm_suspend);
  */
 int tpm_pm_resume(struct device *dev)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	if (chip == NULL)
 		return -ENODEV;
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index a7c3473..b46cf70 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -36,7 +36,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
 	int i, rc;
 	char *str = buf;
 
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	tpm_cmd.header.in = tpm_readpubek_header;
 	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
@@ -92,9 +92,9 @@ static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
 	ssize_t rc;
 	int i, j, num_pcrs;
 	char *str = buf;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
-	rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
+	rc = tpm_getcap(chip, TPM_CAP_PROP_PCR, &cap,
 			"attempting to determine the number of PCRS");
 	if (rc)
 		return 0;
@@ -119,8 +119,8 @@ static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 	cap_t cap;
 	ssize_t rc;
 
-	rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
-			 "attempting to determine the permanent enabled state");
+	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_PERM, &cap,
+			"attempting to determine the permanent enabled state");
 	if (rc)
 		return 0;
 
@@ -135,8 +135,8 @@ static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 	cap_t cap;
 	ssize_t rc;
 
-	rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
-			 "attempting to determine the permanent active state");
+	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_PERM, &cap,
+			"attempting to determine the permanent active state");
 	if (rc)
 		return 0;
 
@@ -151,8 +151,8 @@ static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
 	cap_t cap;
 	ssize_t rc;
 
-	rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
-			 "attempting to determine the owner state");
+	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap,
+			"attempting to determine the owner state");
 	if (rc)
 		return 0;
 
@@ -167,8 +167,8 @@ static ssize_t temp_deactivated_show(struct device *dev,
 	cap_t cap;
 	ssize_t rc;
 
-	rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
-			 "attempting to determine the temporary state");
+	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap,
+			"attempting to determine the temporary state");
 	if (rc)
 		return 0;
 
@@ -180,11 +180,12 @@ static DEVICE_ATTR_RO(temp_deactivated);
 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
+	struct tpm_chip *chip = to_tpm_chip(dev);
 	cap_t cap;
 	ssize_t rc;
 	char *str = buf;
 
-	rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
+	rc = tpm_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap,
 			"attempting to determine the manufacturer");
 	if (rc)
 		return 0;
@@ -192,8 +193,8 @@ static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 		       be32_to_cpu(cap.manufacturer_id));
 
 	/* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
-	rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
-			 "attempting to determine the 1.2 version");
+	rc = tpm_getcap(chip, CAP_VERSION_1_2, &cap,
+			"attempting to determine the 1.2 version");
 	if (!rc) {
 		str += sprintf(str,
 			       "TCG version: %d.%d\nFirmware version: %d.%d\n",
@@ -203,7 +204,7 @@ static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 			       cap.tpm_version_1_2.revMinor);
 	} else {
 		/* Otherwise just use TPM_STRUCT_VER */
-		rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
+		rc = tpm_getcap(chip, CAP_VERSION_1_1, &cap,
 				"attempting to determine the 1.1 version");
 		if (rc)
 			return 0;
@@ -222,7 +223,7 @@ static DEVICE_ATTR_RO(caps);
 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 	if (chip == NULL)
 		return 0;
 
@@ -234,7 +235,7 @@ static DEVICE_ATTR_WO(cancel);
 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	if (chip->duration[TPM_LONG] == 0)
 		return 0;
@@ -251,7 +252,7 @@ static DEVICE_ATTR_RO(durations);
 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return sprintf(buf, "%d %d %d %d [%s]\n",
 		       jiffies_to_usecs(chip->timeout_a),
@@ -281,24 +282,12 @@ static const struct attribute_group tpm_dev_group = {
 	.attrs = tpm_dev_attrs,
 };
 
-int tpm_sysfs_add_device(struct tpm_chip *chip)
+void tpm_sysfs_add_device(struct tpm_chip *chip)
 {
-	int err;
-	err = sysfs_create_group(&chip->dev.parent->kobj,
-				 &tpm_dev_group);
-
-	if (err)
-		dev_err(&chip->dev,
-			"failed to create sysfs attributes, %d\n", err);
-	return err;
-}
-
-void tpm_sysfs_del_device(struct tpm_chip *chip)
-{
-	/* The sysfs routines rely on an implicit tpm_try_get_ops, this
-	 * function is called before ops is null'd and the sysfs core
-	 * synchronizes this removal so that no callbacks are running or can
-	 * run again
+	/* The sysfs routines rely on an implicit tpm_try_get_ops, device_del
+	 * is called before ops is null'd and the sysfs core synchronizes this
+	 * removal so that no callbacks are running or can run again
 	 */
-	sysfs_remove_group(&chip->dev.parent->kobj, &tpm_dev_group);
+	WARN_ON(chip->groups_cnt != 0);
+	chip->groups[chip->groups_cnt++] = &tpm_dev_group;
 }
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 8bc6fb8..508e8e0 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -168,9 +168,9 @@ struct tpm_chip {
 
 	struct dentry **bios_dir;
 
-#ifdef CONFIG_ACPI
-	const struct attribute_group *groups[2];
+	const struct attribute_group *groups[3];
 	unsigned int groups_cnt;
+#ifdef CONFIG_ACPI
 	acpi_handle acpi_dev_handle;
 	char ppi_version[TPM_PPI_VERSION_LEN + 1];
 #endif /* CONFIG_ACPI */
@@ -471,7 +471,8 @@ extern dev_t tpm_devt;
 extern const struct file_operations tpm_fops;
 extern struct idr dev_nums_idr;
 
-ssize_t	tpm_getcap(struct device *, __be32, cap_t *, const char *);
+ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
+		   const char *desc);
 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 		     size_t bufsiz);
 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len,
@@ -496,8 +497,7 @@ extern struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
 extern int tpm_chip_register(struct tpm_chip *chip);
 extern void tpm_chip_unregister(struct tpm_chip *chip);
 
-int tpm_sysfs_add_device(struct tpm_chip *chip);
-void tpm_sysfs_del_device(struct tpm_chip *chip);
+void tpm_sysfs_add_device(struct tpm_chip *chip);
 
 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
 
-- 
2.4.3

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