6 files changed, 84 insertions, 37 deletions

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 250a651ebd95..3f27753d96aa 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -127,6 +127,7 @@ static void tpm_dev_release(struct device *dev)
         idr_remove(&dev_nums_idr, chip->dev_num);
         mutex_unlock(&idr_lock);
 
+        kfree(chip->log.bios_event_log);
         kfree(chip);
 }
 
@@ -345,7 +346,7 @@ int tpm_chip_register(struct tpm_chip *chip)
         tpm_sysfs_add_device(chip);
 
         rc = tpm_bios_log_setup(chip);
-        if (rc)
+        if (rc == -ENODEV)
                 return rc;
 
         tpm_add_ppi(chip);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 9d69580a9743..1ae976894257 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -35,6 +35,8 @@
 #include <linux/cdev.h>
 #include <linux/highmem.h>
 
+#include "tpm_eventlog.h"
+
 enum tpm_const {
         TPM_MINOR = 224,        /* officially assigned */
         TPM_BUFSIZE = 4096,
@@ -146,6 +148,11 @@ enum tpm_chip_flags {
         TPM_CHIP_FLAG_HAVE_TIMEOUTS     = BIT(4),
 };
 
+struct tpm_chip_seqops {
+        struct tpm_chip *chip;
+        const struct seq_operations *seqops;
+};
+
 struct tpm_chip {
         struct device dev;
         struct cdev cdev;
@@ -157,6 +164,10 @@ struct tpm_chip {
         struct rw_semaphore ops_sem;
         const struct tpm_class_ops *ops;
 
+        struct tpm_bios_log log;
+        struct tpm_chip_seqops bin_log_seqops;
+        struct tpm_chip_seqops ascii_log_seqops;
+
         unsigned int flags;
 
         int dev_num;            /* /dev/tpm# */
diff --git a/drivers/char/tpm/tpm_acpi.c b/drivers/char/tpm/tpm_acpi.c
index 565a9478cb94..01dfb35a30e4 100644
--- a/drivers/char/tpm/tpm_acpi.c
+++ b/drivers/char/tpm/tpm_acpi.c
@@ -9,7 +9,7 @@
  *
  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  *
- * Access to the eventlog extended by the TCG BIOS of PC platform
+ * Access to the event log extended by the TCG BIOS of PC platform
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -45,13 +45,15 @@ struct acpi_tcpa {
 };
 
 /* read binary bios log */
-int read_log(struct tpm_bios_log *log)
+int read_log(struct tpm_chip *chip)
 {
         struct acpi_tcpa *buff;
         acpi_status status;
         void __iomem *virt;
         u64 len, start;
+        struct tpm_bios_log *log;
 
+        log = &chip->log;
         if (log->bios_event_log != NULL) {
                 printk(KERN_ERR
                        "%s: ERROR - Eventlog already initialized\n",
@@ -97,13 +99,18 @@ int read_log(struct tpm_bios_log *log)
 
         virt = acpi_os_map_iomem(start, len);
         if (!virt) {
-                kfree(log->bios_event_log);
                 printk("%s: ERROR - Unable to map memory\n", __func__);
-                return -EIO;
+                goto err;
         }
 
         memcpy_fromio(log->bios_event_log, virt, len);
 
         acpi_os_unmap_iomem(virt, len);
         return 0;
+
+err:
+        kfree(log->bios_event_log);
+        log->bios_event_log = NULL;
+        return -EIO;
+
 }
diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c
index 0afb0f4e81f0..2c4bc99729e5 100644
--- a/drivers/char/tpm/tpm_eventlog.c
+++ b/drivers/char/tpm/tpm_eventlog.c
@@ -11,7 +11,7 @@
  *
  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  *
- * Access to the eventlog created by a system's firmware / BIOS
+ * Access to the event log created by a system's firmware / BIOS
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -73,7 +73,8 @@ static const char* tcpa_pc_event_id_strings[] = {
 static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
 {
         loff_t i;
-        struct tpm_bios_log *log = m->private;
+        struct tpm_chip *chip = m->private;
+        struct tpm_bios_log *log = &chip->log;
         void *addr = log->bios_event_log;
         void *limit = log->bios_event_log_end;
         struct tcpa_event *event;
@@ -120,7 +121,8 @@ static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
                                         loff_t *pos)
 {
         struct tcpa_event *event = v;
-        struct tpm_bios_log *log = m->private;
+        struct tpm_chip *chip = m->private;
+        struct tpm_bios_log *log = &chip->log;
         void *limit = log->bios_event_log_end;
         u32 converted_event_size;
         u32 converted_event_type;
@@ -261,13 +263,10 @@ static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
 static int tpm_bios_measurements_release(struct inode *inode,
                                          struct file *file)
 {
-        struct seq_file *seq = file->private_data;
-        struct tpm_bios_log *log = seq->private;
+        struct seq_file *seq = (struct seq_file *)file->private_data;
+        struct tpm_chip *chip = (struct tpm_chip *)seq->private;
 
-        if (log) {
-                kfree(log->bios_event_log);
-                kfree(log);
-        }
+        put_device(&chip->dev);
 
         return seq_release(inode, file);
 }
@@ -323,33 +322,30 @@ static int tpm_bios_measurements_open(struct inode *inode,
                                             struct file *file)
 {
         int err;
-        struct tpm_bios_log *log;
         struct seq_file *seq;
-        const struct seq_operations *seqops =
-                (const struct seq_operations *)inode->i_private;
-
-        log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
-        if (!log)
-                return -ENOMEM;
-
-        if ((err = read_log(log)))
-                goto out_free;
+        struct tpm_chip_seqops *chip_seqops;
+        const struct seq_operations *seqops;
+        struct tpm_chip *chip;
+
+        inode_lock(inode);
+        if (!inode->i_private) {
+                inode_unlock(inode);
+                return -ENODEV;
+        }
+        chip_seqops = (struct tpm_chip_seqops *)inode->i_private;
+        seqops = chip_seqops->seqops;
+        chip = chip_seqops->chip;
+        get_device(&chip->dev);
+        inode_unlock(inode);
 
         /* now register seq file */
         err = seq_open(file, seqops);
         if (!err) {
                 seq = file->private_data;
-                seq->private = log;
-        } else {
-                goto out_free;
+                seq->private = chip;
         }
 
-out:
         return err;
-out_free:
-        kfree(log->bios_event_log);
-        kfree(log);
-        goto out;
 }
 
 static const struct file_operations tpm_bios_measurements_ops = {
@@ -363,10 +359,22 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
 {
         const char *name = dev_name(&chip->dev);
         unsigned int cnt;
+        int rc = 0;
 
         if (chip->flags & TPM_CHIP_FLAG_TPM2)
                 return 0;
 
+        rc = read_log(chip);
+        /*
+         * read_log failure means event log is not supported except for ENOMEM.
+         */
+        if (rc < 0) {
+                if (rc == -ENOMEM)
+                        return -ENODEV;
+                else
+                        return rc;
+        }
+
         cnt = 0;
         chip->bios_dir[cnt] = securityfs_create_dir(name, NULL);
         /* NOTE: securityfs_create_dir can return ENODEV if securityfs is
@@ -376,19 +384,25 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
                 goto err;
         cnt++;
 
+        chip->bin_log_seqops.chip = chip;
+        chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops;
+
         chip->bios_dir[cnt] =
             securityfs_create_file("binary_bios_measurements",
                                    0440, chip->bios_dir[0],
-                                   (void *)&tpm_binary_b_measurements_seqops,
+                                   (void *)&chip->bin_log_seqops,
                                    &tpm_bios_measurements_ops);
         if (IS_ERR(chip->bios_dir[cnt]))
                 goto err;
         cnt++;
 
+        chip->ascii_log_seqops.chip = chip;
+        chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops;
+
         chip->bios_dir[cnt] =
             securityfs_create_file("ascii_bios_measurements",
                                    0440, chip->bios_dir[0],
-                                   (void *)&tpm_ascii_b_measurements_seqops,
+                                   (void *)&chip->ascii_log_seqops,
                                    &tpm_bios_measurements_ops);
         if (IS_ERR(chip->bios_dir[cnt]))
                 goto err;
@@ -405,7 +419,19 @@ err:
 void tpm_bios_log_teardown(struct tpm_chip *chip)
 {
         int i;
+        struct inode *inode;
 
-        for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--)
+        /* securityfs_remove currently doesn't take care of handling sync
+         * between removal and opening of pseudo files. To handle this, a
+         * workaround is added by making i_private = NULL here during removal
+         * and to check it during open(), both within inode_lock()/unlock().
+         * This design ensures that open() either safely gets kref or fails.
+         */
+        for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--) {
+                inode = d_inode(chip->bios_dir[i]);
+                inode_lock(inode);
+                inode->i_private = NULL;
+                inode_unlock(inode);
                 securityfs_remove(chip->bios_dir[i]);
+        }
 }
diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h
index fd3357e3a322..6df2f8e79a8e 100644
--- a/drivers/char/tpm/tpm_eventlog.h
+++ b/drivers/char/tpm/tpm_eventlog.h
@@ -73,7 +73,7 @@ enum tcpa_pc_event_ids {
         HOST_TABLE_OF_DEVICES,
 };
 
-int read_log(struct tpm_bios_log *log);
+int read_log(struct tpm_chip *chip);
 
 #if defined(CONFIG_TCG_IBMVTPM) || defined(CONFIG_TCG_IBMVTPM_MODULE) || \
         defined(CONFIG_ACPI)
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index 570f30c5c5f4..68d891ab55db 100644
--- a/drivers/char/tpm/tpm_of.c
+++ b/drivers/char/tpm/tpm_of.c
@@ -20,12 +20,14 @@
 #include "tpm.h"
 #include "tpm_eventlog.h"
 
-int read_log(struct tpm_bios_log *log)
+int read_log(struct tpm_chip *chip)
 {
         struct device_node *np;
         const u32 *sizep;
         const u64 *basep;
+        struct tpm_bios_log *log;
 
+        log = &chip->log;
         if (log->bios_event_log != NULL) {
                 pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
                 return -EFAULT;