This is a note to let you know that I've just added the patch titled
tpm: Replace device number bitmap with IDR
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tpm-replace-device-number-bitmap-with-idr.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 15516788e581eb32ec1c50e5f00aba3faf95d817 Mon Sep 17 00:00:00 2001
From: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
Date: Mon, 29 Feb 2016 08:53:02 -0500
Subject: tpm: Replace device number bitmap with IDR
From: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
commit 15516788e581eb32ec1c50e5f00aba3faf95d817 upstream.
Replace the device number bitmap with IDR. Extend the number of devices we
can create to 64k.
Since an IDR allows us to associate a pointer with an ID, we use this now
to rewrite tpm_chip_find_get() to simply look up the chip pointer by the
given device ID.
Protect the IDR calls with a mutex.
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-chip.c | 84 ++++++++++++++++++++-------------------
drivers/char/tpm/tpm-interface.c | 1
drivers/char/tpm/tpm.h | 5 --
3 files changed, 48 insertions(+), 42 deletions(-)
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -29,9 +29,8 @@
#include "tpm.h"
#include "tpm_eventlog.h"
-static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
-static LIST_HEAD(tpm_chip_list);
-static DEFINE_SPINLOCK(driver_lock);
+DEFINE_IDR(dev_nums_idr);
+static DEFINE_MUTEX(idr_lock);
struct class *tpm_class;
dev_t tpm_devt;
@@ -92,20 +91,30 @@ EXPORT_SYMBOL_GPL(tpm_put_ops);
*/
struct tpm_chip *tpm_chip_find_get(int chip_num)
{
- struct tpm_chip *pos, *chip = NULL;
+ struct tpm_chip *chip, *res = NULL;
+ int chip_prev;
- rcu_read_lock();
- list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
- if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
- continue;
-
- /* rcu prevents chip from being free'd */
- if (!tpm_try_get_ops(pos))
- chip = pos;
- break;
+ mutex_lock(&idr_lock);
+
+ if (chip_num == TPM_ANY_NUM) {
+ chip_num = 0;
+ do {
+ chip_prev = chip_num;
+ chip = idr_get_next(&dev_nums_idr, &chip_num);
+ if (chip && !tpm_try_get_ops(chip)) {
+ res = chip;
+ break;
+ }
+ } while (chip_prev != chip_num);
+ } else {
+ chip = idr_find_slowpath(&dev_nums_idr, chip_num);
+ if (chip && !tpm_try_get_ops(chip))
+ res = chip;
}
- rcu_read_unlock();
- return chip;
+
+ mutex_unlock(&idr_lock);
+
+ return res;
}
/**
@@ -118,9 +127,10 @@ static void tpm_dev_release(struct devic
{
struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
- spin_lock(&driver_lock);
- clear_bit(chip->dev_num, dev_mask);
- spin_unlock(&driver_lock);
+ mutex_lock(&idr_lock);
+ idr_remove(&dev_nums_idr, chip->dev_num);
+ mutex_unlock(&idr_lock);
+
kfree(chip);
}
@@ -180,21 +190,18 @@ struct tpm_chip *tpmm_chip_alloc(struct
mutex_init(&chip->tpm_mutex);
init_rwsem(&chip->ops_sem);
- INIT_LIST_HEAD(&chip->list);
chip->ops = ops;
- spin_lock(&driver_lock);
- chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
- spin_unlock(&driver_lock);
-
- if (chip->dev_num >= TPM_NUM_DEVICES) {
+ mutex_lock(&idr_lock);
+ rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
+ mutex_unlock(&idr_lock);
+ if (rc < 0) {
dev_err(dev, "No available tpm device numbers\n");
kfree(chip);
- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(rc);
}
-
- set_bit(chip->dev_num, dev_mask);
+ chip->dev_num = rc;
scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num);
@@ -252,19 +259,28 @@ static int tpm_add_char_device(struct tp
return rc;
}
+ /* Make the chip available. */
+ mutex_lock(&idr_lock);
+ idr_replace(&dev_nums_idr, chip, chip->dev_num);
+ mutex_unlock(&idr_lock);
+
return rc;
}
static void tpm_del_char_device(struct tpm_chip *chip)
{
cdev_del(&chip->cdev);
+ device_del(&chip->dev);
+
+ /* Make the chip unavailable. */
+ mutex_lock(&idr_lock);
+ idr_replace(&dev_nums_idr, NULL, chip->dev_num);
+ mutex_unlock(&idr_lock);
/* Make the driver uncallable. */
down_write(&chip->ops_sem);
chip->ops = NULL;
up_write(&chip->ops_sem);
-
- device_del(&chip->dev);
}
static int tpm1_chip_register(struct tpm_chip *chip)
@@ -319,11 +335,6 @@ int tpm_chip_register(struct tpm_chip *c
if (rc)
goto out_err;
- /* Make the chip available. */
- spin_lock(&driver_lock);
- list_add_tail_rcu(&chip->list, &tpm_chip_list);
- spin_unlock(&driver_lock);
-
chip->flags |= TPM_CHIP_FLAG_REGISTERED;
if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
@@ -360,11 +371,6 @@ void tpm_chip_unregister(struct tpm_chip
if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))
return;
- spin_lock(&driver_lock);
- list_del_rcu(&chip->list);
- spin_unlock(&driver_lock);
- synchronize_rcu();
-
if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1127,6 +1127,7 @@ static int __init tpm_init(void)
static void __exit tpm_exit(void)
{
+ idr_destroy(&dev_nums_idr);
class_destroy(tpm_class);
unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
}
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -34,7 +34,7 @@
enum tpm_const {
TPM_MINOR = 224, /* officially assigned */
TPM_BUFSIZE = 4096,
- TPM_NUM_DEVICES = 256,
+ TPM_NUM_DEVICES = 65536,
TPM_RETRY = 50, /* 5 seconds */
};
@@ -200,8 +200,6 @@ struct tpm_chip {
acpi_handle acpi_dev_handle;
char ppi_version[TPM_PPI_VERSION_LEN + 1];
#endif /* CONFIG_ACPI */
-
- struct list_head list;
};
#define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
@@ -497,6 +495,7 @@ static inline void tpm_buf_append_u32(st
extern struct class *tpm_class;
extern dev_t tpm_devt;
extern const struct file_operations tpm_fops;
+extern struct idr dev_nums_idr;
enum tpm_transmit_flags {
TPM_TRANSMIT_UNLOCKED = BIT(0),
Patches currently in stable-queue which might be from stefanb@xxxxxxxxxxxxxxxxxx are
queue-4.4/tpm-fix-a-kernel-memory-leak-in-tpm-sysfs.c.patch
queue-4.4/tpm-replace-device-number-bitmap-with-idr.patch