| Message ID | 20171024184235.GC1806@obsidianresearch.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Jason, Nice to see this patch. Some minor comments below. On 25 October 2017 at 00:12, Jason Gunthorpe <jgunthorpe@obsidianresearch.com> wrote: > The tpm-rng.c approach is completely inconsistent with how the kernel > handles hotplug. Instead manage a hwrng device for each TPM. This will > cause the kernel to read entropy from the TPM when it is plugged in, > and allow access to the TPM rng via /dev/hwrng. > > Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com> > Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> > Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> > --- > drivers/char/hw_random/Kconfig | 13 ----------- > drivers/char/hw_random/Makefile | 1 - > drivers/char/hw_random/tpm-rng.c | 50 ---------------------------------------- > drivers/char/tpm/Kconfig | 13 +++++++++++ > drivers/char/tpm/tpm-chip.c | 41 ++++++++++++++++++++++++++++---- > drivers/char/tpm/tpm-interface.c | 37 ++++++++++++++++------------- > drivers/char/tpm/tpm.h | 5 ++++ > 7 files changed, 76 insertions(+), 84 deletions(-) > delete mode 100644 drivers/char/hw_random/tpm-rng.c > > All, > > It is such a good idea, I took PrasannaKumar's patch, reviewed and > revised it to the level it could be merged. Thank you for this. > This is compile tested only. > > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig > index 95a031e9eced07..a20fed182cbcce 100644 > --- a/drivers/char/hw_random/Kconfig > +++ b/drivers/char/hw_random/Kconfig > @@ -306,19 +306,6 @@ config HW_RANDOM_POWERNV > > If unsure, say Y. > > -config HW_RANDOM_TPM > - tristate "TPM HW Random Number Generator support" > - depends on TCG_TPM > - default HW_RANDOM > - ---help--- > - This driver provides kernel-side support for the Random Number > - Generator in the Trusted Platform Module > - > - To compile this driver as a module, choose M here: the > - module will be called tpm-rng. > - > - If unsure, say Y. > - > config HW_RANDOM_HISI > tristate "Hisilicon Random Number Generator support" > depends on HW_RANDOM && ARCH_HISI > diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile > index 39a67defac67cb..91cb8e8213e7c1 100644 > --- a/drivers/char/hw_random/Makefile > +++ b/drivers/char/hw_random/Makefile > @@ -26,7 +26,6 @@ obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o > obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o > obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o > obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o > -obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o > obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o > obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o > obj-$(CONFIG_HW_RANDOM_MSM) += msm-rng.o > diff --git a/drivers/char/hw_random/tpm-rng.c b/drivers/char/hw_random/tpm-rng.c > deleted file mode 100644 > index d6d448266f0752..00000000000000 > --- a/drivers/char/hw_random/tpm-rng.c > +++ /dev/null > @@ -1,50 +0,0 @@ > -/* > - * Copyright (C) 2012 Kent Yoder IBM Corporation > - * > - * HWRNG interfaces to pull RNG data from a TPM > - * > - * This program is free software; you can redistribute it and/or modify > - * it under the terms of the GNU General Public License version 2 as > - * published by the Free Software Foundation. > - * > - * This program is distributed in the hope that it will be useful, > - * but WITHOUT ANY WARRANTY; without even the implied warranty of > - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > - * GNU General Public License for more details. > - * > - * You should have received a copy of the GNU General Public License > - * along with this program; if not, write to the Free Software > - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA > - */ > - > -#include <linux/module.h> > -#include <linux/hw_random.h> > -#include <linux/tpm.h> > - > -#define MODULE_NAME "tpm-rng" > - > -static int tpm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) > -{ > - return tpm_get_random(TPM_ANY_NUM, data, max); > -} > - > -static struct hwrng tpm_rng = { > - .name = MODULE_NAME, > - .read = tpm_rng_read, > -}; > - > -static int __init rng_init(void) > -{ > - return hwrng_register(&tpm_rng); > -} > -module_init(rng_init); > - > -static void __exit rng_exit(void) > -{ > - hwrng_unregister(&tpm_rng); > -} > -module_exit(rng_exit); > - > -MODULE_LICENSE("GPL v2"); > -MODULE_AUTHOR("Kent Yoder <key@linux.vnet.ibm.com>"); > -MODULE_DESCRIPTION("RNG driver for TPM devices"); > diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig > index a30352202f1fdc..a95725fa77789e 100644 > --- a/drivers/char/tpm/Kconfig > +++ b/drivers/char/tpm/Kconfig > @@ -26,6 +26,19 @@ menuconfig TCG_TPM > > if TCG_TPM > > +config HW_RANDOM_TPM > + tristate "TPM HW Random Number Generator support" > + depends on TCG_TPM && HW_RANDOM > + default HW_RANDOM > + ---help--- > + This driver provides kernel-side support for the Random Number > + Generator in the Trusted Platform Module > + > + To compile this driver as a module, choose M here: the > + module will be called tpm-rng. > + > + If unsure, say Y. > + > config TCG_TIS_CORE > tristate > ---help--- > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index 0eca20c5a80cf2..f3571406fb2995 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -26,6 +26,7 @@ > #include <linux/spinlock.h> > #include <linux/freezer.h> > #include <linux/major.h> > +#include <linux/hw_random.h> > #include "tpm.h" > #include "tpm_eventlog.h" > > @@ -387,6 +388,26 @@ static int tpm_add_legacy_sysfs(struct tpm_chip *chip) > > return 0; > } > + > +static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) > +{ > + struct tpm_chip *chip = container_of(rng, struct tpm_chip, tpm_hwrng); > + > + return tpm_get_random_dev(chip, data, max); > +} > + > +static int tpm_add_hwrng(struct tpm_chip *chip) > +{ > + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > + return 0; Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if condition can be avoided. > + > + snprintf(chip->tpm_hwrng_name, sizeof(chip->tpm_hwrng_name), > + "tpm-rng-%d", chip->dev_num); > + chip->tpm_hwrng.name = chip->tpm_hwrng_name; > + chip->tpm_hwrng.read = tpm_hwrng_read; > + return hwrng_register(&chip->tpm_hwrng); > +} > + > /* > * tpm_chip_register() - create a character device for the TPM chip > * @chip: TPM chip to use. > @@ -419,11 +440,13 @@ int tpm_chip_register(struct tpm_chip *chip) > > tpm_add_ppi(chip); > > + rc = tpm_add_hwrng(chip); > + if (rc) > + goto out_ppi; > + > rc = tpm_add_char_device(chip); > - if (rc) { > - tpm_bios_log_teardown(chip); > - return rc; > - } > + if (rc) > + goto out_hwrng; > > rc = tpm_add_legacy_sysfs(chip); > if (rc) { > @@ -432,6 +455,14 @@ int tpm_chip_register(struct tpm_chip *chip) > } > > return 0; > + > +out_hwrng: > + if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > + hwrng_unregister(&chip->tpm_hwrng); > +out_ppi: > + tpm_bios_log_teardown(chip); > + > + return rc; > } > EXPORT_SYMBOL_GPL(tpm_chip_register); > > @@ -451,6 +482,8 @@ EXPORT_SYMBOL_GPL(tpm_chip_register); > void tpm_chip_unregister(struct tpm_chip *chip) > { > tpm_del_legacy_sysfs(chip); > + if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > + hwrng_unregister(&chip->tpm_hwrng); > tpm_bios_log_teardown(chip); > if (chip->flags & TPM_CHIP_FLAG_TPM2) > cdev_device_del(&chip->cdevs, &chip->devs); > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 1d6729be4cd637..310de288549818 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -1194,9 +1194,8 @@ static const struct tpm_input_header tpm_getrandom_header = { > * > * Returns < 0 on error and the number of bytes read on success > */ > -int tpm_get_random(u32 chip_num, u8 *out, size_t max) > +int tpm_get_random_dev(struct tpm_chip *chip, u8 *out, size_t max) > { > - struct tpm_chip *chip; > struct tpm_cmd_t tpm_cmd; > u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength; > int err, total = 0, retries = 5; > @@ -1205,15 +1204,8 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) > if (!out || !num_bytes || max > TPM_MAX_RNG_DATA) > return -EINVAL; > > - chip = tpm_chip_find_get(chip_num); > - if (chip == NULL) > - return -ENODEV; > - > - if (chip->flags & TPM_CHIP_FLAG_TPM2) { > - err = tpm2_get_random(chip, out, max); > - tpm_put_ops(chip); > - return err; > - } > + if (chip->flags & TPM_CHIP_FLAG_TPM2) > + return tpm2_get_random(chip, out, max); > > do { > tpm_cmd.header.in = tpm_getrandom_header; > @@ -1231,10 +1223,9 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) > > rlength = be32_to_cpu(tpm_cmd.header.out.length); > if (rlength < offsetof(struct tpm_getrandom_out, rng_data) + > - recd) { > - total = -EFAULT; > - break; > - } > + recd) > + return -EFAULT; > + > memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd); > > dest += recd; > @@ -1242,9 +1233,23 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) > num_bytes -= recd; > } while (retries-- && total < max); > > - tpm_put_ops(chip); > return total ? total : -EIO; > } > + > +int tpm_get_random(u32 chip_num, u8 *out, size_t max) > +{ > + int rc; > + struct tpm_chip *chip; > + > + chip = tpm_chip_find_get(chip_num); > + if (chip == NULL) > + return -ENODEV; > + > + rc = tpm_get_random_dev(chip, out, max); > + > + tpm_put_ops(chip); > + return rc; > +} > EXPORT_SYMBOL_GPL(tpm_get_random); > > /** > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 2d5466a72e40f8..0e41e044d81be2 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -26,6 +26,7 @@ > #include <linux/module.h> > #include <linux/delay.h> > #include <linux/fs.h> > +#include <linux/hw_random.h> > #include <linux/mutex.h> > #include <linux/sched.h> > #include <linux/platform_device.h> > @@ -210,6 +211,9 @@ struct tpm_chip { > int dev_num; /* /dev/tpm# */ > unsigned long is_open; /* only one allowed */ > > + char tpm_hwrng_name[64]; > + struct hwrng tpm_hwrng; > + Can this also be put inside the #ifdef? > struct mutex tpm_mutex; /* tpm is processing */ > > unsigned long timeout_a; /* jiffies */ > @@ -548,6 +552,7 @@ void tpm_chip_unregister(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); > +int tpm_get_random_dev(struct tpm_chip *chip, u8 *out, size_t max); > > #ifdef CONFIG_ACPI > extern void tpm_add_ppi(struct tpm_chip *chip); > -- > 2.7.4 > Regards, PrasannaKumar
On Wed, Oct 25, 2017 at 08:15:09PM +0530, PrasannaKumar Muralidharan wrote: > > +static int tpm_add_hwrng(struct tpm_chip *chip) > > +{ > > + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > > + return 0; > > Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if > condition can be avoided. Generally speaking IS_ENABLED is prefered over #ifdef as it reduces the set of compilation combinations. Jason
Hi Jason, On 25 October 2017 at 20:48, Jason Gunthorpe <jgunthorpe@obsidianresearch.com> wrote: > On Wed, Oct 25, 2017 at 08:15:09PM +0530, PrasannaKumar Muralidharan > wrote: > >> > +static int tpm_add_hwrng(struct tpm_chip *chip) >> > +{ >> > + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) >> > + return 0; >> >> Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if >> condition can be avoided. > > Generally speaking IS_ENABLED is prefered over #ifdef as it reduces the > set of compilation combinations. Oh okay. No issues then. Regards, PrasannaKumar
On Wed, Oct 25, 2017 at 08:15:09PM +0530, PrasannaKumar Muralidharan wrote: > > + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > > + return 0; > > Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if > condition can be avoided. Nope. There is no reason to avoid the if-condition. Compiler will take care of it. IS_ENABLED() macro is available just for the purpose Jason is using it. > > + char tpm_hwrng_name[64]; > > + struct hwrng tpm_hwrng; > > + > > Can this also be put inside the #ifdef? Yes. It should be inside #ifdef. /Jarkko
On Wed, Oct 25, 2017 at 08:58:17PM +0200, Jarkko Sakkinen wrote: > On Wed, Oct 25, 2017 at 08:15:09PM +0530, PrasannaKumar Muralidharan wrote: > > > + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > > > + return 0; > > > > Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if > > condition can be avoided. > > Nope. There is no reason to avoid the if-condition. Compiler will take > care of it. IS_ENABLED() macro is available just for the purpose Jason > is using it. > > > > + char tpm_hwrng_name[64]; > > > + struct hwrng tpm_hwrng; > > > + > > > > Can this also be put inside the #ifdef? > > Yes. It should be inside #ifdef. Then we need #idefs in the .c code, IS_ENABLED is not enough :\ I don't think the few bytes matters enough to bother. Jason
On Wed, Oct 25, 2017 at 01:37:07PM -0600, Jason Gunthorpe wrote: > On Wed, Oct 25, 2017 at 08:58:17PM +0200, Jarkko Sakkinen wrote: > > On Wed, Oct 25, 2017 at 08:15:09PM +0530, PrasannaKumar Muralidharan wrote: > > > > + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) > > > > + return 0; > > > > > > Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if > > > condition can be avoided. > > > > Nope. There is no reason to avoid the if-condition. Compiler will take > > care of it. IS_ENABLED() macro is available just for the purpose Jason > > is using it. > > > > > > + char tpm_hwrng_name[64]; > > > > + struct hwrng tpm_hwrng; > > > > + > > > > > > Can this also be put inside the #ifdef? > > > > Yes. It should be inside #ifdef. > > Then we need #idefs in the .c code, IS_ENABLED is not enough :\ I > don't think the few bytes matters enough to bother. > > Jason I'll buy that! A minor tidbit: could the tpm_ prefix removed from those fields? /Jarkko
On Wed, Oct 25, 2017 at 10:00:30PM +0200, Jarkko Sakkinen wrote:
> A minor tidbit: could the tpm_ prefix removed from those fields?
Yes, in v2
I will send v2 when you land your rework patch as this will depend on it.
Jason
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 95a031e9eced07..a20fed182cbcce 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -306,19 +306,6 @@ config HW_RANDOM_POWERNV If unsure, say Y. -config HW_RANDOM_TPM - tristate "TPM HW Random Number Generator support" - depends on TCG_TPM - default HW_RANDOM - ---help--- - This driver provides kernel-side support for the Random Number - Generator in the Trusted Platform Module - - To compile this driver as a module, choose M here: the - module will be called tpm-rng. - - If unsure, say Y. - config HW_RANDOM_HISI tristate "Hisilicon Random Number Generator support" depends on HW_RANDOM && ARCH_HISI diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 39a67defac67cb..91cb8e8213e7c1 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -26,7 +26,6 @@ obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o -obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o obj-$(CONFIG_HW_RANDOM_MSM) += msm-rng.o diff --git a/drivers/char/hw_random/tpm-rng.c b/drivers/char/hw_random/tpm-rng.c deleted file mode 100644 index d6d448266f0752..00000000000000 --- a/drivers/char/hw_random/tpm-rng.c +++ /dev/null @@ -1,50 +0,0 @@ -/* - * Copyright (C) 2012 Kent Yoder IBM Corporation - * - * HWRNG interfaces to pull RNG data from a TPM - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -#include <linux/module.h> -#include <linux/hw_random.h> -#include <linux/tpm.h> - -#define MODULE_NAME "tpm-rng" - -static int tpm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) -{ - return tpm_get_random(TPM_ANY_NUM, data, max); -} - -static struct hwrng tpm_rng = { - .name = MODULE_NAME, - .read = tpm_rng_read, -}; - -static int __init rng_init(void) -{ - return hwrng_register(&tpm_rng); -} -module_init(rng_init); - -static void __exit rng_exit(void) -{ - hwrng_unregister(&tpm_rng); -} -module_exit(rng_exit); - -MODULE_LICENSE("GPL v2"); -MODULE_AUTHOR("Kent Yoder <key@linux.vnet.ibm.com>"); -MODULE_DESCRIPTION("RNG driver for TPM devices"); diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index a30352202f1fdc..a95725fa77789e 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -26,6 +26,19 @@ menuconfig TCG_TPM if TCG_TPM +config HW_RANDOM_TPM + tristate "TPM HW Random Number Generator support" + depends on TCG_TPM && HW_RANDOM + default HW_RANDOM + ---help--- + This driver provides kernel-side support for the Random Number + Generator in the Trusted Platform Module + + To compile this driver as a module, choose M here: the + module will be called tpm-rng. + + If unsure, say Y. + config TCG_TIS_CORE tristate ---help--- diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 0eca20c5a80cf2..f3571406fb2995 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -26,6 +26,7 @@ #include <linux/spinlock.h> #include <linux/freezer.h> #include <linux/major.h> +#include <linux/hw_random.h> #include "tpm.h" #include "tpm_eventlog.h" @@ -387,6 +388,26 @@ static int tpm_add_legacy_sysfs(struct tpm_chip *chip) return 0; } + +static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct tpm_chip *chip = container_of(rng, struct tpm_chip, tpm_hwrng); + + return tpm_get_random_dev(chip, data, max); +} + +static int tpm_add_hwrng(struct tpm_chip *chip) +{ + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) + return 0; + + snprintf(chip->tpm_hwrng_name, sizeof(chip->tpm_hwrng_name), + "tpm-rng-%d", chip->dev_num); + chip->tpm_hwrng.name = chip->tpm_hwrng_name; + chip->tpm_hwrng.read = tpm_hwrng_read; + return hwrng_register(&chip->tpm_hwrng); +} + /* * tpm_chip_register() - create a character device for the TPM chip * @chip: TPM chip to use. @@ -419,11 +440,13 @@ int tpm_chip_register(struct tpm_chip *chip) tpm_add_ppi(chip); + rc = tpm_add_hwrng(chip); + if (rc) + goto out_ppi; + rc = tpm_add_char_device(chip); - if (rc) { - tpm_bios_log_teardown(chip); - return rc; - } + if (rc) + goto out_hwrng; rc = tpm_add_legacy_sysfs(chip); if (rc) { @@ -432,6 +455,14 @@ int tpm_chip_register(struct tpm_chip *chip) } return 0; + +out_hwrng: + if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) + hwrng_unregister(&chip->tpm_hwrng); +out_ppi: + tpm_bios_log_teardown(chip); + + return rc; } EXPORT_SYMBOL_GPL(tpm_chip_register); @@ -451,6 +482,8 @@ EXPORT_SYMBOL_GPL(tpm_chip_register); void tpm_chip_unregister(struct tpm_chip *chip) { tpm_del_legacy_sysfs(chip); + if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) + hwrng_unregister(&chip->tpm_hwrng); tpm_bios_log_teardown(chip); if (chip->flags & TPM_CHIP_FLAG_TPM2) cdev_device_del(&chip->cdevs, &chip->devs); diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 1d6729be4cd637..310de288549818 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1194,9 +1194,8 @@ static const struct tpm_input_header tpm_getrandom_header = { * * Returns < 0 on error and the number of bytes read on success */ -int tpm_get_random(u32 chip_num, u8 *out, size_t max) +int tpm_get_random_dev(struct tpm_chip *chip, u8 *out, size_t max) { - struct tpm_chip *chip; struct tpm_cmd_t tpm_cmd; u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength; int err, total = 0, retries = 5; @@ -1205,15 +1204,8 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) if (!out || !num_bytes || max > TPM_MAX_RNG_DATA) return -EINVAL; - chip = tpm_chip_find_get(chip_num); - if (chip == NULL) - return -ENODEV; - - if (chip->flags & TPM_CHIP_FLAG_TPM2) { - err = tpm2_get_random(chip, out, max); - tpm_put_ops(chip); - return err; - } + if (chip->flags & TPM_CHIP_FLAG_TPM2) + return tpm2_get_random(chip, out, max); do { tpm_cmd.header.in = tpm_getrandom_header; @@ -1231,10 +1223,9 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) rlength = be32_to_cpu(tpm_cmd.header.out.length); if (rlength < offsetof(struct tpm_getrandom_out, rng_data) + - recd) { - total = -EFAULT; - break; - } + recd) + return -EFAULT; + memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd); dest += recd; @@ -1242,9 +1233,23 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) num_bytes -= recd; } while (retries-- && total < max); - tpm_put_ops(chip); return total ? total : -EIO; } + +int tpm_get_random(u32 chip_num, u8 *out, size_t max) +{ + int rc; + struct tpm_chip *chip; + + chip = tpm_chip_find_get(chip_num); + if (chip == NULL) + return -ENODEV; + + rc = tpm_get_random_dev(chip, out, max); + + tpm_put_ops(chip); + return rc; +} EXPORT_SYMBOL_GPL(tpm_get_random); /** diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 2d5466a72e40f8..0e41e044d81be2 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -26,6 +26,7 @@ #include <linux/module.h> #include <linux/delay.h> #include <linux/fs.h> +#include <linux/hw_random.h> #include <linux/mutex.h> #include <linux/sched.h> #include <linux/platform_device.h> @@ -210,6 +211,9 @@ struct tpm_chip { int dev_num; /* /dev/tpm# */ unsigned long is_open; /* only one allowed */ + char tpm_hwrng_name[64]; + struct hwrng tpm_hwrng; + struct mutex tpm_mutex; /* tpm is processing */ unsigned long timeout_a; /* jiffies */ @@ -548,6 +552,7 @@ void tpm_chip_unregister(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); +int tpm_get_random_dev(struct tpm_chip *chip, u8 *out, size_t max); #ifdef CONFIG_ACPI extern void tpm_add_ppi(struct tpm_chip *chip);