Re: [PATCH] tpm: tpm2-space: Resize session and context buffers dynamically
On Thu, Jun 25, 2020 at 08:13:09AM -0400, Stefan Berger wrote: > On 6/25/20 12:24 AM, Jarkko Sakkinen wrote: > > Re-allocate context and session buffers when needed. Scale them in page > > increments so that the reallocation is only seldomly required, and thus > > causes minimal stress to the system. Add a static maximum limit of four > > pages for buffer sizes. > > > > Cc: James Bottomley > > Suggested-by: Stefan Berger > > Signed-off-by: Jarkko Sakkinen > > --- > > Tested only for compilation. > > drivers/char/tpm/tpm2-space.c | 80 --- > > include/linux/tpm.h | 6 ++- > > 2 files changed, 59 insertions(+), 27 deletions(-) > > > > diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c > > index 982d341d8837..acb9e82bf9e8 100644 > > --- a/drivers/char/tpm/tpm2-space.c > > +++ b/drivers/char/tpm/tpm2-space.c > > @@ -15,6 +15,8 @@ > > #include > > #include "tpm.h" > > +#define TPM2_SPACE_MAX_BUFFER_SIZE (4 * PAGE_SIZE) > > PAGE_SIZE is 64k on ppc64. Rather use 4 * 4096? Better to then just put it as 16384. /Jarkko
Re: [PATCH] tpm: tpm2-space: Resize session and context buffers dynamically
On 6/25/20 12:24 AM, Jarkko Sakkinen wrote: Re-allocate context and session buffers when needed. Scale them in page increments so that the reallocation is only seldomly required, and thus causes minimal stress to the system. Add a static maximum limit of four pages for buffer sizes. Cc: James Bottomley Suggested-by: Stefan Berger Signed-off-by: Jarkko Sakkinen --- Tested only for compilation. drivers/char/tpm/tpm2-space.c | 80 --- include/linux/tpm.h | 6 ++- 2 files changed, 59 insertions(+), 27 deletions(-) diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 982d341d8837..acb9e82bf9e8 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -15,6 +15,8 @@ #include #include "tpm.h" +#define TPM2_SPACE_MAX_BUFFER_SIZE (4 * PAGE_SIZE) PAGE_SIZE is 64k on ppc64. Rather use 4 * 4096? Rest looks good. + enum tpm2_handle_types { TPM2_HT_HMAC_SESSION= 0x0200, TPM2_HT_POLICY_SESSION = 0x0300, @@ -47,9 +49,12 @@ int tpm2_init_space(struct tpm_space *space) space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); if (space->session_buf == NULL) { kfree(space->context_buf); + space->context_buf = NULL; return -ENOMEM; } + space->context_size = PAGE_SIZE; + space->session_size = PAGE_SIZE; return 0; } @@ -116,11 +121,13 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf, return 0; } -static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, -unsigned int buf_size, unsigned int *offset) +static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 **buf, +unsigned int *buf_size, unsigned int *offset) { - struct tpm_buf tbuf; + unsigned int new_buf_size; unsigned int body_size; + struct tpm_buf tbuf; + void *new_buf; int rc; rc = tpm_buf_init(, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE); @@ -131,31 +138,48 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, rc = tpm_transmit_cmd(chip, , 0, NULL); if (rc < 0) { - dev_warn(>dev, "%s: failed with a system error %d\n", -__func__, rc); - tpm_buf_destroy(); - return -EFAULT; + rc = -EFAULT; + goto err; } else if (tpm2_rc_value(rc) == TPM2_RC_REFERENCE_H0) { - tpm_buf_destroy(); - return -ENOENT; + rc = -ENOENT; + goto out; } else if (rc) { - dev_warn(>dev, "%s: failed with a TPM error 0x%04X\n", -__func__, rc); - tpm_buf_destroy(); - return -EFAULT; + rc = -EFAULT; + goto err; } body_size = tpm_buf_length() - TPM_HEADER_SIZE; - if ((*offset + body_size) > buf_size) { - dev_warn(>dev, "%s: out of backing storage\n", __func__); - tpm_buf_destroy(); - return -ENOMEM; + /* We grow the buffer in page increments. */ + new_buf_size = PFN_UP(*offset + body_size); + + if (new_buf_size > TPM2_SPACE_MAX_BUFFER_SIZE) { + rc = -ENOMEM; + goto err; } - memcpy([*offset], [TPM_HEADER_SIZE], body_size); + if (new_buf_size > *buf_size) { + new_buf = krealloc(*buf, new_buf_size, GFP_KERNEL); + if (!new_buf) { + rc = -ENOMEM; + goto err; + } + + *buf = new_buf; + *buf_size = new_buf_size; + } + + memcpy(*buf + *offset, [TPM_HEADER_SIZE], body_size); *offset += body_size; + +out: tpm_buf_destroy(); - return 0; + return rc; + +err: + dev_warn(>dev, "%s: ret=%d\n", __func__, rc); + + tpm_buf_destroy(); + return rc; } void tpm2_flush_space(struct tpm_chip *chip) @@ -311,8 +335,10 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd, sizeof(space->context_tbl)); memcpy(>work_space.session_tbl, >session_tbl, sizeof(space->session_tbl)); - memcpy(chip->work_space.context_buf, space->context_buf, PAGE_SIZE); - memcpy(chip->work_space.session_buf, space->session_buf, PAGE_SIZE); + memcpy(chip->work_space.context_buf, space->context_buf, + space->context_size); + memcpy(chip->work_space.session_buf, space->session_buf, + space->session_size); rc = tpm2_load_space(chip); if (rc) { @@ -492,7 +518,8 @@ static int tpm2_save_space(struct tpm_chip *chip) continue; rc = tpm2_save_context(chip, space->context_tbl[i], -
Re: [PATCH] tpm: tpm2-space: Resize session and context buffers dynamically
On Thu, Jun 25, 2020 at 07:24:20AM +0300, Jarkko Sakkinen wrote: > Re-allocate context and session buffers when needed. Scale them in page > increments so that the reallocation is only seldomly required, and thus > causes minimal stress to the system. Add a static maximum limit of four > pages for buffer sizes. > > Cc: James Bottomley > Suggested-by: Stefan Berger > Signed-off-by: Jarkko Sakkinen I'd actually consider #define TPM2_SPACE_DEFAULT_BUFFER_SIZE PAGE_SIZE #define TPM2_SPACE_MAX_BUFFER_SIZE (4 * PAGE_SIZE) /JQ4KKO
[PATCH] tpm: tpm2-space: Resize session and context buffers dynamically
Re-allocate context and session buffers when needed. Scale them in page increments so that the reallocation is only seldomly required, and thus causes minimal stress to the system. Add a static maximum limit of four pages for buffer sizes. Cc: James Bottomley Suggested-by: Stefan Berger Signed-off-by: Jarkko Sakkinen --- Tested only for compilation. drivers/char/tpm/tpm2-space.c | 80 --- include/linux/tpm.h | 6 ++- 2 files changed, 59 insertions(+), 27 deletions(-) diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 982d341d8837..acb9e82bf9e8 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -15,6 +15,8 @@ #include #include "tpm.h" +#define TPM2_SPACE_MAX_BUFFER_SIZE (4 * PAGE_SIZE) + enum tpm2_handle_types { TPM2_HT_HMAC_SESSION= 0x0200, TPM2_HT_POLICY_SESSION = 0x0300, @@ -47,9 +49,12 @@ int tpm2_init_space(struct tpm_space *space) space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); if (space->session_buf == NULL) { kfree(space->context_buf); + space->context_buf = NULL; return -ENOMEM; } + space->context_size = PAGE_SIZE; + space->session_size = PAGE_SIZE; return 0; } @@ -116,11 +121,13 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf, return 0; } -static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, -unsigned int buf_size, unsigned int *offset) +static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 **buf, +unsigned int *buf_size, unsigned int *offset) { - struct tpm_buf tbuf; + unsigned int new_buf_size; unsigned int body_size; + struct tpm_buf tbuf; + void *new_buf; int rc; rc = tpm_buf_init(, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE); @@ -131,31 +138,48 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, rc = tpm_transmit_cmd(chip, , 0, NULL); if (rc < 0) { - dev_warn(>dev, "%s: failed with a system error %d\n", -__func__, rc); - tpm_buf_destroy(); - return -EFAULT; + rc = -EFAULT; + goto err; } else if (tpm2_rc_value(rc) == TPM2_RC_REFERENCE_H0) { - tpm_buf_destroy(); - return -ENOENT; + rc = -ENOENT; + goto out; } else if (rc) { - dev_warn(>dev, "%s: failed with a TPM error 0x%04X\n", -__func__, rc); - tpm_buf_destroy(); - return -EFAULT; + rc = -EFAULT; + goto err; } body_size = tpm_buf_length() - TPM_HEADER_SIZE; - if ((*offset + body_size) > buf_size) { - dev_warn(>dev, "%s: out of backing storage\n", __func__); - tpm_buf_destroy(); - return -ENOMEM; + /* We grow the buffer in page increments. */ + new_buf_size = PFN_UP(*offset + body_size); + + if (new_buf_size > TPM2_SPACE_MAX_BUFFER_SIZE) { + rc = -ENOMEM; + goto err; } - memcpy([*offset], [TPM_HEADER_SIZE], body_size); + if (new_buf_size > *buf_size) { + new_buf = krealloc(*buf, new_buf_size, GFP_KERNEL); + if (!new_buf) { + rc = -ENOMEM; + goto err; + } + + *buf = new_buf; + *buf_size = new_buf_size; + } + + memcpy(*buf + *offset, [TPM_HEADER_SIZE], body_size); *offset += body_size; + +out: tpm_buf_destroy(); - return 0; + return rc; + +err: + dev_warn(>dev, "%s: ret=%d\n", __func__, rc); + + tpm_buf_destroy(); + return rc; } void tpm2_flush_space(struct tpm_chip *chip) @@ -311,8 +335,10 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd, sizeof(space->context_tbl)); memcpy(>work_space.session_tbl, >session_tbl, sizeof(space->session_tbl)); - memcpy(chip->work_space.context_buf, space->context_buf, PAGE_SIZE); - memcpy(chip->work_space.session_buf, space->session_buf, PAGE_SIZE); + memcpy(chip->work_space.context_buf, space->context_buf, + space->context_size); + memcpy(chip->work_space.session_buf, space->session_buf, + space->session_size); rc = tpm2_load_space(chip); if (rc) { @@ -492,7 +518,8 @@ static int tpm2_save_space(struct tpm_chip *chip) continue; rc = tpm2_save_context(chip, space->context_tbl[i], - space->context_buf, PAGE_SIZE, + >context_buf, +