Messages in this thread | | | Date | Thu, 2 Jul 2020 16:55:44 -0700 | From | Jerry Snitselaar <> | Subject | Re: [PATCH] tpm: Define TPM2_SPACE_BUFFER_SIZE to replace the use of PAGE_SIZE |
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On Fri Jul 03 20, Jarkko Sakkinen wrote: >The size of the buffers for storing context's and sessions can vary from >arch to arch as PAGE_SIZE can be anything between 4 kB and 256 kB (the >maximum for PPC64). Define a fixed buffer size set to 16 kB. This should be >enough for most use with three handles (that is how many we allow at the >moment). Parametrize the buffer size while doing this, so that it is easier >to revisit this later on if required. > >Reported-by: Stefan Berger <stefanb@linux.ibm.com> >Cc: stable@vger.kernel.org >Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces") >Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
>--- >v2: Also use the new buffer size for chip->work_buffer (reported by stefanb) > drivers/char/tpm/tpm-chip.c | 9 ++------- > drivers/char/tpm/tpm.h | 5 ++++- > drivers/char/tpm/tpm2-space.c | 26 ++++++++++++++++---------- > drivers/char/tpm/tpmrm-dev.c | 2 +- > include/linux/tpm.h | 5 +++-- > 5 files changed, 26 insertions(+), 21 deletions(-) > >diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c >index 8c77e88012e9..ddaeceb7e109 100644 >--- a/drivers/char/tpm/tpm-chip.c >+++ b/drivers/char/tpm/tpm-chip.c >@@ -386,13 +386,8 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, > chip->cdev.owner = THIS_MODULE; > chip->cdevs.owner = THIS_MODULE; > >- chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); >- if (!chip->work_space.context_buf) { >- rc = -ENOMEM; >- goto out; >- } >- chip->work_space.session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); >- if (!chip->work_space.session_buf) { >+ rc = tpm2_init_space(&chip->work_space, TPM2_SPACE_BUFFER_SIZE); >+ if (rc) { > rc = -ENOMEM; > goto out; > } >diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h >index 0fbcede241ea..947d1db0a5cc 100644 >--- a/drivers/char/tpm/tpm.h >+++ b/drivers/char/tpm/tpm.h >@@ -59,6 +59,9 @@ enum tpm_addr { > > #define TPM_TAG_RQU_COMMAND 193 > >+/* TPM2 specific constants. */ >+#define TPM2_SPACE_BUFFER_SIZE 16384 /* 16 kB */ >+ > struct stclear_flags_t { > __be16 tag; > u8 deactivated; >@@ -228,7 +231,7 @@ unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal); > int tpm2_probe(struct tpm_chip *chip); > int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip); > int tpm2_find_cc(struct tpm_chip *chip, u32 cc); >-int tpm2_init_space(struct tpm_space *space); >+int tpm2_init_space(struct tpm_space *space, unsigned int buf_size); > void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space); > void tpm2_flush_space(struct tpm_chip *chip); > int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd, >diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c >index 982d341d8837..784b8b3cb903 100644 >--- a/drivers/char/tpm/tpm2-space.c >+++ b/drivers/char/tpm/tpm2-space.c >@@ -38,18 +38,21 @@ static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space) > } > } > >-int tpm2_init_space(struct tpm_space *space) >+int tpm2_init_space(struct tpm_space *space, unsigned int buf_size) > { >- space->context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); >+ space->context_buf = kzalloc(buf_size, GFP_KERNEL); > if (!space->context_buf) > return -ENOMEM; > >- space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); >+ space->session_buf = kzalloc(buf_size, GFP_KERNEL); > if (space->session_buf == NULL) { > kfree(space->context_buf); >+ /* Prevent caller getting a dangling pointer. */ >+ space->context_buf = NULL; > return -ENOMEM; > } > >+ space->buf_size = buf_size; > return 0; > } > >@@ -311,8 +314,10 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd, > sizeof(space->context_tbl)); > memcpy(&chip->work_space.session_tbl, &space->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->buf_size); >+ memcpy(chip->work_space.session_buf, space->session_buf, >+ space->buf_size); > > rc = tpm2_load_space(chip); > if (rc) { >@@ -492,7 +497,7 @@ static int tpm2_save_space(struct tpm_chip *chip) > continue; > > rc = tpm2_save_context(chip, space->context_tbl[i], >- space->context_buf, PAGE_SIZE, >+ space->context_buf, space->buf_size, > &offset); > if (rc == -ENOENT) { > space->context_tbl[i] = 0; >@@ -509,9 +514,8 @@ static int tpm2_save_space(struct tpm_chip *chip) > continue; > > rc = tpm2_save_context(chip, space->session_tbl[i], >- space->session_buf, PAGE_SIZE, >+ space->session_buf, space->buf_size, > &offset); >- > if (rc == -ENOENT) { > /* handle error saving session, just forget it */ > space->session_tbl[i] = 0; >@@ -557,8 +561,10 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, > sizeof(space->context_tbl)); > memcpy(&space->session_tbl, &chip->work_space.session_tbl, > sizeof(space->session_tbl)); >- memcpy(space->context_buf, chip->work_space.context_buf, PAGE_SIZE); >- memcpy(space->session_buf, chip->work_space.session_buf, PAGE_SIZE); >+ memcpy(space->context_buf, chip->work_space.context_buf, >+ space->buf_size); >+ memcpy(space->session_buf, chip->work_space.session_buf, >+ space->buf_size); > > return 0; > out: >diff --git a/drivers/char/tpm/tpmrm-dev.c b/drivers/char/tpm/tpmrm-dev.c >index 7a0a7051a06f..eef0fb06ea83 100644 >--- a/drivers/char/tpm/tpmrm-dev.c >+++ b/drivers/char/tpm/tpmrm-dev.c >@@ -21,7 +21,7 @@ static int tpmrm_open(struct inode *inode, struct file *file) > if (priv == NULL) > return -ENOMEM; > >- rc = tpm2_init_space(&priv->space); >+ rc = tpm2_init_space(&priv->space, TPM2_SPACE_BUFFER_SIZE); > if (rc) { > kfree(priv); > return -ENOMEM; >diff --git a/include/linux/tpm.h b/include/linux/tpm.h >index 03e9b184411b..d501156fedda 100644 >--- a/include/linux/tpm.h >+++ b/include/linux/tpm.h >@@ -93,9 +93,10 @@ enum tpm_duration { > > struct tpm_space { > u32 context_tbl[3]; >- u8 *context_buf; >+ u8 *context_buf; > u32 session_tbl[3]; >- u8 *session_buf; >+ u8 *session_buf; >+ u32 buf_size; > }; > > struct tpm_bios_log { >-- >2.25.1 >
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