Messages in this thread | | | Subject | Re: [PATCH] tpm: Define TPM2_SPACE_BUFFER_SIZE to replace the use of PAGE_SIZE | From | Stefan Berger <> | Date | Fri, 26 Jun 2020 12:47:02 -0400 |
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On 6/26/20 10:34 AM, 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). > > 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> > --- > drivers/char/tpm/tpm2-space.c | 27 ++++++++++++++++----------- > 1 file changed, 16 insertions(+), 11 deletions(-) > > diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c > index 982d341d8837..9bef646093d1 100644 > --- a/drivers/char/tpm/tpm2-space.c > +++ b/drivers/char/tpm/tpm2-space.c > @@ -15,6 +15,8 @@ > #include <asm/unaligned.h> > #include "tpm.h" > > +#define TPM2_SPACE_BUFFER_SIZE 16384 /* 16 kB */ > + > enum tpm2_handle_types { > TPM2_HT_HMAC_SESSION = 0x02000000, > TPM2_HT_POLICY_SESSION = 0x03000000, > @@ -40,11 +42,11 @@ static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space) > > int tpm2_init_space(struct tpm_space *space) > { > - space->context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); > + space->context_buf = kzalloc(TPM2_SPACE_BUFFER_SIZE, GFP_KERNEL); > if (!space->context_buf) > return -ENOMEM; > > - space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); > + space->session_buf = kzalloc(TPM2_SPACE_BUFFER_SIZE, GFP_KERNEL); > if (space->session_buf == NULL) { > kfree(space->context_buf); > return -ENOMEM; > @@ -311,8 +313,10 @@ 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, > + TPM2_SPACE_BUFFER_SIZE); > + memcpy(chip->work_space.session_buf, space->session_buf, > + TPM2_SPACE_BUFFER_SIZE); > > rc = tpm2_load_space(chip); > if (rc) { > @@ -492,8 +496,8 @@ static int tpm2_save_space(struct tpm_chip *chip) > continue; > > rc = tpm2_save_context(chip, space->context_tbl[i], > - space->context_buf, PAGE_SIZE, > - &offset); > + space->context_buf, > + TPM2_SPACE_BUFFER_SIZE, &offset); > if (rc == -ENOENT) { > space->context_tbl[i] = 0; > continue; > @@ -509,9 +513,8 @@ static int tpm2_save_space(struct tpm_chip *chip) > continue; > > rc = tpm2_save_context(chip, space->session_tbl[i], > - space->session_buf, PAGE_SIZE, > - &offset); > - > + space->session_buf, > + TPM2_SPACE_BUFFER_SIZE, &offset); > if (rc == -ENOENT) { > /* handle error saving session, just forget it */ > space->session_tbl[i] = 0; > @@ -557,8 +560,10 @@ 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, > + TPM2_SPACE_BUFFER_SIZE); > + memcpy(space->session_buf, chip->work_space.session_buf, > + TPM2_SPACE_BUFFER_SIZE);
work_space.session_buf and context_buf also need allocation changes, otherwise we read from a smaller buffer here. See comment to other patch about tpm-chip.c .
> > return 0; > out:
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