Re: [Qemu-devel] [PATCH v3 03/13] tpm_tis: remove TPMSizeBuffer usage

[Marc-André Lureau]

On Fri, Nov 10, 2017 at 3:11 PM, Stefan Berger
<address@hidden> wrote:
> Remove usage of TPMSizeBuffer. The size of the buffers is limited now
> by s->be_buffer_size, which is the size of the buffer the TIS has
> negotiated with the backend.
>
> Signed-off-by: Stefan Berger <address@hidden>

Reviewed-by: Marc-André Lureau <address@hidden>


> ---
>  hw/tpm/tpm_tis.c | 68 
> ++++++++++++++++++++++++--------------------------------
>  1 file changed, 29 insertions(+), 39 deletions(-)
>
> diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> index 90c6df2..ddfcfc9 100644
> --- a/hw/tpm/tpm_tis.c
> +++ b/hw/tpm/tpm_tis.c
> @@ -64,8 +64,8 @@ typedef struct TPMLocality {
>
>      uint16_t w_offset;
>      uint16_t r_offset;
> -    TPMSizedBuffer w_buffer;
> -    TPMSizedBuffer r_buffer;
> +    unsigned char w_buffer[TPM_TIS_BUFFER_MAX];
> +    unsigned char r_buffer[TPM_TIS_BUFFER_MAX];
>  } TPMLocality;
>
>  typedef struct TPMState {
> @@ -215,23 +215,19 @@ static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
>      return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
>  }
>
> -static uint32_t tpm_tis_get_size_from_buffer(const TPMSizedBuffer *sb)
> -{
> -    return tpm_cmd_get_size(sb->buffer);
> -}
> -
> -static void tpm_tis_show_buffer(const TPMSizedBuffer *sb, const char *string)
> +static void tpm_tis_show_buffer(const unsigned char *buffer,
> +                                size_t buffer_size, const char *string)
>  {
>  #ifdef DEBUG_TIS
>      uint32_t len, i;
>
> -    len = tpm_tis_get_size_from_buffer(sb);
> +    len = MIN(tpm_cmd_get_size(buffer), buffer_size);
>      DPRINTF("tpm_tis: %s length = %d\n", string, len);
>      for (i = 0; i < len; i++) {
>          if (i && !(i % 16)) {
>              DPRINTF("\n");
>          }
> -        DPRINTF("%.2X ", sb->buffer[i]);
> +        DPRINTF("%.2X ", buffer[i]);
>      }
>      DPRINTF("\n");
>  #endif
> @@ -263,7 +259,8 @@ static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
>  {
>      TPMLocality *locty_data = &s->loc[locty];
>
> -    tpm_tis_show_buffer(&s->loc[locty].w_buffer, "tpm_tis: To TPM");
> +    tpm_tis_show_buffer(s->loc[locty].w_buffer, s->be_buffer_size,
> +                        "tpm_tis: To TPM");
>
>      /*
>       * w_offset serves as length indicator for length of data;
> @@ -273,10 +270,10 @@ static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
>
>      s->cmd = (TPMBackendCmd) {
>          .locty = locty,
> -        .in = locty_data->w_buffer.buffer,
> +        .in = locty_data->w_buffer,
>          .in_len = locty_data->w_offset,
> -        .out = locty_data->r_buffer.buffer,
> -        .out_len = locty_data->r_buffer.size
> +        .out = locty_data->r_buffer,
> +        .out_len = s->be_buffer_size,
>      };
>
>      tpm_backend_deliver_request(s->be_driver, &s->cmd);
> @@ -427,7 +424,8 @@ static void tpm_tis_request_completed(TPMIf *ti)
>      s->loc[locty].r_offset = 0;
>      s->loc[locty].w_offset = 0;
>
> -    tpm_tis_show_buffer(&s->loc[locty].r_buffer, "tpm_tis: From TPM");
> +    tpm_tis_show_buffer(s->loc[locty].r_buffer, s->be_buffer_size,
> +                        "tpm_tis: From TPM");
>
>      if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
>          tpm_tis_abort(s, locty);
> @@ -446,9 +444,10 @@ static uint32_t tpm_tis_data_read(TPMState *s, uint8_t 
> locty)
>      uint16_t len;
>
>      if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
> -        len = tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer);
> +        len = MIN(tpm_cmd_get_size(&s->loc[locty].r_buffer),
> +                  s->be_buffer_size);
>
> -        ret = s->loc[locty].r_buffer.buffer[s->loc[locty].r_offset++];
> +        ret = s->loc[locty].r_buffer[s->loc[locty].r_offset++];
>          if (s->loc[locty].r_offset >= len) {
>              /* got last byte */
>              tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
> @@ -494,11 +493,12 @@ static void tpm_tis_dump_state(void *opaque, hwaddr 
> addr)
>              "tpm_tis: result buffer : ",
>              s->loc[locty].r_offset);
>      for (idx = 0;
> -         idx < tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer);
> +         idx < MIN(tpm_cmd_get_size(&s->loc[locty].r_buffer),
> +                   s->be_buffer_size);
>           idx++) {
>          DPRINTF("%c%02x%s",
>                  s->loc[locty].r_offset == idx ? '>' : ' ',
> -                s->loc[locty].r_buffer.buffer[idx],
> +                s->loc[locty].r_buffer[idx],
>                  ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
>      }
>      DPRINTF("\n"
> @@ -506,11 +506,12 @@ static void tpm_tis_dump_state(void *opaque, hwaddr 
> addr)
>              "tpm_tis: request buffer: ",
>              s->loc[locty].w_offset);
>      for (idx = 0;
> -         idx < tpm_tis_get_size_from_buffer(&s->loc[locty].w_buffer);
> +         idx < MIN(tpm_cmd_get_size(s->loc[locty].w_buffer),
> +                   s->be_buffer_size);
>           idx++) {
>          DPRINTF("%c%02x%s",
>                  s->loc[locty].w_offset == idx ? '>' : ' ',
> -                s->loc[locty].w_buffer.buffer[idx],
> +                s->loc[locty].w_buffer[idx],
>                  ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
>      }
>      DPRINTF("\n");
> @@ -572,11 +573,11 @@ static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr 
> addr,
>          if (s->active_locty == locty) {
>              if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
>                  val = TPM_TIS_BURST_COUNT(
> -                       tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer)
> +                       MIN(tpm_cmd_get_size(&s->loc[locty].r_buffer),
> +                           s->be_buffer_size)
>                         - s->loc[locty].r_offset) | s->loc[locty].sts;
>              } else {
> -                avail = s->loc[locty].w_buffer.size
> -                        - s->loc[locty].w_offset;
> +                avail = s->be_buffer_size - s->loc[locty].w_offset;
>                  /*
>                   * byte-sized reads should not return 0x00 for 0x100
>                   * available bytes.
> @@ -924,9 +925,9 @@ static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
>              }
>
>              while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
> -                if (s->loc[locty].w_offset < s->loc[locty].w_buffer.size) {
> -                    s->loc[locty].w_buffer.
> -                        buffer[s->loc[locty].w_offset++] = (uint8_t)val;
> +                if (s->loc[locty].w_offset < s->be_buffer_size) {
> +                    s->loc[locty].w_buffer[s->loc[locty].w_offset++] =
> +                        (uint8_t)val;
>                      val >>= 8;
>                      size--;
>                  } else {
> @@ -940,7 +941,7 @@ static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
>                  /* we have a packet length - see if we have all of it */
>                  bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
>
> -                len = tpm_tis_get_size_from_buffer(&s->loc[locty].w_buffer);
> +                len = tpm_cmd_get_size(&s->loc[locty].w_buffer);
>                  if (len > s->loc[locty].w_offset) {
>                      tpm_tis_sts_set(&s->loc[locty],
>                                      TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
> @@ -979,15 +980,6 @@ static int tpm_tis_do_startup_tpm(TPMState *s, size_t 
> buffersize)
>      return tpm_backend_startup_tpm(s->be_driver, buffersize);
>  }
>
> -static void tpm_tis_realloc_buffer(TPMSizedBuffer *sb,
> -                                   size_t wanted_size)
> -{
> -    if (sb->size != wanted_size) {
> -        sb->buffer = g_realloc(sb->buffer, wanted_size);
> -        sb->size = wanted_size;
> -    }
> -}
> -
>  /*
>   * Get the TPMVersion of the backend device being used
>   */
> @@ -1036,9 +1028,7 @@ static void tpm_tis_reset(DeviceState *dev)
>          s->loc[c].state = TPM_TIS_STATE_IDLE;
>
>          s->loc[c].w_offset = 0;
> -        tpm_tis_realloc_buffer(&s->loc[c].w_buffer, s->be_buffer_size);
>          s->loc[c].r_offset = 0;
> -        tpm_tis_realloc_buffer(&s->loc[c].r_buffer, s->be_buffer_size);
>      }
>
>      tpm_tis_do_startup_tpm(s, s->be_buffer_size);
> --
> 2.5.5
>
>



-- 
Marc-André Lureau