From: Jarkko Sakkinen <[email protected]> Use stack allocation for trivial "low-hanging fruit" sites, which are often also critical code paths associated with probing and power management.
Signed-off-by: Jarkko Sakkinen <[email protected]> --- drivers/char/tpm/tpm2-cmd.c | 57 ++++++++++++++----------------------- 1 file changed, 22 insertions(+), 35 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 245c7c952e82..3c55f60ae4c2 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -382,14 +382,13 @@ EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt); */ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type) { - struct tpm_buf *buf __free(kfree) = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!buf) - return; + u8 buf_data[TPM_BUF_MIN_SIZE]; + struct tpm_buf *buf = (struct tpm_buf *)buf_data; - tpm_buf_init(buf, TPM_BUF_MAX_SIZE); + tpm_buf_init(buf, TPM_BUF_MIN_SIZE); tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN); tpm_buf_append_u16(buf, shutdown_type); - tpm_transmit_cmd(chip, buf, 0, "stopping the TPM"); + tpm_transmit_cmd(chip, buf, 0, "TPM2_Shutdown"); } /** @@ -407,58 +406,49 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type) */ static int tpm2_do_selftest(struct tpm_chip *chip) { + u8 buf_data[TPM_BUF_MIN_SIZE]; + struct tpm_buf *buf = (struct tpm_buf *)buf_data; int full; int rc; - struct tpm_buf *buf __free(kfree) = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - tpm_buf_init(buf, TPM_BUF_MAX_SIZE); - tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST); + tpm_buf_init(buf, TPM_BUF_MIN_SIZE); for (full = 0; full < 2; full++) { tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST); tpm_buf_append_u8(buf, full); - rc = tpm_transmit_cmd(chip, buf, 0, - "attempting the self test"); - + rc = tpm_transmit_cmd(chip, buf, 0, "TPM2_SelfTest"); if (rc == TPM2_RC_TESTING) rc = TPM2_RC_SUCCESS; if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS) return rc; } - return rc; } /** - * tpm2_probe() - probe for the TPM 2.0 protocol + * tpm2_probe() - Probe for the TPM 2.0 protocol * @chip: a &tpm_chip instance * - * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the - * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by - * this function if this is the case. + * Sends an idempotent TPM 2.0 command, and based on the response tag deduces + * whether a functional TPM2 chip is on the other side. When the result is + * positive, TPM_CHIP_FLAG_TPM2 is append to the chip's flags. * * Return: - * 0 on success, - * -errno otherwise + * * 0 on success, + * * -errno otherwise */ int tpm2_probe(struct tpm_chip *chip) { + u8 buf_data[TPM_BUF_MIN_SIZE]; + struct tpm_buf *buf = (struct tpm_buf *)buf_data; struct tpm_header *out; int rc; - struct tpm_buf *buf __free(kfree) = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - tpm_buf_init(buf, TPM_BUF_MAX_SIZE); + tpm_buf_init(buf, TPM_BUF_MIN_SIZE); tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); tpm_buf_append_u32(buf, TPM2_CAP_TPM_PROPERTIES); tpm_buf_append_u32(buf, TPM_PT_TOTAL_COMMANDS); tpm_buf_append_u32(buf, 1); rc = tpm_transmit_cmd(chip, buf, 0, NULL); - /* We ignore TPM return codes on purpose. */ if (rc >= 0) { out = (struct tpm_header *)buf->data; if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS) @@ -651,17 +641,14 @@ EXPORT_SYMBOL_GPL(tpm2_get_cc_attrs_tbl); static int tpm2_startup(struct tpm_chip *chip) { - struct tpm_buf *buf __free(kfree) = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - dev_info(&chip->dev, "starting up the TPM manually\n"); + u8 buf_data[TPM_BUF_MIN_SIZE]; + struct tpm_buf *buf = (struct tpm_buf *)buf_data; - tpm_buf_init(buf, TPM_BUF_MAX_SIZE); + dev_info(&chip->dev, "TPM2_Startup\n"); + tpm_buf_init(buf, TPM_BUF_MIN_SIZE); tpm_buf_reset(buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP); tpm_buf_append_u16(buf, TPM2_SU_CLEAR); - - return tpm_transmit_cmd(chip, buf, 0, "attempting to start the TPM"); + return tpm_transmit_cmd(chip, buf, 0, "TPM2_Startup"); } /** -- 2.39.5
