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tpm: Fix handling of missing event log

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The event log is an optional firmware feature, if the firmware
does not support it then the securityfs files should not be created
and no other notification given.

- Uniformly return -ENODEV from the tpm_bios_log_setup cone if
  no event log is detected.
- Check in ACPI if this node was discovered via ACPI.
- Improve the check in OF to make sure there is a parent and to
  fail detection if the two log properties are not declared
- Pass through all other error codes instead of filtering just some

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
This commit is contained in:
Jason Gunthorpe 2016-11-19 11:18:28 -07:00 committed by Jarkko Sakkinen
parent 005451d44a
commit 0cf577a03f
4 changed files with 26 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/char/tpm/tpm-chip.c
View File

@ -346,7 +346,7 @@ int tpm_chip_register(struct tpm_chip *chip)
tpm_sysfs_add_device(chip);
rc = tpm_bios_log_setup(chip);
if (rc == -ENODEV)
if (rc != 0 && rc != -ENODEV)
return rc;
tpm_add_ppi(chip);

8
drivers/char/tpm/tpm_acpi.c
View File

@ -56,12 +56,18 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
log = &chip->log;
/* Unfortuntely ACPI does not associate the event log with a specific
* TPM, like PPI. Thus all ACPI TPMs will read the same log.
*/
if (!chip->acpi_dev_handle)
return -ENODEV;
/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
status = acpi_get_table(ACPI_SIG_TCPA, 1,
(struct acpi_table_header **)&buff);
if (ACPI_FAILURE(status))
return -EIO;
return -ENODEV;
switch(buff->platform_class) {
case BIOS_SERVER:

26
drivers/char/tpm/tpm_eventlog.c
View File

@ -368,14 +368,21 @@ static int tpm_read_log(struct tpm_chip *chip)
}
rc = tpm_read_log_acpi(chip);
if ((rc == 0) || (rc == -ENOMEM))
if (rc != -ENODEV)
return rc;
rc = tpm_read_log_of(chip);
return rc;
return tpm_read_log_of(chip);
}
/*
* tpm_bios_log_setup() - Read the event log from the firmware
* @chip: TPM chip to use.
*
* If an event log is found then the securityfs files are setup to
* export it to userspace, otherwise nothing is done.
*
* Returns -ENODEV if the firmware has no event log.
*/
int tpm_bios_log_setup(struct tpm_chip *chip)
{
const char *name = dev_name(&chip->dev);
@ -386,15 +393,8 @@ int tpm_bios_log_setup(struct tpm_chip *chip)
return 0;
rc = tpm_read_log(chip);
/*
* read_log failure means event log is not supported except for ENOMEM.
*/
if (rc < 0) {
if (rc == -ENOMEM)
return -ENODEV;
else
return rc;
}
if (rc)
return rc;
cnt = 0;
chip->bios_dir[cnt] = securityfs_create_dir(name, NULL);

11
drivers/char/tpm/tpm_of.c
View File

@ -29,13 +29,16 @@ int tpm_read_log_of(struct tpm_chip *chip)
struct tpm_bios_log *log;
log = &chip->log;
if (chip->dev.parent->of_node)
if (chip->dev.parent && chip->dev.parent->of_node)
np = chip->dev.parent->of_node;
else
return -ENODEV;
sizep = of_get_property(np, "linux,sml-size", NULL);
if (sizep == NULL)
basep = of_get_property(np, "linux,sml-base", NULL);
if (sizep == NULL && basep == NULL)
return -ENODEV;
if (sizep == NULL || basep == NULL)
return -EIO;
if (*sizep == 0) {
@ -43,10 +46,6 @@ int tpm_read_log_of(struct tpm_chip *chip)
return -EIO;
}
basep = of_get_property(np, "linux,sml-base", NULL);
if (basep == NULL)
return -EIO;
log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
if (!log->bios_event_log)
return -ENOMEM;