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tpm: fix compat 'ppi' link handling in tpm_chip_register()

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__compat_only_sysfs_link_entry_to_kobj() was unconditionally called for
TPM1 chips, which caused crash on Acer C720 laptop where DSM for the
ACPI object did not exist.

There are two reasons for unwanted behavior:

* The code did not check whether
  __compat_only_sysfs_link_entry_to_kobj() returned -ENOENT. This is
  OK. It just meanst that ppi is not available.
* The code did not clean up properly. Compat link should added only
  after all other init is done.

This patch sorts out these issues.

Fixes: 9b774d5cf2
Reported-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jeremiah Mahler <jmmahler@gmail.com>
Acked-by: Peter Huewe <PeterHuewe@gmx.de>
This commit is contained in:
Jarkko Sakkinen 2015-11-07 13:33:25 +02:00
parent 2e31125c24
commit d56e4f7534
1 changed files with 10 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/char/tpm/tpm-chip.c
View File

@ -226,14 +226,6 @@ int tpm_chip_register(struct tpm_chip *chip)
if (rc)
goto out_err;
if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj,
&chip->dev.kobj,
"ppi");
if (rc)
goto out_err;
}
/* Make the chip available. */
spin_lock(&driver_lock);
list_add_tail_rcu(&chip->list, &tpm_chip_list);
@ -241,6 +233,16 @@ int tpm_chip_register(struct tpm_chip *chip)
chip->flags |= TPM_CHIP_FLAG_REGISTERED;
if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj,
&chip->dev.kobj,
"ppi");
if (rc && rc != -ENOENT) {
tpm_chip_unregister(chip);
return rc;
}
}
return 0;
out_err:
tpm1_chip_unregister(chip);