From: Jarkko Sakkinen Date: Sat, 7 Nov 2015 11:33:25 +0000 (+0200) Subject: tpm: fix compat 'ppi' link handling in tpm_chip_register() X-Git-Tag: firefly_0821_release~176^2~702^2~1^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d56e4f75346933dd2cb11533a668ce883908c859;p=firefly-linux-kernel-4.4.55.git tpm: fix compat 'ppi' link handling in tpm_chip_register() __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: 9b774d5cf2db Reported-by: Jeremiah Mahler Signed-off-by: Jarkko Sakkinen Tested-by: Jeremiah Mahler Acked-by: Peter Huewe --- diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index a5cdce74adab..45cc39aabeee 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -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);