[RFC PATCH 1/4] New flags for TPM chip avoiding filesystem registrations

[Stefan Berger <stefanb-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>]

From: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>

Introduce 2 new flags that prevent the registration of TPM devices
with sysfs and securityfs. None of the exising devices set these flags.

Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
---
 drivers/char/tpm/tpm-chip.c | 14 +++++++++-----
 drivers/char/tpm/tpm.h      |  2 ++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index fbd75c5..f2da376 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -182,11 +182,14 @@ static int tpm1_chip_register(struct tpm_chip *chip)
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		return 0;
 
-	rc = tpm_sysfs_add_device(chip);
-	if (rc)
-		return rc;
+	if (!(chip->flags & TPM_CHIP_FLAG_NO_SYSFS)) {
+		rc = tpm_sysfs_add_device(chip);
+		if (rc)
+			return rc;
+	}
 
-	chip->bios_dir = tpm_bios_log_setup(chip->devname);
+	if (!(chip->flags & TPM_CHIP_FLAG_NO_LOG))
+		chip->bios_dir = tpm_bios_log_setup(chip->devname);
 
 	return 0;
 }
@@ -199,7 +202,8 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
 	if (chip->bios_dir)
 		tpm_bios_log_teardown(chip->bios_dir);
 
-	tpm_sysfs_del_device(chip);
+	if (!(chip->flags & TPM_CHIP_FLAG_NO_SYSFS))
+		tpm_sysfs_del_device(chip);
 }
 
 /*
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index a4257a3..dfa755b 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -168,6 +168,8 @@ struct tpm_vendor_specific {
 enum tpm_chip_flags {
 	TPM_CHIP_FLAG_REGISTERED	= BIT(0),
 	TPM_CHIP_FLAG_TPM2		= BIT(1),
+	TPM_CHIP_FLAG_NO_SYSFS		= BIT(3),
+	TPM_CHIP_FLAG_NO_LOG		= BIT(4),
 };
 
 struct tpm_chip {
-- 
2.4.3


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