603654946ebe99b16c1c05b4e546c3373b6c73b115580e69e58b3954.patch

From f68ef175da77be8eb2709afbe7ff60d8e555794e Mon Sep 17 00:00:00 2001
From: Zyta Szpak <zyta@google.com>
Date: Mon, 13 Dec 2021 11:48:52 +0000
Subject: [PATCH] FIXUP: CHROMIUM: tpm: remove hardcoded index
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Remove the WARN_ON groups_cnt being zero.

When the warning was added it was assumed that sysfs attributes
always land in 0-index and the for-loop in tpm_add_legacy_sysfs had it
hardcoded to 0. To be compliant with this it had to be checked if we are
starting from 0 when adding groups in tpm-sysfs.c, otherwise it was
missing the right place in the table.

Add checking if attributes group name was defined for each group in
the table.

If name is defined then the sysfs entries land in 'name' subdirectory.
This case is handled separately for each dir (like ppi). If name is not
defined, we create legacy sysfs entry for every attribute of this group.

Fixes: WARNING: CPU: 2 PID: 1 at
drivers/char/tpm/tpm-sysfs.c:612 tpm_sysfs_add_device+0x426/0x4c7
and improper legacy sysfs mapping (missing entries)

BUG=b:197836367
TEST=build kernel from chromeos-kernelupstream-5.14-rc7 branch with debug
options enabled for delbin/caroline; load the kernel and observe warnings
during boot

Signed-off-by: Zyta Szpak <zyta@google.com>
Change-Id: I3676f407a0fcc168a880f083e0b91ac2c74bb2c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3329890
Reviewed-by: Yi Chou <yich@google.com>
Commit-Queue: Yi Chou <yich@google.com>
Commit-Queue: Łukasz Bartosik <ukaszb@google.com>
---
 drivers/char/tpm/tpm-chip.c  | 30 ++++++++++++++++++++++--------
 drivers/char/tpm/tpm-sysfs.c |  2 --
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 968cf0ab6638..e37ff7d32d16 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -465,6 +465,7 @@ static void tpm_del_char_device(struct tpm_chip *chip)
 static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
 {
 	struct attribute **i;
+	int k;
 
 	if (chip->flags & TPM_CHIP_FLAG_VIRTUAL ||
 		tpm_is_firmware_upgrade(chip))
@@ -472,8 +473,14 @@ static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
 
 	sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
 
-	for (i = chip->groups[0]->attrs; *i != NULL; ++i)
-		sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
+	for (k = 0; k < chip->groups_cnt; k++) {
+		if (chip->groups[k]->name)
+			continue;
+		else {
+			for (i = chip->groups[k]->attrs; *i != NULL; ++i)
+				sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
+		}
+	}
 }
 
 /* For compatibility with legacy sysfs paths we provide symlinks from the
@@ -484,6 +491,7 @@ static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
 {
 	struct attribute **i;
 	int rc;
+	int k;
 
 	if (chip->flags & TPM_CHIP_FLAG_VIRTUAL ||
 		tpm_is_firmware_upgrade(chip))
@@ -495,12 +503,18 @@ static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
 		return rc;
 
 	/* All the names from tpm-sysfs */
-	for (i = chip->groups[0]->attrs; *i != NULL; ++i) {
-		rc = compat_only_sysfs_link_entry_to_kobj(
-		    &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name, NULL);
-		if (rc) {
-			tpm_del_legacy_sysfs(chip);
-			return rc;
+	for (k = 0; k < chip->groups_cnt; k++) {
+		if (chip->groups[k]->name)
+			continue;
+		else {
+			for (i = chip->groups[k]->attrs; *i != NULL; ++i) {
+				rc = compat_only_sysfs_link_entry_to_kobj(
+					&chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name, NULL);
+				if (rc) {
+					tpm_del_legacy_sysfs(chip);
+					return rc;
+				}
+			}
 		}
 	}
 
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 0116f46d1977..4781bd2f4fde 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -609,8 +609,6 @@ void tpm_sysfs_add_device(struct tpm_chip *chip)
 	/* FIXME: update tpm_sysfs to explicitly lock chip->ops for TPM 2.0 */
 	int i;
 
-	WARN_ON(chip->groups_cnt != 0);
-
 	if (tpm_is_firmware_upgrade(chip))
 		return;
 
-- 
2.36.0.rc0.470.gd361397f0d-goog