From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/char/tpm/tpmrm-dev.c | 54 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 drivers/char/tpm/tpmrm-dev.c (limited to 'drivers/char/tpm/tpmrm-dev.c') diff --git a/drivers/char/tpm/tpmrm-dev.c b/drivers/char/tpm/tpmrm-dev.c new file mode 100644 index 000000000..19e8f2779 --- /dev/null +++ b/drivers/char/tpm/tpmrm-dev.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017 James.Bottomley@HansenPartnership.com + */ +#include +#include "tpm-dev.h" + +struct tpmrm_priv { + struct file_priv priv; + struct tpm_space space; +}; + +static int tpmrm_open(struct inode *inode, struct file *file) +{ + struct tpm_chip *chip; + struct tpmrm_priv *priv; + int rc; + + chip = container_of(inode->i_cdev, struct tpm_chip, cdevs); + priv = kzalloc_obj(*priv); + if (priv == NULL) + return -ENOMEM; + + rc = tpm2_init_space(&priv->space, TPM2_SPACE_BUFFER_SIZE); + if (rc) { + kfree(priv); + return -ENOMEM; + } + + tpm_common_open(file, chip, &priv->priv, &priv->space); + + return nonseekable_open(inode, file); +} + +static int tpmrm_release(struct inode *inode, struct file *file) +{ + struct file_priv *fpriv = file->private_data; + struct tpmrm_priv *priv = container_of(fpriv, struct tpmrm_priv, priv); + + tpm_common_release(file, fpriv); + tpm2_del_space(fpriv->chip, &priv->space); + kfree(priv); + + return 0; +} + +const struct file_operations tpmrm_fops = { + .owner = THIS_MODULE, + .open = tpmrm_open, + .read = tpm_common_read, + .write = tpm_common_write, + .poll = tpm_common_poll, + .release = tpmrm_release, +}; -- cgit v1.3.1