From: "Jarkko Sakkinen" <jarkko@kernel.org>
To: "Mikko Rapeli" <mikko.rapeli@linaro.org>,
"Ard Biesheuvel" <ardb@kernel.org>, <linux-efi@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>,
"Ilias Apalodimas" <ilias.apalodimas@linaro.org>,
"Lennart Poettering" <lennart@poettering.net>
Subject: Re: [PATCH] efi: expose TPM event log to userspace via sysfs
Date: Fri, 26 Apr 2024 14:48:39 +0300 [thread overview]
Message-ID: <D0U14GGWT2AW.XRFW7MB1QZFV@kernel.org> (raw)
In-Reply-To: <20240422112711.362779-1-mikko.rapeli@linaro.org>
On Mon Apr 22, 2024 at 2:27 PM EEST, Mikko Rapeli wrote:
> Documentation/ABI/testing/sysfs-firmware-efi | 12 ++++++++++++
> drivers/firmware/efi/efi.c | 13 +++++++++++++
> 2 files changed, 25 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-firmware-efi b/Documentation/ABI/testing/sysfs-firmware-efi
> index 5e4d0b27cdfe..caaff27cc73e 100644
> --- a/Documentation/ABI/testing/sysfs-firmware-efi
> +++ b/Documentation/ABI/testing/sysfs-firmware-efi
> @@ -36,3 +36,15 @@ Description: Displays the content of the Runtime Configuration Interface
> Table version 2 on Dell EMC PowerEdge systems in binary format
> Users: It is used by Dell EMC OpenManage Server Administrator tool to
> populate BIOS setup page.
> +
> +What: /sys/firmware/efi/tpm_log
*Conditional* suggestion: s/tpm_log/tpm_event_log/
I.e. if we want this better to use the most popular name.
> +Date: April 2024
> +Contact: Mikko Rapeli <mikko.rapeli@linaro.org>
> +Description: If EFI firmware supports TPM device and measurements were done
> + then a TPM event log has very likely been generated and provided
> + to the kernel. This serves as indicator for userspace to load
> + TPM drivers and to start related service early in the boot sequence,
> + e.g. initramfs, where full bus probes and device scans are not yet
> + done.
> +Users: systemd will use this interface to support TPM drivers as modules also
> + for early initramfs
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 4fcda50acfa4..94773e8b8806 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -162,6 +162,13 @@ static ssize_t fw_platform_size_show(struct kobject *kobj,
> return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
> }
>
> +static ssize_t tpm_log_show(struct kobject *kobj,
> + struct kobj_attribute *attr, char *buf)
> +{
> + return sprintf(buf, "TPMEventLog=0x%lx", efi.tpm_log);
It is also asymmetric with the log message as we can see here. Why you
want to put that prefix and not just print the number? Why hex and not
just %lu?
> +}
> +static struct kobj_attribute efi_attr_tpm_log = __ATTR_RO_MODE(tpm_log, 0400);
> +
> extern __weak struct kobj_attribute efi_attr_fw_vendor;
> extern __weak struct kobj_attribute efi_attr_runtime;
> extern __weak struct kobj_attribute efi_attr_config_table;
> @@ -459,6 +466,12 @@ static int __init efisubsys_init(void)
> platform_device_register_simple("efi_secret", 0, NULL, 0);
> #endif
>
> + if (efi.tpm_log != EFI_INVALID_TABLE_ADDR) {
> + error = sysfs_create_file(efi_kobj, &efi_attr_tpm_log.attr);
> + if (error)
> + pr_err("sysfs create file failed with error %d.\n", error);
> + }
s/err/warn/
Why "sys create file" and not "sys_create_file"?
> +
> return 0;
>
> err_remove_group:
BR, Jarkko
prev parent reply other threads:[~2024-04-26 11:48 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-22 11:27 [PATCH] efi: expose TPM event log to userspace via sysfs Mikko Rapeli
2024-04-22 12:42 ` James Bottomley
2024-04-22 13:08 ` Mikko Rapeli
2024-04-22 13:32 ` Ilias Apalodimas
2024-04-22 13:38 ` James Bottomley
2024-04-22 13:54 ` Ilias Apalodimas
2024-04-22 14:31 ` James Bottomley
2024-04-22 15:22 ` Ilias Apalodimas
2024-04-24 17:15 ` Ard Biesheuvel
2024-04-25 8:56 ` Mikko Rapeli
2024-04-25 13:50 ` Jarkko Sakkinen
2024-04-25 9:58 ` Lennart Poettering
2024-04-25 10:36 ` Ard Biesheuvel
2024-04-25 11:13 ` Lennart Poettering
2024-04-25 11:47 ` Ilias Apalodimas
2024-04-25 13:36 ` Lennart Poettering
2024-04-25 13:46 ` James Bottomley
2024-04-25 13:24 ` James Bottomley
2024-04-25 13:39 ` Mikko Rapeli
2024-04-25 13:40 ` Lennart Poettering
2024-04-25 14:01 ` Jarkko Sakkinen
2024-04-26 7:35 ` Jarkko Sakkinen
2024-04-26 7:40 ` Jarkko Sakkinen
2024-04-26 8:19 ` Mikko Rapeli
2024-04-26 8:23 ` Jarkko Sakkinen
2024-04-22 14:57 ` Mikko Rapeli
2024-04-26 11:41 ` Jarkko Sakkinen
2024-04-26 11:48 ` Jarkko Sakkinen [this message]
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