linux-kernel - Re: [PATCH] PCI/IDE: Fix duplicate stream symlink names for TSM class devices

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251223173157.GA4025076@bhelgaas>
Date: Tue, 23 Dec 2025 11:31:57 -0600
From: Bjorn Helgaas <helgaas@...nel.org>
To: Xu Yilun <yilun.xu@...ux.intel.com>
Cc: linux-coco@...ts.linux.dev, linux-pci@...r.kernel.org,
	dan.j.williams@...el.com, yilun.xu@...el.com,
	baolu.lu@...ux.intel.com, zhenzhong.duan@...el.com,
	linux-kernel@...r.kernel.org, yi1.lai@...el.com
Subject: Re: [PATCH] PCI/IDE: Fix duplicate stream symlink names for TSM
 class devices

On Tue, Dec 23, 2025 at 04:56:01PM +0800, Xu Yilun wrote:
> The symlink name streamH.R.E is unique within a specific host bridge but
> not across the system. Error occurs e.g. when creating the first stream
> on a second host bridge:
> 
> [ 1244.034755] sysfs: cannot create duplicate filename '/devices/faux/tdx_host/tsm/tsm0/stream0.0.0'

Drop timestamp because it's no relevant.  Indent quoted material two
spaces.

> Fix this by adding host bridge name into symlink name for TSM class
> devices. It should be OK to change the uAPI to
> /sys/class/tsm/tsmN/pciDDDD:BB:streamH.R.E since it's new and has few
> users.

Looks like this adds "pciDDDD:BB:" to one name, which is described
here and in the Documentation/ABI change.

> Internally in the IDE library, store the full name in struct pci_ide
> so TSM symlinks can use it directly, while PCI host bridge symlinks
> can skip the host bridge name to keep concise.

And shortens this name, but no example or doc update?  Or maybe the
shortening just strips the "pciDDDD:BB" to preserve the existing names
somewhere else?

I'm just confused about which symlinks are changing (adding
"pciDDDD:BB") and which are being kept concise (either by staying the
same or being shortened).

> Fixes: a4438f06b1db ("PCI/TSM: Report active IDE streams")
> Reported-by: Yi Lai <yi1.lai@...el.com>
> Signed-off-by: Xu Yilun <yilun.xu@...ux.intel.com>
> ---
>  Documentation/ABI/testing/sysfs-class-tsm |  2 +-
>  drivers/pci/ide.c                         | 12 +++++++++---
>  2 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-tsm b/Documentation/ABI/testing/sysfs-class-tsm
> index 6fc1a5ac6da1..eff71e42c60e 100644
> --- a/Documentation/ABI/testing/sysfs-class-tsm
> +++ b/Documentation/ABI/testing/sysfs-class-tsm
> @@ -8,7 +8,7 @@ Description:
>  		link encryption and other device-security features coordinated
>  		through a platform tsm.
>  
> -What:		/sys/class/tsm/tsmN/streamH.R.E
> +What:		/sys/class/tsm/tsmN/pciDDDD:BB:streamH.R.E
>  Contact:	linux-pci@...r.kernel.org
>  Description:
>  		(RO) When a host bridge has established a secure connection via
> diff --git a/drivers/pci/ide.c b/drivers/pci/ide.c
> index f0ef474e1a0d..db1c7423bf39 100644
> --- a/drivers/pci/ide.c
> +++ b/drivers/pci/ide.c
> @@ -425,6 +425,7 @@ int pci_ide_stream_register(struct pci_ide *ide)
>  	struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
>  	struct pci_ide_stream_id __sid;
>  	u8 ep_stream, rp_stream;
> +	const char *short_name;
>  	int rc;
>  
>  	if (ide->stream_id < 0 || ide->stream_id > U8_MAX) {
> @@ -441,13 +442,16 @@ int pci_ide_stream_register(struct pci_ide *ide)
>  
>  	ep_stream = ide->partner[PCI_IDE_EP].stream_index;
>  	rp_stream = ide->partner[PCI_IDE_RP].stream_index;
> -	const char *name __free(kfree) = kasprintf(GFP_KERNEL, "stream%d.%d.%d",
> +	const char *name __free(kfree) = kasprintf(GFP_KERNEL, "%s:stream%d.%d.%d",
> +						   dev_name(&hb->dev),
>  						   ide->host_bridge_stream,
>  						   rp_stream, ep_stream);
>  	if (!name)
>  		return -ENOMEM;
>  
> -	rc = sysfs_create_link(&hb->dev.kobj, &pdev->dev.kobj, name);
> +	/* Skip host bridge name in the host bridge context */
> +	short_name = name + strlen(dev_name(&hb->dev)) + 1;
> +	rc = sysfs_create_link(&hb->dev.kobj, &pdev->dev.kobj, short_name);
>  	if (rc)
>  		return rc;
>  
> @@ -471,8 +475,10 @@ void pci_ide_stream_unregister(struct pci_ide *ide)
>  {
>  	struct pci_dev *pdev = ide->pdev;
>  	struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
> +	const char *short_name;
>  
> -	sysfs_remove_link(&hb->dev.kobj, ide->name);
> +	short_name = ide->name + strlen(dev_name(&hb->dev)) + 1;
> +	sysfs_remove_link(&hb->dev.kobj, short_name);
>  	kfree(ide->name);
>  	ida_free(&hb->ide_stream_ids_ida, ide->stream_id);
>  	ide->name = NULL;
> 
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> -- 
> 2.25.1
>