Re: [PATCH] PCI: don't allow unbinding host controllers that aren't prepared

From: Bjorn Helgaas
Date: Fri Apr 21 2017 - 15:05:16 EST

On Thu, Mar 30, 2017 at 06:12:03PM -0700, Brian Norris wrote:
> Many PCI host controller drivers aren't prepared to have their devices
> unbound from them forcefully (e.g., through /sys/.../<driver>/unbind),
> as they don't provide any driver .remove callback, where they'd detach
> the root bus, release resources, etc. Keeping the driver built in (i.e.,
> not a loadable module) is not enough; and providing no .remove callback
> just means we don't do any teardown.
>
> To rule out the possibility of unbinding a device via sysfs, we need to
> set the ".suppress_bind_attrs" field.
>
> I found the suspect drivers via the following search:
>
> git grep -l platform_driver $(git grep -L -e '\.remove' -e suppress_bind_attrs drivers/pci/)
>
> Then I inspected them to ensure that
> (a) they set up a PCI bus in their probe() and
> (b) they don't have a remove() callback for undoing the setup
>
> I excluded drivers/pci/host/pcie-rockchip.c, because I've implemented
> remove() support elsewhere [1].
>
> [1] https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1349576.html
> [PATCH v2 3/5] PCI: rockchip: add remove() support
>
> Suggested-by: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>

Applied to pci/remove for v4.12, thanks, Brian!

> ---
> Not tested, other than to compile a few of these.
>
> drivers/pci/dwc/pci-imx6.c | 1 +
> drivers/pci/dwc/pci-layerscape.c | 1 +
> drivers/pci/dwc/pcie-armada8k.c | 1 +
> drivers/pci/dwc/pcie-artpec6.c | 1 +
> drivers/pci/dwc/pcie-designware-plat.c | 1 +
> drivers/pci/dwc/pcie-hisi.c | 2 ++
> drivers/pci/dwc/pcie-spear13xx.c | 1 +
> drivers/pci/host/pci-ftpci100.c | 1 +
> drivers/pci/host/pci-host-generic.c | 1 +
> drivers/pci/host/pci-thunder-ecam.c | 1 +
> drivers/pci/host/pci-thunder-pem.c | 1 +
> drivers/pci/host/pci-versatile.c | 1 +
> drivers/pci/host/pci-xgene.c | 1 +
> 13 files changed, 14 insertions(+)
>
> diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
> index 801e46cd266d..f85a063e9964 100644
> --- a/drivers/pci/dwc/pci-imx6.c
> +++ b/drivers/pci/dwc/pci-imx6.c
> @@ -725,6 +725,7 @@ static struct platform_driver imx6_pcie_driver = {
> .driver = {
> .name = "imx6q-pcie",
> .of_match_table = imx6_pcie_of_match,
> + .suppress_bind_attrs = true,
> },
> .shutdown = imx6_pcie_shutdown,
> };
> diff --git a/drivers/pci/dwc/pci-layerscape.c b/drivers/pci/dwc/pci-layerscape.c
> index c32e392a0ae6..880f345bff43 100644
> --- a/drivers/pci/dwc/pci-layerscape.c
> +++ b/drivers/pci/dwc/pci-layerscape.c
> @@ -305,6 +305,7 @@ static struct platform_driver ls_pcie_driver = {
> .driver = {
> .name = "layerscape-pcie",
> .of_match_table = ls_pcie_of_match,
> + .suppress_bind_attrs = true,
> },
> };
> builtin_platform_driver_probe(ls_pcie_driver, ls_pcie_probe);
> diff --git a/drivers/pci/dwc/pcie-armada8k.c b/drivers/pci/dwc/pcie-armada8k.c
> index f110e3b24a26..9d8f7e4db5df 100644
> --- a/drivers/pci/dwc/pcie-armada8k.c
> +++ b/drivers/pci/dwc/pcie-armada8k.c
> @@ -262,6 +262,7 @@ static struct platform_driver armada8k_pcie_driver = {
> .driver = {
> .name = "armada8k-pcie",
> .of_match_table = of_match_ptr(armada8k_pcie_of_match),
> + .suppress_bind_attrs = true,
> },
> };
> builtin_platform_driver(armada8k_pcie_driver);
> diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
> index fcd3ef845883..7a86d4b4dcc1 100644
> --- a/drivers/pci/dwc/pcie-artpec6.c
> +++ b/drivers/pci/dwc/pcie-artpec6.c
> @@ -290,6 +290,7 @@ static struct platform_driver artpec6_pcie_driver = {
> .driver = {
> .name = "artpec6-pcie",
> .of_match_table = artpec6_pcie_of_match,
> + .suppress_bind_attrs = true,
> },
> };
> builtin_platform_driver(artpec6_pcie_driver);
> diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
> index b6c832ba39dd..bdb75a5758ae 100644
> --- a/drivers/pci/dwc/pcie-designware-plat.c
> +++ b/drivers/pci/dwc/pcie-designware-plat.c
> @@ -129,6 +129,7 @@ static struct platform_driver dw_plat_pcie_driver = {
> .driver = {
> .name = "dw-pcie",
> .of_match_table = dw_plat_pcie_of_match,
> + .suppress_bind_attrs = true,
> },
> .probe = dw_plat_pcie_probe,
> };
> diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> index fd66a3199db7..088ed5e4e46b 100644
> --- a/drivers/pci/dwc/pcie-hisi.c
> +++ b/drivers/pci/dwc/pcie-hisi.c
> @@ -334,6 +334,7 @@ static struct platform_driver hisi_pcie_driver = {
> .driver = {
> .name = "hisi-pcie",
> .of_match_table = hisi_pcie_of_match,
> + .suppress_bind_attrs = true,
> },
> };
> builtin_platform_driver(hisi_pcie_driver);
> @@ -391,6 +392,7 @@ static struct platform_driver hisi_pcie_almost_ecam_driver = {
> .driver = {
> .name = "hisi-pcie-almost-ecam",
> .of_match_table = hisi_pcie_almost_ecam_of_match,
> + .suppress_bind_attrs = true,
> },
> };
> builtin_platform_driver(hisi_pcie_almost_ecam_driver);
> diff --git a/drivers/pci/dwc/pcie-spear13xx.c b/drivers/pci/dwc/pcie-spear13xx.c
> index eaa4ea8e2ea4..0d117499da0d 100644
> --- a/drivers/pci/dwc/pcie-spear13xx.c
> +++ b/drivers/pci/dwc/pcie-spear13xx.c
> @@ -308,6 +308,7 @@ static struct platform_driver spear13xx_pcie_driver = {
> .driver = {
> .name = "spear-pcie",
> .of_match_table = of_match_ptr(spear13xx_pcie_of_match),
> + .suppress_bind_attrs = true,
> },
> };
>
> diff --git a/drivers/pci/host/pci-ftpci100.c b/drivers/pci/host/pci-ftpci100.c
> index 4ae5418a1aad..9d2713707a91 100644
> --- a/drivers/pci/host/pci-ftpci100.c
> +++ b/drivers/pci/host/pci-ftpci100.c
> @@ -556,6 +556,7 @@ static struct platform_driver faraday_pci_driver = {
> .driver = {
> .name = "ftpci100",
> .of_match_table = of_match_ptr(faraday_pci_of_match),
> + .suppress_bind_attrs = true,
> },
> .probe = faraday_pci_probe,
> };
> diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
> index c05ea9d72f69..7d709a7e0aa8 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -60,6 +60,7 @@ static struct platform_driver gen_pci_driver = {
> .driver = {
> .name = "pci-host-generic",
> .of_match_table = gen_pci_of_match,
> + .suppress_bind_attrs = true,
> },
> .probe = gen_pci_probe,
> };
> diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c
> index 3f54a43bbbea..fc0ca03f280e 100644
> --- a/drivers/pci/host/pci-thunder-ecam.c
> +++ b/drivers/pci/host/pci-thunder-ecam.c
> @@ -373,6 +373,7 @@ static struct platform_driver thunder_ecam_driver = {
> .driver = {
> .name = KBUILD_MODNAME,
> .of_match_table = thunder_ecam_of_match,
> + .suppress_bind_attrs = true,
> },
> .probe = thunder_ecam_probe,
> };
> diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
> index 52b5bdccf5f0..4260b0765949 100644
> --- a/drivers/pci/host/pci-thunder-pem.c
> +++ b/drivers/pci/host/pci-thunder-pem.c
> @@ -416,6 +416,7 @@ static struct platform_driver thunder_pem_driver = {
> .driver = {
> .name = KBUILD_MODNAME,
> .of_match_table = thunder_pem_of_match,
> + .suppress_bind_attrs = true,
> },
> .probe = thunder_pem_probe,
> };
> diff --git a/drivers/pci/host/pci-versatile.c b/drivers/pci/host/pci-versatile.c
> index 5ebee7d37ff5..5a5b84227eb6 100644
> --- a/drivers/pci/host/pci-versatile.c
> +++ b/drivers/pci/host/pci-versatile.c
> @@ -221,6 +221,7 @@ static struct platform_driver versatile_pci_driver = {
> .driver = {
> .name = "versatile-pci",
> .of_match_table = versatile_pci_of_match,
> + .suppress_bind_attrs = true,
> },
> .probe = versatile_pci_probe,
> };
> diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
> index 1a6108788f6f..517bea33809f 100644
> --- a/drivers/pci/host/pci-xgene.c
> +++ b/drivers/pci/host/pci-xgene.c
> @@ -697,6 +697,7 @@ static struct platform_driver xgene_pcie_driver = {
> .driver = {
> .name = "xgene-pcie",
> .of_match_table = of_match_ptr(xgene_pcie_match_table),
> + .suppress_bind_attrs = true,
> },
> .probe = xgene_pcie_probe_bridge,
> };
> --
> 2.12.2.564.g063fe858b8-goog
>