Niklas Schnelle f86ca2b553 s390/pci: Prevent self deletion in disable_slot() ... commit 47c3978448 upstream. As disable_slot() takes a struct zpci_dev from the Configured to the Standby state. In Standby there is still a hotplug slot so this is not usually a case of sysfs self deletion. This is important because self deletion gets very hairy in terms of locking (see for example recover_store() in arch/s390/pci/pci_sysfs.c). Because the pci_dev_put() is not within the critical section of the zdev->state_lock however, disable_slot() can turn into a case of self deletion if zPCI device event handling slips between the mutex_unlock() and the pci_dev_put(). If the latter is the last put and zpci_release_device() is called this then tries to remove the hotplug slot via zpci_exit_slot() which will try to remove the hotplug slot directory the disable_slot() is part of i.e. self deletion. Prevent this by widening the zdev->state_lock critical section to include the pci_dev_put() which is then guaranteed to happen with the struct zpci_dev still in Standby state ensuring it will not lead to a zpci_release_device() call as at least the zPCI event handling code still holds a reference. Cc: stable@vger.kernel.org Fixes: a46044a92a ("s390/pci: fix zpci_zdev_put() on reserve") Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com> Tested-by: Gerd Bayer <gbayer@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-06-27 11:11:14 +01:00
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acpi_pcihp.c
acpiphp_ampere_altra.c
acpiphp_core.c
acpiphp_glue.c
acpiphp_ibm.c
acpiphp.h
cpci_hotplug_core.c
cpci_hotplug_pci.c
cpci_hotplug.h
cpcihp_generic.c
cpcihp_zt5550.c
cpcihp_zt5550.h
cpqphp_core.c
cpqphp_ctrl.c
cpqphp_nvram.c
cpqphp_nvram.h
cpqphp_pci.c
cpqphp_sysfs.c
cpqphp.h
ibmphp_core.c
ibmphp_ebda.c
ibmphp_hpc.c
ibmphp_pci.c
ibmphp_res.c
ibmphp.h
Kconfig
Makefile
pci_hotplug_core.c
pciehp_core.c
pciehp_ctrl.c
pciehp_hpc.c
pciehp_pci.c
pciehp.h
pnv_php.c
rpadlpar_core.c
rpadlpar_sysfs.c
rpadlpar.h
rpaphp_core.c
rpaphp_pci.c
rpaphp_slot.c
rpaphp.h
s390_pci_hpc.c	s390/pci: Prevent self deletion in disable_slot()	2025-06-27 11:11:14 +01:00
shpchp_core.c
shpchp_ctrl.c
shpchp_hpc.c
shpchp_pci.c
shpchp_sysfs.c
shpchp.h
TODO