APPLIED(F): [SRU][F][G][PATCH v3 0/1] s390x/pci: do not allow to create more pci functions than configured via CONFIG_PCI_NR_FUNCTIONS

[Khaled Elmously]

On 2020-05-06 09:21:01 , frank.heimes at canonical.com wrote:
> Buglink: https://bugs.launchpad.net/bugs/1874057
> 
> SRU Justification:
> 
> [Impact]
> 
> * PCI Functions with UIDs >128 are currently not accounted correctly in the s390x/pci (zPCI) code.
> 
> * Furthermore, the code allows that more than CONFIG_PCI_NR_FUNCTIONS are created.
> 
> * This can lead to issues with data structures which were only allocated for CONFIG_PCI_NR_FUNCTIONS.
> 
> [Fix]
> 
> * Backport: https://launchpadlibrarian.net/478235080/0001-s390-pci-Fix-zpci_alloc_domain-over-allocation.patch
> 
> [Test Case]
> 
> * Set the kernel parameter CONFIG_PCI_NR_FUNCTIONS to a specific (reasonablly low) number.
> 
> * And check if more PCI functions can be created than specified by CONFIG_PCI_NR_FUNCTIONS (e.g. using a RoCE adapter) and watch for kernel message 'Adding PCI function ... failed'
> 
> [Regression Potential] 
> 
> * There is regression potential can be considered as low, since:
> 
> * the zPCI cards are less wide spread than for example ccw adapters on s390x
> 
> * the fix got already upstream accepted in 5.7, hence upstream reviewed, too
> 
> * the modifications span just two files and both are s390x arch specific
> 
> [Other Info]
> 
> * The above patch (file) is based on commit 969ae01bab2fe938b4c8324836038b5ac1c78fac ("s390/pci: Fix zpci_alloc_domain() over allocation"), but this backport was needed for getting it applied to focal master-next
> 
> * The commit itself got upstream accepted with kernel v5.7-rc1, hence should automatically land in 'gorilla', but since gorilla is still on a 5.4 kernel adding 'G' to this SRU
> 
> Niklas Schnelle (1):
>   s390/pci: Fix zpci_alloc_domain() over allocation
> 
>  arch/s390/include/asm/pci.h |  1 +
>  arch/s390/pci/pci.c         | 34 ++++++++++++++++++++--------------
>  2 files changed, 21 insertions(+), 14 deletions(-)
> 
> -- 
> 2.25.1
> 
> 
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