arm64/pmap: Modify condition of valid_memattr that cannot be true
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Authored by timo.voelker_fh-muenster.de on Thu, Feb 26, 4:07 PM.

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andrew
tuexen
manu

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rG0272359ada14: arm64/pmap: fix pmap_is_valid_memattr()

Summary

The function pmap_is_valid_memattr(pmap, mode) checks whether the given variable mode is between the two constant values VM_MEMATTR_DEVICE and VM_MEMATTR_WRITE_THROUGH. After the code for this function was written, the value of VM_MEMATTR_DEVICE changed from 0 to 4. Since VM_MEMATTR_WRITE_THROUGH is still 3, the condition is always false.

This patch changes the condition to check whether mode is equal to any of the VM_MEMATTR* constants.

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rG FreeBSD src repository

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timo.voelker_fh-muenster.de created this revision.Thu, Feb 26, 4:07 PM

Herald added a reviewer: manu. · View Herald TranscriptThu, Feb 26, 4:07 PM

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timo.voelker_fh-muenster.de requested review of this revision.Thu, Feb 26, 4:07 PM

Does this patch solve any problem?

In D55534#1270843, @tuexen wrote:

Does this patch solve any problem?

Yes. I tried to dump the content of a PCI BAR with:

pciconf -D pci0:0:10:0 0x18 | hexdump

This command failed with EINVAL. It calls pci_bar_mmap(pcidev, pbm) in sys/dev/pci/pci_user.c, which returns EINVAL if pmap_is_valid_memattr(pmap, mode) returns false. With this patch, I was able to dump the content of the PCI BAR.

In D55534#1271706, @timo.voelker_fh-muenster.de wrote:
In D55534#1270843, @tuexen wrote:

Does this patch solve any problem?

Yes. I tried to dump the content of a PCI BAR with:
pciconf -D pci0:0:10:0 0x18 | hexdump
This command failed with EINVAL. It calls pci_bar_mmap(pcidev, pbm) in sys/dev/pci/pci_user.c, which returns EINVAL if pmap_is_valid_memattr(pmap, mode) returns false. With this patch, I was able to dump the content of the PCI BAR.