NACK: [SRU][B/F:linux-kvm][PATCH v2 0/1] UBUNTU: [Config] kvm: Add support for modifying LDT

[Roxana Nicolescu]

On 29/03/2023 21:19, Cory Todd wrote:
> On Mon, Mar 27, 2023 at 02:44:02PM +0200, Roxana Nicolescu wrote:
>> BugLink: https://bugs.launchpad.net/bugs/2009442
>>
>> SRU Justification:
>>
>> [Impact]
>> bionic/focal linux-kvm failure in glibc autopkgtest
>>
>> FAIL: misc/tst-bz21269
>> original exit status 1
>> error: ../sysdeps/unix/sysv/linux/i386/tst-bz21269.c:55:
>> not true: syscall (SYS_modify_ldt, 1, ptr, bytecount) == 0
>> error: 1 test failures
>>
>> Syscall modify_ldt is not enabled because
>> CONFIG_MODIFY_LDT_SYSCALL=n for bionic/focal-kvm,
>> even though generic and newer versions (even kvm derivativatives)
>> have it enabled.
>>
>> [Fix]
>> Custom patch to bionic/focal-kvm to enable CONFIG_MODIFY_LDT_SYSCALL.
>>
>> [Test Plan]
>> Built on cbd and tested autopkgtest glibc locally in a vm.
>>
>> [Where problems could occur]
>> 1. Regression probability is pretty low, we are adding functionality
>> not previously present but looking at jammy this test is fine.
>> 2. Enabling this adds a small  overhead to context switches
>> and increases the low level  kernel attack surface.
>>
>> v2:
>> 1. Modified the annotation file.
>> 2. Set CONFIG_X86_16BIT=n to avoid getting the prompt that interrupts
>> the build process.
>>
>> Roxana Nicolescu (1):
>>    UBUNTU: [Config] kvm: Add support for modifying LDT
>>
> The annotations for bionic:linux-kvm need a second look. We see a
> compilation error due to check-config.
>
> check-config: FAIL (y != m): CONFIG_MODIFY_LDT_SYSCALL policy<{'amd64': 'm'}> mark<ENFORCED> note<LP: #2009442>
>
> - corytodd
>
>
I modified the commit but did not recreate the patch :facepalm.
I sent a v3.
Thanks for catching this.

Roxana