[SRU][jammy/linux-azure-5.19, kinetic/linux-azure, lunar/linux-azure][PATCH] Revert "UBUNTU: SAUCE: TDX: Work around the segfault issue in glibc 2.35 in Ubuntu 22.04."

[Tim Gardner]

On 3/22/23 2:40 AM, Stefan Bader wrote:
> On 21.03.23 16:27, Ioanna Alifieraki wrote:
>> BugLink: https://bugs.launchpad.net/bugs/2011421
>>
>> This reverts commit 5e304319d26d7003e648bd7a68322537dddbdaed.
> 
> The bug report needs an also-affects for linux-azure. Tim, maybe you 
> could set things up correctly. I guess jammy:linux-azure-5.19 does not 
> have to be mentioned or done individually. What is unclear to me is 
> whether this maybe also affects jammy:linux-azure which, though its not 
> the default, should also be a possible selection.
> 
> -Stefan
> 

I've updated the bug report with kernel tasks.

Jammy linux-azure does not require this revert since it has no TDX support.

Only Kinetic linux-azure needs the revert. Jammy linux-azure-5.19 will 
inherit the revert.

Lunar linux-azure requires no change since glibc should be fixed in time 
for release.

As mentioned before, I'll delay applying this revert until after glibc 
has been released to updates. The kernel glibc patch is benign in the 
face of a fixed glibc, so overlapping the patched kernel with a fixed 
glibc should be OK.

rtg

>>
>> Commit 5e304319d26d ("UBUNTU: SAUCE: TDX: Work around the segfault issue
>> in glibc 2.35 in Ubuntu 22.04.") was added to work around a bug in
>> glibc. Glibc is getting fixed in LP#2011421 and we can drop this.
>>
>> Signed-off-by: Ioanna Alifieraki <ioanna-maria.alifieraki at canonical.com>
>> ---
>>   arch/x86/coco/tdx/tdx.c | 12 ------------
>>   1 file changed, 12 deletions(-)
>>
>> diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
>> index 3c853e18320e..b7af93ca319e 100644
>> --- a/arch/x86/coco/tdx/tdx.c
>> +++ b/arch/x86/coco/tdx/tdx.c
>> @@ -318,18 +318,6 @@ static int handle_cpuid(struct pt_regs *regs, 
>> struct ve_info *ve)
>>           .r13 = regs->cx,
>>       };
>> -    /*
>> -     * Work around the segfault issue in glibc 2.35 in Ubuntu 22.04.
>> -     * See https://sourceware.org/bugzilla/show_bug.cgi?id=28784
>> -     * Ubuntu 22.04/22.10/23.04's glibc should pick up this glibc fix:
>> -     * 
>> https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=c242fcce06e3102ca663b2f992611d0bda4f2668
>> -     */
>> -    if (regs->ax == 2) {
>> -        regs->ax = 0xf1ff01;
>> -        regs->bx = regs->cx = regs->dx = 0;
>> -        return ve_instr_len(ve);
>> -    }
>> -
>>       /*
>>        * Only allow VMM to control range reserved for hypervisor
>>        * communication.
> 

-- 
-----------
Tim Gardner
Canonical, Inc