Re: [PATCHv2 0/8] arm64: ftrace cleanup + FTRACE_WITH_REGS

[Amit Kachhap <amit.kachhap@arm.com>]

Hi,

On 11/4/19 7:34 PM, Mark Rutland wrote:
> On Mon, Nov 04, 2019 at 01:03:51PM +0000, Amit Kachhap wrote:
>>
>>
>> On 11/4/19 6:26 PM, Will Deacon wrote:
>>> On Sat, Nov 02, 2019 at 05:42:25PM +0530, Amit Daniel Kachhap wrote:
>>>> On 10/29/19 10:28 PM, Mark Rutland wrote:
>>>>> This series is a reworked version of Torsten's FTRACE_WITH_REGS series
>>>>> [1]. I've tried to rework the existing code in preparatory patches so
>>>>> that the patchable-function-entry bits slot in with fewer surprises.
>>>>> This version is based on v5.4-rc3, and can be found in my
>>>>> arm64/ftrace-with-regs branch [2].
>>>>>
>>>>> Patch 1 adds an (optional) ftrace_init_nop(), which the core code uses
>>>>> to initialize callsites. This allows us to avoid a synthetic MCOUNT_ADDR
>>>>> symbol, and more cleanly separates the one-time initialization of the
>>>>> callsite from dynamic NOP<->CALL modification. Architectures which don't
>>>>> implement this get the existing ftrace_make_nop() with MCOUNT_ADDR.
>>>>>
>>>>> Recently parisc gained ftrace support using patchable-function-entry.
>>>>> Patch 2 makes the handling of module callsite locations common in
>>>>> kernel/module.c with a new FTRACE_CALLSITE_SECTION definition, and
>>>>> removed the newly redundant bits from arch/parisc.
>>>>>
>>>>> Patches 3 and 4 move the module PLT initialization to module load time,
>>>>> which simplifies runtime callsite modification. This also means that we
>>>>> don't transitently mark the module text RW, and will allow for the
>>>>> removal of module_disable_ro().
>>>>>
>>>>> Patches 5 and 6 add some trivial infrastructure, with patch 7 finally
>>>>> adding FTRACE_WITH_REGS support. Additional work will be required for
>>>>> livepatching (e.g. implementing reliable stack trace), which is
>>>>> commented as part of patch 7.
>>>>>
>>>>> Patch 8 is a trivial cleanup atop of the rest of the series, making the
>>>>> code easier to read and less susceptible to config-specific breakage.
>>>> I tested the whole series with my latest in-kernel ptrauth patches [1]
>>>> and graph_tracer/function_graph_tracer works fine, So for the whole series,
>>>> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
>>>>
>>>> Also I gave few minor comments in the individual patches. With those
>>>> comments,
>>>> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
>> Oops sorry I meant,
>> Reviewed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
> 
> Thanks!
> 
> I've added the Tested-by for the whole series, and the Reviewed-by for
> patches 4 and 7. I haven't added it for patch 1 just yet; please reply
> to my comment there if you'd still like to add a Reviewed-by.

Those were minor comments. Please go ahead and add the Reviewed-by's.
Thanks,
Amit

> 
> Mark.
>