Re: [PATCH v6 0/2] ARM: Implement MODULE_PLT support in FTRACE

[Florian Fainelli]

Hi Alexander,

On 2/17/2020 6:09 AM, Alexander X Sverdlin wrote:
> From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
> 
> FTRACE's function tracer currently doesn't always work on ARM with
> MODULE_PLT option enabled. If the module is loaded too far, FTRACE's
> code modifier cannot cope with introduced veneers and turns the
> function tracer off globally.
> 
> ARM64 already has a solution for the problem, refer to the following
> patches:
> 
> arm64: ftrace: emit ftrace-mod.o contents through code
> arm64: module-plts: factor out PLT generation code for ftrace
> arm64: ftrace: fix !CONFIG_ARM64_MODULE_PLTS kernels
> arm64: ftrace: fix building without CONFIG_MODULES
> arm64: ftrace: add support for far branches to dynamic ftrace
> arm64: ftrace: don't validate branch via PLT in ftrace_make_nop()
> 
> But the presented ARM variant has just a half of the footprint in terms of
> the changed LoCs. It also retains the code validation-before-modification
> instead of switching it off.

We have been using those patches and I was wondering what happened after
this version since they did not show up upstream nor in Russell's patch
tracker? Would you be willing to resubmit them?

Thanks!
-- 
Florian