Hello Florian, On 27/01/2021 05:48, Florian Fainelli wrote: >> 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?
it's a pity, but nobody ever showed any interest to take them to fix real problem in FTRACE. A grain of salt would be to remind, that no-one also replied that the series helped him or a Tested-by: tag. This would probably wake more interest from maintainers side. Of course I can re-send them because I personally re-base them regularly. -- Best regards, Alexander Sverdlin.
