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RFC arm64: add livepatch support

Li Bin linux-arm-kernel lkml 1 version New

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  1. v1 RFC Latest0 of 4 patches 0 repliesNew

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Cover letter [RFC 0/4] arm64: add livepatch support
Quoted 10 lines · Jiri Kosina
Quoted 8 lines · AKASHI Takahiro

This patchset enables livepatch support on arm64.

Livepatch was merged in v4.0, and allows replacying a function dynamically based on ftrace framework, but it also requires -mfentry option of gcc. Currently arm64 gcc doesn't support it, but by adding a helper function to ftrace, we will be able to support livepatch on arch's which don't support this option.

Quoted 6 lines
Quoted 2 lines

I submit this patchset as RFC since I'm not quite sure that I'm doing in the right way, or we should definitely support -fentry instead.

I don't have arm64 cross-compiler handy, could you please copy/paste how does function prologue, generated by gcc -pg on arm64 look like?

The function prologue on arm64 with gcc -pg look like as following:
func:

        stp     x29, x30, [sp, -48]!
        add     x29, sp, 0
        mov     x1, x30
        str     w0, [x29,28]
        mov     x0, x1
        bl      _mcount
	...

Thanks,
Li Bin

Quoted 2 lines

Thanks,

Read the cover letter in its thread