答复: Meet compiled kernel binaray abnormal issue while enabling generic kasan in kernel 6.12 with some default KBUILD_RUSTFLAGS on

["刘海燕 (Haiyan Liu)" <haiyan.liu@unisoc.com>]

> -----邮件原件-----
> 发件人: Miguel Ojeda <ojeda@kernel.org>
> 发送时间: 2025年7月15日 4:05
> 收件人: 刘海燕 (Haiyan Liu) <haiyan.liu@unisoc.com>
> 抄送: 周平 (Ping Zhou/9032) <Ping.Zhou1@unisoc.com>; 代子为 (Ziwei Dai) <Ziwei.Dai@unisoc.com>; 杨丽娜 (Lina Yang)
> <lina.yang@unisoc.com>; linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; rust-for-linux@vger.kernel.org; 王双
> (Shuang Wang) <shuang.wang@unisoc.com>; Andrey Ryabinin <ryabinin.a.a@gmail.com>; Alexander Potapenko <glider@google.com>;
> Andrey Konovalov <andreyknvl@gmail.com>; Dmitry Vyukov <dvyukov@google.com>; Vincenzo Frascino <vincenzo.frascino@arm.com>;
> kasan-dev@googlegroups.com; Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Arve Hjønnevåg <arve@android.com>; Todd Kjos
> <tkjos@android.com>; Martijn Coenen <maco@android.com>; Joel Fernandes <joelagnelf@nvidia.com>; Christian Brauner
> <christian@brauner.io>; Carlos Llamas <cmllamas@google.com>; Suren Baghdasaryan <surenb@google.com>; Jamie Cunliffe
> <Jamie.Cunliffe@arm.com>; Catalin Marinas <catalin.marinas@arm.com>
> 主题: Re: Meet compiled kernel binaray abnormal issue while enabling generic kasan in kernel 6.12 with some default KBUILD_RUSTFLAGS
> on
> 
> 
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> On Mon, 14 Jul 2025 03:12:33 +0000 "刘海燕 (Haiyan Liu)" <haiyan.liu@unisoc.com> wrote:
> >
> > After I delete the rust build flags, the asan.module_ctor binary is right and kasan feature works fine.Could you help check why
> KBUILD_RUSTFLAGS impacts kernel complication with kasan feature enabled and how can this issue fixed?
> 
> I assume Rust is enabled in that kernel, right? Or do you mean that somehow removing those lines from the `Makefile` makes the issue go
> away even if Rust is not enabled?
 
Rust is enabled in kernel, and rustc version is 1.82.0. I want to know why the pacisap/autiasp are not in pair.

> Could you please share your kernel commit and the full configuration? From a quick build arm64 KASAN in v6.12.38, I see the
> `paciasp`/`autiasp` pair in one of the Rust object files:

The commit changes the fragment and diff is:
+CONFIG_CMDLINE="stack_depot_disable=off kasan.stacktrace=on kasan.fault=panic kvm-arm.mode=protected cgroup_disable=pressure"
+CONFIG_KASAN_GENERIC=y
Only two rust-related global variables in fmr.rs and layout.rs have this issue. Their asan.module_ctor complied binaries are wrong.

>     0000000000000000 <asan.module_ctor>:
>            0: d503233f          paciasp
>            4: f81f0ffe          str     x30, [sp, #-0x10]!
>            8: 90000000          adrp    x0, 0x0 <asan.module_ctor>
>            c: 91000000          add     x0, x0, #0x0
>           10: 52800601          mov     w1, #0x30               // =48
>           14: 94000000          bl      0x14 <asan.module_ctor+0x14>
>           18: f84107fe          ldr     x30, [sp], #0x10
>           1c: d50323bf          autiasp
>           20: d65f03c0          ret
> 
> But I am definitely not an expert at all in this, so Cc'ing KASAN and Android maintainers:
> https://lore.kernel.org/rust-for-linux/4c459085b9ae42bdbf99b6014952b965@BJMBX01.spreadtrum.com/
> 
> Cheers,
> Miguel