Messages in this thread | | | From | Mauro Rossi <> | Date | Sun, 29 May 2022 20:46:54 +0200 | Subject | Re: arch/x86/entry/entry: RFC on recent kernels building error with llvm 11.0.2 internal assembler |
| |
On Mon, May 9, 2022 at 2:07 AM Nathan Chancellor <nathan@kernel.org> wrote: > > On Sat, May 07, 2022 at 02:19:00PM +0200, Mauro Rossi wrote: > > > > Alternatively, you could apply the hack that Nick inserted into Android > > > > for this issue if upgrading your toolchain or turning off the integrated > > > > assembler is not possible: > > > > > > > > https://android.googlesource.com/kernel/common/+/e58f084735b8abf744d61083b92172ee23d45aae > > > > > > > > I really do not mean to sound dismissive or rude, I apologize if it > > > > comes off that way, but we have worked quite hard to avoid inserting > > > > unnecessary workarounds, as they are ultimately technical debt that can > > > > be hard to manage over the long term. > > > > > > > > Cheers, > > > > Nathan > > > > > > Thanks a lot Nathan > > > > > > It is definitely the clang version 11.0.x which is not updated in aosp > > > Android 11 production tags > > > > > > I will use Nick's workaround which works since only lsl %rax, %rax is > > > currently happening > > > > > > Many thanks, problem solved > > > > Hello, > > I'm back again because I was assuming that Nick's workaround was working ok, > > but I have found that ARCH=x86_64 i.e. 64bit built kernel is causing > > an immediate hard reboot at initrd execution, > > just after hitting [ENTER] at grub/efi menu. > > It looks like there was a follow up fix for that workaround, maybe that > resolves this issue as well? > > https://android.googlesource.com/kernel/common/+/cc7f7a84191f5defc2ea4633eeea4acb4486b549 > > > ARCh=x86 i.e. 32bit kernel binary is not affected, but is Nick's > > workaround targeting 32 bit kernel builds? > > No, the file that the build error originates from (entry_64.S) is only > built on x86_64. > > > How do aosp android-mailine kernels avoid this instantaneous hard reboot issue? > > That hack was reverted once the toolchain was upgraded: > > https://android.googlesource.com/kernel/common/+/ff0216d09fd31802537f2d1702ec2f3e9be73aa3 > https://android.googlesource.com/kernel/common/+/3c2c8d8f7f2639e319212d10cb8df5bd13098dae > > Cheers, > Nathan
Hello,
sorry i still have the issue when building with hack "ANDROID: x86: entry: work around LLVM_IAS=1 bug in LSL" I'd just like to understand why I get instant reboot in 64bit kernel built with LLVM_IAS=1
I searched for the places where #include "calling.h" is used
utente@utente-3TB:~/r-x86_kernel/kernel$ grep -r \#include\ \"calling arch/x86/entry/thunk_64.S:#include "calling.h" arch/x86/entry/entry_32.S:#include "calling.h" arch/x86/entry/entry_64_compat.S:#include "calling.h" arch/x86/entry/entry_64.S:#include "calling.h"
Probably the hardcoding done in the hack is impacting some other asm target built in 64 bit kernel and causes a wrong X86 instruction , is there a way to refine the #if defto avoid that problem while still building with LLVM_IAS=1 ?
Thanks for the info Mauro
| |