On Thu, 17 Sep 2020 at 03:53, Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > On Tue, Sep 15, 2020 at 11:14 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > > > Remove some occurrences of ADRL in the SHA NEON code adopted from the > > OpenSSL project. > > > > I will leave it to the Clang folks to decide whether this needs to be > > backported and how far, but a Cc stable seems reasonable here. > > > > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Cc: Stefan Agner <stefan@xxxxxxxx> > > Cc: Peter Smith <Peter.Smith@xxxxxxx> > > Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Thanks! > Thanks Ard: > compile+boot tested each combination of: > > [gcc, clang]x[defconfig, defconfig+CONFIG_THUMB2_KERNEL=y]. > > Now, if I additionally apply: > 1. this series > 2. the adr_l series: > https://lore.kernel.org/linux-arm-kernel/20200914095706.3985-1-ardb@xxxxxxxxxx/ > 3. unrelated fix for -next #1: > https://lore.kernel.org/lkml/20200916200255.1382086-1-ndesaulniers@xxxxxxxxxx/ > 4. unrelated fix for -next #2: > https://lore.kernel.org/linux-mm/20200917001934.2793370-1-ndesaulniers@xxxxxxxxxx/ > 5. small fixup to 01/12 from #2: > https://lore.kernel.org/linux-arm-kernel/CAMj1kXFmF_24d-7W8AWTJR-PCcja7bUdHhYKptGQmsV4vNp=sA@xxxxxxxxxxxxxx/ > 6. vfp fixup for thumb+gcc: > https://lore.kernel.org/linux-arm-kernel/CAMj1kXHEpPc0MSoMrCxEkyb44AkLM2NJJGtOXLpr6kxBHS0vfA@xxxxxxxxxxxxxx/ > 7. disable CONFIG_IWMMXT https://github.com/ClangBuiltLinux/linux/issues/975 > > Then build with Clang's integrated assembler: > $ ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make LLVM=1 LLVM_IAS=1 -j71 > > I see a bunch of warnings > (https://github.com/ClangBuiltLinux/linux/issues/858) which we will > fix, but I am able to build and boot. (CONFIG_THUMB2_KERNEL=y has > many more issues, so I didn't pursue that further). > > Either way, these two adrl patches go a long way towards getting Clang > to assemble an ARCH=arm kernel; thank you for all of the work that > went into them. > My pleasure :-) > One thing I noticed was that if I grep for `adrl` with all of the > above applied within arch/arm, I do still see two more instances: > > crypto/sha256-armv4.pl > 609: adrl $Ktbl,K256 > > crypto/sha256-core.S_shipped > 2679: adrl r3,K256 > > Maybe those can be fixed up in patch 01/02 of this series for a v2? I > guess in this cover letter, you did specify *some occurrences of > ADRL*. It looks like those are guarded by > 605 # ifdef __thumb2__ > ... > 608 # else > 609 adrl $Ktbl,K256 > > So are these always built as thumb2? > No need. The code in question is never assembled when built as part of the kernel, only when building OpenSSL for user space. It appears upstream has removed this already, but they have also been playing weird games with the license blocks, so I'd prefer fixing the code here rather than pulling the latest version.
