Re: [AARCH64] Disable pc relative literal load irrespective of TARGET_FIX_ERR_A53_84341

[Kugan Vivekanandarajah <kugan dot vivekanandarajah at linaro dot org>]

Ping ?

Thanks,
Kugan

On 27 June 2017 at 11:20, Kugan Vivekanandarajah
<kugan.vivekanandarajah@linaro.org> wrote:
> https://gcc.gnu.org/ml/gcc-patches/2016-03/msg00614.html  added this
> workaround to get kernel building with when TARGET_FIX_ERR_A53_843419
> is enabled.
>
> This was added to support building kernel loadable modules. In kernel,
> when CONFIG_ARM64_ERRATUM_843419 is selected, the relocation needed
> for ADRP/LDR (R_AARCH64_ADR_PREL_PG_HI21 and
> R_AARCH64_ADR_PREL_PG_HI21_NC are removed from the kernel to avoid
> loading objects with possibly offending sequence). Thus, it could only
> support pc relative literal loads.
>
> However, the following patch was posted to kernel to add
> -mpc-relative-literal-loads
> http://www.spinics.net/lists/arm-kernel/msg476149.html
>
> -mpc-relative-literal-loads is unconditionally added to the kernel
> build as can be seen from:
> https://github.com/torvalds/linux/blob/master/arch/arm64/Makefile
>
> Therefore this patch removes the hunk so that applications like
> SPECcpu2017's 521/621.wrf can be built (with LTO in this case) without
> -mno-pc-relative-literal-loads
>
> Bootstrapped and regression tested on aarch64-linux-gnu with no new regressions.
>
> Is this OK for trunk?
>
> Thanks,
> Kugan
>
> gcc/testsuite/ChangeLog:
>
> 2017-06-27  Kugan Vivekanandarajah  <kuganv@linaro.org>
>
>     * gcc.target/aarch64/pr63304_1.c: Remove-mno-fix-cortex-a53-843419.
>
> gcc/ChangeLog:
>
> 2017-06-27  Kugan Vivekanandarajah  <kuganv@linaro.org>
>
>     * config/aarch64/aarch64.c (aarch64_override_options_after_change_1):
>     Disable pc relative literal load irrespective of TARGET_FIX_ERR_A53_84341
>     for default.