| Message ID | 20171103171203.107569-12-samitolvanen@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 3 November 2017 at 17:11, Sami Tolvanen <samitolvanen@google.com> wrote: > CONFIG_CLANG_LTO depends on GNU gold, which can generate ADR_PREL_PG_HI21 > relocations even with --fix-cortex-a53-843419. > > Since ARM64_ERRATUM_843419 disables kernel support for these relocations, > disable the erratum when LTO is used. > I wonder it makes sense to disable such relocations entirely when we enable this erratum. If the toolchain does not generate them, they shouldn't occur in the first place, and having this dependency here seems awkward as well. > Signed-off-by: Sami Tolvanen <samitolvanen@google.com> > --- > arch/arm64/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 0df64a6a56d4..43ccddb7c8ec 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -433,6 +433,7 @@ config ARM64_ERRATUM_845719 > > config ARM64_ERRATUM_843419 > bool "Cortex-A53: 843419: A load or store might access an incorrect address" > + depends on !CLANG_LTO > default y > select ARM64_MODULE_CMODEL_LARGE if MODULES > help > -- > 2.15.0.403.gc27cc4dac6-goog > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Fri, Nov 03, 2017 at 08:13:20PM +0000, Ard Biesheuvel wrote: > I wonder it makes sense to disable such relocations entirely when we > enable this erratum. If the toolchain does not generate them, they > shouldn't occur in the first place, and having this dependency here > seems awkward as well. I agree. Unless someone objects, I'll replace this in v2 with a patch that leaves the relocations in module.c even when the erratum is selected. Sami
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0df64a6a56d4..43ccddb7c8ec 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -433,6 +433,7 @@ config ARM64_ERRATUM_845719 config ARM64_ERRATUM_843419 bool "Cortex-A53: 843419: A load or store might access an incorrect address" + depends on !CLANG_LTO default y select ARM64_MODULE_CMODEL_LARGE if MODULES help
CONFIG_CLANG_LTO depends on GNU gold, which can generate ADR_PREL_PG_HI21 relocations even with --fix-cortex-a53-843419. Since ARM64_ERRATUM_843419 disables kernel support for these relocations, disable the erratum when LTO is used. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+)