Messages in this thread | | | From | Kees Cook <> | Date | Wed, 10 Aug 2016 11:38:57 -0700 | Subject | Re: [PATCH 0/3] arm64: put objects into proper sections |
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On Wed, Aug 10, 2016 at 3:05 AM, Jisheng Zhang <jszhang@marvell.com> wrote: > + Kees, > > On Wed, 10 Aug 2016 15:19:16 +0800 Jisheng Zhang wrote: > >> This series tries to put objects into proper sections to avoid >> pontential unnecessary DDR traffics: >> >> patch1 puts alloc_vectors_page() into .init section. This is a clean up >> patch. >> >> patch2 puts vdso_pages, vdso_spec and vectors_page into read_mostly >> section, since they are read mostly in hot path. >> >> patch3 puts cpu_ops into read_mostly section, since it's read mostly >> int hot path such as arm_cpuidle_suspend(). > > Is it better to mark them as __ro_after_init, suggestions are appreciated.
If something is actually never updated after __init, yes, please use __ro_after_init.
-Kees
> > Thanks, > Jisheng > >> >> >> Before this series: >> >> ffff000008d660f0 b undef_lock >> ffff000008d660f8 b vectors_page >> ffff000008d66100 b vdso_pages >> ffff000008d66108 b vdso_spec >> ffff000008d66148 B cpu_ops >> ffff000008d66348 b patch_lock >> >> After this series: >> >> ffff000008ca5b08 D static_key_initialized >> ffff000008ca5b10 d vectors_page >> ffff000008ca5b18 d vdso_pages >> ffff000008ca5b20 d vdso_spec >> ffff000008ca5b60 D cpu_ops >> ffff000008ca5d60 D elf_hwcap >> ffff000008ca5d68 D compat_elf_hwcap >> ffff000008ca5d6c D compat_elf_hwcap2 >> >> Although there's no obvious issue with current code, because undef_lock and >> patch_lock is rarely used, but the situation may change in the future, so >> let's move them into proper sections now. >> >> Jisheng Zhang (3): >> arm64: vdso: add __init section marker to alloc_vectors_page >> arm64: vdso: put read only/mostly objects into proper sections >> arm64: kernel: declare cpu_ops __read_mostly >> >> arch/arm64/kernel/cpu_ops.c | 2 +- >> arch/arm64/kernel/vdso.c | 31 +++++++++++++++---------------- >> 2 files changed, 16 insertions(+), 17 deletions(-) >> >
-- Kees Cook Nexus Security
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