Messages in this thread | | | Date | Thu, 28 Jan 2021 20:26:49 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v2 4/4] arm64: kaslr: support randomized module area with KASAN_VMALLOC |
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On Thu, Jan 28, 2021 at 04:53:26PM +0800, Lecopzer Chen wrote: > > > On Sat, Jan 09, 2021 at 06:32:52PM +0800, Lecopzer Chen wrote: > > > After KASAN_VMALLOC works in arm64, we can randomize module region > > > into vmalloc area now. > > > > > > Test: > > > VMALLOC area ffffffc010000000 fffffffdf0000000 > > > > > > before the patch: > > > module_alloc_base/end ffffffc008b80000 ffffffc010000000 > > > after the patch: > > > module_alloc_base/end ffffffdcf4bed000 ffffffc010000000 > > > > > > And the function that insmod some modules is fine. > > > > > > Suggested-by: Ard Biesheuvel <ardb@kernel.org> > > > Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> > > > --- > > > arch/arm64/kernel/kaslr.c | 18 ++++++++++-------- > > > arch/arm64/kernel/module.c | 16 +++++++++------- > > > 2 files changed, 19 insertions(+), 15 deletions(-) > > > > > > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c > > > index 1c74c45b9494..a2858058e724 100644 > > > --- a/arch/arm64/kernel/kaslr.c > > > +++ b/arch/arm64/kernel/kaslr.c > > > @@ -161,15 +161,17 @@ u64 __init kaslr_early_init(u64 dt_phys) > > > /* use the top 16 bits to randomize the linear region */ > > > memstart_offset_seed = seed >> 48; > > > > > > - if (IS_ENABLED(CONFIG_KASAN_GENERIC) || > > > - IS_ENABLED(CONFIG_KASAN_SW_TAGS)) > > > + if (!IS_ENABLED(CONFIG_KASAN_VMALLOC) && > > > + (IS_ENABLED(CONFIG_KASAN_GENERIC) || > > > > CONFIG_KASAN_VMALLOC depends on CONFIG_KASAN_GENERIC so why is this > > necessary? > > > > Will > > CONFIG_KASAN_VMALLOC=y means CONFIG_KASAN_GENERIC=y > but CONFIG_KASAN_GENERIC=y doesn't means CONFIG_KASAN_VMALLOC=y > > So this if-condition allows only KASAN rather than > KASAN + KASAN_VMALLOC enabled. > > Please correct me if I'm wrong.
Sorry, you're completely right -- I missed the '!' when I read this initially.
Will
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