On Mon, 8 Aug 2022 at 03:31, Sasha Levin <sashal@xxxxxxxxxx> wrote: > > From: Ard Biesheuvel <ardb@xxxxxxxxxx> > > [ Upstream commit 2e945851e26836c0f2d34be3763ddf55870e49fe ] > > Some early boot code runs before the virtual placement of the kernel is > finalized, and we used to go back to the very start and recreate the ID > map along with the page tables describing the virtual kernel mapping, > and this involved setting some global variables with the caches off. > > In order to ensure that global state created by the KASLR code is not > corrupted by the cache invalidation that occurs in that case, we needed > to clean those global variables to the PoC explicitly. > > This is no longer needed now that the ID map is created only once (and > the associated global variable updates are no longer repeated). So drop > the cache maintenance that is no longer necessary. > > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > Link: https://lore.kernel.org/r/20220624150651.1358849-9-ardb@xxxxxxxxxx > Signed-off-by: Will Deacon <will@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> NAK This patch *must* *not* be backported. It will break the boot. And again, *please* stop spamming people with broken backports like this. Can you explain why it is justified to use a bot to generate hundreds of patches, and leave it to overloaded maintainers to spot the ones that are broken? Is it because your time is more valuable than mine? I have already asked (and you have already agreed) to disregard all patches authored by me from this broken-by-design process. But here we are, with yet another set of broken patches queued up all the way back to v5.15. So please, don't use AUTOSEL on *any* patch that was authored by me. I understand the concept of a -stable kernel. I known what cc:stable means. I know that a fixes: tag means. I don't need help from your bot, it is only causing grief. Thanks, Ard. > --- > arch/arm64/kernel/kaslr.c | 11 ----------- > 1 file changed, 11 deletions(-) > > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c > index 418b2bba1521..d5542666182f 100644 > --- a/arch/arm64/kernel/kaslr.c > +++ b/arch/arm64/kernel/kaslr.c > @@ -13,7 +13,6 @@ > #include <linux/pgtable.h> > #include <linux/random.h> > > -#include <asm/cacheflush.h> > #include <asm/fixmap.h> > #include <asm/kernel-pgtable.h> > #include <asm/memory.h> > @@ -72,9 +71,6 @@ u64 __init kaslr_early_init(void) > * we end up running with module randomization disabled. > */ > module_alloc_base = (u64)_etext - MODULES_VSIZE; > - dcache_clean_inval_poc((unsigned long)&module_alloc_base, > - (unsigned long)&module_alloc_base + > - sizeof(module_alloc_base)); > > /* > * Try to map the FDT early. If this fails, we simply bail, > @@ -174,13 +170,6 @@ u64 __init kaslr_early_init(void) > module_alloc_base += (module_range * (seed & ((1 << 21) - 1))) >> 21; > module_alloc_base &= PAGE_MASK; > > - dcache_clean_inval_poc((unsigned long)&module_alloc_base, > - (unsigned long)&module_alloc_base + > - sizeof(module_alloc_base)); > - dcache_clean_inval_poc((unsigned long)&memstart_offset_seed, > - (unsigned long)&memstart_offset_seed + > - sizeof(memstart_offset_seed)); > - > return offset; > } > > -- > 2.35.1 >
