From eb48d154cd0dade56a0e244f0cfa198ea2925ed3 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 2 Aug 2021 13:38:29 +0100 Subject: arm64: Move .hyp.rodata outside of the _sdata.._edata range The HYP rodata section is currently lumped together with the BSS, which isn't exactly what is expected (it gets registered with kmemleak, for example). Move it away so that it is actually marked RO. As an added benefit, it isn't registered with kmemleak anymore. Fixes: 380e18ade4a5 ("KVM: arm64: Introduce a BSS section for use at Hyp") Suggested-by: Catalin Marinas Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org #5.13 Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210802123830.2195174-2-maz@kernel.org --- arch/arm64/kernel/vmlinux.lds.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 709d2c433c5e..f6b1a88245db 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -181,6 +181,8 @@ SECTIONS /* everything from this point to __init_begin will be marked RO NX */ RO_DATA(PAGE_SIZE) + HYPERVISOR_DATA_SECTIONS + idmap_pg_dir = .; . += IDMAP_DIR_SIZE; idmap_pg_end = .; @@ -260,8 +262,6 @@ SECTIONS _sdata = .; RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN) - HYPERVISOR_DATA_SECTIONS - /* * Data written with the MMU off but read with the MMU on requires * cache lines to be invalidated, discarding up to a Cache Writeback -- cgit v1.2.3 From 47e6223c841e029bfc23c3ce594dac5525cebaf8 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 2 Aug 2021 13:38:30 +0100 Subject: KVM: arm64: Unregister HYP sections from kmemleak in protected mode Booting a KVM host in protected mode with kmemleak quickly results in a pretty bad crash, as kmemleak doesn't know that the HYP sections have been taken away. This is specially true for the BSS section, which is part of the kernel BSS section and registered at boot time by kmemleak itself. Unregister the HYP part of the BSS before making that section HYP-private. The rest of the HYP-specific data is obtained via the page allocator or lives in other sections, none of which is subjected to kmemleak. Fixes: 90134ac9cabb ("KVM: arm64: Protect the .hyp sections from the host") Reviewed-by: Quentin Perret Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org # 5.13 Link: https://lore.kernel.org/r/20210802123830.2195174-3-maz@kernel.org --- arch/arm64/kvm/arm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e9a2b8f27792..52242f32c4be 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -1982,6 +1983,12 @@ static int finalize_hyp_mode(void) if (ret) return ret; + /* + * Exclude HYP BSS from kmemleak so that it doesn't get peeked + * at, which would end badly once the section is inaccessible. + * None of other sections should ever be introspected. + */ + kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); ret = pkvm_mark_hyp_section(__hyp_bss); if (ret) return ret; -- cgit v1.2.3