On Thursday 29 Jul 2021 at 14:50:16 (+0100), Marc Zyngier wrote:
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.
Make the unregistration from kmemleak part of marking the sections as HYP-private. The rest of the HYP-specific data is obtained via the page allocator, which is not subjected to kmemleak.
Fixes: 90134ac9cabb ("KVM: arm64: Protect the .hyp sections from the host") Signed-off-by: Marc Zyngier maz@kernel.org Cc: Quentin Perret qperret@google.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: stable@vger.kernel.org # 5.13
arch/arm64/kvm/arm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e9a2b8f27792..23f12e602878 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -15,6 +15,7 @@ #include <linux/fs.h> #include <linux/mman.h> #include <linux/sched.h> +#include <linux/kmemleak.h> #include <linux/kvm.h> #include <linux/kvm_irqfd.h> #include <linux/irqbypass.h> @@ -1960,8 +1961,12 @@ static inline int pkvm_mark_hyp(phys_addr_t start, phys_addr_t end) } #define pkvm_mark_hyp_section(__section) \ +({ \
- u64 sz = __section##_end - __section##_start; \
- kmemleak_free_part(__section##_start, sz); \ pkvm_mark_hyp(__pa_symbol(__section##_start), \
__pa_symbol(__section##_end))
__pa_symbol(__section##_end)); \+})
At some point we should also look into unmapping these sections from EL1 stage-1 as well, as that should lead to better error messages in case the host accesses hyp-private memory some other way. But this patch makes sense on its own, so:
Reviewed-by: Quentin Perret qperret@google.com
Thanks, Quentin