[PATCH v2 3/4] KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr
From: Marc Zyngier <maz@kernel.org>
Date: 2020-06-10 11:35:11
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Sparse complains that __hyp_this_cpu_ptr() returns something
that is flagged noderef and not in the correct address space
(both being the result of the __percpu annotation).
Pretend that __hyp_this_cpu_ptr() knows what it is doing by
forcefully casting the pointer with __kernel __force.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
Notes:
v2: Add __verify_pcpu_ptr() as suggested by Andrew Scull.
arch/arm64/include/asm/kvm_asm.h | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 0c9b5fc4ba0a..d9b7da15dbca 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h@@ -81,12 +81,19 @@ extern u32 __kvm_get_mdcr_el2(void); extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; -/* Home-grown __this_cpu_{ptr,read} variants that always work at HYP */ +/* + * Home-grown __this_cpu_{ptr,read} variants that always work at HYP, + * provided that sym is really a *symbol* and not a pointer obtained from + * a data structure. As for SHIFT_PERCPU_PTR(), the creative casting keeps + * sparse quiet. + */ #define __hyp_this_cpu_ptr(sym) \ ({ \ - void *__ptr = hyp_symbol_addr(sym); \ + void *__ptr; \ + __verify_pcpu_ptr(&sym); \ + __ptr = hyp_symbol_addr(sym); \ __ptr += read_sysreg(tpidr_el2); \ - (typeof(&sym))__ptr; \ + (typeof(sym) __kernel __force *)__ptr; \ }) #define __hyp_this_cpu_read(sym) \
--
2.26.2
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