From: Marc Zyngier <maz@kernel.org>
To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Cc: kernel-team@android.com, James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH] KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr
Date: Mon, 8 Jun 2020 09:57:31 +0100 [thread overview]
Message-ID: <20200608085731.1405854-1-maz@kernel.org> (raw)
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>
---
arch/arm64/include/asm/kvm_asm.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 0c9b5fc4ba0a..82691406d493 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -81,12 +81,17 @@ 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); \
__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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next reply other threads:[~2020-06-08 8:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-08 8:57 Marc Zyngier [this message]
2020-06-08 15:00 ` [PATCH] KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr Andrew Scull
2020-06-08 16:31 ` Marc Zyngier
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