From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
kvm@vger.kernel.org, Suzuki K Poulose <suzuki.poulose@arm.com>,
James Morse <james.morse@arm.com>,
Andrew Scull <ascull@google.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
kvmarm@lists.cs.columbia.edu,
Julien Thierry <julien.thierry.kdev@gmail.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 07/11] KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr
Date: Thu, 11 Jun 2020 10:09:52 +0100 [thread overview]
Message-ID: <20200611090956.1537104-8-maz@kernel.org> (raw)
In-Reply-To: <20200611090956.1537104-1-maz@kernel.org>
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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next prev parent reply other threads:[~2020-06-11 9:12 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-11 9:09 [GIT PULL] KVM/arm64 fixes for 5.8, take #1 Marc Zyngier
2020-06-11 9:09 ` [PATCH 01/11] KVM: arm64: Flush the instruction cache if not unmapping the VM on reboot Marc Zyngier
2020-06-11 9:09 ` [PATCH 02/11] KVM: arm64: Stop writing aarch32's CSSELR into ACTLR Marc Zyngier
2020-06-11 9:09 ` [PATCH 03/11] KVM: arm64: Add emulation for 32bit guests accessing ACTLR2 Marc Zyngier
2020-06-11 9:09 ` [PATCH 04/11] KVM: arm64: Stop save/restoring ACTLR_EL1 Marc Zyngier
2020-06-11 9:09 ` [PATCH 05/11] KVM: arm64: Save the host's PtrAuth keys in non-preemptible context Marc Zyngier
2020-06-11 9:09 ` [PATCH 06/11] KVM: arm64: Handle PtrAuth traps early Marc Zyngier
2020-06-11 9:09 ` Marc Zyngier [this message]
2020-06-11 9:09 ` [PATCH 08/11] KVM: arm64: Remove host_cpu_context member from vcpu structure Marc Zyngier
2020-06-11 9:09 ` [PATCH 09/11] KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts Marc Zyngier
2020-06-11 9:09 ` [PATCH 10/11] KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception Marc Zyngier
2020-06-11 9:09 ` [PATCH 11/11] KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h Marc Zyngier
2020-06-11 18:04 ` [GIT PULL] KVM/arm64 fixes for 5.8, take #1 Paolo Bonzini
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