[PATCH 1/3] KVM: arm64: fix override-init warnings in W=1 builds

From: Sebastian Ott
Date: Fri Jul 12 2024 - 07:04:02 EST


Remove double initializations in cases where that's easily possible
- like extra NULL initialization in static global structures. In the
other cases just silence -Woverride-init.

To fix warnings like the following:
arch/arm64/kvm/hyp/vhe/switch.c:271:43: warning: initialized field overwritten [-Woverride-init]
271 | [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,
| ^~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxx>
---
arch/arm64/kvm/handle_exit.c | 5 +++++
arch/arm64/kvm/hyp/nvhe/switch.c | 6 ++----
arch/arm64/kvm/hyp/vhe/switch.c | 3 +--
arch/arm64/kvm/sys_regs.c | 5 +++++
4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index d7c2990e7c9e..2c049746657c 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -291,6 +291,9 @@ static int handle_svc(struct kvm_vcpu *vcpu)
return 1;
}

+__diag_push();
+__diag_ignore_all("-Woverride-init", "Allow field overrides in exit_handlers");
+
static exit_handle_fn arm_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
[ESR_ELx_EC_WFx] = kvm_handle_wfx,
@@ -319,6 +322,8 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_PAC] = kvm_handle_ptrauth,
};

+__diag_pop();
+
static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
{
u64 esr = kvm_vcpu_get_esr(vcpu);
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 6af179c6356d..bf49afc01542 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -200,8 +200,7 @@ static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
}
}

-static const exit_handler_fn hyp_exit_handlers[] = {
- [0 ... ESR_ELx_EC_MAX] = NULL,
+static const exit_handler_fn hyp_exit_handlers[ESR_ELx_EC_MAX + 1] = {
[ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,
[ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg,
[ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd,
@@ -212,8 +211,7 @@ static const exit_handler_fn hyp_exit_handlers[] = {
[ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops,
};

-static const exit_handler_fn pvm_exit_handlers[] = {
- [0 ... ESR_ELx_EC_MAX] = NULL,
+static const exit_handler_fn pvm_exit_handlers[ESR_ELx_EC_MAX + 1] = {
[ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64,
[ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted,
[ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 77010b76c150..4e4ff2bd51c9 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -415,8 +415,7 @@ static bool kvm_hyp_handle_sysreg_vhe(struct kvm_vcpu *vcpu, u64 *exit_code)
return kvm_hyp_handle_sysreg(vcpu, exit_code);
}

-static const exit_handler_fn hyp_exit_handlers[] = {
- [0 ... ESR_ELx_EC_MAX] = NULL,
+static const exit_handler_fn hyp_exit_handlers[ESR_ELx_EC_MAX + 1] = {
[ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,
[ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg_vhe,
[ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd,
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c90324060436..00fb6f1e9a48 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2255,6 +2255,9 @@ static bool access_zcr_el2(struct kvm_vcpu *vcpu,
return true;
}

+__diag_push();
+__diag_ignore_all("-Woverride-init", "Allow field overrides in sys_reg_descs");
+
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
@@ -2803,6 +2806,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
EL2_REG(SP_EL2, NULL, reset_unknown, 0),
};

+__diag_pop();
+
static bool kvm_supported_tlbi_s12_op(struct kvm_vcpu *vpcu, u32 instr)
{
struct kvm *kvm = vpcu->kvm;
--
2.42.0