Using unreachable() at default of switch generates an extra branch at end of the function, and compiler won't generate a ret to close this branch because it knows it's unreachable. If there's no instruction in this branch, compiler will generate a NOP, And it will confuse objtool to warn this NOP as a fall through branch. In fact these branches are actually unreachable, so we can replace unreachable() with returning a -EINVAL value. Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx> --- arch/arm64/kvm/hyp/vgic-v3-sr.c | 7 +++---- drivers/irqchip/irq-gic-v3.c | 2 +- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c index 4fb419f7b8b6..f3cee92c3038 100644 --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c @@ -6,7 +6,6 @@ #include <hyp/adjust_pc.h> -#include <linux/compiler.h> #include <linux/irqchip/arm-gic-v3.h> #include <linux/kvm_host.h> @@ -55,7 +54,7 @@ static u64 __gic_v3_get_lr(unsigned int lr) return read_gicreg(ICH_LR15_EL2); } - unreachable(); + return -EINVAL; } static void __gic_v3_set_lr(u64 val, int lr) @@ -166,7 +165,7 @@ static u32 __vgic_v3_read_ap0rn(int n) val = read_gicreg(ICH_AP0R3_EL2); break; default: - unreachable(); + val = -EINVAL; } return val; @@ -190,7 +189,7 @@ static u32 __vgic_v3_read_ap1rn(int n) val = read_gicreg(ICH_AP1R3_EL2); break; default: - unreachable(); + val = -EINVAL; } return val; diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index b252d5534547..2ef98e32d257 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -475,7 +475,7 @@ static u32 __gic_get_ppi_index(irq_hw_number_t hwirq) case EPPI_RANGE: return hwirq - EPPI_BASE_INTID + 16; default: - unreachable(); + return -EINVAL; } } -- 2.17.1
