[PATCH v6 32/33] arm64: irq-gic: Replace unreachable() with -EINVAL
From: Chen Zhongjin <hidden>
Date: 2022-06-23 01:54:22
Also in:
linux-arch, linux-arm-kernel, linux-kbuild, live-patching, lkml
Subsystem:
arm generic interrupt controller drivers, arm64 port (aarch64 architecture), irqchip drivers, kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Marc Zyngier, Catalin Marinas, Will Deacon, Thomas Gleixner, Oliver Upton, Linus Torvalds
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 <redacted> --- 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