linux-kernel - [RFC PATCH v4 19/37] arm64: irq-gic: Replace unreachable() with -EINVAL

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220429094355.122389-20-chenzhongjin@huawei.com>
Date:   Fri, 29 Apr 2022 17:43:37 +0800
From:   Chen Zhongjin <chenzhongjin@...wei.com>
To:     <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-arch@...r.kernel.org>
CC:     <jthierry@...hat.com>, <catalin.marinas@....com>,
        <will@...nel.org>, <masahiroy@...nel.org>, <jpoimboe@...hat.com>,
        <peterz@...radead.org>, <ycote@...hat.com>,
        <herbert@...dor.apana.org.au>, <mark.rutland@....com>,
        <davem@...emloft.net>, <ardb@...nel.org>, <maz@...nel.org>,
        <tglx@...utronix.de>, <luc.vanoostenryck@...il.com>,
        <chenzhongjin@...wei.com>
Subject: [RFC PATCH v4 19/37] arm64: irq-gic: Replace unreachable() with -EINVAL

Using unreachable() at end of function generates an extra NOP for
.unreachable section. It can confuse objtool to warn this NOP as
fall through instruction.

Considering that these branches are actually unreachable, replace
unreachable() with returning a -EINVAL value.

Signed-off-by: Chen Zhongjin <chenzhongjin@...wei.com>
---
 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