x86: Convert unreachable() to BUG()

Avoid unreachable() as it can (and will in the absence of UBSAN) generate fallthrough code. Use BUG() so we get a UD2 trap (with unreachable annotation). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/20241128094312.028316261@infradead.org
mariux64 · Dec 2, 2024 · 2190966 · 2190966
1 parent c837de3
commit 2190966
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diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
@@ -838,7 +838,7 @@ void __noreturn stop_this_cpu(void *dummy)
 #ifdef CONFIG_SMP
 	if (smp_ops.stop_this_cpu) {
 		smp_ops.stop_this_cpu();
-		unreachable();
+		BUG();
 	}
 #endif
 

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
@@ -883,7 +883,7 @@ static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 
 	if (smp_ops.stop_this_cpu) {
 		smp_ops.stop_this_cpu();
-		unreachable();
+		BUG();
 	}
 
 	/* Assume hlt works */

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
@@ -3820,7 +3820,7 @@ static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc)
 		goto next_range;
 	}
 
-	unreachable();
+	BUG();
 }
 
 static int __sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu)