linux-kernel - [PATCH] MIPS: Remove noreturn attribute for die()

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Date:   Tue,  1 Aug 2023 18:59:59 +0800
From:   Tiezhu Yang <yangtiezhu@...ngson.cn>
To:     Thomas Bogendoerfer <tsbogend@...ha.franken.de>
Cc:     linux-mips@...r.kernel.org, linux-kernel@...r.kernel.org,
        loongson-kernel@...ts.loongnix.cn
Subject: [PATCH] MIPS: Remove noreturn attribute for die()

If notify_die() returns NOTIFY_STOP, there is no need to call
make_task_dead(), we can remove noreturn attribute for die(),
this is similar with arm64, riscv and csky.

While at it, modify the die() declaration in ptrace.h to fix
the following checkpatch warnings:

  WARNING: function definition argument 'const char *' should also have an identifier name
  WARNING: function definition argument 'struct pt_regs *' should also have an identifier name

Additionally, also remove noreturn attribute for nmi_exception_handler
due to it calls die(), otherwise there exists the following build error:

  arch/mips/kernel/traps.c:2001:1: error: 'noreturn' function does return [-Werror]

Signed-off-by: Tiezhu Yang <yangtiezhu@...ngson.cn>
---
 arch/mips/include/asm/ptrace.h |  2 +-
 arch/mips/kernel/traps.c       | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h
index daf3cf2..14d2ee9 100644
--- a/arch/mips/include/asm/ptrace.h
+++ b/arch/mips/include/asm/ptrace.h
@@ -159,7 +159,7 @@ static inline long regs_return_value(struct pt_regs *regs)
 extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall);
 extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);
 
-extern void die(const char *, struct pt_regs *) __noreturn;
+void die(const char *str, struct pt_regs *regs);
 
 static inline void die_if_kernel(const char *str, struct pt_regs *regs)
 {
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 246c6a6..4f5140f 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -391,16 +391,15 @@ void show_registers(struct pt_regs *regs)
 
 static DEFINE_RAW_SPINLOCK(die_lock);
 
-void __noreturn die(const char *str, struct pt_regs *regs)
+void die(const char *str, struct pt_regs *regs)
 {
 	static int die_counter;
-	int sig = SIGSEGV;
+	int ret;
 
 	oops_enter();
 
-	if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
-		       SIGSEGV) == NOTIFY_STOP)
-		sig = 0;
+	ret = notify_die(DIE_OOPS, str, regs, 0,
+			 current->thread.trap_nr, SIGSEGV);
 
 	console_verbose();
 	raw_spin_lock_irq(&die_lock);
@@ -422,7 +421,8 @@ void __noreturn die(const char *str, struct pt_regs *regs)
 	if (regs && kexec_should_crash(current))
 		crash_kexec(regs);
 
-	make_task_dead(sig);
+	if (ret != NOTIFY_STOP)
+		make_task_dead(SIGSEGV);
 }
 
 extern struct exception_table_entry __start___dbe_table[];
@@ -1986,7 +1986,7 @@ int register_nmi_notifier(struct notifier_block *nb)
 	return raw_notifier_chain_register(&nmi_chain, nb);
 }
 
-void __noreturn nmi_exception_handler(struct pt_regs *regs)
+void nmi_exception_handler(struct pt_regs *regs)
 {
 	char str[100];
 
-- 
2.1.0