Commit 6933c11f authored by Tiezhu Yang's avatar Tiezhu Yang Committed by Huacai Chen
Browse files

LoongArch: Do not kill the task in die() if notify_die() returns NOTIFY_STOP 

If notify_die() returns NOTIFY_STOP, honor the return value from the
handler chain invocation in die() and return without killing the task
as, through a debugger, the fault may have been fixed. It makes sense
even if ignoring the event will make the system unstable: by allowing
access through a debugger it has been compromised already anyway. It
makes our port consistent with x86, arm64, riscv and csky.

Commit 20c0d2d4 ("[PATCH] i386: pass proper trap numbers to die
chain handlers") may be the earliest of similar changes.

Link: https://lore.kernel.org/r/43DDF02E.76F0.0078.0@novell.com/


Signed-off-by: default avatarTiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent a746ceb1

arch/loongarch/include/asm/ptrace.h

+1 −1
Original line number Diff line number Diff line
@@ -162,7 +162,7 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long val 
#define instruction_pointer(regs) ((regs)->csr_era)

#define profile_pc(regs) instruction_pointer(regs)



extern void die(const char *, struct pt_regs *) __noreturn;

extern void die(const char *, struct pt_regs *);



static inline void die_if_kernel(const char *str, struct pt_regs *regs)

{

arch/loongarch/kernel/traps.c

+6 −6
Original line number Diff line number Diff line
@@ -383,16 +383,15 @@ 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)

{

	int ret;

	static int die_counter;

	int sig = SIGSEGV;



	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);
@@ -414,7 +413,8 @@ void __noreturn die(const char *str, struct pt_regs *regs) 
	if (panic_on_oops)

		panic("Fatal exception");



	make_task_dead(sig);

	if (ret != NOTIFY_STOP)

		make_task_dead(SIGSEGV);

}



static inline void setup_vint_size(unsigned int size)