From 6933c11fb501a40681d43336b3e0eee9df2abee0 Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Fri, 25 Aug 2023 23:40:26 +0800 Subject: [PATCH] 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 20c0d2d44029 ("[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: Tiezhu Yang Signed-off-by: Huacai Chen --- arch/loongarch/include/asm/ptrace.h | 2 +- arch/loongarch/kernel/traps.c | 12 ++++++------ 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/loongarch/include/asm/ptrace.h b/arch/loongarch/include/asm/ptrace.h index 35f0958163ac..164bc90672e4 100644 --- a/arch/loongarch/include/asm/ptrace.h +++ b/arch/loongarch/include/asm/ptrace.h @@ -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) { diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index 8fb5e7a77145..dfb34cc8b7e6 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -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)