If notify_die() returns NOTIFY_STOP, honor the return value from the
handler chain invocation in die() 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. So we can remove the noreturn
attribute for die() to make 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/all/alpine.DEB.2.21.2308132148500.8596@xxxxxxxxxxxxxxxxx/
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
arch/mips/include/asm/ptrace.h | 2 +-
arch/mips/kernel/traps.c | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h
index daf3cf2..aee8e0a 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;
+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/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 7a34674..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[];
--
2.1.0
