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

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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 <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Tiezhu Yang 2023-08-25 23:40:26 +08:00 committed by Huacai Chen
parent a746ceb1f3
commit 6933c11fb5
2 changed files with 7 additions and 7 deletions
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2
arch/loongarch/include/asm/ptrace.h
View File

@ -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)
{

12
arch/loongarch/kernel/traps.c
View File

@ -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)