In some exception handlers, the interrupt is not reenabled by daifclr at first. The later process may call local_irq_enable() to enable the interrupt, like gic_handle_irq(). As we known, function local_irq_enable() just change the pmr now. The following codes what i found may cause a deadlock or some issues else:
do_sp_pc_abort <- el0_sp_pc do_el0_ia_bp_hardening <- el0_ia kgdb_roundup_cpus <- el1_dbg Signed-off-by: Wei Li <[email protected]> --- arch/arm64/kernel/kgdb.c | 4 ++++ arch/arm64/mm/fault.c | 6 ++++++ 2 files changed, 10 insertions(+) diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index a20de58061a8..119fbf2c0788 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -25,6 +25,7 @@ #include <linux/kgdb.h> #include <linux/kprobes.h> #include <linux/sched/task_stack.h> +#include <linux/irqchip/arm-gic-v3.h> #include <asm/debug-monitors.h> #include <asm/insn.h> @@ -291,6 +292,9 @@ static void kgdb_call_nmi_hook(void *ignored) void kgdb_roundup_cpus(unsigned long flags) { + if (gic_prio_masking_enabled()) + gic_arch_enable_irqs(); + local_irq_enable(); smp_call_function(kgdb_call_nmi_hook, NULL, 0); local_irq_disable(); diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 97ba2ba78aee..f7c39a0b28bc 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -32,6 +32,7 @@ #include <linux/perf_event.h> #include <linux/preempt.h> #include <linux/hugetlb.h> +#include <linux/irqchip/arm-gic-v3.h> #include <asm/bug.h> #include <asm/cmpxchg.h> @@ -780,6 +781,8 @@ asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, if (addr > TASK_SIZE) arm64_apply_bp_hardening(); + if (gic_prio_masking_enabled()) + gic_arch_enable_irqs(); local_irq_enable(); do_mem_abort(addr, esr, regs); } @@ -794,6 +797,9 @@ asmlinkage void __exception do_sp_pc_abort(unsigned long addr, if (user_mode(regs)) { if (instruction_pointer(regs) > TASK_SIZE) arm64_apply_bp_hardening(); + + if (gic_prio_masking_enabled()) + gic_arch_enable_irqs(); local_irq_enable(); } -- 2.17.1
