riscv: vector: only enable interrupts in the first-use trap

The function irqentry_exit_to_user_mode() must be called with interrupt
disabled. The caller of do_trap_insn_illegal() also assumes running
without interrupts. So, we should turn off interrupts after
riscv_v_first_use_handler() returns.

Fixes: cd054837243b ("riscv: Allocate user's vector context in the first-use trap")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230625155416.18629-1-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 5158961..bc02b28 100644 (file)
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -150,12 +150,18 @@ DO_ERROR_INFO(do_trap_insn_fault,
 
 asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *regs)
 {
+       bool handled;
+
        if (user_mode(regs)) {
                irqentry_enter_from_user_mode(regs);
 
                local_irq_enable();
 
-               if (!riscv_v_first_use_handler(regs))
+               handled = riscv_v_first_use_handler(regs);
+
+               local_irq_disable();
+
+               if (!handled)
                        do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc,
                                      "Oops - illegal instruction");