From cd054837243b5f36ff395c21135ff153871180f1 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:08 +0000 Subject: riscv: Allocate user's vector context in the first-use trap Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/traps.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'arch/riscv/kernel/traps.c') diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 8c258b78c925..05ffdcd1424e 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -26,6 +26,7 @@ #include #include #include +#include int show_unhandled_signals = 1; @@ -145,8 +146,29 @@ DO_ERROR_INFO(do_trap_insn_misaligned, SIGBUS, BUS_ADRALN, "instruction address misaligned"); DO_ERROR_INFO(do_trap_insn_fault, SIGSEGV, SEGV_ACCERR, "instruction access fault"); -DO_ERROR_INFO(do_trap_insn_illegal, - SIGILL, ILL_ILLOPC, "illegal instruction"); + +asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *regs) +{ + if (user_mode(regs)) { + irqentry_enter_from_user_mode(regs); + + local_irq_enable(); + + if (!riscv_v_first_use_handler(regs)) + do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc, + "Oops - illegal instruction"); + + irqentry_exit_to_user_mode(regs); + } else { + irqentry_state_t state = irqentry_nmi_enter(regs); + + do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc, + "Oops - illegal instruction"); + + irqentry_nmi_exit(regs, state); + } +} + DO_ERROR_INFO(do_trap_load_fault, SIGSEGV, SEGV_ACCERR, "load access fault"); #ifndef CONFIG_RISCV_M_MODE -- cgit v1.2.3 From 163e76cc6ef43b7a5e9b6e245a6d6667c9d9b4a7 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Tue, 13 Jun 2023 21:30:16 -0400 Subject: riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add independent irq stacks for percpu to prevent kernel stack overflows. It is also compatible with VMAP_STACK by arch_alloc_vmap_stack. Tested-by: Jisheng Zhang Signed-off-by: Guo Ren Signed-off-by: Guo Ren Cc: Clément Léger Link: https://lore.kernel.org/r/20230614013018.2168426-2-guoren@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/traps.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) (limited to 'arch/riscv/kernel/traps.c') diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 05ffdcd1424e..5158961ea977 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -27,6 +27,7 @@ #include #include #include +#include int show_unhandled_signals = 1; @@ -327,16 +328,46 @@ asmlinkage __visible noinstr void do_page_fault(struct pt_regs *regs) } #endif -asmlinkage __visible noinstr void do_irq(struct pt_regs *regs) +static void noinstr handle_riscv_irq(struct pt_regs *regs) { struct pt_regs *old_regs; - irqentry_state_t state = irqentry_enter(regs); irq_enter_rcu(); old_regs = set_irq_regs(regs); handle_arch_irq(regs); set_irq_regs(old_regs); irq_exit_rcu(); +} + +asmlinkage void noinstr do_irq(struct pt_regs *regs) +{ + irqentry_state_t state = irqentry_enter(regs); +#ifdef CONFIG_IRQ_STACKS + if (on_thread_stack()) { + ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id()) + + IRQ_STACK_SIZE/sizeof(ulong); + __asm__ __volatile( + "addi sp, sp, -"RISCV_SZPTR "\n" + REG_S" ra, (sp) \n" + "addi sp, sp, -"RISCV_SZPTR "\n" + REG_S" s0, (sp) \n" + "addi s0, sp, 2*"RISCV_SZPTR "\n" + "move sp, %[sp] \n" + "move a0, %[regs] \n" + "call handle_riscv_irq \n" + "addi sp, s0, -2*"RISCV_SZPTR"\n" + REG_L" s0, (sp) \n" + "addi sp, sp, "RISCV_SZPTR "\n" + REG_L" ra, (sp) \n" + "addi sp, sp, "RISCV_SZPTR "\n" + : + : [sp] "r" (sp), [regs] "r" (regs) + : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", + "t0", "t1", "t2", "t3", "t4", "t5", "t6", + "memory"); + } else +#endif + handle_riscv_irq(regs); irqentry_exit(regs, state); } -- cgit v1.2.3