diff options
| author | Sami Tolvanen <samitolvanen@google.com> | 2023-09-27 22:48:03 +0000 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-10-27 14:43:09 -0700 |
| commit | c40fef858d002fb027033c572ac8bdf8756a2c6b (patch) | |
| tree | 86f759f14b79e2ee70406408bfa50ebafd9a8a92 | |
| parent | d1584d791a297aa8ed93503382a682a6ecfc4218 (diff) | |
riscv: Use separate IRQ shadow call stacks
When both CONFIG_IRQ_STACKS and SCS are enabled, also use a separate
per-CPU shadow call stack.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230927224757.1154247-13-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/include/asm/scs.h | 7 | ||||
| -rw-r--r-- | arch/riscv/kernel/entry.S | 7 | ||||
| -rw-r--r-- | arch/riscv/kernel/irq.c | 21 |
3 files changed, 35 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/scs.h b/arch/riscv/include/asm/scs.h index 94726ea773e3..0e45db78b24b 100644 --- a/arch/riscv/include/asm/scs.h +++ b/arch/riscv/include/asm/scs.h @@ -13,6 +13,11 @@ XIP_FIXUP_OFFSET gp .endm +/* Load the per-CPU IRQ shadow call stack to gp. */ +.macro scs_load_irq_stack tmp + load_per_cpu gp, irq_shadow_call_stack_ptr, \tmp +.endm + /* Load task_scs_sp(current) to gp. */ .macro scs_load_current REG_L gp, TASK_TI_SCS_SP(tp) @@ -34,6 +39,8 @@ _skip_scs: .macro scs_load_init_stack .endm +.macro scs_load_irq_stack tmp +.endm .macro scs_load_current .endm .macro scs_load_current_if_task_changed prev diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 52793193a763..3a0db310325a 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -237,12 +237,19 @@ SYM_FUNC_START(call_on_irq_stack) REG_S s0, STACKFRAME_FP(sp) addi s0, sp, STACKFRAME_SIZE_ON_STACK + /* Switch to the per-CPU shadow call stack */ + scs_save_current + scs_load_irq_stack t0 + /* Switch to the per-CPU IRQ stack and call the handler */ load_per_cpu t0, irq_stack_ptr, t1 li t1, IRQ_STACK_SIZE add sp, t0, t1 jalr a1 + /* Switch back to the thread shadow call stack */ + scs_load_current + /* Switch back to the thread stack and restore ra and s0 */ addi sp, s0, -STACKFRAME_SIZE_ON_STACK REG_L ra, STACKFRAME_RA(sp) diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index 95dafdcbd135..7bfea97ee7e7 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -9,6 +9,7 @@ #include <linux/irqchip.h> #include <linux/irqdomain.h> #include <linux/module.h> +#include <linux/scs.h> #include <linux/seq_file.h> #include <asm/sbi.h> #include <asm/smp.h> @@ -34,6 +35,24 @@ EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode); #ifdef CONFIG_IRQ_STACKS #include <asm/irq_stack.h> +DECLARE_PER_CPU(ulong *, irq_shadow_call_stack_ptr); + +#ifdef CONFIG_SHADOW_CALL_STACK +DEFINE_PER_CPU(ulong *, irq_shadow_call_stack_ptr); +#endif + +static void init_irq_scs(void) +{ + int cpu; + + if (!scs_is_enabled()) + return; + + for_each_possible_cpu(cpu) + per_cpu(irq_shadow_call_stack_ptr, cpu) = + scs_alloc(cpu_to_node(cpu)); +} + DEFINE_PER_CPU(ulong *, irq_stack_ptr); #ifdef CONFIG_VMAP_STACK @@ -76,6 +95,7 @@ void do_softirq_own_stack(void) #endif /* CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK */ #else +static void init_irq_scs(void) {} static void init_irq_stacks(void) {} #endif /* CONFIG_IRQ_STACKS */ @@ -87,6 +107,7 @@ int arch_show_interrupts(struct seq_file *p, int prec) void __init init_IRQ(void) { + init_irq_scs(); init_irq_stacks(); irqchip_init(); if (!handle_arch_irq) |