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-rw-r--r--arch/riscv/kernel/entry.S572
1 files changed, 220 insertions, 352 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index b9eda3fcbd6d..9b9dec6893b8 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -7,28 +7,117 @@
#include <linux/init.h>
#include <linux/linkage.h>
+#include <asm/alternative-macros.h>
#include <asm/asm.h>
#include <asm/csr.h>
+#include <asm/scs.h>
#include <asm/unistd.h>
+#include <asm/page.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/errata_list.h>
+#include <linux/sizes.h>
+
+ .section .irqentry.text, "ax"
+
+.macro new_vmalloc_check
+ REG_S a0, TASK_TI_A0(tp)
+ csrr a0, CSR_CAUSE
+ /* Exclude IRQs */
+ blt a0, zero, .Lnew_vmalloc_restore_context_a0
+
+ REG_S a1, TASK_TI_A1(tp)
+ /* Only check new_vmalloc if we are in page/protection fault */
+ li a1, EXC_LOAD_PAGE_FAULT
+ beq a0, a1, .Lnew_vmalloc_kernel_address
+ li a1, EXC_STORE_PAGE_FAULT
+ beq a0, a1, .Lnew_vmalloc_kernel_address
+ li a1, EXC_INST_PAGE_FAULT
+ bne a0, a1, .Lnew_vmalloc_restore_context_a1
+
+.Lnew_vmalloc_kernel_address:
+ /* Is it a kernel address? */
+ csrr a0, CSR_TVAL
+ bge a0, zero, .Lnew_vmalloc_restore_context_a1
+
+ /* Check if a new vmalloc mapping appeared that could explain the trap */
+ REG_S a2, TASK_TI_A2(tp)
+ /*
+ * Computes:
+ * a0 = &new_vmalloc[BIT_WORD(cpu)]
+ * a1 = BIT_MASK(cpu)
+ */
+ lw a2, TASK_TI_CPU(tp)
+ /*
+ * Compute the new_vmalloc element position:
+ * (cpu / 64) * 8 = (cpu >> 6) << 3
+ */
+ srli a1, a2, 6
+ slli a1, a1, 3
+ la a0, new_vmalloc
+ add a0, a0, a1
+ /*
+ * Compute the bit position in the new_vmalloc element:
+ * bit_pos = cpu % 64 = cpu - (cpu / 64) * 64 = cpu - (cpu >> 6) << 6
+ * = cpu - ((cpu >> 6) << 3) << 3
+ */
+ slli a1, a1, 3
+ sub a1, a2, a1
+ /* Compute the "get mask": 1 << bit_pos */
+ li a2, 1
+ sll a1, a2, a1
+
+ /* Check the value of new_vmalloc for this cpu */
+ REG_L a2, 0(a0)
+ and a2, a2, a1
+ beq a2, zero, .Lnew_vmalloc_restore_context
+
+ /* Atomically reset the current cpu bit in new_vmalloc */
+ amoxor.d a0, a1, (a0)
+
+ /* Only emit a sfence.vma if the uarch caches invalid entries */
+ ALTERNATIVE("sfence.vma", "nop", 0, RISCV_ISA_EXT_SVVPTC, 1)
+
+ REG_L a0, TASK_TI_A0(tp)
+ REG_L a1, TASK_TI_A1(tp)
+ REG_L a2, TASK_TI_A2(tp)
+ csrw CSR_SCRATCH, x0
+ sret
-#if !IS_ENABLED(CONFIG_PREEMPTION)
-.set resume_kernel, restore_all
-#endif
+.Lnew_vmalloc_restore_context:
+ REG_L a2, TASK_TI_A2(tp)
+.Lnew_vmalloc_restore_context_a1:
+ REG_L a1, TASK_TI_A1(tp)
+.Lnew_vmalloc_restore_context_a0:
+ REG_L a0, TASK_TI_A0(tp)
+.endm
-ENTRY(handle_exception)
+
+SYM_CODE_START(handle_exception)
/*
* If coming from userspace, preserve the user thread pointer and load
* the kernel thread pointer. If we came from the kernel, the scratch
* register will contain 0, and we should continue on the current TP.
*/
csrrw tp, CSR_SCRATCH, tp
- bnez tp, _save_context
+ bnez tp, .Lsave_context
-_restore_kernel_tpsp:
+.Lrestore_kernel_tpsp:
csrr tp, CSR_SCRATCH
+
+#ifdef CONFIG_64BIT
+ /*
+ * The RISC-V kernel does not eagerly emit a sfence.vma after each
+ * new vmalloc mapping, which may result in exceptions:
+ * - if the uarch caches invalid entries, the new mapping would not be
+ * observed by the page table walker and an invalidation is needed.
+ * - if the uarch does not cache invalid entries, a reordered access
+ * could "miss" the new mapping and traps: in that case, we only need
+ * to retry the access, no sfence.vma is required.
+ */
+ new_vmalloc_check
+#endif
+
REG_S sp, TASK_TI_KERNEL_SP(tp)
#ifdef CONFIG_VMAP_STACK
@@ -39,48 +128,23 @@ _restore_kernel_tpsp:
REG_L sp, TASK_TI_KERNEL_SP(tp)
#endif
-_save_context:
+.Lsave_context:
REG_S sp, TASK_TI_USER_SP(tp)
REG_L sp, TASK_TI_KERNEL_SP(tp)
addi sp, sp, -(PT_SIZE_ON_STACK)
REG_S x1, PT_RA(sp)
REG_S x3, PT_GP(sp)
REG_S x5, PT_T0(sp)
- REG_S x6, PT_T1(sp)
- REG_S x7, PT_T2(sp)
- REG_S x8, PT_S0(sp)
- REG_S x9, PT_S1(sp)
- REG_S x10, PT_A0(sp)
- REG_S x11, PT_A1(sp)
- REG_S x12, PT_A2(sp)
- REG_S x13, PT_A3(sp)
- REG_S x14, PT_A4(sp)
- REG_S x15, PT_A5(sp)
- REG_S x16, PT_A6(sp)
- REG_S x17, PT_A7(sp)
- REG_S x18, PT_S2(sp)
- REG_S x19, PT_S3(sp)
- REG_S x20, PT_S4(sp)
- REG_S x21, PT_S5(sp)
- REG_S x22, PT_S6(sp)
- REG_S x23, PT_S7(sp)
- REG_S x24, PT_S8(sp)
- REG_S x25, PT_S9(sp)
- REG_S x26, PT_S10(sp)
- REG_S x27, PT_S11(sp)
- REG_S x28, PT_T3(sp)
- REG_S x29, PT_T4(sp)
- REG_S x30, PT_T5(sp)
- REG_S x31, PT_T6(sp)
+ save_from_x6_to_x31
/*
* Disable user-mode memory access as it should only be set in the
* actual user copy routines.
*
- * Disable the FPU to detect illegal usage of floating point in kernel
- * space.
+ * Disable the FPU/Vector to detect illegal usage of floating point
+ * or vector in kernel space.
*/
- li t0, SR_SUM | SR_FS
+ li t0, SR_SUM | SR_FS_VS
REG_L s0, TASK_TI_USER_SP(tp)
csrrc s1, CSR_STATUS, t0
@@ -102,23 +166,16 @@ _save_context:
csrw CSR_SCRATCH, x0
/* Load the global pointer */
-.option push
-.option norelax
- la gp, __global_pointer$
-.option pop
+ load_global_pointer
-#ifdef CONFIG_TRACE_IRQFLAGS
- call __trace_hardirqs_off
-#endif
+ /* Load the kernel shadow call stack pointer if coming from userspace */
+ scs_load_current_if_task_changed s5
-#ifdef CONFIG_CONTEXT_TRACKING_USER
- /* If previous state is in user mode, call user_exit_callable(). */
- li a0, SR_PP
- and a0, s1, a0
- bnez a0, skip_context_tracking
- call user_exit_callable
-skip_context_tracking:
+#ifdef CONFIG_RISCV_ISA_V_PREEMPTIVE
+ move a0, sp
+ call riscv_v_context_nesting_start
#endif
+ move a0, sp /* pt_regs */
/*
* MSB of cause differentiates between
@@ -126,134 +183,35 @@ skip_context_tracking:
*/
bge s4, zero, 1f
- la ra, ret_from_exception
-
/* Handle interrupts */
- move a0, sp /* pt_regs */
- la a1, generic_handle_arch_irq
- jr a1
-1:
- /*
- * Exceptions run with interrupts enabled or disabled depending on the
- * state of SR_PIE in m/sstatus.
- */
- andi t0, s1, SR_PIE
- beqz t0, 1f
- /* kprobes, entered via ebreak, must have interrupts disabled. */
- li t0, EXC_BREAKPOINT
- beq s4, t0, 1f
-#ifdef CONFIG_TRACE_IRQFLAGS
- call __trace_hardirqs_on
-#endif
- csrs CSR_STATUS, SR_IE
-
+ call do_irq
+ j ret_from_exception
1:
- la ra, ret_from_exception
- /* Handle syscalls */
- li t0, EXC_SYSCALL
- beq s4, t0, handle_syscall
-
/* Handle other exceptions */
slli t0, s4, RISCV_LGPTR
la t1, excp_vect_table
la t2, excp_vect_table_end
- move a0, sp /* pt_regs */
add t0, t1, t0
/* Check if exception code lies within bounds */
- bgeu t0, t2, 1f
- REG_L t0, 0(t0)
- jr t0
-1:
- tail do_trap_unknown
-
-handle_syscall:
-#ifdef CONFIG_RISCV_M_MODE
- /*
- * When running is M-Mode (no MMU config), MPIE does not get set.
- * As a result, we need to force enable interrupts here because
- * handle_exception did not do set SR_IE as it always sees SR_PIE
- * being cleared.
- */
- csrs CSR_STATUS, SR_IE
-#endif
-#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER)
- /* Recover a0 - a7 for system calls */
- REG_L a0, PT_A0(sp)
- REG_L a1, PT_A1(sp)
- REG_L a2, PT_A2(sp)
- REG_L a3, PT_A3(sp)
- REG_L a4, PT_A4(sp)
- REG_L a5, PT_A5(sp)
- REG_L a6, PT_A6(sp)
- REG_L a7, PT_A7(sp)
-#endif
- /* save the initial A0 value (needed in signal handlers) */
- REG_S a0, PT_ORIG_A0(sp)
- /*
- * Advance SEPC to avoid executing the original
- * scall instruction on sret
- */
- addi s2, s2, 0x4
- REG_S s2, PT_EPC(sp)
- /* Trace syscalls, but only if requested by the user. */
- REG_L t0, TASK_TI_FLAGS(tp)
- andi t0, t0, _TIF_SYSCALL_WORK
- bnez t0, handle_syscall_trace_enter
-check_syscall_nr:
- /* Check to make sure we don't jump to a bogus syscall number. */
- li t0, __NR_syscalls
- la s0, sys_ni_syscall
- /*
- * Syscall number held in a7.
- * If syscall number is above allowed value, redirect to ni_syscall.
- */
- bgeu a7, t0, 3f
-#ifdef CONFIG_COMPAT
- REG_L s0, PT_STATUS(sp)
- srli s0, s0, SR_UXL_SHIFT
- andi s0, s0, (SR_UXL >> SR_UXL_SHIFT)
- li t0, (SR_UXL_32 >> SR_UXL_SHIFT)
- sub t0, s0, t0
- bnez t0, 1f
-
- /* Call compat_syscall */
- la s0, compat_sys_call_table
- j 2f
-1:
-#endif
- /* Call syscall */
- la s0, sys_call_table
-2:
- slli t0, a7, RISCV_LGPTR
- add s0, s0, t0
- REG_L s0, 0(s0)
+ bgeu t0, t2, 3f
+ REG_L t1, 0(t0)
+2: jalr t1
+ j ret_from_exception
3:
- jalr s0
-ret_from_syscall:
- /* Set user a0 to kernel a0 */
- REG_S a0, PT_A0(sp)
- /*
- * We didn't execute the actual syscall.
- * Seccomp already set return value for the current task pt_regs.
- * (If it was configured with SECCOMP_RET_ERRNO/TRACE)
- */
-ret_from_syscall_rejected:
-#ifdef CONFIG_DEBUG_RSEQ
- move a0, sp
- call rseq_syscall
-#endif
- /* Trace syscalls, but only if requested by the user. */
- REG_L t0, TASK_TI_FLAGS(tp)
- andi t0, t0, _TIF_SYSCALL_WORK
- bnez t0, handle_syscall_trace_exit
+ la t1, do_trap_unknown
+ j 2b
+SYM_CODE_END(handle_exception)
+ASM_NOKPROBE(handle_exception)
-ret_from_exception:
+/*
+ * The ret_from_exception must be called with interrupt disabled. Here is the
+ * caller list:
+ * - handle_exception
+ * - ret_from_fork
+ */
+SYM_CODE_START_NOALIGN(ret_from_exception)
REG_L s0, PT_STATUS(sp)
- csrc CSR_STATUS, SR_IE
-#ifdef CONFIG_TRACE_IRQFLAGS
- call __trace_hardirqs_off
-#endif
#ifdef CONFIG_RISCV_M_MODE
/* the MPP value is too large to be used as an immediate arg for addi */
li t0, SR_MPP
@@ -261,38 +219,28 @@ ret_from_exception:
#else
andi s0, s0, SR_SPP
#endif
- bnez s0, resume_kernel
+ bnez s0, 1f
-resume_userspace:
- /* Interrupts must be disabled here so flags are checked atomically */
- REG_L s0, TASK_TI_FLAGS(tp) /* current_thread_info->flags */
- andi s1, s0, _TIF_WORK_MASK
- bnez s1, work_pending
-
-#ifdef CONFIG_CONTEXT_TRACKING_USER
- call user_enter_callable
+#ifdef CONFIG_KSTACK_ERASE
+ call stackleak_erase_on_task_stack
#endif
/* Save unwound kernel stack pointer in thread_info */
addi s0, sp, PT_SIZE_ON_STACK
REG_S s0, TASK_TI_KERNEL_SP(tp)
+ /* Save the kernel shadow call stack pointer */
+ scs_save_current
+
/*
* Save TP into the scratch register , so we can find the kernel data
* structures again.
*/
csrw CSR_SCRATCH, tp
-
-restore_all:
-#ifdef CONFIG_TRACE_IRQFLAGS
- REG_L s1, PT_STATUS(sp)
- andi t0, s1, SR_PIE
- beqz t0, 1f
- call __trace_hardirqs_on
- j 2f
1:
- call __trace_hardirqs_off
-2:
+#ifdef CONFIG_RISCV_ISA_V_PREEMPTIVE
+ move a0, sp
+ call riscv_v_context_nesting_end
#endif
REG_L a0, PT_STATUS(sp)
/*
@@ -322,32 +270,7 @@ restore_all:
REG_L x3, PT_GP(sp)
REG_L x4, PT_TP(sp)
REG_L x5, PT_T0(sp)
- REG_L x6, PT_T1(sp)
- REG_L x7, PT_T2(sp)
- REG_L x8, PT_S0(sp)
- REG_L x9, PT_S1(sp)
- REG_L x10, PT_A0(sp)
- REG_L x11, PT_A1(sp)
- REG_L x12, PT_A2(sp)
- REG_L x13, PT_A3(sp)
- REG_L x14, PT_A4(sp)
- REG_L x15, PT_A5(sp)
- REG_L x16, PT_A6(sp)
- REG_L x17, PT_A7(sp)
- REG_L x18, PT_S2(sp)
- REG_L x19, PT_S3(sp)
- REG_L x20, PT_S4(sp)
- REG_L x21, PT_S5(sp)
- REG_L x22, PT_S6(sp)
- REG_L x23, PT_S7(sp)
- REG_L x24, PT_S8(sp)
- REG_L x25, PT_S9(sp)
- REG_L x26, PT_S10(sp)
- REG_L x27, PT_S11(sp)
- REG_L x28, PT_T3(sp)
- REG_L x29, PT_T4(sp)
- REG_L x30, PT_T5(sp)
- REG_L x31, PT_T6(sp)
+ restore_from_x6_to_x31
REG_L x2, PT_SP(sp)
@@ -356,134 +279,28 @@ restore_all:
#else
sret
#endif
-
-#if IS_ENABLED(CONFIG_PREEMPTION)
-resume_kernel:
- REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
- bnez s0, restore_all
- REG_L s0, TASK_TI_FLAGS(tp)
- andi s0, s0, _TIF_NEED_RESCHED
- beqz s0, restore_all
- call preempt_schedule_irq
- j restore_all
-#endif
-
-work_pending:
- /* Enter slow path for supplementary processing */
- la ra, ret_from_exception
- andi s1, s0, _TIF_NEED_RESCHED
- bnez s1, work_resched
-work_notifysig:
- /* Handle pending signals and notify-resume requests */
- csrs CSR_STATUS, SR_IE /* Enable interrupts for do_notify_resume() */
- move a0, sp /* pt_regs */
- move a1, s0 /* current_thread_info->flags */
- tail do_notify_resume
-work_resched:
- tail schedule
-
-/* Slow paths for ptrace. */
-handle_syscall_trace_enter:
- move a0, sp
- call do_syscall_trace_enter
- move t0, a0
- REG_L a0, PT_A0(sp)
- REG_L a1, PT_A1(sp)
- REG_L a2, PT_A2(sp)
- REG_L a3, PT_A3(sp)
- REG_L a4, PT_A4(sp)
- REG_L a5, PT_A5(sp)
- REG_L a6, PT_A6(sp)
- REG_L a7, PT_A7(sp)
- bnez t0, ret_from_syscall_rejected
- j check_syscall_nr
-handle_syscall_trace_exit:
- move a0, sp
- call do_syscall_trace_exit
- j ret_from_exception
+SYM_INNER_LABEL(ret_from_exception_end, SYM_L_GLOBAL)
+SYM_CODE_END(ret_from_exception)
+ASM_NOKPROBE(ret_from_exception)
#ifdef CONFIG_VMAP_STACK
-handle_kernel_stack_overflow:
- la sp, shadow_stack
- addi sp, sp, SHADOW_OVERFLOW_STACK_SIZE
+SYM_CODE_START_LOCAL(handle_kernel_stack_overflow)
+ /* we reach here from kernel context, sscratch must be 0 */
+ csrrw x31, CSR_SCRATCH, x31
+ asm_per_cpu sp, overflow_stack, x31
+ li x31, OVERFLOW_STACK_SIZE
+ add sp, sp, x31
+ /* zero out x31 again and restore x31 */
+ xor x31, x31, x31
+ csrrw x31, CSR_SCRATCH, x31
- //save caller register to shadow stack
- addi sp, sp, -(PT_SIZE_ON_STACK)
- REG_S x1, PT_RA(sp)
- REG_S x5, PT_T0(sp)
- REG_S x6, PT_T1(sp)
- REG_S x7, PT_T2(sp)
- REG_S x10, PT_A0(sp)
- REG_S x11, PT_A1(sp)
- REG_S x12, PT_A2(sp)
- REG_S x13, PT_A3(sp)
- REG_S x14, PT_A4(sp)
- REG_S x15, PT_A5(sp)
- REG_S x16, PT_A6(sp)
- REG_S x17, PT_A7(sp)
- REG_S x28, PT_T3(sp)
- REG_S x29, PT_T4(sp)
- REG_S x30, PT_T5(sp)
- REG_S x31, PT_T6(sp)
-
- la ra, restore_caller_reg
- tail get_overflow_stack
-
-restore_caller_reg:
- //save per-cpu overflow stack
- REG_S a0, -8(sp)
- //restore caller register from shadow_stack
- REG_L x1, PT_RA(sp)
- REG_L x5, PT_T0(sp)
- REG_L x6, PT_T1(sp)
- REG_L x7, PT_T2(sp)
- REG_L x10, PT_A0(sp)
- REG_L x11, PT_A1(sp)
- REG_L x12, PT_A2(sp)
- REG_L x13, PT_A3(sp)
- REG_L x14, PT_A4(sp)
- REG_L x15, PT_A5(sp)
- REG_L x16, PT_A6(sp)
- REG_L x17, PT_A7(sp)
- REG_L x28, PT_T3(sp)
- REG_L x29, PT_T4(sp)
- REG_L x30, PT_T5(sp)
- REG_L x31, PT_T6(sp)
-
- //load per-cpu overflow stack
- REG_L sp, -8(sp)
addi sp, sp, -(PT_SIZE_ON_STACK)
//save context to overflow stack
REG_S x1, PT_RA(sp)
REG_S x3, PT_GP(sp)
REG_S x5, PT_T0(sp)
- REG_S x6, PT_T1(sp)
- REG_S x7, PT_T2(sp)
- REG_S x8, PT_S0(sp)
- REG_S x9, PT_S1(sp)
- REG_S x10, PT_A0(sp)
- REG_S x11, PT_A1(sp)
- REG_S x12, PT_A2(sp)
- REG_S x13, PT_A3(sp)
- REG_S x14, PT_A4(sp)
- REG_S x15, PT_A5(sp)
- REG_S x16, PT_A6(sp)
- REG_S x17, PT_A7(sp)
- REG_S x18, PT_S2(sp)
- REG_S x19, PT_S3(sp)
- REG_S x20, PT_S4(sp)
- REG_S x21, PT_S5(sp)
- REG_S x22, PT_S6(sp)
- REG_S x23, PT_S7(sp)
- REG_S x24, PT_S8(sp)
- REG_S x25, PT_S9(sp)
- REG_S x26, PT_S10(sp)
- REG_S x27, PT_S11(sp)
- REG_S x28, PT_T3(sp)
- REG_S x29, PT_T4(sp)
- REG_S x30, PT_T5(sp)
- REG_S x31, PT_T6(sp)
+ save_from_x6_to_x31
REG_L s0, TASK_TI_KERNEL_SP(tp)
csrr s1, CSR_STATUS
@@ -499,23 +316,62 @@ restore_caller_reg:
REG_S s5, PT_TP(sp)
move a0, sp
tail handle_bad_stack
+SYM_CODE_END(handle_kernel_stack_overflow)
+ASM_NOKPROBE(handle_kernel_stack_overflow)
#endif
-END(handle_exception)
-
-ENTRY(ret_from_fork)
- la ra, ret_from_exception
- tail schedule_tail
-ENDPROC(ret_from_fork)
+SYM_CODE_START(ret_from_fork_kernel_asm)
+ call schedule_tail
+ move a0, s1 /* fn_arg */
+ move a1, s0 /* fn */
+ move a2, sp /* pt_regs */
+ call ret_from_fork_kernel
+ j ret_from_exception
+SYM_CODE_END(ret_from_fork_kernel_asm)
-ENTRY(ret_from_kernel_thread)
+SYM_CODE_START(ret_from_fork_user_asm)
call schedule_tail
- /* Call fn(arg) */
- la ra, ret_from_exception
- move a0, s1
- jr s0
-ENDPROC(ret_from_kernel_thread)
+ move a0, sp /* pt_regs */
+ call ret_from_fork_user
+ j ret_from_exception
+SYM_CODE_END(ret_from_fork_user_asm)
+#ifdef CONFIG_IRQ_STACKS
+/*
+ * void call_on_irq_stack(struct pt_regs *regs,
+ * void (*func)(struct pt_regs *));
+ *
+ * Calls func(regs) using the per-CPU IRQ stack.
+ */
+SYM_FUNC_START(call_on_irq_stack)
+ /* Create a frame record to save ra and s0 (fp) */
+ addi sp, sp, -STACKFRAME_SIZE_ON_STACK
+ REG_S ra, STACKFRAME_RA(sp)
+ 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)
+ REG_L s0, STACKFRAME_FP(sp)
+ addi sp, sp, STACKFRAME_SIZE_ON_STACK
+
+ ret
+SYM_FUNC_END(call_on_irq_stack)
+#endif /* CONFIG_IRQ_STACKS */
/*
* Integer register context switch
@@ -527,7 +383,7 @@ ENDPROC(ret_from_kernel_thread)
* The value of a0 and a1 must be preserved by this function, as that's how
* arguments are passed to schedule_tail.
*/
-ENTRY(__switch_to)
+SYM_FUNC_START(__switch_to)
/* Save context into prev->thread */
li a4, TASK_THREAD_RA
add a3, a0, a4
@@ -546,7 +402,18 @@ ENTRY(__switch_to)
REG_S s9, TASK_THREAD_S9_RA(a3)
REG_S s10, TASK_THREAD_S10_RA(a3)
REG_S s11, TASK_THREAD_S11_RA(a3)
+
+ /* save the user space access flag */
+ csrr s0, CSR_STATUS
+ REG_S s0, TASK_THREAD_SUM_RA(a3)
+
+ /* Save the kernel shadow call stack pointer */
+ scs_save_current
/* Restore context from next->thread */
+ REG_L s0, TASK_THREAD_SUM_RA(a4)
+ li s1, SR_SUM
+ and s0, s0, s1
+ csrs CSR_STATUS, s0
REG_L ra, TASK_THREAD_RA_RA(a4)
REG_L sp, TASK_THREAD_SP_RA(a4)
REG_L s0, TASK_THREAD_S0_RA(a4)
@@ -563,8 +430,10 @@ ENTRY(__switch_to)
REG_L s11, TASK_THREAD_S11_RA(a4)
/* The offset of thread_info in task_struct is zero. */
move tp, a1
+ /* Switch to the next shadow call stack */
+ scs_load_current
ret
-ENDPROC(__switch_to)
+SYM_FUNC_END(__switch_to)
#ifndef CONFIG_MMU
#define do_page_fault do_trap_unknown
@@ -573,7 +442,7 @@ ENDPROC(__switch_to)
.section ".rodata"
.align LGREG
/* Exception vector table */
-ENTRY(excp_vect_table)
+SYM_DATA_START_LOCAL(excp_vect_table)
RISCV_PTR do_trap_insn_misaligned
ALT_INSN_FAULT(RISCV_PTR do_trap_insn_fault)
RISCV_PTR do_trap_insn_illegal
@@ -582,21 +451,20 @@ ENTRY(excp_vect_table)
RISCV_PTR do_trap_load_fault
RISCV_PTR do_trap_store_misaligned
RISCV_PTR do_trap_store_fault
- RISCV_PTR do_trap_ecall_u /* system call, gets intercepted */
+ RISCV_PTR do_trap_ecall_u /* system call */
RISCV_PTR do_trap_ecall_s
RISCV_PTR do_trap_unknown
RISCV_PTR do_trap_ecall_m
- /* instruciton page fault */
+ /* instruction page fault */
ALT_PAGE_FAULT(RISCV_PTR do_page_fault)
RISCV_PTR do_page_fault /* load page fault */
RISCV_PTR do_trap_unknown
RISCV_PTR do_page_fault /* store page fault */
-excp_vect_table_end:
-END(excp_vect_table)
+SYM_DATA_END_LABEL(excp_vect_table, SYM_L_LOCAL, excp_vect_table_end)
#ifndef CONFIG_MMU
-ENTRY(__user_rt_sigreturn)
+SYM_DATA_START(__user_rt_sigreturn)
li a7, __NR_rt_sigreturn
- scall
-END(__user_rt_sigreturn)
+ ecall
+SYM_DATA_END(__user_rt_sigreturn)
#endif