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ARC: entry: rework (non-functional)
- comments update - rename syscall_trace_entry - use PT_xxx in entry code Signed-off-by: Vineet Gupta <vgupta@kernel.org>
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Vineet Gupta
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fd476197c6
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c505b0da76
@ -48,14 +48,18 @@
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/*------------------------------------------------------------------------*/
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.macro INTERRUPT_PROLOGUE
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; (A) Before jumping to Interrupt Vector, hardware micro-ops did following:
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; Before jumping to Interrupt Vector, hardware micro-ops did following:
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; 1. SP auto-switched to kernel mode stack
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; 2. STATUS32.Z flag set if in U mode at time of interrupt (U:1,K:0)
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; 3. Auto save: (mandatory) Push PC and STAT32 on stack
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; hardware does even if CONFIG_ARC_IRQ_NO_AUTOSAVE
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; 4. Auto save: (optional) r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI
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; 4a. Auto save: (optional) r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI
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;
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; (B) Manually saved some regs: r12,r30, sp,fp,gp, ACCL pair
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; Now
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; 4b. If Auto-save (optional) not enabled in hw, manually save them
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; 5. Manually save: r12,r30, sp,fp,gp, ACCL pair
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;
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; At the end, SP points to pt_regs
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#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
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; carve pt_regs on stack (case #3), PC/STAT32 already on stack
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@ -73,13 +77,14 @@
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/*------------------------------------------------------------------------*/
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.macro EXCEPTION_PROLOGUE
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; (A) Before jumping to Exception Vector, hardware micro-ops did following:
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; Before jumping to Exception Vector, hardware micro-ops did following:
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; 1. SP auto-switched to kernel mode stack
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; 2. STATUS32.Z flag set if in U mode at time of exception (U:1,K:0)
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;
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; (B) Manually save the complete reg file below
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; Now manually save rest of reg file
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; At the end, SP points to pt_regs
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sub sp, sp, SZ_PT_REGS ; carve pt_regs
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sub sp, sp, SZ_PT_REGS ; carve space for pt_regs
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; _HARD saves r10 clobbered by _SOFT as scratch hence comes first
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@ -136,8 +141,8 @@
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ST2 gp, fp, PT_r26 ; gp (r26), fp (r27)
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st r12, [sp, PT_sp + 4]
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st r30, [sp, PT_sp + 8]
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st r12, [sp, PT_r12]
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st r30, [sp, PT_r30]
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; Saving pt_regs->sp correctly requires some extra work due to the way
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; Auto stack switch works
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@ -244,7 +249,7 @@
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btst r0, STATUS_U_BIT ; Z flag set if K, used in restoring SP
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ld r10, [sp, PT_event + 4]
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ld r10, [sp, PT_bta]
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sr r10, [erbta]
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LD2 r10, r11, PT_ret
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@ -170,12 +170,13 @@
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PUSHAX erbta
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lr r10, [ecr]
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st r10, [sp, PT_event] /* EV_Trap expects r10 to have ECR */
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st r10, [sp, PT_event]
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#ifdef CONFIG_ARC_CURR_IN_REG
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/* gp already saved on stack: now load with "current" */
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GET_CURR_TASK_ON_CPU gp
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#endif
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; OUTPUT: r10 has ECR expected by EV_Trap
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.endm
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/*--------------------------------------------------------------
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@ -75,7 +75,7 @@ struct pt_regs {
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unsigned long event;
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};
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unsigned long bta; /* bta_l1, bta_l2, erbta */
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unsigned long bta; /* erbta */
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unsigned long r26; /* gp */
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unsigned long fp;
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@ -47,6 +47,7 @@ int main(void)
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DEFINE(PT_status32, offsetof(struct pt_regs, status32));
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DEFINE(PT_event, offsetof(struct pt_regs, event));
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DEFINE(PT_bta, offsetof(struct pt_regs, bta));
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DEFINE(PT_sp, offsetof(struct pt_regs, sp));
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DEFINE(PT_r0, offsetof(struct pt_regs, r0));
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DEFINE(PT_r1, offsetof(struct pt_regs, r1));
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@ -160,20 +160,19 @@ END(EV_Extension)
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; syscall Tracing
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; ---------------------------------------------
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tracesys:
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; save EFA in case tracer wants the PC of traced task
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; using ERET won't work since next-PC has already committed
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; safekeep EFA (r12) if syscall tracer wanted PC
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; for traps, ERET is pre-commit so points to next-PC
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GET_CURR_TASK_FIELD_PTR TASK_THREAD, r11
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st r12, [r11, THREAD_FAULT_ADDR] ; thread.fault_address
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; PRE Sys Call Ptrace hook
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mov r0, sp ; pt_regs needed
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bl @syscall_trace_entry
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; PRE syscall trace hook
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mov r0, sp ; pt_regs
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bl @syscall_trace_enter
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; Tracing code now returns the syscall num (orig or modif)
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mov r8, r0
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; Do the Sys Call as we normally would.
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; Validate the Sys Call number
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cmp r8, NR_syscalls - 1
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mov.hi r0, -ENOSYS
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bhi tracesys_exit
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@ -190,36 +189,36 @@ tracesys:
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ld r6, [sp, PT_r6]
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ld r7, [sp, PT_r7]
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ld.as r9, [sys_call_table, r8]
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jl [r9] ; Entry into Sys Call Handler
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jl [r9]
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tracesys_exit:
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st r0, [sp, PT_r0] ; sys call return value in pt_regs
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st r0, [sp, PT_r0]
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;POST Sys Call Ptrace Hook
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; POST syscall trace hook
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mov r0, sp ; pt_regs needed
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bl @syscall_trace_exit
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b ret_from_exception ; NOT ret_from_system_call at is saves r0 which
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; we'd done before calling post hook above
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; don't call ret_from_system_call as it saves r0, already done above
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b ret_from_exception
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; ---------------------------------------------
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; Breakpoint TRAP
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; ---------------------------------------------
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trap_with_param:
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mov r0, r12 ; EFA in case ptracer/gdb wants stop_pc
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mov r1, sp
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mov r1, sp ; pt_regs
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; Save callee regs in case gdb wants to have a look
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; SP will grow up by size of CALLEE Reg-File
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; save callee regs in case tracer/gdb wants to peek
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SAVE_CALLEE_SAVED_USER
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; save location of saved Callee Regs @ thread_struct->pc
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; safekeep ref to callee regs
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GET_CURR_TASK_FIELD_PTR TASK_THREAD, r10
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st sp, [r10, THREAD_CALLEE_REG]
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; Call the trap handler
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; call the non syscall trap handler
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bl do_non_swi_trap
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; unwind stack to discard Callee saved Regs
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; unwind stack to discard callee regs
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DISCARD_CALLEE_SAVED_USER
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b ret_from_exception
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@ -237,31 +236,27 @@ ENTRY(EV_Trap)
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FAKE_RET_FROM_EXCPN
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;============ TRAP 1 :breakpoints
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; Check ECR for trap with arg (PROLOGUE ensures r10 has ECR)
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;============ TRAP N : breakpoints, kprobes etc
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bmsk.f 0, r10, 7
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bnz trap_with_param
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;============ TRAP (no param): syscall top level
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;============ TRAP 0 (no param): syscall
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; If syscall tracing ongoing, invoke pre-post-hooks
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; syscall tracing ongoing, invoke pre-post-hooks around syscall
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GET_CURR_THR_INFO_FLAGS r10
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and.f 0, r10, _TIF_SYSCALL_WORK
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bnz tracesys ; this never comes back
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;============ Normal syscall case
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; syscall num shd not exceed the total system calls avail
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cmp r8, NR_syscalls - 1
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mov.hi r0, -ENOSYS
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bhi .Lret_from_system_call
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; Offset into the syscall_table and call handler
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ld.as r9,[sys_call_table, r8]
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jl [r9] ; Entry into Sys Call Handler
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jl [r9]
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.Lret_from_system_call:
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st r0, [sp, PT_r0] ; sys call return value in pt_regs
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; fall through to ret_from_exception
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@ -339,7 +339,7 @@ long arch_ptrace(struct task_struct *child, long request,
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return ret;
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}
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asmlinkage int syscall_trace_entry(struct pt_regs *regs)
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asmlinkage int syscall_trace_enter(struct pt_regs *regs)
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{
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if (test_thread_flag(TIF_SYSCALL_TRACE))
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if (ptrace_report_syscall_entry(regs))
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