.section .text.user_handle,"ax"
.balign 4
.global __user_task_blob_start
__user_task_blob_start:
    // Same user VA, different private root and data/stack pages for A/B.
    mov x19, x0
    movz x20, #0x1000
    movk x20, #0x8000, lsl #16
    mov x21, #0x55
    str x19, [x20]
    sub sp, sp, #16
    str x19, [sp]
    movz x9, #0xa11a
    cmp x19, x9
    b.eq .Lhandle_a
    movz x9, #0xb22b
    cmp x19, x9
    b.ne .Lhandle_fail

.Lhandle_b:
    mov x7, #1
    // A's live handle 1 must be invisible to B.
    mov x0, #1
    mov x8, #9
    svc #0x42
    movn x9, #8
    cmp x0, x9
    b.ne .Lhandle_fail
    // B owns handle 2 (clock resource).
    mov x0, #2
    mov x8, #8
    svc #0x42
    cmp x0, #2
    b.ne .Lhandle_fail
    mov x22, x0
    // Both slots occupied; no third descriptor is issued.
    mov x0, #1
    mov x8, #8
    svc #0x42
    movn x9, #23
    cmp x0, x9
    b.ne .Lhandle_fail
    mov x8, #6
    svc #0x42
    cbnz x0, .Lhandle_fail
    cmp x22, #2
    b.ne .Lhandle_fail
    cmp x21, #0x55
    b.ne .Lhandle_fail
    ldr x9, [x20]
    cmp x9, x19
    b.ne .Lhandle_fail
    ldr x9, [sp]
    cmp x9, x19
    b.ne .Lhandle_fail
    // A has closed 1. It must stay stale after A exits.
    mov x0, #1
    mov x8, #9
    svc #0x42
    movn x9, #8
    cmp x0, x9
    b.ne .Lhandle_fail
    mov x0, x22
    mov x8, #9
    svc #0x42
    cmp x0, #2
    b.ne .Lhandle_fail
    mov x0, x22
    mov x8, #10
    svc #0x42
    cbnz x0, .Lhandle_fail
    mov x0, x19
    mov x8, #2
    svc #0x42
    b .Lhandle_fail

.Lhandle_a:
    mov x7, #1
    mov x0, #1
    mov x8, #8
    svc #0x42
    cmp x0, #1
    b.ne .Lhandle_fail
    mov x22, x0
    mov x8, #6
    svc #0x42
    cbnz x0, .Lhandle_fail
    cmp x22, #1
    b.ne .Lhandle_fail
    cmp x21, #0x55
    b.ne .Lhandle_fail
    ldr x9, [x20]
    cmp x9, x19
    b.ne .Lhandle_fail
    ldr x9, [sp]
    cmp x9, x19
    b.ne .Lhandle_fail
    // A still owns 1; B's live handle 2 is foreign to A.
    mov x0, x22
    mov x8, #9
    svc #0x42
    cmp x0, #1
    b.ne .Lhandle_fail
    mov x0, #2
    mov x8, #9
    svc #0x42
    movn x9, #8
    cmp x0, x9
    b.ne .Lhandle_fail
    mov x0, x22
    mov x8, #10
    svc #0x42
    cbnz x0, .Lhandle_fail
    mov x0, x19
    mov x8, #2
    svc #0x42
.Lhandle_fail:
    brk #0xbad
    b .Lhandle_fail
.global __user_task_blob_end
__user_task_blob_end: