mmap read or write deadlock

[korli]

Test MMapFileTest.SelfRead or MMapFileTest.SelfWrite from https://dev.haiku-os.org/ticket/19438

kdebug> bt 451
stack trace for thread 451 "mmap_test"
    kernel stack: 0xffffffff81f07000 to 0xffffffff81f0c000
      user stack: 0x00007fb0a24f9000 to 0x00007fb0a34f9000
frame                       caller             <image>:function + offset
 0 ffffffff81f0b4d0 (+ 160) ffffffff800a631e   <kernel_x86_64> reschedule(int) + 0x6ae
 1 ffffffff81f0b500 (+  48) ffffffff8008fc36   <kernel_x86_64> thread_block + 0xc6
 2 ffffffff81f0b550 (+  80) ffffffff801563c9   <kernel_x86_64> VMCache::WaitForPageEvents(vm_page*, unsigned int, bool) + 0x79
 3 ffffffff81f0b6b0 (+ 352) ffffffff80136d8b   <kernel_x86_64> vm_soft_fault(VMAddressSpace*, unsigned long, bool, bool, bool, vm_page**) + 0x11fb
 4 ffffffff81f0b7b0 (+ 256) ffffffff80143021   <kernel_x86_64> vm_page_fault + 0x181
 5 ffffffff81f0b7f0 (+  64) ffffffff801699be   <kernel_x86_64> x86_page_fault_exception + 0x18e
 6 ffffffff81f0bb48 (+ 856) ffffffff8015ecfc   <kernel_x86_64> int_bottom + 0x80
kernel iframe at 0xffffffff81f0bb48 (end = 0xffffffff81f0bc10)
 rax 0x0                   rbx 0x800                 rcx 0x800
 rdx 0x800                 rsi 0xffffff002a36d000    rdi 0xe557198000
 rbp 0xffffffff81f0bc40     r8 0xffffff002a26d000     r9 0xffffffff801768d0
 r10 0xe557198000          r11 0x7d                  r12 0xffffff002a36d000
 r13 0xe557198000          r14 0x800                 r15 0x0
 rip 0xffffffff80183876    rsp 0xffffffff81f0bc10 rflags 0x50212
 vector: 0xe, error code: 0x2
 7 ffffffff81f0bc40 (+ 248) ffffffff80183876   <kernel_x86_64> memcpy + 0x26
 8 ffffffff81f0bcc0 (+ 128) ffffffff80134264   <kernel_x86_64> _ZN12_GLOBAL(???, user_access, ???, arch_cpu_user_memcpy, ???, ???, ???, ???, ???, ???, ???, ???) + 0xc4
 9 ffffffff81f0bd10 (+  80) ffffffff801396a9   <kernel_x86_64> user_memcpy + 0x89
10 ffffffff81f0be70 (+ 352) ffffffff81121f2e   </boot/system/add-ons/kernel/file_systems/ramfs> DataContainer::_DoCacheIO[clone .localalias] (long, unsigned char*, long, unsigned long*, bool) + 0x29e
11 ffffffff81f0bec0 (+  80) ffffffff8112646c   </boot/system/add-ons/kernel/file_systems/ramfs> ramfs_read(fs_volume*, fs_vnode*, void*, long, void*, unsigned long*) + 0x9c
12 ffffffff81f0bf20 (+  96) ffffffff800f8433   <kernel_x86_64> common_user_io(int, long, void*, unsigned long, bool) + 0x1d3
13 ffffffff81f0bf30 (+  16) ffffffff8015efff   <kernel_x86_64> x86_64_syscall_entry + 0xfb
user iframe at 0xffffffff81f0bf30 (end = 0xffffffff81f0bff8)
 rax 0x94                  rbx 0x1                   rcx 0x11187d5e20c
 rdx 0xe557198000          rsi 0xffffffffffffffff    rdi 0x4
 rbp 0x7fb0a34f87e0         r8 0xff                   r9 0x0
 r10 0x800                 r11 0x202                 r12 0xe44ac56a20
 r13 0x113dcc38ade         r14 0x0                   r15 0x113dcbff1f0
 rip 0x11187d5e20c         rsp 0x7fb0a34f87c8     rflags 0x202
 vector: 0x63, error code: 0x0
14 00007fb0a34f87e0 (+   0) 0000011187d5e20c   </boot/system/lib/libroot.so> _kern_read + 0x0c
15 00007fb0a34f8820 (+  64) 000001981c835af6   </boot/home/mmap_test> _start (nearest) + 0x9e36
16 00007fb0a34f88b0 (+ 144) 000001981c847233   </boot/home/mmap_test> _start (nearest) + 0x1b573
17 00007fb0a34f88f0 (+  64) 00000113dcc35d91   </boot/system/lib/libgtest.so.1.> testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 0x41
18 00007fb0a34f8920 (+  48) 00000113dcc23046   </boot/system/lib/libgtest.so.1.> testing::Test::Run() + 0xe6
19 00007fb0a34f8970 (+  80) 00000113dcc231f5   </boot/system/lib/libgtest.so.1.> testing::TestInfo::Run() + 0x185
20 00007fb0a34f89e0 (+ 112) 00000113dcc23437   </boot/system/lib/libgtest.so.1.> testing::TestSuite::Run() + 0x217
21 00007fb0a34f8aa0 (+ 192) 00000113dcc2e50c   </boot/system/lib/libgtest.so.1.> testing::internal::UnitTestImpl::RunAllTests() + 0x34c
22 00007fb0a34f8b10 (+ 112) 00000113dcc23640   </boot/system/lib/libgtest.so.1.> testing::UnitTest::Run() + 0x80
23 00007fb0a34f8b20 (+  16) 000001981c88e697   </boot/home/mmap_test> RUN_ALL_TESTS() + 0x11
24 00007fb0a34f8b40 (+  32) 000001981c88e67e   </boot/home/mmap_test> gvisor::testing::RunAllTests() + 0x22
25 00007fb0a34f8b60 (+  32) 000001981c88e588   </boot/home/mmap_test> main + 0x27
26 00007fb0a34f8b90 (+  48) 000001981c82bcfe   </boot/home/mmap_test> _start + 0x3e
27 00007fb0a34f8bc0 (+  48) 000001e0e346edd5   </boot/system/runtime_loader> runtime_loader + 0x115
28 0000000000000000 (+   0) 00007f7f5c2b0258   <commpage> commpage_thread_exit + 0x00