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cdm_adapter: do not SetTimer when session get closed Block SetTimer w…
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…hile CloseSession is active to avoid endless loop.

Sometimes when stopping a playback Kodi crashes with a following backtrace:

    (__m=<optimized out>, this=<optimized out>)
    at /usr/include/c++/12.1.0/bits/atomic_base.h:486
        __b = <optimized out>
    at /usr/include/c++/12.1.0/atomic:87
    (adp=std::shared_ptr<media::CdmAdapter> (use count 1, weak count 1) = {...}, delay=<optimized out>, context=<optimized out>)
    at /usr/src/debug/kodi-addon-inputstream-adaptive/inputstream.adaptive-20.3.3-Nexus/wvdecrypter/cdm/media/cdm/cdm_adapter.cc:81
    at /usr/include/c++/12.1.0/bits/invoke.h:96, unsigned long long, void*), std::shared_ptr<media::CdmAdapter>, long long, void*> >::_M_invoke<0u, 1u, 2u, 3u>(std::_Index_tuple<0u, 1u, 2u, 3u>)
    (this=<optimized out>) at /usr/include/c++/12.1.0/bits/std_thread.h:252
    at /usr/include/c++/12.1.0/bits/std_thread.h:259
    at /usr/include/c++/12.1.0/bits/std_thread.h:210
    at /usr/src/debug/gcc/libstdc++-v3/src/c++11/thread.cc:82
        ret = <optimized out>
        pd = 0x85cf9080
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {857629366, 66004830, -2049994624, -2008033272, -2008033282, 338, -2008033281, 8387456, -2058383360, -2049995908, 1920, 1080, 3840, 2160, 0, 10000000, -1431355392, 1107558643, 0 <repeats 46 times>}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        robust = <optimized out>

After searching in the github history it came out that there was a
similar issue adressed in xbmc#728.

For some reason that piece of code got removed in
xbmc@8889fe9
(in pull request xbmc#883).

The stack trace is from the Raspberry Pi 4 machine. But I can also reproduce the issue
on my x86_64 Linux machine by adding a 1s sleep in the beginning of CdmAdapter::SetTimer.

In order to reproduce it is necessary to quickly play/stop streams.
Script attached at the end of the commit message can be used to ease the reproduction.
In my environment running the script for 1-3 minutes makes Kodi crash.
Although the root cause described in xbmc#729
was a busy loop. Right now address sanitizer reports:
```
AddressSanitizer:DEADLYSIGNAL
=================================================================
==108079==ERROR: AddressSanitizer: SEGV on unknown address 0x7f6e314f7d4a (pc 0x7f6e314f7d4a bp 0x7f6e263fd830 sp 0x7f6e263fd720 T464)
==108079==The signal is caused by a READ memory access.
==108079==Hint: PC is at a non-executable region. Maybe a wild jump?
    #0 0x7f6e314f7d4a  (<unknown module>)
    xbmc#1 0x7f6e3151c066  (<unknown module>)
    xbmc#2 0x7f6e31526947  (<unknown module>)
    xbmc#3 0x7f6e31526729  (<unknown module>)
    xbmc#4 0x7f6e31526620  (<unknown module>)
    xbmc#5 0x7f6e315265a1  (<unknown module>)
    xbmc#6 0x7f6e31526585  (<unknown module>)
    xbmc#7 0x7f6e46ed72c2 in execute_native_thread_routine /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:82

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (<unknown module>)
Thread T464 created by T51 here:
    #0 0x7f6e49464207 in __interceptor_pthread_create /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_interceptors.cpp:207
    xbmc#1 0x7f6e46ed73a9 in __gthread_create /usr/src/debug/gcc/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu/bits/gthr-default.h:663
    xbmc#2 0x7f6e46ed73a9 in std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:147
    xbmc#3 0x7f6e31522028  (<unknown module>)
    xbmc#4 0x7f6e27569d40  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x969d40)
    xbmc#5 0x7f6e2757e7fc  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x97e7fc)
    xbmc#6 0x7f6e27569c36  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x969c36)
    xbmc#7 0x7f6e3151fb28  (<unknown module>)
    xbmc#8 0x7f6e3151c0b1  (<unknown module>)
    xbmc#9 0x7f6e31526947  (<unknown module>)
    xbmc#10 0x7f6e31526729  (<unknown module>)
    xbmc#11 0x7f6e31526620  (<unknown module>)
    xbmc#12 0x7f6e315265a1  (<unknown module>)
    xbmc#13 0x7f6e31526585  (<unknown module>)
    xbmc#14 0x7f6e46ed72c2 in execute_native_thread_routine /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:82

Thread T51 created by T45 here:
    #0 0x7f6e49464207 in __interceptor_pthread_create /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_interceptors.cpp:207
    xbmc#1 0x7f6e46ed73a9 in __gthread_create /usr/src/debug/gcc/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu/bits/gthr-default.h:663
    xbmc#2 0x7f6e46ed73a9 in std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:147
    xbmc#3 0x7f6e31522028  (<unknown module>)
    xbmc#4 0x7f6e27569d40  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x969d40)
    xbmc#5 0x7f6e2757e7fc  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x97e7fc)
    xbmc#6 0x7f6e2757e70e  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x97e70e)
    xbmc#7 0x7f6e274e4ecc  (/home/dobo/.kodi/cdm/libwidevinecdm.so+0x8e4ecc)
    xbmc#8 0x7f6e3151f280  (<unknown module>)
    xbmc#9 0x7f6e314e9ea1  (<unknown module>)
    xbmc#10 0x7f6e314e49bb  (<unknown module>)
    xbmc#11 0x7f6e314f45ce  (<unknown module>)
    xbmc#12 0x7f6e2889228f in SESSION::CSession::InitializeDRM(bool) /home/dobo/kodi/inputstream.adaptive/src/Session.cpp:643
    xbmc#13 0x7f6e28893279 in SESSION::CSession::InitializePeriod(bool) /home/dobo/kodi/inputstream.adaptive/src/Session.cpp:723
    xbmc#14 0x7f6e2888e36d in SESSION::CSession::Initialize() /home/dobo/kodi/inputstream.adaptive/src/Session.cpp:266
    xbmc#15 0x7f6e28775f4c in CInputStreamAdaptive::Open(kodi::addon::InputstreamProperty const&) /home/dobo/kodi/inputstream.adaptive/src/main.cpp:101
    xbmc#16 0x7f6e287871a1 in kodi::addon::CInstanceInputStream::ADDON_Open(AddonInstance_InputStream const*, INPUTSTREAM_PROPERTY*) (/usr/lib/kodi/addons/inputstream.adaptive/inputstream.adaptive.so.20.3.2+0x3871a1)
    xbmc#17 0x55c2811f4ddc in CInputStreamAddon::Open() (/usr/lib/kodi/kodi.bin+0xb66ddc)

Thread T45 created by T0 here:
    #0 0x7f6e49464207 in __interceptor_pthread_create /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_interceptors.cpp:207
    xbmc#1 0x7f6e46ed73a9 in __gthread_create /usr/src/debug/gcc/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu/bits/gthr-default.h:663
    xbmc#2 0x7f6e46ed73a9 in std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:147
```

The root cause of the crash is unknown as it comes directly from
libwidevine library. But it crashes when we call cdm->TimerExpired when
the session is closed. After applying mentioned commit I'm not able
to reproduce the crash anymore.

Script to reproduce the issue:
```
set -x

URI='Change it to some uri to play'

while true; do
  curl -s "http://kodi:kodi@127.0.0.1:8080/jsonrpc" -H 'Content-Type: application/json' --data "{\"jsonrpc\":\"2.0\",\"method\":\"Player.Open\",\"params\":{\"item\":{\"file\":\"$URI\"}}}"
  sleep $[ ($RANDOM % 70 + 30) / 10.0 ]

  curl -s "http://kodi:kodi@127.0.0.1:8080/jsonrpc" -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","method":"Player.Stop","params":{"playerid":1}}'
  sleep 1
done
```
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@Portisch @dobo90
Portisch authored and dobo90 committed Feb 14, 2023
1 parent c88ce9e commit d6856de
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Showing 3 changed files with 22 additions and 1 deletion.
12 changes: 11 additions & 1 deletion wvdecrypter/cdm/media/cdm/cdm_adapter.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -137,6 +137,7 @@ CdmAdapter::CdmAdapter(
, cdm_config_(cdm_config)
, active_buffer_(0)
, cdm9_(0), cdm10_(0), cdm11_(0)
, session_active_(false)
{
//DCHECK(!key_system_.empty());
Initialize();
Expand Down Expand Up @@ -329,10 +330,16 @@ void CdmAdapter::UpdateSession(uint32_t promise_id,
response, response_size);
}

void CdmAdapter::SetSessionActive()
{
session_active_ = true;
}

void CdmAdapter::CloseSession(uint32_t promise_id,
const char* session_id,
uint32_t session_id_size)
{
session_active_ = false;
exit_thread_flag = true;
while (timer_thread_running)
{
Expand Down Expand Up @@ -507,7 +514,10 @@ cdm::Buffer* CdmAdapter::Allocate(uint32_t capacity)
void CdmAdapter::SetTimer(int64_t delay_ms, void* context)
{
//LICENSERENEWAL
std::thread(timerfunc, shared_from_this(), delay_ms, context).detach();
if (session_active_)
{
std::thread(timerfunc, shared_from_this(), delay_ms, context).detach();
}
}

cdm::Time CdmAdapter::GetCurrentWallTime()
Expand Down
4 changes: 4 additions & 0 deletions wvdecrypter/cdm/media/cdm/cdm_adapter.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -109,6 +109,8 @@ class CdmAdapter : public std::enable_shared_from_this<CdmAdapter>
const uint8_t* response,
uint32_t response_size);

void SetSessionActive();

void CloseSession(uint32_t promise_id,
const char* session_id,
uint32_t session_id_size);
Expand Down Expand Up @@ -247,6 +249,8 @@ class CdmAdapter : public std::enable_shared_from_this<CdmAdapter>
cdm::ContentDecryptionModule_10 *cdm10_;
cdm::ContentDecryptionModule_11 *cdm11_;

std::atomic<bool> session_active_;

DISALLOW_COPY_AND_ASSIGN(CdmAdapter);
};

Expand Down
7 changes: 7 additions & 0 deletions wvdecrypter/wvdecrypter.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -158,6 +158,7 @@ class WV_CencSingleSampleDecrypter : public Adaptive_CencSingleSampleDecrypter

void GetCapabilities(const uint8_t* key, uint32_t media, SSD_DECRYPTER::SSD_CAPS &caps);
virtual const char *GetSessionId() override;
void SetSessionActive();
void CloseSessionId();
AP4_DataBuffer GetChallengeData();

Expand Down Expand Up @@ -401,6 +402,7 @@ void WV_DRM::OnCDMMessage(const char* session, uint32_t session_size, CDMADPMSG
if (msg == CDMADPMSG::kSessionMessage)
{
(*b)->SetSession(session, session_size, data, data_size);
(*b)->SetSessionActive();
}
else if (msg == CDMADPMSG::kSessionKeysChange)
(*b)->AddSessionKey(data, data_size, status);
Expand Down Expand Up @@ -583,6 +585,11 @@ const char *WV_CencSingleSampleDecrypter::GetSessionId()
return session_.empty()? nullptr : session_.c_str();
}

void WV_CencSingleSampleDecrypter::SetSessionActive()
{
drm_.GetCdmAdapter()->SetSessionActive();
}

void WV_CencSingleSampleDecrypter::CloseSessionId()
{
if (!session_.empty())
Expand Down

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