PocketBook-KOReader: a document reader for PDF, DJVU, EPUB, FB2, CBZ, ... (AGPLv3)

[pazos]

Originally Posted by LucyOne

Sorry, I haven't updated yet. My crashlog also said "cannot register font".

Failed to register fonts is a non-fatal error. You won't be able to use these fonts but the program should work without problems.

For reference, the issue fixed in master would look like:

./luajit: ./ffi/framebuffer_mxcfb.lua:707: attempt to call method 'isRemarkable' (a nil value)
stack traceback: (...)

[NiLuJe]

As for the segfault, details of what was exactly done to trigger it would help (or, better, a stacktrace or a coredump, he said hopefully ^^).

[dekani]

Hello,

I have same issue also with latest development version. (and few latest build versions)
No generated coredump or useful information when segfault occurs.

I have do changes in bin/libs folders (with last stable version) to try to fix it and finally succeeded to start v2020.01.31-ge49198c-2020-02-11 version.
It seems issue is located in libs folder and especially with libcurl.so.4 library.
If I remove it, koreader starts successfully with my Inkpad 3.

I will do more tests, to confirm, as my test version contains many merged binaries/libraries changes.

[Frenzie]

libcurl shouldn't even be loaded (by LuaJIT, anyway) O-o

[dekani]

Ok.
I just do a clean install (with latest nightly build zip package) and remove libcurl library and can confirm KOReader starts. (same segmentation fault at startup with it)

[NiLuJe]

What @Frenzie said. o_O.

When *exactly* does it crash?

Can we get a coredump (start it in a shell after a ulimit -c unlimited)?

Does the stock system happen to ship *a* version of libcurl somewhere? (extra nasty points if it's statically linked somewhere).

[dekani]

I will try to install a ssh / shell package for pocketbook devices (ssh-fwv5.zip), use konsole software available in vlasovsoft pocketbook package or install pocketbook sdk package first.
I will see if it works and/or if I can connect to my device as I have no unix shell access at the moment to do the test.
I haven't found yet also a native ldd command tool (it seems to be included in pocket book sdk package) to have more details about loaded dependencies.
No other versions of curl library installed or available on my device. (static or dynamic - .a or .so)

[dekani]

Segfault also occurs, for me, as described in kryptos1967 crash log. (Just after sqlite3 context is loaded)

[NiLuJe]

Yeah, we rarely have a native ldd script on these, which is why I usually ship readelf or elfutil's readelf in my own stuff. But I don't do PB, sorry .

In any case, I checked, and nothing seems to be erroneously linked to libcurl on our end.
And I can't pinpoint a stray require "curl" somewhere in the Lua code either (because that would attempt to load native code in addition to Lua packages). :S

[NiLuJe]

@dekani: Does this build fare any better? (Or, well, even starts, since it's built with a new TC I basically pulled out of my ass? ).

[dekani]

Here is result with test build and clean install (I just added the end of crash.log file) :

ffi.load: libs/libmupdf.so
ffi.load: libs/libwrap-mupdf.so
ffi.load: libs/libfreetype.so.6
02/12/20-06:17:55 INFO  opening file ./help/quickstart-en-v2019.12-95-gf8a34ce5_2020-02-12.html
02/12/20-06:17:55 INFO  Loading plugins from directory: plugins
Process has been terminated by signal {SIGSEGV::SEGV_MAPERR}
Segmentation fault

And without curl lib (only for information):

ffi.load: libs/libmupdf.so
ffi.load: libs/libwrap-mupdf.so
ffi.load: libs/libfreetype.so.6
02/12/20-06:26:14 INFO  opening file ./help/quickstart-en-v2019.12-95-gf8a34ce5_2020-02-12.html
02/12/20-06:26:14 INFO  Loading plugins from directory: plugins
ffi.load: sqlite3
02/12/20-06:26:14 INFO  Plugin  plugins/keepalive.koplugin/main.lua  has been disabled.
02/12/20-06:26:14 INFO  Plugin  plugins/hello.koplugin/main.lua  has been disabled.
ffi.load: z
ffi.load: sqlite3
02/12/20-06:26:14 INFO  Plugin  plugins/autosuspend.koplugin/main.lua  has been disabled.
02/12/20-06:26:14 INFO  Plugin  plugins/autofrontlight.koplugin/main.lua  has been disabled.
02/12/20-06:26:14 INFO  RD loaded plugin SSH at plugins/SSH.koplugin

[Frenzie]

Since it says loading plugins, could you please try what happens if you disable them all?

You can do that by adding this to settings.reader.lua:

    ["plugins_disabled"] = {
        ["kobolight"] = true,
        ["backgroundrunner"] = true,
        ["newsdownloader"] = true,
        ["systemstat"] = true,
        ["autosuspend"] = true,
        ["calibrecompanion"] = true,
        ["texteditor"] = true,
        ["autoturn"] = true,
        ["zsync"] = true,
        ["storagestat"] = true,
        ["statistics"] = true,
        ["goodreads"] = true,
        ["readtimer"] = true,
        ["evernote"] = true,
        ["terminal"] = true,
        ["batterystat"] = true,
        ["coverbrowser"] = true,
        ["SSH"] = true,
        ["perceptionexpander"] = true,
        ["docsettingtweak"] = true,
        ["kosync"] = true,
        ["send2ebook"] = true,
        ["keepalive"] = true,
        ["wallabag"] = true
    },

If the program should load, you can continue to determine if toggling any particular plugin triggers the problem by enabling them one by one (which requires a restart in between).

sqlite3 is used in coverbrowser & statistics for example, though I don't understand what curl could have to do with it.

[NiLuJe]

An obvious candidate would be zsync, since it's not out of question that Lua might be doing something dumb when trying to find a "zsync" something in its package path...

Which begs another question: if you have shell access, and with the libcurl in place, does running zsync2 actually work?

EDIT: FWIW, just ran a strace on a full vanilla install on a PW2, and it's not touching a hair of libcurl ^^. The old PB SDK *was* shipping libcurl, though (as well as a lot of other random crap).

EDIT²: But looking at the searchpath order in the strace, it's conceivable that something could be loaded from outside KOReader... Something that could conceivably depend on libcurl, and blow up when it gets fed our own instead of the one it expects...

strace -fitv -e trace=file ./reader.lua /whatever/the/startup/path/is/on/pb would help .

[dekani]

Same result when all plugins are disabled. (settings.reader.lua edited as described)
I have also tried to load a complex epub tutorial at startup. (480 pages - correctly open/displayed with KOReader)
It takes ~20sec before segfault occurs. (loading screen "Open file ... is still displayed before crash)

I'm still doing tests to start a unix shell to provide more information.

02/12/20-19:30:02 INFO  opening file /mnt/ext1/#Livres/#Epub/Development/Vue Js Docs.epub
02/12/20-19:30:02 INFO  Loading plugins from directory: plugins
02/12/20-19:30:02 INFO  Plugin  plugins/autofrontlight.koplugin/main.lua  has been disabled.
02/12/20-19:30:02 INFO  Plugin  plugins/hello.koplugin/main.lua  has been disabled.
02/12/20-19:30:02 INFO  RD loaded plugin timesync at plugins/timesync.koplugin
CRE: document loaded, but styles re-init needed (cause: peculiar CSS pseudoclasses met)
CRE: styles re-init needed after load, re-rendering
Process has been terminated by signal {SIGSEGV::SEGV_MAPERR}
Segmentation fault

[dekani]

I finally succeed to launch a bash shell as root using telnet and wifi... (vi is also available as text editor)
I have changed ulimit to unlimited as described and successfully launch KOReader from command line, it generates a core file, crash log with segfault in koreader folder but core file size is 0 bytes and its content is really empty...

Here is a part of set command, ulimit value (after it has been changed) and core result:

HOME=/
HOSTNAME=pocketbook
HOSTTYPE=arm
IFS=$' \t\n'
LINES=24
MACHTYPE=arm-none-linux-gnueabi
MAILCHECK=60
OLDPWD=/mnt/ext1/applications
OPTERR=1
OPTIND=1
OSTYPE=linux-gnueabi
PATH=/mnt/ext1/system/bin:/sbin:/bin:/usr/bin
PIPESTATUS=([0]="0")
PPID=1125
PS1='\s-\v\$ '
PS2='> '
PS4='+ '
PWD=/mnt/ext1/applications/koreader
QT_QPA_PLATFORM=pocketbook
SHELL=/bin/sh
SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments
SHLVL=1
TERM=vt102
UID=101
USER=root
_=clear
partitions=
bash-4.1$
bash-4.1$ ulimit
unlimited
bash-4.1$ ls -al
drwxrwxrwx    7 root     root          4096 Feb 11 07:33 common
-rwxrwxrwx    1 root     root             0 Feb 12 20:20 core
-rwxrwxrwx    1 root     root         36421 Feb 12 20:20 crash.log