Christian, > You put that quite large buffer on stack. Does the page fault occur > in the stack area 0x40000000..0x50000000? Our stacks have a limited > size and do not grow automatically.
That is what I suspect too. After some further testing, I found out that the segfault occurs for buffer sizes above 12kB, which I suppose is the default stack size in Genode. Assuming that I cannot easily move the buffer to the heap, I'll have to extend the stack. I suppose the way to go is to create a new Genode::Thread for which I can allocate a sufficiently large stack, right? By the way, you can find the code on github: https://github.com/ValiValpas/genode/commit/96ef7acec75c87865b1021d77645a3494b13ac40 I'm NOT using the staging branch. Cheers Johannes On Fri, 31 Oct 2014 08:30:06 +0100 Christian Helmuth <[email protected]> wrote: > Hey, > > You put that quite large buffer on stack. Does the page fault occur > in the stack area 0x40000000..0x50000000? Our stacks have a limited > size and do not grow automatically. > > Greets > Christian > > On October 30, 2014 8:01:05 PM CET, Johannes Schlatow > <[email protected]> wrote: > >Hey everyone, > > > >I'm using some 3rd party code that depends on zlib. In particular, it > >uses gzread() in order to read a file. Unfortunately, the > >corresponding piece of code causes a segfault in ld.lib.so. > > > >I narrowed this down to the following minimum example: > > > > gzFile gzfile_components = gzopen("test.txt", "rb"); > > unsigned char buffer[1024*1024]; > > gzread(gzfile_components, buffer, sizeof(buffer)); > > > >As you can see, the buffer is quite large but this the actual (and > >reasonable) value used in the 3rd party code. > >As soon as I reduce the size to e.g. 4096, the segfault is gone. > > > >The file I used has a size of 293 bytes. I'm using base-linux. > >I also remember using this code successfully on a different computer > >with an older version of Genode (14.03). > > > >Any ideas/comments on this? > > > >------------------------------------------------------------------------------ > >_______________________________________________ > >genode-main mailing list > >[email protected] > >https://lists.sourceforge.net/lists/listinfo/genode-main > -- Johannes Schlatow, M.Sc. IDA, Institute of Computer and Network Engineering Technische Universität Braunschweig Hans-Sommer-Str. 66 38106 Braunschweig - Germany Phone +49 531 391 - 9668 www.ida.ing.tu-bs.de [email protected] ------------------------------------------------------------------------------ _______________________________________________ genode-main mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/genode-main
