On Thu, Sep 10, 2015 at 10:30 AM, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Thu, Sep 10, 2015 at 08:42:57AM +0200, Dr. H. Nikolaus Schaller wrote: >> ... >> >> Now, disabling CONFIG_ARCH_MULTI_V6 also makes the bug go away and adding the >> >> #if 0 //__LINUX_ARM_ARCH__ >= 7 >> makes it re-appear. >> >> A while ago I tried to debug running the x-server under strace and could find that it also has >> something to do with SIGALRM. >> >> And that is very consistent with “enable/disable” by modifying arch/arm/kernel/signal.c > > It would be really nice if someone could diagnose what's going on here. > What exception is causing the X server to be killed (someone said a > segfault)? What is the register state at the point that happens? What > does the code look like Is it happening inside the SIGALRM handler, or > when the SIGALRM handler has returned? > > I'd suggest attaching gdb to the X server, but remember to set gdb to > ignore SIGPIPEs. It's actually pretty random, see some debug sessions in [1]. The first one is the most useful one, but I haven't though of checking what pixman_rasterize_edges() was doing when the signal arrived, and most often the "less useful" segfaults occur. However from the disassembly (see debug1_libpixman.gz) it can be seen that the signal arrived right after IT. [1] http://notaz.gp2x.de/tmp/thumb_segfault/ Gražvydas -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
