Hello, I'm debugging sporadic application crashes on arm-linux. I get 28-MiB core files (twice as much the app could theoretically use) with overwritten memory. When I built the app with -fmudflapth -fstack-protector-all -lmudflapth -lssp -lpthread (the app is single-threaded, but links to libxml2, which requires lpthread), the compiler produced many warnings that #pragma redefine_extern is not supported. With an instrumented app, I got unregister violations on g_list_remove on arm-linux. I managed to reproduce that on arm-linux with a sample program doing g_list_append 20K times and then g_list_remove'ing everything. However, the results do not seem to be consistent. On i386-linux, mudflap reports read violations for the same program. Valgrind on i386 doesn't report any problems except still allocated memory (which is ok). My own malloc hooks (implemented according to http://www.gnu.org/software/libc/manual/html_mono/libc.html#Hooks-for-Malloc) that add a pointer to a list when it is allocated, and removing after it is deallocated, do not detect any problems on arm-linux. On the target, I'm using Linux 2.6.20 with glibc 2.3.6 and gcc 4.1.1, glibc 2.3.2 built for arm-unknown-linux-gnu with crosstool (I've tried both glibc 2.3.6 and 2.3.2 on the target, with the same result). On i386, it's gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21). Questions: 1. Is #pragma redefine_extern important for mudflap? The manual says it is implemented only for Solaris. If mudflap didn't work due to that, then I don't see how it could report any violations at all, so I assume there should be some other mechanism for arm-linux, no? 2. Do I understand correctly that unregister violation is a double free? 3. How can I debug my app? Should mudflap from 4.1.1 work on my platform, or should I use a newer version? Thanks in advance, -- Baurzhan Ismagulov http://www.kz-easy.com/
