[Crash-utility] [PATCH] crash-gcore-command extension module: ARM64 support

Hello Daisuke, Attached is a patch to introduce support for the ARM64 architecture for the gcore extension module. The patch is fairly straight-forward other than the fact that on ARM64 machines, the chain of headers included from the crash utility's "defs.h" looks like this: /usr/include/crash/defs.h /usr/include/signal.h /usr/include/sys/ucontext.h /usr/include/sys/procfs.h The <sys/procfs.h> file defines several of the ELF-related structures that are hard-coded in gcore_defs.h, causing compile failures due to duplicate structure declarations. Note that the <sys/ucontext.h> file on the other three architectures does not #include <sys/procfs.h> so there are no conflicts. It would be possible to move all architectures to include <sys/procfs.h>, but for example, that would also bring in the <sys/user.h> definition of the user_regs_struct, which in turn causes a myriad of register name mismatches in gcore_x86.c. So for the sake of simplicity, wherever there is an ARM64-only duplicate structure or definition in gcore_defs.h, I've encapsulated them by: #if defined(X86) || defined(X86_64) || defined(ARM) Also, there are two generic fixes, one where the gcore module fails on Linux 3.11 and later kernels due to a structure member name change, and another that changes the getopt() return variable to an "int" instead of a "char". Here are the details: gcore.mk: - Introduce ARM64 as a supported architecture - Add libgcore/gcore_arm64 to GCORE_CFILES gcore.c: - In cmd_gcore() change "c" type to "int" to correctly match the return type of getopt(); without it, the while loop spins indefinitely on ARM64. - In gcore_offset_table_init(), account for the Linux 3.11 structure member name-change from ns_proxy.pid_ns to ns_proxy.pid_ns_for_children; without it, the gcore command fails during initialization. libgcore/gcore_defs.h: - Add ARM64 ELF- and REGSET_VIEW-related #defines required for each architecture. - Account for variable page sizes in ARM64. - Restrict the hard-coded ELF_NGREG, elf_siginfo, elf_prstatus, __kernel_old_uid_t and __kernel_old_gid_t, and elf_prsinfo definitions to X86, X86_64 and ARM architectures. - Add ARM64 thread_struct_fpsmid_state and thread_struct_tp_value offsets to gcore_offset_table. libgcore/gcore_coredump.c: - In fill_prstatus_note(), account for the ARM64 usage of "user_pt_regs" structure instead of the "user_regs_struct" used by the other architectures. libgcore/gcore_arm64.c: - Implement ARM64-specific user_regset and user_regset_view structures and all required support functions. Please accept these changes into an new package version. Thanks, Dave