Re: [Crash-utility] question about kernel module dwarf unwinder support

Hi All, We have ported crash-utility to TileGX arch and it generally works well. For stack backtrace, we are using dwarf based approach and using .debug_frame section. Currently, the problem is letting dwarf unwinder support kernel module (.ko), we have work out this problem by quite ugly way: * we modified target independent code in kernel.c to invoke new added tilegx hook "tilegx_add_module_unwind_table" for "mod -s" command. diff --git a/kernel.c b/kernel.c index 3fc0b68..5f3f2ef 100755 --- a/kernel.c +++ b/kernel.c @@ -3760,6 +3760,10 @@ do_module_cmd(ulong flag, char *modref, ulong address, break; case LOAD_SPECIFIED_MODULE_SYMBOLS: + #ifdef TILEGX + if (!tilegx_add_module_unwind_table(modref, objfile, address)) + error(FATAL, "cannot load debug frame from: %s\n", objfile); + #endif * in "tilegx_add_module_unwind_table" we parse .ko file, locate .debug_frame/.rela.debug_frame, perform relocation on .debug_frame, then add the relocated .debug_frame to module unwind table list. then later, the if the pc is in module address space, then module unwind table list will be searched instead of kernel unwinder table. I don't know if this approach will be accepted by the community when we return all our TileGX backend. Are there any better approach to support kernel module dwarf unwinding that will not affect the target-indepent code? thanks in advance.