Add today dumping of stack frame sizes to my dwarfdump (well, where they are exists). Format of .debug_frame section obviously was invented by martian misantrophes so patch is huge and ugly
Sample of output for some random function from mips kernel:
// Addr 0x183D27C .text
// Frame Size 18
// FileName: drivers/char/random.c
// LocalVars:
// LVar0, tag 6965A71
// int ret
// LVar1, tag 6965A8F
// bool branch
ssize_t random_read_iter(struct kiocb* kiocb,struct iov_iter* iter);
and the same in JSON format:
"110516780":{"type":"function","file":"drivers/char/random.c","type_id":"110427157","name":"random_read_iter","addr":"25416316","section":".text","frame_size":"24","params":[{"name":"kiocb","id":"110516807","type_id":"110466611"},{"name":"iter","id":"110516828","type_id":"110470510"}],"lvars":["110516849":{"type":"var","file":"drivers/char/random.c","owner":"110516780","type_id":"110426600","name":"ret"},
"110516879":{"type":"var","file":"drivers/char/random.c","owner":"110516780","type_id":"110427073","name":"branch"}]}
Unfortunately dwarfdump can't work with kernel modules bcs they are actually just object files and for this sad reason they have relocations even for debug sections. So to properly deal with this files I need to apply relocations first and this is arch-specific action (which I prefer to avoid)
Binutils has 2 solution of this problem:
- objcopy calls bfd_simple_get_relocated_section_contents from libbfd.so and this means that tool should have dependency from it
- readelf has it's own relocation code in apply_relocations and this is huge pile of code
And I really don’t like both of the above approaches