[Libunwind-devel] AARCH64 ILP32 support

[Krishnanjanappa, Jagadeesh]

Hello,

Recently, I tried to print unwind info of a testcase on AARCH64 ILP32 (big endian) using libunwind.
By default, the support for AARCH64 ILP32 is not present in libunwind, the attached patch adds support
to print unwind info for AARCH64 ILP32 and enables to load .debug_frame for both AARCH64 and AARCH64 ILP32 inorder to display unwind info of __start procedure.

testcase: unwind.c

#define UNW_LOCAL_ONLY
#include<libunwind.h>
#include<stdio.h>
void show_backtrace (void) {
  unw_cursor_t cursor; unw_context_t uc;
  unw_word_t ip, sp, offt;
  char name [20];

  unw_getcontext(&uc);
  unw_init_local(&cursor, &uc);
  while (unw_step(&cursor) > 0) {
    unw_get_reg(&cursor, UNW_REG_IP, &ip);
    unw_get_reg(&cursor, UNW_REG_SP, &sp);
    unw_get_proc_name(&cursor, name, 20, &offt);
    printf ("ip = %lx, sp = %lx", (long) ip, (long) sp);
    printf (", procedure = %s\n", name);
  }
}

void call_backtrace(void) {
  show_backtrace();
}

int main()
{
call_backtrace();
}

compile and excute commands on AARCH64:
gcc -mbig-endian -g -funwind-tables -I /usr/include/ -L /usr/lib64/ -lunwind -lunwind-aarch64 unwind.c -o unwind
./unwind

output:
ip = 400a5c, sp = 7fe06eea30, procedure = call_backtrace
ip = 400a70, sp = 7fe06eea40, procedure = main
ip = 7faa5d1788, sp = 7fe06eea50, procedure = __libc_start_main
ip = 40082c, sp = 7fe06eeb90, procedure = _start

Please let me know if any changes required.

Regards,
Jagadeesh

libunwind_aarch64_ILP32_support.patch
Description: libunwind_aarch64_ILP32_support.patch