Replace the dynamic allocation in os_backtrace_symbols() with a static
buffer embedded in struct backtrace_ctx. This avoids malloc recursion
when backtrace is called from within dlmalloc (e.g., for the upcoming
mcheck caller-tracking).
The API gets a complete rework as part of this:
- Combine addrs[] and syms[] arrays into struct backtrace_frame with
addr and sym fields
- Store the strings in a unified buffer, with pointers from an array
- Change os_backtrace_symbols() to take ctx pointer and fill sym_buf
- Remove os_backtrace_symbols_free() as nothing needs freeing
- Rename BACKTRACE_MAX to BACKTRACE_MAX_FRAMES
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
e1e95b2887