Add a new function backtrace_str() that returns a condensed backtrace
string containing function names and line numbers separated by " <-".
For example: "func_a:123 <-func_b:456 <-func_c:789"
This is useful for logging and debugging where a compact representation
of the call stack is needed. The depth is controlled by the new
CONFIG_BACKTRACE_DEPTH option (default 3).
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
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>
Display relative paths instead of absolute paths in backtrace output,
making the output cleaner and more portable across different build
environments.
This works by adding a SRCTREE define to lib/backtrace.c and stripping
it from filenames when printing.
Series-to: concept
Series-cc: heinrich
Cover-letter:
backtrace: Add runtime support for looking at the backtrace
In some cases the backtrace contains useful information, such as whether
a particular function was called earlier in the stack.
This series provides a very simple backtrace library, along with some
sandbox-specific functions to allow it to work. It is designed such that
another arch could implement it.
A new 'backtrace' command provides access to the backtrace.
END
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
Provide an API to access the backtrace, in an arch-neutral way.
The backtrace can be retrieved, examined and printed.
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
