When CONFIG_MCHECK_HEAP_PROTECTION is enabled, use backtrace_str() to
capture the caller information for each malloc/calloc/realloc/memalign
call. This information is stored in the mcheck header and can be viewed
with 'malloc dump'.
Add a flag to disable the backtrace when the stack is corrupted, since
the backtrace code tries to walks the invalid stack frames and will
crash.
Note: A few allocations made during libbacktrace initialisation may
not have caller info since they occur during the first backtrace call.
Example output showing caller info:
18a1d010 90 used log_init:453 <-board_init_r:774
18a1d0a0 6060 used membuf_new:420 <-console_record
18a3b840 90 used of_alias_scan:911 <-board_init_
Fix up the backtrace test to avoid recursion.
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
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>
