| Summary: | Malloc is always called by stack back strace function | ||
|---|---|---|---|
| Product: | glibc | Reporter: | H.J. Lu <hjl.tools> |
| Component: | libc | Assignee: | Ulrich Drepper <drepper.fsp> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | glibc-bugs |
| Priority: | P2 | Flags: | fweimer:
security-
|
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
I changed the comment. |
In /usr/include/execinfo.h, there are /* This function is similar to backtrace_symbols() but it writes the result immediately to a file and can therefore also be used in situations where malloc() is not usable anymore. */ extern void backtrace_symbols_fd (void *__const *__array, int __size, int __fd) __THROW __nonnull ((1)); The problem is stack bcktrace functions in glibc do dlopen (libgcc_s.so.1), which will call malloc. That is malloc will be always called no matter which function you use. Even if you build the executable with -shared-libgcc, dl_open_worker will call dl_map_object_deps which will call malloc. What dl_open_worker should do when a DSO to be dlopened is already on the DT_NEEDED list in the executable?