build-id - Example code for reading an ELF binary's .note.gnu.build-id section, from the program itself

Age	Commit message (Collapse)	Author
2020-06-24	Remove usage of bash '&>' redirection	Neil Roza
	On systems where /bin/sh is dash, this would lead to empty .expected and .results files and thus make check would always succeed. Closes: #1
2020-03-28	README.md: Wordsmithing, formatting improvements	Matt Turner

2020-03-25	Add README.MD and LICENSE	Matt Turner

2020-03-24	Always build with -fPIC	Matt Turner
	The dladdr(3) explains that dladdr often doesn't do what you expect because the function pointer will point to the PLT entry in the original object and not the actual function itself.
2019-04-25	Test that by_symbol returns the same nhdr as by_name	Matt Turner

2019-04-25	Fix address comparison for binaries with LOAD vaddr > 0	Matt Turner
	Cherry-picked from Mesa commit 02e2009b929a (util/build-id: Fix address comparison for binaries with LOAD vaddr > 0) by Stephan Gerhold.
2019-04-25	Add a program using dlopen	Matt Turner

2019-04-25	Add a check target to the Makefile	Matt Turner

2017-11-25	Add macros to build on OpenBSD	Matt Turner
	From upstream Mesa commit a042465c218e ("util/build-id: define ElfW and NT_GNU_BUILD_ID if needed")
2017-11-24	Add build_id_find_nhdr_by_symbol()	Matt Turner

2017-11-24	Add "by_name" to function name	Matt Turner
	In preparation for adding a "by_symbol" equivalent.
2017-11-24	Simplify code structure to match upstream Mesa	Matt Turner

2017-11-24	Rename "note" to "build_id_note" to avoid potential collisions	Matt Turner

2017-11-24	Change API to match upstream Mesa	Matt Turner

2017-11-24	Add .gitignore	Matt Turner

2017-02-14	Remove unused headers.	Matt Turner

2016-12-14	Use dl_iterate_phdr() instead of a linker script.	Matt Turner
	According to Mike Frysinger [1] it is not reliable to read ELF sections at runtime, which the previous method involving the linker script was doing. Instead, use dl_iterate_phdr() to find the build id. [1] https://sourceware.org/ml/binutils/2016-12/msg00207.html
2016-12-08	Make the linker script work.	Matt Turner
	Previously the build-id program (which was reading its own build-id worked) but the so-build-id program (was was reading the linked DSO's build id) did not. I speculated that the __note_gnu_build_id_start symbol was not being relocated properly since its address in the DSO was somewhat before the .text section, while the __note_gnu_build_id_end symbol was correct. I could even read the build-id which ended at the end symbol. I noticed that in the output of "ld --verbose" that there is only a ".interp" section immediately before .note.gnu.build-id, while in "ld --verbose -shared" there is nothing before .note.gnu.build-id. I think that probably points to the problem, but I am not sure exactly what it is.
2016-12-08	Initial commit	Matt Turner