From c7aa8596de86fb667914ccb95c10495ad056ff96 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Mon, 22 Jun 2020 10:56:38 +0100 Subject: rtld: Clean up PT_NOTE and add PT_GNU_PROPERTY handling Add generic code to handle PT_GNU_PROPERTY notes. Invalid content is ignored, _dl_process_pt_gnu_property is always called after PT_LOAD segments are mapped and it has no failure modes. Currently only one NT_GNU_PROPERTY_TYPE_0 note is handled, which contains target specific properties: the _dl_process_gnu_property hook is called for each property. The old _dl_process_pt_note and _rtld_process_pt_note differ in how the program header is read. The old _dl_process_pt_note is called before PT_LOAD segments are mapped and _rtld_process_pt_note is called after PT_LOAD segments are mapped. The old _rtld_process_pt_note is removed and _dl_process_pt_note is always called after PT_LOAD segments are mapped and now it has no failure modes. The program headers are scanned backwards so that PT_NOTE can be skipped if PT_GNU_PROPERTY exists. Co-Authored-By: H.J. Lu Reviewed-by: Adhemerval Zanella --- elf/rtld.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'elf/rtld.c') diff --git a/elf/rtld.c b/elf/rtld.c index 882b070cc0..f4c2602d65 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1507,11 +1507,17 @@ of this helper program; chances are you did not intend to run this program.\n\ main_map->l_relro_addr = ph->p_vaddr; main_map->l_relro_size = ph->p_memsz; break; - + } + /* Process program headers again, but scan them backwards so + that PT_NOTE can be skipped if PT_GNU_PROPERTY exits. */ + for (ph = &phdr[phnum]; ph != phdr; --ph) + switch (ph[-1].p_type) + { case PT_NOTE: - if (_rtld_process_pt_note (main_map, ph)) - _dl_error_printf ("\ -ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); + _dl_process_pt_note (main_map, &ph[-1]); + break; + case PT_GNU_PROPERTY: + _dl_process_pt_gnu_property (main_map, &ph[-1]); break; } -- cgit v1.2.3