| Alexey Dobriyan | 5c2c34a | 2023-04-15 20:37:29 +0300 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | ================================= |
| 4 | Linux-specific ELF idiosyncrasies |
| 5 | ================================= |
| 6 | |
| 7 | Definitions |
| 8 | =========== |
| 9 | |
| 10 | "First" program header is the one with the smallest offset in the file: |
| 11 | e_phoff. |
| 12 | |
| 13 | "Last" program header is the one with the biggest offset in the file: |
| 14 | e_phoff + (e_phnum - 1) * sizeof(Elf_Phdr). |
| 15 | |
| 16 | PT_INTERP |
| 17 | ========= |
| 18 | |
| 19 | First PT_INTERP program header is used to locate the filename of ELF |
| 20 | interpreter. Other PT_INTERP headers are ignored (since Linux 2.4.11). |
| 21 | |
| 22 | PT_GNU_STACK |
| 23 | ============ |
| 24 | |
| 25 | Last PT_GNU_STACK program header defines userspace stack executability |
| 26 | (since Linux 2.6.6). Other PT_GNU_STACK headers are ignored. |
| 27 | |
| 28 | PT_GNU_PROPERTY |
| 29 | =============== |
| 30 | |
| 31 | ELF interpreter's last PT_GNU_PROPERTY program header is used (since |
| 32 | Linux 5.8). If interpreter doesn't have one, then the last PT_GNU_PROPERTY |
| 33 | program header of an executable is used. Other PT_GNU_PROPERTY headers |
| 34 | are ignored. |
