mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-15 23:25:07 +00:00
ed13fc33f7
This change allows growing struct kernel_symbol without wasting bytes to alignment. It also concretized the alignment of ksymtab entries if relative references are used for ksymtab entries. struct kernel_symbol was already implicitly being aligned to the word size, except on x86_64 and m68k, where it is aligned to 16 and 2 bytes, respectively. As far as I can tell there is no requirement for aligning struct kernel_symbol to 16 bytes on x86_64, but gcc aligns structs to their size, and the linker aligns the custom __ksymtab sections to the largest data type contained within, so setting KSYM_ALIGN to 16 was necessary to stay consistent with the code generated for non-ASM EXPORT_SYMBOL(). Now that non-ASM EXPORT_SYMBOL() explicitly aligns to word size (8), KSYM_ALIGN is no longer necessary. In case of relative references, the alignment has been changed accordingly to not waste space when adding new struct members. As for m68k, struct kernel_symbol is aligned to 2 bytes even though the structure itself is 8 bytes; using a 4-byte alignment shouldn't hurt. I manually verified the output of the __ksymtab sections didn't change on x86, x86_64, arm, arm64 and m68k. As expected, the section contents didn't change, and the ELF section alignment only changed on x86_64 and m68k. Feedback from other archs more than welcome. Co-developed-by: Martijn Coenen <maco@android.com> Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> |
||
|---|---|---|
| .. | ||
| 68000 | ||
| amiga | ||
| apollo | ||
| atari | ||
| bvme6000 | ||
| coldfire | ||
| configs | ||
| emu | ||
| fpsp040 | ||
| hp300 | ||
| ifpsp060 | ||
| include | ||
| kernel | ||
| lib | ||
| mac | ||
| math-emu | ||
| mm | ||
| mvme16x | ||
| mvme147 | ||
| q40 | ||
| sun3 | ||
| sun3x | ||
| tools/amiga | ||
| install.sh | ||
| Kconfig | ||
| Kconfig.bus | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Kconfig.devices | ||
| Kconfig.machine | ||
| Makefile | ||