kernel: Fix defining of .init_array and .fini_array sections

These input sections can have decimal numbers as the priority suffix.
Clang emits the '%u' form, while SORT is an alias for SORT_BY_NAME,
hence will result in wrong order of constructors / destructors in
output sections. Fix by using the correct sorting command
SORT_BY_INIT_PRIORITY instead [1].

The functions referenced by section .fini_array is in the normal order,
but been executed in the reverse order. The order is same with
.init_array section.

Currently these sections are not used, there should be no functional
change.

Note: As for the .ctors and .dtors sections, both Clang and GCC emit
the priority suffix in the form of '%05u', so there is no semantic
difference between SORT_BY_NAME and SORT_BY_INIT_PRIORITY for those
sections [2].

This fix is extracted from a bigger patch [3] of hselasky, with
additional fix for .fini_array section.

1. https://sourceware.org/binutils/docs/ld/Input-Section-Wildcards.html
2. https://reviews.llvm.org/D91187
3. https://reviews.freebsd.org/D40467

Reviewed by:	imp (previous version)
Obtained from:	hselasky
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D45194

(cherry picked from commit e15b5ba77d693609c9a452d1b0a1cdd5eb29350d)
This commit is contained in:
Zhenlei Huang 2024-09-02 12:26:47 +08:00
parent 08a7825f05
commit 1d94490aee
2 changed files with 4 additions and 4 deletions

View file

@ -93,15 +93,15 @@ SECTIONS
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(SORT_BY_INIT_PRIORITY(.init_array.*)))
KEEP (*(.init_array))
PROVIDE_HIDDEN (__init_array_end = .);
}
.fini_array :
{
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(SORT_BY_INIT_PRIORITY(.fini_array.*)))
KEEP (*(.fini_array))
KEEP (*(SORT(.fini_array.*)))
PROVIDE_HIDDEN (__fini_array_end = .);
}
_start_ctors = .;

View file

@ -87,15 +87,15 @@ SECTIONS
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(SORT_BY_INIT_PRIORITY(.init_array.*)))
KEEP (*(.init_array))
PROVIDE_HIDDEN (__init_array_end = .);
}
.fini_array :
{
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(SORT_BY_INIT_PRIORITY(.fini_array.*)))
KEEP (*(.fini_array))
KEEP (*(SORT(.fini_array.*)))
PROVIDE_HIDDEN (__fini_array_end = .);
}
_start_ctors = .;