The branch main has been updated by dchagin:
URL:
https://cgit.FreeBSD.org/src/commit/?id=f049c92ad6c38ef42265956545897d8e3be1c228
commit f049c92ad6c38ef42265956545897d8e3be1c228
Author: Dmitry Chagin <dcha...@freebsd.org>
AuthorDate: 2023-07-01 07:52:10 +0000
Commit: Dmitry Chagin <dcha...@freebsd.org>
CommitDate: 2023-07-01 07:52:10 +0000
csu: Add the prologue and epilogue to the _init and _fini on x86_64
Normally, modern unwinders uses Dwarf information to unwind stack,
however in case when the code is not annotated by Dwarf instructions,
unwinders fallbacks to a frame-pointer based algorithm.
That is allows libunwind to unwind stack from global constructors and
destructors. Also it makes gdb happy as it printed nonexistent frame
before.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40795
---
lib/csu/amd64/crti.S | 6 ++++--
lib/csu/amd64/crtn.S | 4 ++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/lib/csu/amd64/crti.S b/lib/csu/amd64/crti.S
index 618dca178877..05b8ad8a431a 100644
--- a/lib/csu/amd64/crti.S
+++ b/lib/csu/amd64/crti.S
@@ -31,13 +31,15 @@ __FBSDID("$FreeBSD$");
.globl _init
.type _init,@function
_init:
- subq $8,%rsp
+ pushq %rbp
+ movq %rsp,%rbp
.section .fini,"ax",@progbits
.align 4
.globl _fini
.type _fini,@function
_fini:
- subq $8,%rsp
+ pushq %rbp
+ movq %rsp,%rbp
.section .note.GNU-stack,"",%progbits
diff --git a/lib/csu/amd64/crtn.S b/lib/csu/amd64/crtn.S
index c411f001ac1f..50b5003b9f7c 100644
--- a/lib/csu/amd64/crtn.S
+++ b/lib/csu/amd64/crtn.S
@@ -27,11 +27,11 @@
__FBSDID("$FreeBSD$");
.section .init,"ax",@progbits
- addq $8,%rsp
+ popq %rbp
ret
.section .fini,"ax",@progbits
- addq $8,%rsp
+ popq %rbp
ret
.section .note.GNU-stack,"",%progbits
