The branch stable/13 has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=787be9e9c32a3cf6e9999f175555bbdcb31f61f2
commit 787be9e9c32a3cf6e9999f175555bbdcb31f61f2
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2022-08-08 16:30:56 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2022-08-15 01:04:23 +0000
Merge libcxxrt commit 5d8a15823a103bbc27f1bfdcf2b5aa008fab57dd
Fix two bugs in __cxa_end_cleanup()
Per the EHABI32 specification, __cxa_end_cleanup must take care to
preserve registers before calling _Unwind_Resume(). So, libcxxrt uses
an assembly stub which preserves caller-saved registers around the call
to __cxa_get_cleanup(). But:
- it failed to restore them properly,
- it did not preserve the link register.
Fix both of these problems. This is needed to fix exception unwinding
on FreeBSD with LLVM 14. Note that r4 is callee-saved but is pushed
onto the stack to preserve stack pointer alignment.
Sponsored-by: The FreeBSD Foundation
(cherry picked from commit cbd1e83154af8bae3daa3919bb2746d587436515)
---
contrib/libcxxrt/exception.cc | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/contrib/libcxxrt/exception.cc b/contrib/libcxxrt/exception.cc
index f28082ab7e80..6c5196876b10 100644
--- a/contrib/libcxxrt/exception.cc
+++ b/contrib/libcxxrt/exception.cc
@@ -1577,8 +1577,10 @@ asm (
".type __cxa_end_cleanup, \"function\" \n"
"__cxa_end_cleanup: \n"
" push {r1, r2, r3, r4} \n"
+" mov r4, lr \n"
" bl __cxa_get_cleanup \n"
-" push {r1, r2, r3, r4} \n"
+" mov lr, r4 \n"
+" pop {r1, r2, r3, r4} \n"
" b _Unwind_Resume \n"
" bl abort \n"
".popsection \n"
