git: 6ee34bca48a9 - main - crtbegin: accurately check for the end of .dtors

[Konstantin Belousov]

The branch main has been updated by kib:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=6ee34bca48a9e0867d46b24a78855e225d46ddda

commit 6ee34bca48a9e0867d46b24a78855e225d46ddda
Author:     Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2025-01-27 19:21:20 +0000
Commit:     Konstantin Belousov <k...@freebsd.org>
CommitDate: 2025-01-28 22:59:20 +0000

    crtbegin: accurately check for the end of .dtors
    
    not relying only on the end section marker, but also checking for the
    section size when iterating.
    
    Reported by:    kargl
    Analyzed by:    dim
    Reviewed by:    andrew, dim
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D48700
---
 lib/csu/common/crtbegin.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/csu/common/crtbegin.c b/lib/csu/common/crtbegin.c
index d6978859af4a..06fe990052f7 100644
--- a/lib/csu/common/crtbegin.c
+++ b/lib/csu/common/crtbegin.c
@@ -66,19 +66,27 @@ static crt_func __DTOR_LIST__[] __section(".dtors") __used 
= {
        (crt_func)-1
 };
 
+extern const char startof_dtors[] __asm(".startof..dtors")
+    __weak_symbol __hidden;
+extern const char sizeof_dtors[] __asm(".sizeof..dtors")
+    __weak_symbol __hidden;
+
 static void
 __do_global_dtors_aux(void)
 {
        crt_func fn;
+       uintptr_t dtors_end;
        int n;
 
 #ifdef SHARED
        run_cxa_finalize();
 #endif
 
+       dtors_end = (uintptr_t)&startof_dtors + (uintptr_t)&sizeof_dtors;
        for (n = 1;; n++) {
                fn = __DTOR_LIST__[n];
-               if (fn == (crt_func)0 || fn == (crt_func)-1)
+               if (fn == (crt_func)0 || fn == (crt_func)-1 || (dtors_end > 0 &&
+                   (uintptr_t)&__DTOR_LIST__[n] >= dtors_end))
                        break;
                fn();
        }