[gcc r15-4842] Always set SECTION_RELRO for or .data.rel.ro{, .local} [PR116887]

[Xi Ruoyao via Gcc-cvs]

https://gcc.gnu.org/g:c8d35f2ecbf124bdd164dbb1c36de9d90695843b

commit r15-4842-gc8d35f2ecbf124bdd164dbb1c36de9d90695843b
Author: Xi Ruoyao <xry...@xry111.site>
Date:   Fri Oct 11 02:44:27 2024 +0800

    Always set SECTION_RELRO for or .data.rel.ro{,.local} [PR116887]
    
    At least two ports (hppa and loongarch) need to set SECTION_RELRO for
    .data.rel.ro{,.local} in section_type_flags (PR52999 and PR116887), and
    I cannot see a reason not to just set it in the generic code.
    
    With this applied we can also remove the hppa-specific
    pa_section_type_flags in a future patch.
    
    gcc/ChangeLog:
    
            PR target/116887
            * varasm.cc (default_section_type_flags): Always set
            SECTION_RELRO if name is .data.rel.ro{,.local}.
    
    gcc/testsuite/ChangeLog:
    
            PR target/116887
            * gcc.dg/pr116887.c: New test.

Diff:
---
 gcc/testsuite/gcc.dg/pr116887.c | 23 +++++++++++++++++++++++
 gcc/varasm.cc                   | 10 ++++------
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/pr116887.c b/gcc/testsuite/gcc.dg/pr116887.c
new file mode 100644
index 000000000000..b7255e09a18a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr116887.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-fpic" } */
+
+struct link_map
+{
+  struct link_map *l_next;
+};
+struct rtld_global
+{
+  struct link_map *_ns_loaded;
+  char buf[4096];
+  struct link_map _dl_rtld_map;
+};
+extern struct rtld_global _rtld_global;
+static int _dlfo_main __attribute__ ((section (".data.rel.ro"), used));
+void
+_dlfo_process_initial (int ns)
+{
+  for (struct link_map *l = _rtld_global._ns_loaded; l != ((void *)0);
+       l = l->l_next)
+    if (l == &_rtld_global._dl_rtld_map)
+      asm ("");
+}
diff --git a/gcc/varasm.cc b/gcc/varasm.cc
index deefbac5b7b2..0712b4860294 100644
--- a/gcc/varasm.cc
+++ b/gcc/varasm.cc
@@ -6884,6 +6884,9 @@ default_section_type_flags (tree decl, const char *name, 
int reloc)
 
   if (decl && TREE_CODE (decl) == FUNCTION_DECL)
     flags = SECTION_CODE;
+  else if (strcmp (name, ".data.rel.ro") == 0
+          || strcmp (name, ".data.rel.ro.local") == 0)
+    flags = SECTION_WRITE | SECTION_RELRO;
   else if (decl)
     {
       enum section_category category
@@ -6897,12 +6900,7 @@ default_section_type_flags (tree decl, const char *name, 
int reloc)
        flags = SECTION_WRITE;
     }
   else
-    {
-      flags = SECTION_WRITE;
-      if (strcmp (name, ".data.rel.ro") == 0
-         || strcmp (name, ".data.rel.ro.local") == 0)
-       flags |= SECTION_RELRO;
-    }
+    flags = SECTION_WRITE;
 
   if (decl && DECL_P (decl) && DECL_COMDAT_GROUP (decl))
     flags |= SECTION_LINKONCE;