gas: Allow SHF_GNU_RETAIN on all sections

Since SHF_GNU_RETAIN is allowed on all sections, strip SHF_GNU_RETAIN
when checking incorrect section attributes.

	PR gas/27412
	* config/obj-elf.c (obj_elf_change_section): Strip SHF_GNU_RETAIN
	when checking incorrect section attributes.
	* testsuite/gas/elf/elf.exp: Run section28 and section29.
	* testsuite/gas/elf/section28.d: New file.
	* testsuite/gas/elf/section28.s: Likewise.
	* testsuite/gas/elf/section29.d: Likewise.
	* testsuite/gas/elf/section29.s: Likewise.

7 files changed, 66 insertions, 6 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 7978254..87fa8e7 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,14 @@
+2021-02-16  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/27412
+	* config/obj-elf.c (obj_elf_change_section): Strip SHF_GNU_RETAIN
+	when checking incorrect section attributes.
+	* testsuite/gas/elf/elf.exp: Run section28 and section29.
+	* testsuite/gas/elf/section28.d: New file.
+	* testsuite/gas/elf/section28.s: Likewise.
+	* testsuite/gas/elf/section29.d: Likewise.
+	* testsuite/gas/elf/section29.s: Likewise.
+
 2021-02-16  Jan Beulich  <jbeulich@suse.com>
 
 	* testsuite/gas/i386/sse-check.s,
diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
index f52dc69..2fb8ccd 100644
--- a/gas/config/obj-elf.c
+++ b/gas/config/obj-elf.c
@@ -667,39 +667,45 @@ obj_elf_change_section (const char *name,
 					| SHF_MASKPROC))
 			      & ~ssect->attr) != 0)
 	{
+	  /* Strip SHF_GNU_RETAIN.  */
+	  bfd_vma generic_attr = attr;
+	  if (elf_tdata (stdoutput)->has_gnu_osabi)
+	    generic_attr &= ~SHF_GNU_RETAIN;
+
 	  /* As a GNU extension, we permit a .note section to be
 	     allocatable.  If the linker sees an allocatable .note
 	     section, it will create a PT_NOTE segment in the output
 	     file.  We also allow "x" for .note.GNU-stack.  */
 	  if (ssect->type == SHT_NOTE
-	      && (attr == SHF_ALLOC || attr == SHF_EXECINSTR))
+	      && (generic_attr == SHF_ALLOC
+		  || generic_attr == SHF_EXECINSTR))
 	    ;
 	  /* Allow different SHF_MERGE and SHF_STRINGS if we have
 	     something like .rodata.str.  */
 	  else if (ssect->suffix_length == -2
 		   && name[ssect->prefix_length] == '.'
-		   && (attr
+		   && (generic_attr
 		       & ~ssect->attr
 		       & ~SHF_MERGE
 		       & ~SHF_STRINGS) == 0)
 	    ;
 	  /* .interp, .strtab and .symtab can have SHF_ALLOC.  */
-	  else if (attr == SHF_ALLOC
+	  else if (generic_attr == SHF_ALLOC
 		   && (strcmp (name, ".interp") == 0
 		       || strcmp (name, ".strtab") == 0
 		       || strcmp (name, ".symtab") == 0))
 	    override = TRUE;
 	  /* .note.GNU-stack can have SHF_EXECINSTR.  */
-	  else if (attr == SHF_EXECINSTR
+	  else if (generic_attr == SHF_EXECINSTR
 		   && strcmp (name, ".note.GNU-stack") == 0)
 	    override = TRUE;
 #ifdef TC_ALPHA
 	  /* A section on Alpha may have SHF_ALPHA_GPREL.  */
-	  else if ((attr & ~ssect->attr) == SHF_ALPHA_GPREL)
+	  else if ((generic_attr & ~ssect->attr) == SHF_ALPHA_GPREL)
 	    override = TRUE;
 #endif
 #ifdef TC_RX
-	  else if (attr == (SHF_EXECINSTR | SHF_WRITE | SHF_ALLOC)
+	  else if (generic_attr == (SHF_EXECINSTR | SHF_WRITE | SHF_ALLOC)
 		   && (ssect->type == SHT_INIT_ARRAY
 		       || ssect->type == SHT_FINI_ARRAY
 		       || ssect->type == SHT_PREINIT_ARRAY))
diff --git a/gas/testsuite/gas/elf/elf.exp b/gas/testsuite/gas/elf/elf.exp
index 2917ea9..525f47c 100644
--- a/gas/testsuite/gas/elf/elf.exp
+++ b/gas/testsuite/gas/elf/elf.exp
@@ -273,6 +273,8 @@ if { [is_elf_format] } then {
     run_dump_test "section25"
     run_dump_test "section26"
     run_dump_test "section27"
+    run_dump_test "section28"
+    run_dump_test "section29"
     run_dump_test "sh-link-zero"
     run_dump_test "dwarf2-1" $dump_opts
     run_dump_test "dwarf2-2" $dump_opts
diff --git a/gas/testsuite/gas/elf/section28.d b/gas/testsuite/gas/elf/section28.d
new file mode 100644
index 0000000..a1fd65b
--- /dev/null
+++ b/gas/testsuite/gas/elf/section28.d
@@ -0,0 +1,15 @@
+#readelf: -h -S --wide
+#name: SHF_GNU_RETAIN sections 28
+#notarget: ![supports_gnu_osabi]
+
+#...
+ +OS/ABI: +UNIX - (GNU|FreeBSD)
+#...
+  \[..\] \.note\.Linux +NOTE +[0-9a-f]+ [0-9a-f]+ [0-9a-f]+ 00 +A +0.*
+#...
+  \[..\] \.note\.Linux +NOTE +[0-9a-f]+ [0-9a-f]+ [0-9a-f]+ 00 +AR +0.*
+#...
+  \[..\] \.note\.foo +NOTE +[0-9a-f]+ [0-9a-f]+ [0-9a-f]+ 00 +0 +.*
+#...
+  \[..\] \.note\.foo +NOTE +[0-9a-f]+ [0-9a-f]+ [0-9a-f]+ 00 +R +0 +.*
+#pass
diff --git a/gas/testsuite/gas/elf/section28.s b/gas/testsuite/gas/elf/section28.s
new file mode 100644
index 0000000..ebcf42c
--- /dev/null
+++ b/gas/testsuite/gas/elf/section28.s
@@ -0,0 +1,11 @@
+	.section	.note.Linux,"a"
+	.word	1
+
+	.section	.note.Linux,"aR"
+	.word	1
+
+	.section	.note.foo
+	.word	1
+
+	.section	.note.foo,"R"
+	.word	1
diff --git a/gas/testsuite/gas/elf/section29.d b/gas/testsuite/gas/elf/section29.d
new file mode 100644
index 0000000..7e1b482
--- /dev/null
+++ b/gas/testsuite/gas/elf/section29.d
@@ -0,0 +1,11 @@
+#readelf: -h -S --wide
+#name: SHF_GNU_RETAIN sections 29
+#notarget: ![supports_gnu_osabi]
+
+#...
+ +OS/ABI: +UNIX - (GNU|FreeBSD)
+#...
+  \[..\] \.rodata\.str1\.1 +PROGBITS +[0-9a-f]+ [0-9a-f]+ 0+4 +01 +AMS +0 +0 +1
+#...
+  \[..\] \.rodata\.str1\.1 +PROGBITS +[0-9a-f]+ [0-9a-f]+ 0+4 +01 +AMSR +0 +0 +1
+#pass
diff --git a/gas/testsuite/gas/elf/section29.s b/gas/testsuite/gas/elf/section29.s
new file mode 100644
index 0000000..772031e
--- /dev/null
+++ b/gas/testsuite/gas/elf/section29.s
@@ -0,0 +1,4 @@
+	.section	.rodata.str1.1,"aMS",%progbits,1
+	.asciz "foo"
+	.section	.rodata.str1.1,"aMSR",%progbits,1
+	.asciz "bar"