From: Indu Bhagat <indu.bhagat@oracle.com>
Date: Sat, 12 Jul 2025 09:08:06 +0000 (+0200)
Subject: ld: aarch64: make EH Frame parsing aware of augmentation char 'G'
X-Git-Tag: binutils-2_45~46
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=427363b461dc40e4e03bef27d2d52623b800f312;p=thirdparty%2Fbinutils-gdb.git

ld: aarch64: make EH Frame parsing aware of augmentation char 'G'

As per the DWARF for the Arm 64-bit Architecture (AArch64)
specification, the augmentation char 'G' indicates that associated
frames may modify MTE tags on the stack space they use.

Add knowledge of the 'G' augmentation char to the EH Frame parsing
code.

ChangeLog:

        * bfd/elf-eh-frame.c (_bfd_elf_parse_eh_frame): Accommodate
	augmentation char 'G'.
        * ld/testsuite/ld-aarch64/aarch64-elf.exp: New test.
        * ld/testsuite/ld-aarch64/mte-tagged-frame-bar.s: New test.
        * ld/testsuite/ld-aarch64/mte-tagged-frame-foo.s: New test.
        * ld/testsuite/ld-aarch64/mte-tagged-frame.d: New test.
---

diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c
index aca16170a56..dc0d2e097f5 100644
--- a/bfd/elf-eh-frame.c
+++ b/bfd/elf-eh-frame.c
@@ -802,6 +802,7 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
 		switch (*aug++)
 		  {
 		  case 'B':
+		  case 'G':
 		    if (abfd->arch_info->arch != bfd_arch_aarch64)
 		      goto unrecognized;
 		    break;
diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp
index 4de498fc381..2d444e7d1e2 100644
--- a/ld/testsuite/ld-aarch64/aarch64-elf.exp
+++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp
@@ -376,6 +376,8 @@ run_dump_test_lp64 "variant_pcs-r"
 run_dump_test_lp64 "variant_pcs-shared"
 run_dump_test_lp64 "variant_pcs-now"
 
+run_dump_test_lp64 "mte-tagged-frame"
+
 set aarch64elflinktests {
   {"ld-aarch64/so with global symbol" "-shared" "" "" {copy-reloc-so.s}
     {} "copy-reloc-so.so"}
diff --git a/ld/testsuite/ld-aarch64/mte-tagged-frame-bar.s b/ld/testsuite/ld-aarch64/mte-tagged-frame-bar.s
new file mode 100644
index 00000000000..0bd56191912
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/mte-tagged-frame-bar.s
@@ -0,0 +1,17 @@
+	.text
+	.global bar
+	.type bar, %function
+bar:
+	.cfi_startproc
+	.cfi_mte_tagged_frame
+        stp     x19, x20, [sp, -144]!
+        .cfi_def_cfa_offset 144
+        .cfi_offset 19, -144
+        .cfi_offset 20, -136
+        ldp     x19, x20, [sp], 144
+        .cfi_restore 20
+        .cfi_restore 19
+        .cfi_def_cfa_offset 0
+        ret
+	.cfi_endproc
+	.size bar, .-bar
diff --git a/ld/testsuite/ld-aarch64/mte-tagged-frame-foo.s b/ld/testsuite/ld-aarch64/mte-tagged-frame-foo.s
new file mode 100644
index 00000000000..af5a8c42f95
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/mte-tagged-frame-foo.s
@@ -0,0 +1,16 @@
+	.text
+	.global foo
+	.type foo, %function
+foo:
+	.cfi_startproc
+        stp     x19, x20, [sp, -32]!
+        .cfi_def_cfa_offset 32
+        .cfi_offset 19, -32
+        .cfi_offset 20, -16
+        ldp     x19, x20, [sp], 32
+        .cfi_restore 20
+        .cfi_restore 19
+        .cfi_def_cfa_offset 0
+        ret
+	.cfi_endproc
+	.size foo, .-foo
diff --git a/ld/testsuite/ld-aarch64/mte-tagged-frame.d b/ld/testsuite/ld-aarch64/mte-tagged-frame.d
new file mode 100644
index 00000000000..dd667fe5ca7
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/mte-tagged-frame.d
@@ -0,0 +1,35 @@
+#source: mte-tagged-frame-foo.s
+#source: mte-tagged-frame-bar.s
+#ld: -shared
+#objdump: -Wf
+#name: MTE tagged EH Frame FDE
+
+#...
+Contents of the .eh_frame section:
+
+00000000 0000000000000010 00000000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+00000014 0000000000000020 00000018 FDE cie=00000000 pc=[a-f0-9]+\.\.[a-f0-9]+
+#...
+
+00000038 0000000000000014 00000000 CIE
+  Version:               1
+  Augmentation:          "zRG"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+  DW_CFA_nop
+  DW_CFA_nop
+  DW_CFA_nop
+
+00000050 000000000000001c 0000001c FDE cie=00000038 pc=[a-f0-9]+\.\.[a-f0-9]+
+#...