package/elf2flt: fix fatal error regression on m68k, xtensa, riscv64

This series fixes a fatal error at link time on m68k, xtensa,
and riscv64, caused by a bad upstream elf2flt commit.

Without this patch, m68k, xtensa, and riscv64 would result in
a fatal error:
ERROR: text=0x3bab8 overlaps data=0x33f60 ?

With this patch, qemu_m68k_mcf5208_defconfig,
qemu_riscv64_nommu_virt_defconfig, and
qemu_xtensa_lx60_nommu_defconfig builds properly.

riscv64 and m68k boots to login prompt.
xtensa crashes when loading init, the same behavior as when
reverting the bad upstream elf2flt commit completely.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 9dd179d43ffe9be98035f921a0db2bf051b632fb)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/elf2flt/0004-elf2flt-create-a-common-helper-function.patch

@@ -0,0 +1,76 @@
+From 37e1e0ace8ccebf54ec2f5522bfc1f9db86946ad Mon Sep 17 00:00:00 2001
+From: Niklas Cassel <niklas.cassel@wdc.com>
+Date: Tue, 9 Aug 2022 12:13:50 +0200
+Subject: [PATCH] elf2flt: create a common helper function
+
+In order to make the code more maintainable,
+move duplicated code to a common helper function.
+
+No functional change intended.
+
+Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
+---
+ elf2flt.c | 19 +++++++++++--------
+ 1 file changed, 11 insertions(+), 8 deletions(-)
+
+diff --git a/elf2flt.c b/elf2flt.c
+index 669591e..9c32f9a 100644
+--- a/elf2flt.c
++++ b/elf2flt.c
+@@ -337,6 +337,13 @@ compare_relocs (const void *pa, const void *pb)
+ }
+ #endif
+ 
++static bool
++ro_reloc_data_section_should_be_in_text(asection *s)
++{
++  return (s->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
++	  (SEC_DATA | SEC_READONLY | SEC_RELOC);
++}
++
+ static uint32_t *
+ output_relocs (
+   bfd *abs_bfd,
+@@ -428,8 +435,7 @@ output_relocs (
+ 	 */
+ 	if ((!pic_with_got || ALWAYS_RELOC_TEXT) &&
+ 	    ((a->flags & SEC_CODE) ||
+-	    ((a->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
+-		         (SEC_DATA | SEC_READONLY | SEC_RELOC))))
++	     ro_reloc_data_section_should_be_in_text(a)))
+ 		sectionp = text + (a->vma - text_vma);
+ 	else if (a->flags & SEC_DATA)
+ 		sectionp = data + (a->vma - data_vma);
+@@ -1893,8 +1899,7 @@ int main(int argc, char *argv[])
+     bfd_vma sec_vma;
+ 
+     if ((s->flags & SEC_CODE) ||
+-       ((s->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
+-                    (SEC_DATA | SEC_READONLY | SEC_RELOC))) {
++	ro_reloc_data_section_should_be_in_text(s)) {
+       vma = &text_vma;
+       len = &text_len;
+     } else if (s->flags & SEC_DATA) {
+@@ -1932,8 +1937,7 @@ int main(int argc, char *argv[])
+    * data sections.*/
+   for (s = abs_bfd->sections; s != NULL; s = s->next)
+     if ((s->flags & SEC_CODE) ||
+-       ((s->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
+-                    (SEC_DATA | SEC_READONLY | SEC_RELOC)))
++	ro_reloc_data_section_should_be_in_text(s))
+       if (!bfd_get_section_contents(abs_bfd, s,
+ 				   text + (s->vma - text_vma), 0,
+ 				   bfd_section_size(abs_bfd, s)))
+@@ -1962,8 +1966,7 @@ int main(int argc, char *argv[])
+    * data sections already included in the text output section.*/
+   for (s = abs_bfd->sections; s != NULL; s = s->next)
+     if ((s->flags & SEC_DATA) &&
+-       ((s->flags & (SEC_READONLY | SEC_RELOC)) !=
+-                    (SEC_READONLY | SEC_RELOC)))
++	!ro_reloc_data_section_should_be_in_text(s))
+       if (!bfd_get_section_contents(abs_bfd, s,
+ 				   data + (s->vma - data_vma), 0,
+ 				   bfd_section_size(abs_bfd, s)))
+-- 
+2.37.1
+

package/elf2flt/0005-elf2flt-fix-fatal-error-regression-on-m68k-xtensa-ri.patch

@@ -0,0 +1,73 @@
+From 65ac5f9e69cfb989d970da74c41e478774d29be5 Mon Sep 17 00:00:00 2001
+From: Niklas Cassel <niklas.cassel@wdc.com>
+Date: Tue, 9 Aug 2022 21:06:05 +0200
+Subject: [PATCH] elf2flt: fix fatal error regression on m68k, xtensa,
+ riscv64
+
+Commit ba379d08bb78 ("elf2flt: fix for segfault on some ARM ELFs")
+changed the condition of which input sections that should be included
+in the .text output section from:
+((a->flags & (SEC_DATA | SEC_READONLY)) == (SEC_DATA | SEC_READONLY))
+to:
+((a->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
+(SEC_DATA | SEC_READONLY | SEC_RELOC))
+
+On ARM, the .eh_frame input section does not have the SEC_RELOC flag
+set, so this specific change had no effect on ARM.
+
+However, on e.g. m68k and riscv64, the .eh_frame input section does
+have the SEC_RELOC flag set, which means that after commit ba379d08bb78
+("elf2flt: fix for segfault on some ARM ELFs"), read-only relocation
+data sections were placed in .text output section, instead of .data
+output section.
+
+This will result in a fatal error on m68k, xtensa and riscv64:
+ERROR: text=0x3bab8 overlaps data=0x33f60 ?
+
+This is because elf2flt cannot append to .text after .data has been
+appended to.
+
+Note that the binutils maintainer says that the correct thing is
+to put read-only relocation data sections in .text:
+https://sourceware.org/legacy-ml/binutils/2019-10/msg00132.html
+
+So the proper fix is probably to rewrite elf2flt so that it can append
+to .text after .data has been appended to (which will require elf2flt
+to move/relocate everything that has already been appended to .data,
+since the virtual addresses are contiguous).
+
+However, for now, add an exception for m68k, xtensa and riscv64
+(specifically for the problematic input section, .eh_frame), so that we
+get the same behavior as older elf2flt releases, where we put read-only
+relocation data in .data, which was working perfectly fine.
+
+Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
+---
+ elf2flt.c | 11 +++++++++--
+ 1 file changed, 9 insertions(+), 2 deletions(-)
+
+diff --git a/elf2flt.c b/elf2flt.c
+index 9c32f9a..a680c89 100644
+--- a/elf2flt.c
++++ b/elf2flt.c
+@@ -340,8 +340,15 @@ compare_relocs (const void *pa, const void *pb)
+ static bool
+ ro_reloc_data_section_should_be_in_text(asection *s)
+ {
+-  return (s->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
+-	  (SEC_DATA | SEC_READONLY | SEC_RELOC);
++  if ((s->flags & (SEC_DATA | SEC_READONLY | SEC_RELOC)) ==
++      (SEC_DATA | SEC_READONLY | SEC_RELOC)) {
++#if defined(TARGET_m68k) || defined(TARGET_riscv64) || defined(TARGET_xtensa)
++    if (!strcmp(".eh_frame", s->name))
++      return false;
++#endif
++    return true;
++  }
++  return false;
+ }
+ 
+ static uint32_t *
+-- 
+2.37.1
+