package/elf2flt/0002-elf2flt-fix-relocations-for-read-only-data.patch

From 6006e8d789f7a1129414fb3a8c930b094af0cafa Mon Sep 17 00:00:00 2001
From: Greg Ungerer <gerg@kernel.org>
Date: Wed, 6 Nov 2019 21:19:24 +0100
Subject: [PATCH] elf2flt: fix relocations for read-only data

Readonly data sections are mapped into the "text" section in the
elf2flt.ld linker script. The relocation generation code is not handling
that case properly though, and is actually mapping any data section type
into the "data" section of the target binary.

This problem case has been detected with elf2flt core dumping when used
with binutils-2.33.1 (on ARM architecture targets). See thread at:

   https://sourceware.org/ml/binutils/2019-10/msg00132.html

Tested by Christophe Priouzeau [1]

* binutils 2.33.1
* buildroot 2019.11-rc1
* patch on top of elf2flt (patch available on this thread)
* configuration: stm32f469-disco with initramfs configuration on buildroot

Result:
Build: OK, all the binaries are generated
Runtime test on stm32f469-disco: OK

[1] https://github.com/uclinux-dev/elf2flt/issues/12

Signed-off-by: Greg Ungerer <gerg@kernel.org>
Signed-off-by: Romain Naour <romain.naour@smile.fr>
Cc: Christophe Priouzeau <christophe.priouzeau@st.com>
---
 elf2flt.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/elf2flt.c b/elf2flt.c
index 67f720a..8973cef 100644
--- a/elf2flt.c
+++ b/elf2flt.c
@@ -418,10 +418,12 @@ output_relocs (
 //		continue;
 
 	/*
-	 *	Only relocate things in the data sections if we are PIC/GOT.
-	 *	otherwise do text as well
+	 * Only relocate things in the writable data sections if we are PIC/GOT.
+	 * Otherwise do text (and read only data) as well.
 	 */
-	if ((!pic_with_got || ALWAYS_RELOC_TEXT) && (a->flags & SEC_CODE))
+	if ((!pic_with_got || ALWAYS_RELOC_TEXT) &&
+	    ((a->flags & SEC_CODE) ||
+	    ((a->flags & (SEC_DATA | SEC_READONLY)) == (SEC_DATA | SEC_READONLY))))
 		sectionp = text + (a->vma - text_vma);
 	else if (a->flags & SEC_DATA)
 		sectionp = data + (a->vma - data_vma);
-- 
2.21.0