From 8bcba7032e380b69ef8a684706473509c1bcb5f7 Mon Sep 17 00:00:00 2001
From: Rahul Chaudhry <rahulchaudhry@google.com>
Date: Sat, 17 Mar 2018 15:31:31 -0800
Subject: [PATCH 07/14] move SHT_RELR section type to the generic range.

Proposal for adding SHT_RELR sections in generic-abi is at
https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg

Experimental support for SHT_RELR sections is available in the aosp
binutils repository, with the section type and dynamic array tags
defined in the OS specific range.

This patch moves those definitions to the generic range so we can load
binaries containing SHT_RELR sections using the experimental support in
sys-libs/glibc.

SHT_RELR sections are supported for arm, aarch64, and x86_64 targets.
To enable them, pass '--experimental-use-relr' flag to gold.

Definitions for the new ELF section type and dynamic array tags, as well
as the encoding used in the new section are all under discussion and are
subject to change. We plan to send the patch upstream after the gABI has
been updated to include the new definitions.

[Adrian Ratiu: rebased from v2.27 to v2.35.1]
[Adrian Ratiu: regenerated as proper git format-patch.]

Change-Id: I933355aa2da06b7c58de2e6e7ff93798ad6eb156
---
 elfcpp/elfcpp.h      | 18 +++++++-----------
 include/elf/common.h | 17 ++++++-----------
 2 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/elfcpp/elfcpp.h b/elfcpp/elfcpp.h
index 9bbe4bfef86..a3a25de4c16 100644
--- a/elfcpp/elfcpp.h
+++ b/elfcpp/elfcpp.h
@@ -358,6 +358,7 @@ enum SHT
   SHT_PREINIT_ARRAY = 16,
   SHT_GROUP = 17,
   SHT_SYMTAB_SHNDX = 18,
+  SHT_RELR = 19,
   SHT_LOOS = 0x60000000,
   SHT_HIOS = 0x6fffffff,
   SHT_LOPROC = 0x70000000,
@@ -386,10 +387,6 @@ enum SHT
   SHT_SUNW_versym = 0x6fffffff,
   SHT_GNU_versym = 0x6fffffff,
 
-  // Experimental support for SHT_RELR sections. For details, see proposal
-  // at https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg
-  SHT_RELR = 0x6fffff00,
-
   SHT_SPARC_GOTDATA = 0x70000000,
 
   // ARM-specific section types.
@@ -725,6 +722,11 @@ enum DT
 
   DT_PREINIT_ARRAY = 32,
   DT_PREINIT_ARRAYSZ = 33,
+  DT_SYMTAB_SHNDX = 34,
+  DT_RELRSZ = 35,
+  DT_RELR = 36,
+  DT_RELRENT = 37,
+
   DT_LOOS = 0x6000000d,
   DT_HIOS = 0x6ffff000,
   DT_LOPROC = 0x70000000,
@@ -759,6 +761,7 @@ enum DT
   DT_SYMINFO = 0x6ffffeff,
   DT_ADDRRNGHI = 0x6ffffeff,
 
+  DT_RELRCOUNT = 0x6ffffff8,
   DT_RELACOUNT = 0x6ffffff9,
   DT_RELCOUNT = 0x6ffffffa,
   DT_FLAGS_1 = 0x6ffffffb,
@@ -769,13 +772,6 @@ enum DT
 
   DT_VERSYM = 0x6ffffff0,
 
-  // Experimental support for SHT_RELR sections. For details, see proposal
-  // at https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg
-  DT_RELR = 0x6fffe000,
-  DT_RELRSZ = 0x6fffe001,
-  DT_RELRENT = 0x6fffe003,
-  DT_RELRCOUNT = 0x6fffe005,
-
   // Specify the value of _GLOBAL_OFFSET_TABLE_.
   DT_PPC_GOT = 0x70000000,
 
diff --git a/include/elf/common.h b/include/elf/common.h
index 83374777d20..79c3a2fbbd5 100644
--- a/include/elf/common.h
+++ b/include/elf/common.h
@@ -506,6 +506,7 @@
 #define SHT_PREINIT_ARRAY 16		/* Array of ptrs to pre-init funcs */
 #define SHT_GROUP	  17		/* Section contains a section group */
 #define SHT_SYMTAB_SHNDX  18		/* Indices for SHN_XINDEX entries */
+#define SHT_RELR	  19		/* Relative relocations, only offsets */
 
 #define SHT_LOOS	0x60000000	/* First of OS specific semantics */
 #define SHT_HIOS	0x6fffffff	/* Last of OS specific semantics */
@@ -526,10 +527,6 @@
 #define SHT_GNU_verneed	SHT_SUNW_verneed
 #define SHT_GNU_versym	SHT_SUNW_versym
 
-/* Experimental support for SHT_RELR sections. For details, see proposal
-   at https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg */
-#define SHT_RELR	0x6fffff00	/* Relative relocations, only offsets */
-
 #define SHT_LOPROC	0x70000000	/* Processor-specific semantics, lo */
 #define SHT_HIPROC	0x7FFFFFFF	/* Processor-specific semantics, hi */
 #define SHT_LOUSER	0x80000000	/* Application-specific semantics */
@@ -988,6 +985,10 @@
 #define DT_PREINIT_ARRAY   32
 #define DT_PREINIT_ARRAYSZ 33
 #define DT_SYMTAB_SHNDX    34
+#define DT_RELRSZ          35
+#define DT_RELR            36
+#define DT_RELRENT         37
+
 
 /* Note, the Oct 4, 1999 draft of the ELF ABI changed the values
    for DT_LOOS and DT_HIOS.  Some implementations however, use
@@ -1034,6 +1035,7 @@
 #define DT_SYMINFO	0x6ffffeff
 #define DT_ADDRRNGHI	0x6ffffeff
 
+#define DT_RELRCOUNT	0x6ffffff8
 #define DT_RELACOUNT	0x6ffffff9
 #define DT_RELCOUNT	0x6ffffffa
 #define DT_FLAGS_1	0x6ffffffb
@@ -1045,13 +1047,6 @@
 /* This tag is a GNU extension to the Solaris version scheme.  */
 #define DT_VERSYM	0x6ffffff0
 
-/* Experimental support for SHT_RELR sections. For details, see proposal
-   at https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg */
-#define DT_RELR		0x6fffe000
-#define DT_RELRSZ	0x6fffe001
-#define DT_RELRENT	0x6fffe003
-#define DT_RELRCOUNT	0x6fffe005
-
 #define DT_LOPROC	0x70000000
 #define DT_HIPROC	0x7fffffff
 
-- 
2.31.1