This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH] PowerPC64: Report overflow on @h and @ha relocations


[PATCH] PowerPC64: Report overflow on @h and @ha relocations

Hello,

this patch updates glibc in accordance with the binutils patch checked in here:
https://sourceware.org/ml/binutils/2013-10/msg00372.html

This changes the various R_PPC64_..._HI and _HA relocations to report
32-bit overflows.  The motivation is that existing uses of @h / @ha
are to build up 32-bit offsets (for the "medium model" TOC access
that GCC now defaults to), and we'd really like to see failures at
link / load time rather than silent truncations.

For those rare cases where a modifier is needed to build up a 64-bit
constant, new relocations _HIGH / _HIGHA are supported.

The patch also fixes a bug in overflow checking for the R_PPC64_ADDR30
and R_PPC64_ADDR32 relocations.

Tested on powerpc64-linux and powerpc64le-linux.

OK for mainline?

Bye,
Ulrich

ChangeLog:

2013-11-12  Alan Modra  <amodra@gmail.com>

	* elf/elf.h (R_PPC64_TLSGD, R_PPC64_TLSLD, R_PPC64_TOCSAVE): Define.
	(R_PPC64_ADDR16_HIGH, R_PPC64_ADDR16_HIGHA): Likewise.
	(R_PPC64_TPREL16_HIGH, R_PPC64_TPREL16_HIGHA): Likewise.
	(R_PPC64_DTPREL16_HIGH, R_PPC64_DTPREL16_HIGHA): Likewise.

	* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela): Add
	overflow checking for R_PPC64_ADDR16_HI, R_PPC64_ADDR16_HA,
	R_PPC64_TPREL16_HI, and R_PPC64_TPREL16_HA.
	Support new R_PPC64_ADDR16_HIGH, R_PPC64_ADDR16_HIGHA,
	R_PPC64_TPREL16_HIGH, and R_PPC64_TPREL16_HIGHA relocations.
	Fix overflow checking for R_PPC64_ADDR30 and R_PPC64_ADDR32.


Index: glibc/elf/elf.h
===================================================================
--- glibc.orig/elf/elf.h
+++ glibc/elf/elf.h
@@ -2252,6 +2252,17 @@ typedef Elf32_Addr Elf32_Conflict;
 #define R_PPC64_DTPREL16_HIGHERA 104 /* half16	(sym+add)@dtprel@highera */
 #define R_PPC64_DTPREL16_HIGHEST 105 /* half16	(sym+add)@dtprel@highest */
 #define R_PPC64_DTPREL16_HIGHESTA 106 /* half16	(sym+add)@dtprel@highesta */
+#define R_PPC64_TLSGD		107 /* none	(sym+add)@tlsgd */
+#define R_PPC64_TLSLD		108 /* none	(sym+add)@tlsld */
+#define R_PPC64_TOCSAVE		109 /* none */
+
+/* Added when HA and HI relocs were changed to report overflows.  */
+#define R_PPC64_ADDR16_HIGH	110
+#define R_PPC64_ADDR16_HIGHA	111
+#define R_PPC64_TPREL16_HIGH	112
+#define R_PPC64_TPREL16_HIGHA	113
+#define R_PPC64_DTPREL16_HIGH	114
+#define R_PPC64_DTPREL16_HIGHA	115
 
 /* GNU extension to support local ifunc.  */
 #define R_PPC64_JMP_IREL	247
Index: glibc/sysdeps/powerpc/powerpc64/dl-machine.h
===================================================================
--- glibc.orig/sysdeps/powerpc/powerpc64/dl-machine.h
+++ glibc/sysdeps/powerpc/powerpc64/dl-machine.h
@@ -669,11 +669,25 @@ elf_machine_rela (struct link_map *map,
 
     case R_PPC64_TPREL16_HI:
       value = elf_machine_tprel (map, sym_map, sym, reloc);
+      if (dont_expect (value + 0x80000000 >= 0x100000000LL))
+	_dl_reloc_overflow (map, "R_PPC64_TPREL16_HI", reloc_addr, refsym);
+      *(Elf64_Half *) reloc_addr = PPC_HI (value);
+      break;
+
+    case R_PPC64_TPREL16_HIGH:
+      value = elf_machine_tprel (map, sym_map, sym, reloc);
       *(Elf64_Half *) reloc_addr = PPC_HI (value);
       break;
 
     case R_PPC64_TPREL16_HA:
       value = elf_machine_tprel (map, sym_map, sym, reloc);
+      if (dont_expect (value + 0x80008000 >= 0x100000000LL))
+	_dl_reloc_overflow (map, "R_PPC64_TPREL16_HA", reloc_addr, refsym);
+      *(Elf64_Half *) reloc_addr = PPC_HA (value);
+      break;
+
+    case R_PPC64_TPREL16_HIGHA:
+      value = elf_machine_tprel (map, sym_map, sym, reloc);
       *(Elf64_Half *) reloc_addr = PPC_HA (value);
       break;
 
@@ -709,17 +723,23 @@ elf_machine_rela (struct link_map *map,
       break;
 
     case R_PPC64_ADDR16_HI:
+      if (dont_expect (value + 0x80000000 >= 0x100000000LL))
+	_dl_reloc_overflow (map, "R_PPC64_ADDR16_HI", reloc_addr, refsym);
+    case R_PPC64_ADDR16_HIGH:
       *(Elf64_Half *) reloc_addr = PPC_HI (value);
       break;
 
     case R_PPC64_ADDR16_HA:
+      if (dont_expect (value + 0x80008000 >= 0x100000000LL))
+	_dl_reloc_overflow (map, "R_PPC64_ADDR16_HA", reloc_addr, refsym);
+    case R_PPC64_ADDR16_HIGHA:
       *(Elf64_Half *) reloc_addr = PPC_HA (value);
       break;
 
     case R_PPC64_ADDR30:
       {
 	Elf64_Addr delta = value - (Elf64_Xword) reloc_addr;
-	if (dont_expect ((delta + 0x80000000) >= 0x10000000
+	if (dont_expect ((delta + 0x80000000) >= 0x100000000LL
 			 || (delta & 3) != 0))
 	  _dl_reloc_overflow (map, "R_PPC64_ADDR30", reloc_addr, refsym);
 	BIT_INSERT (*(Elf64_Word *) reloc_addr, delta, 0xfffffffc);
@@ -755,7 +775,7 @@ elf_machine_rela (struct link_map *map,
       return;
 
     case R_PPC64_ADDR32:
-      if (dont_expect ((value + 0x80000000) >= 0x10000000))
+      if (dont_expect ((value + 0x80000000) >= 0x100000000LL))
 	_dl_reloc_overflow (map, "R_PPC64_ADDR32", reloc_addr, refsym);
       *(Elf64_Word *) reloc_addr = value;
       return;
-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]