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[PATCH] PowerPC64: Report overflow on @h and @ha relocations
- From: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Date: Tue, 12 Nov 2013 22:20:34 +0100 (CET)
- Subject: [PATCH] PowerPC64: Report overflow on @h and @ha relocations
- Authentication-results: sourceware.org; auth=none
[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