[Bug ld/20402] New: ld.bfd for AArch64 emits R_AARCH64_RELATIVE relocations against SHN_ABS symbols
https://sourceware.org/bugzilla/show_bug.cgi?id=20402
Bug ID: 20402
Summary: ld.bfd for AArch64 emits R_AARCH64_RELATIVE
relocations against SHN_ABS symbols
Product: binutils
Version: 2.28 (HEAD)
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: ld
Assignee: unassigned at sourceware dot org
Reporter: ard.biesheuvel at linaro dot org
Target Milestone: ---
ld.bfd in -pie mode will 'optimize' away a R_AARCH64_ABS64 relocation against a
hidden SHN_ABS symbol by replacing it with a R_AARCH64_RELATIVE relocation,
which obviously makes the resulting value in the place dependent on the load
offset rather than fixed.
Instead, I would expect either the relocation to be preserved as a
R_AARCH64_ABS64 relocation to be resolved at load time, or be optimized away
completely, since the symbol is hidden and therefore not preemptible and could
thus be fully resolved at link time.
I don't have a small test case handy (I found this while working on KASLR for
arm64 Linux), but the following hunk fixes the problem completely for me: it
not only prevents the R_AARCH64_RELATIVE relocation from being emitted, but it
fully resolves the relocation and puts the correct 64-bit absolute value in the
place in the ELF binary.
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 3435a3d67339..d1068f56c4ee 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -5191,7 +5191,8 @@
&& h->dynindx != -1
&& (!bfd_link_pic (info)
|| !SYMBOLIC_BIND (info, h)
- || !h->def_regular))
+ || !h->def_regular
+ || sym->st_shndx == SHN_ABS))
outrel.r_info = ELFNN_R_INFO (h->dynindx, r_type);
else
{
(
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[Bug ld/20402] ld.bfd for AArch64 emits R_AARCH64_RELATIVE relocations against SHN_ABS symbols
https://sourceware.org/bugzilla/show_bug.cgi?id=20402 --- Comment #1 from Ard Biesheuvel --- Uhm, actually it does not fix it. I will try to come up with a small reproducing test case. -- You are receiving this mail because: You are on the CC list for the bug. ___ bug-binutils mailing list bug-binutils@gnu.org https://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/20402] ld.bfd for AArch64 emits R_AARCH64_RELATIVE relocations against SHN_ABS symbols
https://sourceware.org/bugzilla/show_bug.cgi?id=20402 --- Comment #2 from Ard Biesheuvel --- The issue can be reproduced by: abs.s - .quad foo, bar abs.lds --- HIDDEN(foo = ABSOLUTE(0xff00ff11ff22ff33)); bar = ABSOLUTE(0xff44ff55ff66ff77); Build using aarch64-linux-gnu-gcc -pie -nostdlib -o abs -T abs.lds abs.s which produces a binary containing the following relocations Relocation section '.rela.dyn' at offset 0x100c8 contains 2 entries: Offset Info Type Sym. ValueSym. Name + Addend 0403 R_AARCH64_RELATIV-ff00ee00dd00cd 0008 00020101 R_AARCH64_ABS64 ff44ff55ff66ff77 bar + 0 -- You are receiving this mail because: You are on the CC list for the bug. ___ bug-binutils mailing list bug-binutils@gnu.org https://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug gold/20404] New: gold/configure --help shall print "
https://sourceware.org/bugzilla/show_bug.cgi?id=20404
Bug ID: 20404
Summary: gold/configure --help shall print "
Product: binutils
Version: 2.28 (HEAD)
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: gold
Assignee: ccoutant at gmail dot com
Reporter: dilyan.palauzov at aegee dot org
CC: ian at airs dot com
Target Milestone: ---
Provided that gold/configure always turns on "--enable-relro", contrary to
ld/configure, as gold/configure.tgt and ld/configure.tgt differ, gold/configure
--help shall print
--disable-relrodisable -z relro in ELF linker by default
to indicate, that by not specifying anything, relro will be enabled implicitly
in the compiled gold. Currently gold/configure --help prints "--enable-relro
enable -z relro in ELF linker by default" which indicates the opposite.
Please consider adjusting the output of ld.gold --help as follows.
diff --git a/gold/configure.ac b/gold/configure.ac
index de3b630..742af37 100644
--- a/gold/configure.ac
+++ b/gold/configure.ac
@@ -118,8 +118,8 @@ AM_CONDITIONAL(PLUGINS, test "$plugins" = "yes")
ac_default_ld_z_relro=unset
# Provide a configure time option to override our default.
AC_ARG_ENABLE(relro,
- AS_HELP_STRING([--enable-relro],
- [enable -z relro in ELF linker by default]),
+ AS_HELP_STRING([--disable-relro],
+ [disable -z relro in ELF linker by default]),
[case "${enableval}" in
yes) ac_default_ld_z_relro=1 ;;
no) ac_default_ld_z_relro=0 ;;
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