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[committed] PR ld/22966: Fix n64 MIPS `.got.plt' range checks
- From: "Maciej W. Rozycki" <macro at mips dot com>
- To: <binutils at sourceware dot org>
- Date: Wed, 20 Jun 2018 00:43:05 +0100
- Subject: [committed] PR ld/22966: Fix n64 MIPS `.got.plt' range checks
The addressable signed 32-bit range for n64 MIPS `.got.plt' references
is from 0xffffffff7fff8000 to 0x7fff7fff, due to how the composition of
an LUI and an LD instruction works for address calculation in the 64-bit
addressing mode, such as when CP0.Status.UX=1.
We currently have a range check in `mips_finish_exec_plt', however it is
not correct as it verifies that the `.got.plt' start address referred is
between 0xffffffff80000000 and 0x7fffffff. It is also implemented as an
assertion rather than a proper error message despite that the situation
can be triggered by user input. Additionally there is no check made for
individual `.got.plt' entries referred even though they can be out of
range while the `.got.plt' start address is not.
Fix all these problems and use the correct range for the check, limiting
it to n64 output files, and then issue a proper error message both in
`mips_finish_exec_plt' and in `_bfd_mips_elf_finish_dynamic_symbol',
suggesting the use of the `-Ttext-segment=...' option that will often
work and with the default linker scripts in particular. Add suitable
tests covering boundary cases.
bfd/
PR ld/22966
* elfxx-mips.c (_bfd_mips_elf_finish_dynamic_symbol): Verify the
`.got.plt' entry referred is in range.
(mips_finish_exec_plt): Correct the range check for `.got.plt'
start. Replace the assertion used for that with a proper error
message.
ld/
PR ld/22966
* testsuite/ld-mips-elf/n64-plt-1.dd: New test.
* testsuite/ld-mips-elf/n64-plt-1.gd: New test.
* testsuite/ld-mips-elf/n64-plt-2.ed: New test.
* testsuite/ld-mips-elf/n64-plt-3.ed: New test.
* testsuite/ld-mips-elf/n64-plt-4.dd: New test.
* testsuite/ld-mips-elf/n64-plt-4.gd: New test.
* testsuite/ld-mips-elf/n64-plt-1.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt-2.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt-3.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt-4.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt.s: New test source.
* testsuite/ld-mips-elf/n64-plt-lib.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
---
bfd/elfxx-mips.c | 31 +++++++++++++++++++++--
ld/testsuite/ld-mips-elf/mips-elf.exp | 44 +++++++++++++++++++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-1.dd | 26 +++++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-1.gd | 18 +++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-1.ld | 22 ++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-2.ed | 1
ld/testsuite/ld-mips-elf/n64-plt-2.ld | 23 +++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-3.ed | 1
ld/testsuite/ld-mips-elf/n64-plt-3.ld | 23 +++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-4.dd | 26 +++++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-4.gd | 18 +++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-4.ld | 23 +++++++++++++++++
ld/testsuite/ld-mips-elf/n64-plt-lib.s | 11 ++++++++
ld/testsuite/ld-mips-elf/n64-plt.s | 9 ++++++
14 files changed, 274 insertions(+), 2 deletions(-)
binutils-mips64-bfd-finish-exec-plt-addr-err.diff
Index: binutils/bfd/elfxx-mips.c
===================================================================
--- binutils.orig/bfd/elfxx-mips.c 2018-06-19 22:47:14.359931720 +0100
+++ binutils/bfd/elfxx-mips.c 2018-06-20 00:21:32.504579640 +0100
@@ -10602,6 +10602,22 @@ _bfd_mips_elf_finish_dynamic_symbol (bfd
got_address_high = ((got_address + 0x8000) >> 16) & 0xffff;
got_address_low = got_address & 0xffff;
+ /* The PLT sequence is not safe for N64 if .got.plt entry's address
+ cannot be loaded in two instructions. */
+ if (ABI_64_P (output_bfd)
+ && ((got_address + 0x80008000) & ~(bfd_vma) 0xffffffff) != 0)
+ {
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("%pB: `%pA' entry VMA of %#" PRIx64 " outside the 32-bit range "
+ "supported; consider using `-Ttext-segment=...'"),
+ output_bfd,
+ htab->root.sgotplt->output_section,
+ (int64_t) got_address);
+ bfd_set_error (bfd_error_no_error);
+ return FALSE;
+ }
+
/* Initially point the .got.plt entry at the PLT header. */
loc = (htab->root.sgotplt->contents
+ got_index * MIPS_ELF_GOT_SIZE (dynobj));
@@ -11246,8 +11262,19 @@ mips_finish_exec_plt (bfd *output_bfd, s
/* The PLT sequence is not safe for N64 if .got.plt's address can
not be loaded in two instructions. */
- BFD_ASSERT ((gotplt_value & ~(bfd_vma) 0x7fffffff) == 0
- || ~(gotplt_value | 0x7fffffff) == 0);
+ if (ABI_64_P (output_bfd)
+ && ((gotplt_value + 0x80008000) & ~(bfd_vma) 0xffffffff) != 0)
+ {
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("%pB: `%pA' start VMA of %#" PRIx64 " outside the 32-bit range "
+ "supported; consider using `-Ttext-segment=...'"),
+ output_bfd,
+ htab->root.sgotplt->output_section,
+ (int64_t) gotplt_value);
+ bfd_set_error (bfd_error_no_error);
+ return FALSE;
+ }
/* Install the PLT header. */
loc = htab->root.splt->contents;
Index: binutils/ld/testsuite/ld-mips-elf/mips-elf.exp
===================================================================
--- binutils.orig/ld/testsuite/ld-mips-elf/mips-elf.exp 2018-06-19 22:46:17.225755900 +0100
+++ binutils/ld/testsuite/ld-mips-elf/mips-elf.exp 2018-06-19 22:47:28.515330588 +0100
@@ -1167,6 +1167,50 @@ if { $linux_gnu } {
}
}
+# Verify graceful handling of n64 PLT 32-bit range overflows. Given
+# that the alignment of `.got.plt' is 8 the highest usable positive
+# address is 0x7fff7ff8 and the lowest usable negative address is
+# 0xffffffff7fff8000.
+if { $linux_gnu } {
+ run_ld_link_tests [list \
+ [list "Shared library for MIPS n64 PLT 32-bit range tests" \
+ "-shared $abi_ldflags(n64)" "" \
+ "$abi_asflags(n64)" \
+ { n64-plt-lib.s } \
+ {} \
+ "n64-plt-lib.so"] \
+ [list "MIPS n64 PLT 32-bit range test 1" \
+ "$abi_ldflags(n64) -T n64-plt-1.ld -e foo" \
+ "tmpdir/n64-plt-lib.so" \
+ "$abi_asflags(n64)" \
+ { n64-plt.s } \
+ { { objdump -d n64-plt-1.dd } \
+ { readelf -A n64-plt-1.gd } } \
+ "n64-plt-1"] \
+ [list "MIPS n64 PLT 32-bit range test 2" \
+ "$abi_ldflags(n64) -T n64-plt-2.ld -e foo" \
+ "tmpdir/n64-plt-lib.so" \
+ "$abi_asflags(n64)" \
+ { n64-plt.s } \
+ { { ld n64-plt-2.ed } } \
+ "n64-plt-2"] \
+ [list "MIPS n64 PLT 32-bit range test 3" \
+ "$abi_ldflags(n64) -T n64-plt-3.ld -e foo" \
+ "tmpdir/n64-plt-lib.so" \
+ "$abi_asflags(n64)" \
+ { n64-plt.s } \
+ { { ld n64-plt-3.ed } } \
+ "n64-plt-3"] \
+ [list "MIPS n64 PLT 32-bit range test 4" \
+ "$abi_ldflags(n64) -T n64-plt-4.ld -e foo" \
+ "tmpdir/n64-plt-lib.so" \
+ "$abi_asflags(n64)" \
+ { n64-plt.s } \
+ { { objdump -d n64-plt-4.dd } \
+ { readelf -A n64-plt-4.gd } } \
+ "n64-plt-4"]]
+}
+
# PR ld/19908 export class tests.
if { $linux_gnu } {
run_ld_link_tests [list \
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-1.dd
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-1.dd 2018-06-19 22:47:28.569493049 +0100
@@ -0,0 +1,26 @@
+.*: +file format .*mips.*
+
+Disassembly of section \.plt:
+
+0000000010000280 <_PROCEDURE_LINKAGE_TABLE_>:
+ 10000280: 3c0e7fff lui t2,0x7fff
+ 10000284: ddd97fe8 ld t9,32744\(t2\)
+ 10000288: 25ce7fe8 addiu t2,t2,32744
+ 1000028c: 030ec023 subu t8,t8,t2
+ 10000290: 03e07825 move t3,ra
+ 10000294: 0018c0c2 srl t8,t8,0x3
+ 10000298: 0320f809 jalr t9
+ 1000029c: 2718fffe addiu t8,t8,-2
+
+00000000100002a0 <bar@plt>:
+ 100002a0: 3c0f7fff lui t3,0x7fff
+ 100002a4: ddf97ff8 ld t9,32760\(t3\)
+ 100002a8: 03200008 jr t9
+ 100002ac: 25f87ff8 addiu t8,t3,32760
+
+Disassembly of section \.text:
+
+00000000100002b0 <foo>:
+ 100002b0: 080000a8 j 100002a0 <bar@plt>
+ 100002b4: 00000000 nop
+ \.\.\.
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-1.gd
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-1.gd 2018-06-19 22:47:28.594595851 +0100
@@ -0,0 +1,18 @@
+Primary GOT:
+ Canonical gp value: 000000007ffffff0
+
+ Reserved entries:
+ Address Access Initial Purpose
+ 000000007fff8000 -32752\(gp\) 0000000000000000 Lazy resolver
+ 000000007fff8008 -32744\(gp\) 8000000000000000 Module pointer \(GNU extension\)
+
+PLT GOT:
+
+ Reserved entries:
+ Address Initial Purpose
+ 000000007fff7fe8 0000000000000000 PLT lazy resolver
+ 000000007fff7ff0 0000000000000000 Module pointer
+
+ Entries:
+ Address Initial Sym\.Val\. Type Ndx Name
+ 000000007fff7ff8 0000000010000280 0000000000000000 FUNC UND bar
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-1.ld
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-1.ld 2018-06-19 22:47:28.608688974 +0100
@@ -0,0 +1,22 @@
+MEMORY
+{
+ text (rx) : ORIGIN = 0x10000000, LENGTH = 0x10000
+ data (w) : ORIGIN = 0x7fff7fe8, LENGTH = 0x10000
+}
+SECTIONS
+{
+ .dynamic : { *(.dynamic) } >text
+ .hash : { *(.hash) } >text
+ .dynsym : { *(.dynsym) } >text
+ .dynstr : { *(.dynstr) } >text
+ .rel.plt : { *(.rel.plt) } >text
+ .plt : { *(.plt) } >text
+ .text : { *(.text) } >text
+ .interp : { *(.interp) } >text
+ .got.plt : { *(.got.plt) } >data
+ .got : { *(.got) } >data
+ .symtab : { *(.symtab) }
+ .strtab : { *(.strtab) }
+ .shstrtab : { *(.shstrtab) }
+ /DISCARD/ : { *(*) }
+}
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-2.ed
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-2.ed 2018-06-19 22:47:28.630749435 +0100
@@ -0,0 +1 @@
+[^\n]*: `\.got\.plt' entry VMA of 0x7fff8000 outside the 32-bit range supported; consider using `-Ttext-segment=\.\.\.'
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-2.ld
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-2.ld 2018-06-19 22:47:28.647799518 +0100
@@ -0,0 +1,23 @@
+MEMORY
+{
+ text (rx) : ORIGIN = 0x10000000, LENGTH = 0x10000
+ data (w) : ORIGIN = 0x7fff7ff0, LENGTH = 0x10000
+}
+SECTIONS
+{
+ .dynamic : { *(.dynamic) } >text
+ .hash : { *(.hash) } >text
+ .dynsym : { *(.dynsym) } >text
+ .dynstr : { *(.dynstr) } >text
+ .rel.plt : { *(.rel.plt) } >text
+ .plt : { *(.plt) } >text
+ .text : { *(.text) } >text
+ .interp : { *(.interp) } >text
+ .got.plt : { *(.got.plt) } >data
+ .rld.map : { *(.rld.map) } >data
+ .got : { *(.got) } >data
+ .symtab : { *(.symtab) }
+ .strtab : { *(.strtab) }
+ .shstrtab : { *(.shstrtab) }
+ /DISCARD/ : { *(*) }
+}
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-3.ed
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-3.ed 2018-06-19 22:47:28.666882645 +0100
@@ -0,0 +1 @@
+[^\n]*: `\.got\.plt' start VMA of 0xffffffff7fff7ff0 outside the 32-bit range supported; consider using `-Ttext-segment=\.\.\.'
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-3.ld
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-3.ld 2018-06-19 22:47:28.687943603 +0100
@@ -0,0 +1,23 @@
+MEMORY
+{
+ text (rx) : ORIGIN = 0xffffffff10000000, LENGTH = 0x10000
+ data (w) : ORIGIN = 0xffffffff7fff7ff0, LENGTH = 0x10000
+}
+SECTIONS
+{
+ .dynamic : { *(.dynamic) } >text
+ .hash : { *(.hash) } >text
+ .dynsym : { *(.dynsym) } >text
+ .dynstr : { *(.dynstr) } >text
+ .rel.plt : { *(.rel.plt) } >text
+ .plt : { *(.plt) } >text
+ .text : { *(.text) } >text
+ .interp : { *(.interp) } >text
+ .got.plt : { *(.got.plt) } >data
+ .rld.map : { *(.rld.map) } >data
+ .got : { *(.got) } >data
+ .symtab : { *(.symtab) }
+ .strtab : { *(.strtab) }
+ .shstrtab : { *(.shstrtab) }
+ /DISCARD/ : { *(*) }
+}
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-4.dd
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-4.dd 2018-06-19 22:47:28.715113710 +0100
@@ -0,0 +1,26 @@
+.*: +file format .*mips.*
+
+Disassembly of section \.plt:
+
+ffffffff10000280 <_PROCEDURE_LINKAGE_TABLE_>:
+ffffffff10000280: 3c0e8000 lui t2,0x8000
+ffffffff10000284: ddd98000 ld t9,-32768\(t2\)
+ffffffff10000288: 25ce8000 addiu t2,t2,-32768
+ffffffff1000028c: 030ec023 subu t8,t8,t2
+ffffffff10000290: 03e07825 move t3,ra
+ffffffff10000294: 0018c0c2 srl t8,t8,0x3
+ffffffff10000298: 0320f809 jalr t9
+ffffffff1000029c: 2718fffe addiu t8,t8,-2
+
+ffffffff100002a0 <bar@plt>:
+ffffffff100002a0: 3c0f8000 lui t3,0x8000
+ffffffff100002a4: ddf98010 ld t9,-32752\(t3\)
+ffffffff100002a8: 03200008 jr t9
+ffffffff100002ac: 25f88010 addiu t8,t3,-32752
+
+Disassembly of section \.text:
+
+ffffffff100002b0 <foo>:
+ffffffff100002b0: 080000a8 j ffffffff100002a0 <bar@plt>
+ffffffff100002b4: 00000000 nop
+ \.\.\.
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-4.gd
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-4.gd 2018-06-19 22:47:28.738435251 +0100
@@ -0,0 +1,18 @@
+Primary GOT:
+ Canonical gp value: ffffffff80000010
+
+ Reserved entries:
+ Address Access Initial Purpose
+ ffffffff7fff8020 -32752\(gp\) 0000000000000000 Lazy resolver
+ ffffffff7fff8028 -32744\(gp\) 8000000000000000 Module pointer \(GNU extension\)
+
+PLT GOT:
+
+ Reserved entries:
+ Address Initial Purpose
+ ffffffff7fff8000 0000000000000000 PLT lazy resolver
+ ffffffff7fff8008 0000000000000000 Module pointer
+
+ Entries:
+ Address Initial Sym\.Val\. Type Ndx Name
+ ffffffff7fff8010 ffffffff10000280 0000000000000000 FUNC UND bar
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-4.ld
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-4.ld 2018-06-19 22:47:28.772052263 +0100
@@ -0,0 +1,23 @@
+MEMORY
+{
+ text (rx) : ORIGIN = 0xffffffff10000000, LENGTH = 0x10000
+ data (w) : ORIGIN = 0xffffffff7fff8000, LENGTH = 0x10000
+}
+SECTIONS
+{
+ .dynamic : { *(.dynamic) } >text
+ .hash : { *(.hash) } >text
+ .dynsym : { *(.dynsym) } >text
+ .dynstr : { *(.dynstr) } >text
+ .rel.plt : { *(.rel.plt) } >text
+ .plt : { *(.plt) } >text
+ .text : { *(.text) } >text
+ .interp : { *(.interp) } >text
+ .got.plt : { *(.got.plt) } >data
+ .rld.map : { *(.rld.map) } >data
+ .got : { *(.got) } >data
+ .symtab : { *(.symtab) }
+ .strtab : { *(.strtab) }
+ .shstrtab : { *(.shstrtab) }
+ /DISCARD/ : { *(*) }
+}
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt-lib.s
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt-lib.s 2018-06-19 22:47:28.801603334 +0100
@@ -0,0 +1,11 @@
+ .abicalls
+ .text
+
+ .globl bar
+ .ent bar
+bar:
+ .frame $sp, 0, $31
+ .mask 0x00000000, 0
+ .fmask 0x00000000, 0
+ jr $31
+ .end bar
Index: binutils/ld/testsuite/ld-mips-elf/n64-plt.s
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils/ld/testsuite/ld-mips-elf/n64-plt.s 2018-06-19 22:47:28.817672777 +0100
@@ -0,0 +1,9 @@
+ .abicalls
+ .option pic0
+ .text
+
+ .globl foo
+ .ent foo
+foo:
+ j bar
+ .end foo