[binutils-gdb] gold: x86-64: Fix TLSDESC relaxation for x32
H.J. Lu
hjl@sourceware.org
Fri May 1 17:12:17 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ccf20d460f73c48f3334e1401558df342c77ac8a
commit ccf20d460f73c48f3334e1401558df342c77ac8a
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 1 10:11:06 2020 -0700
gold: x86-64: Fix TLSDESC relaxation for x32
X32 TLSDESC sequences can be:
40 8d 05 00 00 00 00 rex lea foo@TLSDESC(%rip), %reg
...
67 ff 10 call *foo@TLSCALL(%eax)
or the same sequence as LP64:
48 8d 05 00 00 00 00 lea foo@TLSDESC(%rip), %reg
...
ff 10 call *foo@TLSCALL(%rax)
We need to support both sequences for x32. For both GDesc -> IE/LE
transitions,
67 ff 10 call *foo@TLSCALL(%eax)
should relaxed to
0f 1f 00 nopl (%rax)
For GDesc -> LE transition,
40 8d 05 00 00 00 00 rex lea foo@TLSDESC(%rip), %reg
should relaxed to
40 c7 c0 fc ff ff ff rex movl $foo@tpoff, %reg
For GDesc -> IE transition,
40 8d 05 00 00 00 00 rex lea foo@TLSDESC(%rip), %reg
should relaxed to
40 8b 05 00 00 00 00 rex movl foo@gottpoff(%rip), %eax
PR gold/25426
* x86_64.cc (Target_x86_64<size>::Relocate::tls_desc_gd_to_ie):
For x32, relax "rex leal foo@tlsdesc(%rip), %reg" to
"rex movl foo@gottpoff(%rip), %eax" and relax ""call *(%eax)"
to "nopl (%rax)".
(Target_x86_64<size>::Relocate::tls_desc_gd_to_le): For x32,
relax "rex leal foo@tlsdesc(%rip), %reg" to
"rex movl foo@tpoff, %eax" and relax "call *foo@tlscall(%eax)"
to "nopl (%rax)".
* testsuite/Makefile.am (tls_test_gnu2.o): Depend on
gcctestdir/as.
(tls_test_file2_gnu2.o): Likewise.
(tls_test_c_gnu2.o): Likewise.
* testsuite/Makefile.in: Regenerated.
Diff:
---
gold/ChangeLog | 17 +++++++++++
gold/testsuite/Makefile.am | 6 ++--
gold/testsuite/Makefile.in | 6 ++--
gold/x86_64.cc | 76 +++++++++++++++++++++++++++++++++++-----------
4 files changed, 82 insertions(+), 23 deletions(-)
diff --git a/gold/ChangeLog b/gold/ChangeLog
index 0b7cb07fddf..23fb0709806 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,20 @@
+2020-05-01 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR gold/25426
+ * x86_64.cc (Target_x86_64<size>::Relocate::tls_desc_gd_to_ie):
+ For x32, relax "rex leal foo@tlsdesc(%rip), %reg" to
+ "rex movl foo@gottpoff(%rip), %eax" and relax ""call *(%eax)"
+ to "nopl (%rax)".
+ (Target_x86_64<size>::Relocate::tls_desc_gd_to_le): For x32,
+ relax "rex leal foo@tlsdesc(%rip), %reg" to
+ "rex movl foo@tpoff, %eax" and relax "call *foo@tlscall(%eax)"
+ to "nopl (%rax)".
+ * testsuite/Makefile.am (tls_test_gnu2.o): Depend on
+ gcctestdir/as.
+ (tls_test_file2_gnu2.o): Likewise.
+ (tls_test_c_gnu2.o): Likewise.
+ * testsuite/Makefile.in: Regenerated.
+
2020-05-01 H.J. Lu <hongjiu.lu@intel.com>
PR gold/25473
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index 6187554c325..ceba00243ea 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -1032,11 +1032,11 @@ if TLS_GNU2_DIALECT
check_PROGRAMS += tls_shared_gnu2_gd_to_ie_test
-tls_test_gnu2.o: tls_test.cc
+tls_test_gnu2.o: tls_test.cc gcctestdir/as
$(CXXCOMPILE) -c -fpic -mtls-dialect=gnu2 -o $@ $<
-tls_test_file2_gnu2.o: tls_test_file2.cc
+tls_test_file2_gnu2.o: tls_test_file2.cc gcctestdir/as
$(CXXCOMPILE) -c -fpic -mtls-dialect=gnu2 -o $@ $<
-tls_test_c_gnu2.o: tls_test_c.c
+tls_test_c_gnu2.o: tls_test_c.c gcctestdir/as
$(COMPILE) -c -fpic -mtls-dialect=gnu2 $(TLS_TEST_C_CFLAGS) -o $@ $<
tls_test_gnu2_shared2.so: tls_test_file2_gnu2.o gcctestdir/ld
$(CXXLINK) -shared tls_test_file2_gnu2.o
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 8d2f142a6f7..5fed355247c 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -8275,11 +8275,11 @@ uninstall-am:
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_TRUE@ tls_test_c_pic.o gcctestdir/ld
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_TRUE@ $(CXXLINK) $(THREADFLAGS) -pie tls_test_main_pie.o tls_test_pic.o tls_test_file2_pic.o tls_test_c_pic.o $(THREADLIBS)
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_gnu2.o: tls_test.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_gnu2.o: tls_test.cc gcctestdir/as
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@ $(CXXCOMPILE) -c -fpic -mtls-dialect=gnu2 -o $@ $<
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_file2_gnu2.o: tls_test_file2.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_file2_gnu2.o: tls_test_file2.cc gcctestdir/as
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@ $(CXXCOMPILE) -c -fpic -mtls-dialect=gnu2 -o $@ $<
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_c_gnu2.o: tls_test_c.c
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_c_gnu2.o: tls_test_c.c gcctestdir/as
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@ $(COMPILE) -c -fpic -mtls-dialect=gnu2 $(TLS_TEST_C_CFLAGS) -o $@ $<
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@tls_test_gnu2_shared2.so: tls_test_file2_gnu2.o gcctestdir/ld
@GCC_TRUE@@NATIVE_LINKER_TRUE@@TLS_GNU2_DIALECT_TRUE@@TLS_TRUE@ $(CXXLINK) -shared tls_test_file2_gnu2.o
diff --git a/gold/x86_64.cc b/gold/x86_64.cc
index d4f1d6b2324..1d9d9209bf3 100644
--- a/gold/x86_64.cc
+++ b/gold/x86_64.cc
@@ -5472,12 +5472,15 @@ Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
{
if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
{
- // leaq foo@tlsdesc(%rip), %rax
- // ==> movq foo@gottpoff(%rip), %rax
+ // LP64: leaq foo@tlsdesc(%rip), %rax
+ // ==> movq foo@gottpoff(%rip), %rax
+ // X32: rex leal foo@tlsdesc(%rip), %eax
+ // ==> rex movl foo@gottpoff(%rip), %eax
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- ((view[-3] & 0xfb) == 0x48
+ (((view[-3] & 0xfb) == 0x48
+ || (size == 32 && (view[-3] & 0xfb) == 0x40))
&& view[-2] == 0x8d
&& (view[-1] & 0xc7) == 0x05));
view[-2] = 0x8b;
@@ -5486,14 +5489,32 @@ Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
}
else
{
- // call *foo@tlscall(%rax)
- // ==> nop; nop
+ // LP64: call *foo@tlscall(%rax)
+ // ==> xchg %ax, %ax
+ // X32: call *foo@tlscall(%eax)
+ // ==> nopl (%rax)
gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
+ int prefix = 0;
+ if (size == 32 && view[0] == 0x67)
+ {
+ tls::check_range(relinfo, relnum, rela.get_r_offset(),
+ view_size, 3);
+ prefix = 1;
+ }
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- view[0] == 0xff && view[1] == 0x10);
- view[0] = 0x66;
- view[1] = 0x90;
+ view[prefix] == 0xff && view[prefix + 1] == 0x10);
+ if (prefix)
+ {
+ view[0] = 0x0f;
+ view[1] = 0x1f;
+ view[2] = 0x00;
+ }
+ else
+ {
+ view[0] = 0x66;
+ view[1] = 0x90;
+ }
}
}
@@ -5513,15 +5534,18 @@ Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
{
if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
{
- // leaq foo@tlsdesc(%rip), %rax
- // ==> movq foo@tpoff, %rax
+ // LP64: leaq foo@tlsdesc(%rip), %rax
+ // ==> movq foo@tpoff, %rax
+ // X32: rex leal foo@tlsdesc(%rip), %eax
+ // ==> rex movl foo@tpoff, %eax
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- ((view[-3] & 0xfb) == 0x48
+ (((view[-3] & 0xfb) == 0x48
+ || (size == 32 && (view[-3] & 0xfb) == 0x40))
&& view[-2] == 0x8d
&& (view[-1] & 0xc7) == 0x05));
- view[-3] = 0x48 | ((view[-3] >> 2) & 1);
+ view[-3] = (view[-3] & 0x48) | ((view[-3] >> 2) & 1);
view[-2] = 0xc7;
view[-1] = 0xc0 | ((view[-1] >> 3) & 7);
value -= tls_segment->memsz();
@@ -5529,14 +5553,32 @@ Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
}
else
{
- // call *foo@tlscall(%rax)
- // ==> nop; nop
+ // LP64: call *foo@tlscall(%rax)
+ // ==> xchg %ax, %ax
+ // X32: call *foo@tlscall(%eax)
+ // ==> nopl (%rax)
gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
+ int prefix = 0;
+ if (size == 32 && view[0] == 0x67)
+ {
+ tls::check_range(relinfo, relnum, rela.get_r_offset(),
+ view_size, 3);
+ prefix = 1;
+ }
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- view[0] == 0xff && view[1] == 0x10);
- view[0] = 0x66;
- view[1] = 0x90;
+ view[prefix] == 0xff && view[prefix + 1] == 0x10);
+ if (prefix)
+ {
+ view[0] = 0x0f;
+ view[1] = 0x1f;
+ view[2] = 0x00;
+ }
+ else
+ {
+ view[0] = 0x66;
+ view[1] = 0x90;
+ }
}
}
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