[lld] r333769 - [PPC64] Add support for initial-exec TLS model

Zaara Syeda via llvm-commits llvm-commits at lists.llvm.org
Fri Jun 1 08:20:57 PDT 2018


Author: syzaara
Date: Fri Jun  1 08:20:56 2018
New Revision: 333769

URL: http://llvm.org/viewvc/llvm-project?rev=333769&view=rev
Log:
[PPC64] Add support for initial-exec TLS model

This patch adds the relocations needed support the initial-exec TLS model:
R_PPC64_GOT_TPREL16_HA
R_PPC64_GOT_TPREL16_LO_DS
R_PPC64_GOT_TPREL16_DS
R_PPC64_GOT_TPREL16_HI
R_PPC64_TLS

Differential Revision: https://reviews.llvm.org/D47455

Added:
    lld/trunk/test/ELF/Inputs/ppc64-tls.s
    lld/trunk/test/ELF/ppc64-initial-exec-tls.s
Modified:
    lld/trunk/ELF/Arch/PPC64.cpp

Modified: lld/trunk/ELF/Arch/PPC64.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Arch/PPC64.cpp?rev=333769&r1=333768&r2=333769&view=diff
==============================================================================
--- lld/trunk/ELF/Arch/PPC64.cpp (original)
+++ lld/trunk/ELF/Arch/PPC64.cpp Fri Jun  1 08:20:56 2018
@@ -83,6 +83,8 @@ PPC64::PPC64() {
   TlsModuleIndexRel = R_PPC64_DTPMOD64;
   TlsOffsetRel = R_PPC64_DTPREL64;
 
+  TlsGotRel = R_PPC64_TPREL64;
+
   // We need 64K pages (at least under glibc/Linux, the loader won't
   // set different permissions on a finer granularity than that).
   DefaultMaxPageSize = 65536;
@@ -180,8 +182,14 @@ RelExpr PPC64::getRelExpr(RelType Type,
   case R_PPC64_GOT_TLSLD16_HI:
   case R_PPC64_GOT_TLSLD16_LO:
     return R_TLSLD_GOT;
+  case R_PPC64_GOT_TPREL16_HA:
+  case R_PPC64_GOT_TPREL16_LO_DS:
+  case R_PPC64_GOT_TPREL16_DS:
+  case R_PPC64_GOT_TPREL16_HI:
+    return R_GOT_OFF;
   case R_PPC64_TLSGD:
   case R_PPC64_TLSLD:
+  case R_PPC64_TLS:
     return R_HINT;
   default:
     return R_ABS;
@@ -231,13 +239,16 @@ static std::pair<RelType, uint64_t> toAd
   case R_PPC64_TOC16:
     return {R_PPC64_ADDR16, V};
   case R_PPC64_TOC16_DS:
+  case R_PPC64_GOT_TPREL16_DS:
     return {R_PPC64_ADDR16_DS, V};
   case R_PPC64_GOT_TLSGD16_HA:
   case R_PPC64_GOT_TLSLD16_HA:
+  case R_PPC64_GOT_TPREL16_HA:
   case R_PPC64_TOC16_HA:
     return {R_PPC64_ADDR16_HA, V};
   case R_PPC64_GOT_TLSGD16_HI:
   case R_PPC64_GOT_TLSLD16_HI:
+  case R_PPC64_GOT_TPREL16_HI:
   case R_PPC64_TOC16_HI:
     return {R_PPC64_ADDR16_HI, V};
   case R_PPC64_GOT_TLSGD16_LO:
@@ -245,6 +256,7 @@ static std::pair<RelType, uint64_t> toAd
   case R_PPC64_TOC16_LO:
     return {R_PPC64_ADDR16_LO, V};
   case R_PPC64_TOC16_LO_DS:
+  case R_PPC64_GOT_TPREL16_LO_DS:
     return {R_PPC64_ADDR16_LO_DS, V};
   default:
     return {Type, Val};

Added: lld/trunk/test/ELF/Inputs/ppc64-tls.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/ppc64-tls.s?rev=333769&view=auto
==============================================================================
--- lld/trunk/test/ELF/Inputs/ppc64-tls.s (added)
+++ lld/trunk/test/ELF/Inputs/ppc64-tls.s Fri Jun  1 08:20:56 2018
@@ -0,0 +1,20 @@
+	.text
+	.abiversion 2
+	.type	a, at object # @a
+	.type	b, at object # @a
+	.type	c, at object # @a
+	.section	.tdata,"awT", at progbits
+	.globl	a
+a:
+	.long	10                      # 0xa
+	.size	a, 4
+
+	.globl	b
+b:
+	.long	10                      # 0xa
+	.size	b, 4
+
+	.globl	c
+c:
+	.long	10                      # 0xa
+	.size	c, 4

Added: lld/trunk/test/ELF/ppc64-initial-exec-tls.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/ppc64-initial-exec-tls.s?rev=333769&view=auto
==============================================================================
--- lld/trunk/test/ELF/ppc64-initial-exec-tls.s (added)
+++ lld/trunk/test/ELF/ppc64-initial-exec-tls.s Fri Jun  1 08:20:56 2018
@@ -0,0 +1,102 @@
+// REQUIRES: ppc
+
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %p/Inputs/ppc64-tls.s -o %t2.o
+// RUN: ld.lld -shared %t2.o -o %t2.so
+// RUN: ld.lld -dynamic-linker /lib64/ld64.so.2 %t.o %t2.so -o %t
+// RUN: llvm-readelf -relocations --wide %t.o | FileCheck --check-prefix=InputRelocs %s
+// RUN: llvm-readelf -relocations --wide %t | FileCheck --check-prefix=OutputRelocs %s
+// RUN: llvm-objdump --section-headers %t | FileCheck --check-prefix=CheckGot %s
+// RUN: llvm-objdump -D %t | FileCheck --check-prefix=Dis %s
+
+// RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
+// RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %p/Inputs/ppc64-tls.s -o %t2.o
+// RUN: ld.lld -shared %t2.o -o %t2.so
+// RUN: ld.lld -dynamic-linker /lib64/ld64.so.2 %t.o %t2.so -o %t
+// RUN: llvm-readelf -relocations --wide %t.o | FileCheck --check-prefix=InputRelocs %s
+// RUN: llvm-readelf -relocations --wide %t | FileCheck --check-prefix=OutputRelocs %s
+// RUN: llvm-objdump --section-headers %t | FileCheck --check-prefix=CheckGot %s
+// RUN: llvm-objdump -D %t | FileCheck --check-prefix=Dis %s
+
+	.text
+	.abiversion 2
+	.file	"intial_exec.c"
+	.globl	test_initial_exec                    # -- Begin function test_initial_exec
+	.p2align	4
+	.type	test_initial_exec, at function
+test_initial_exec:                                   # @test_initial_exec
+.Lfunc_begin0:
+.Lfunc_gep0:
+	addis 2, 12, .TOC.-.Lfunc_gep0 at ha
+	addi 2, 2, .TOC.-.Lfunc_gep0 at l
+.Lfunc_lep0:
+	.localentry	test_initial_exec, .Lfunc_lep0-.Lfunc_gep0
+# %bb.0:                                # %entry
+	li 3, 0
+	stw 3, -12(1)
+	addis 3, 2, a at got@tprel at ha
+	ld 3, a at got@tprel at l(3)
+	lwzx 4, 3, a at tls
+	extsw 3, 4
+	blr
+
+
+test_hi:
+.Lfunc_gep1:
+  addis 2, 12, .TOC.-.Lfunc_gep1 at ha
+  addi  2, 2,  .TOC.-.Lfunc_gep1 at l
+.Lfunc_lep1:
+  .localentry test2, .Lfunc_lep1-.Lfunc_gep1
+  addis 3, 0, b at got@tprel at h
+  blr
+
+test_ds:
+.Lfunc_gep2:
+  addis 2, 12, .TOC.-.Lfunc_gep2 at ha
+  addi 2, 2, .TOC.-.Lfunc_gep2 at l
+.Lfunc_lep2:
+  .localentry test16, .Lfunc_lep2-.Lfunc_gep2
+  addi 3, 0, c at got@tprel
+  blr
+
+// Verify that the input has every initial-exec tls relocation type.
+// InputRelocs: Relocation section '.rela.text'
+// InputRelocs: R_PPC64_GOT_TPREL16_HA {{0+}} a + 0
+// InputRelocs: R_PPC64_GOT_TPREL16_LO_DS {{0+}} a + 0
+// InputRelocs: R_PPC64_TLS {{0+}} a + 0
+// InputRelocs: R_PPC64_GOT_TPREL16_HI {{0+}} b + 0
+// InputRelocs: R_PPC64_GOT_TPREL16_DS {{0+}} c + 0
+
+// There is a got entry for each tls variable that is accessed with the
+// initial-exec model to be filled in by the dynamic linker.
+// OutputRelocs: Relocation section '.rela.dyn' at offset 0x{{[0-9a-f]+}} contains 3 entries:
+// OutputRelocs: R_PPC64_TPREL64  {{0+}}  a + 0
+// OutputRelocs: R_PPC64_TPREL64  {{0+}}  b + 0
+// OutputRelocs: R_PPC64_TPREL64  {{0+}}  c + 0
+
+// Check that the got has 4 entires. (1 for the TOC and 3 entries for TLS
+// variables). Also verify the address so we can check
+// the offsets we calculated for each relocation type.
+// CheckGot: got          00000020 00000000100200c0
+
+// GOT stats at 0x100200c0, so TOC will be 0x100280c0
+
+// We are building the address of the first TLS got entry which contains the
+// offset of the tls variable relative to the thread pointer.
+// 0x100200c8 (got[1]).
+// #ha(a at got@tprel) --> (0x100200c8 - 0x100280c0 + 0x8000) >> 16 = 0
+// #lo(a at got@tprel)) --> (0x100200c8 - 0x100280c0) & 0xFFFF =  -7ff8 = -32760
+// Dis:  test_initial_exec:
+// Dis:    addis 3, 2, 0
+// Dis:    ld 3, -32760(3)
+// Dis:    lwzx 4, 3, 13
+
+// Second TLS got entry starts at got[2] 0x100200d0
+// #hi(b at got@tprel) --> (0x100200d0 - 0x100280c0) >> 16 = -1
+// Dis: test_hi:
+// Dis:   lis 3, -1
+
+// Third TLS got entry starts at got[3] 0x100200d8.
+// c at got@tprel--> (0x100200d8. -  0x100280c0) = -0x7fe8 = 32744
+// Dis: test_ds:
+// Dis:   li 3, -32744




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