[llvm-branch-commits] [lld] [llvm] release/18.x: [RISCV][lld] Set the type of TLSDESC relocation's referenced local symbol to STT_NOTYPE (PR #91678)

via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Thu May 9 16:11:25 PDT 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lld-elf

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport f6f474c4ef9694a4ca8f08d59fd112c250fb9c73 dfe4ca9b7f4a422500d78280dc5eefd1979939e6

Requested by: @<!-- -->ilovepi

---
Full diff: https://github.com/llvm/llvm-project/pull/91678.diff


5 Files Affected:

- (modified) lld/ELF/Relocations.cpp (+4-1) 
- (modified) lld/test/ELF/riscv-tlsdesc-relax.s (+8) 
- (modified) lld/test/ELF/riscv-tlsdesc.s (+35-5) 
- (modified) llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp (-2) 
- (added) llvm/test/CodeGen/RISCV/tlsdesc-symbol.ll (+24) 


``````````diff
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 619fbaf5dc545..92a1b9baaca3d 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -1480,7 +1480,10 @@ template <class ELFT, class RelTy> void RelocationScanner::scanOne(RelTy *&i) {
 
   // Process TLS relocations, including TLS optimizations. Note that
   // R_TPREL and R_TPREL_NEG relocations are resolved in processAux.
-  if (sym.isTls()) {
+  //
+  // Some RISCV TLSDESC relocations reference a local NOTYPE symbol,
+  // but we need to process them in handleTlsRelocation.
+  if (sym.isTls() || oneof<R_TLSDESC_PC, R_TLSDESC_CALL>(expr)) {
     if (unsigned processed =
             handleTlsRelocation(type, sym, *sec, offset, addend, expr)) {
       i += processed - 1;
diff --git a/lld/test/ELF/riscv-tlsdesc-relax.s b/lld/test/ELF/riscv-tlsdesc-relax.s
index fb24317e6535c..5718d4175be11 100644
--- a/lld/test/ELF/riscv-tlsdesc-relax.s
+++ b/lld/test/ELF/riscv-tlsdesc-relax.s
@@ -33,12 +33,14 @@
 # GD64-NEXT:         c.add   a0, tp
 # GD64-NEXT:         jal     {{.*}} <foo>
 ## &.got[c]-. = 0x20c0+8 - 0x1020 = 0x10a8
+# GD64-LABEL: <.Ltlsdesc_hi1>:
 # GD64-NEXT:   1020: auipc   a4, 0x1
 # GD64-NEXT:         ld      a5, 0xa8(a4)
 # GD64-NEXT:         addi    a0, a4, 0xa8
 # GD64-NEXT:         jalr    t0, 0x0(a5)
 # GD64-NEXT:         c.add   a0, tp
 ## &.got[c]-. = 0x20c0+8 - 0x1032 = 0x1096
+# GD64-LABEL: <.Ltlsdesc_hi2>:
 # GD64-NEXT:   1032: auipc   a6, 0x1
 # GD64-NEXT:         ld      a7, 0x96(a6)
 # GD64-NEXT:         addi    a0, a6, 0x96
@@ -64,6 +66,7 @@
 # LE64-NEXT:         jal     {{.*}} <foo>
 # LE64-NEXT:                 R_RISCV_JAL foo
 # LE64-NEXT:                 R_RISCV_RELAX *ABS*
+# LE64-LABEL: <.Ltlsdesc_hi1>:
 # LE64-NEXT:         addi    a0, zero, 0x7ff
 # LE64-NEXT:                 R_RISCV_TLSDESC_HI20 b
 # LE64-NEXT:                 R_RISCV_RELAX *ABS*
@@ -71,6 +74,7 @@
 # LE64-NEXT:                 R_RISCV_TLSDESC_ADD_LO12 .Ltlsdesc_hi1
 # LE64-NEXT:                 R_RISCV_TLSDESC_CALL .Ltlsdesc_hi1
 # LE64-NEXT:         c.add   a0, tp
+# LE64-LABEL: <.Ltlsdesc_hi2>:
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:                 R_RISCV_TLSDESC_HI20 b
 # LE64-NEXT:         addi    zero, zero, 0x0
@@ -93,9 +97,11 @@
 # LE64A-NEXT:         addi    a0, a0, -0x479
 # LE64A-NEXT:         c.add   a0, tp
 # LE64A-NEXT:         jal     {{.*}} <foo>
+# LE64A-LABEL: <.Ltlsdesc_hi1>:
 # LE64A-NEXT:         lui     a0, 0x2
 # LE64A-NEXT:         addi    a0, a0, -0x479
 # LE64A-NEXT:         c.add   a0, tp
+# LE64A-LABEL: <.Ltlsdesc_hi2>:
 # LE64A-NEXT:         addi    zero, zero, 0x0
 # LE64A-NEXT:         addi    zero, zero, 0x0
 # LE64A-NEXT:         lui     a0, 0x2
@@ -115,10 +121,12 @@
 # IE64-NEXT:         c.add   a0, tp
 # IE64-NEXT:         jal     {{.*}} <foo>
 ## &.got[c]-. = 0x120e0+8 - 0x11018 = 0x10d0
+# IE64-LABEL: <.Ltlsdesc_hi1>:
 # IE64-NEXT:  11018: auipc   a0, 0x1
 # IE64-NEXT:         ld      a0, 0xd0(a0)
 # IE64-NEXT:         c.add   a0, tp
 ## &.got[c]-. = 0x120e0+8 - 0x1102a = 0x10be
+# IE64-LABEL: <.Ltlsdesc_hi2>:
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:  1102a: auipc   a0, 0x1
diff --git a/lld/test/ELF/riscv-tlsdesc.s b/lld/test/ELF/riscv-tlsdesc.s
index 1738f86256caa..935ecbddfbfff 100644
--- a/lld/test/ELF/riscv-tlsdesc.s
+++ b/lld/test/ELF/riscv-tlsdesc.s
@@ -29,6 +29,14 @@
 # RUN: ld.lld -e 0 -z now a.32.o c.32.so -o a.32.ie
 # RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.32.ie | FileCheck %s --check-prefix=IE32
 
+## Prior to https://github.com/llvm/llvm-project/pull/85817 the local TLSDESC
+## labels would be marked STT_TLS, resulting in an error "has an STT_TLS symbol but doesn't have an SHF_TLS section"
+
+# RUN: llvm-mc -triple=riscv64 -filetype=obj d.s -o d.64.o
+# RUN: ld.lld -shared -soname=d.64.so -o d.64.so d.64.o --fatal-warnings
+# RUN: llvm-mc -triple=riscv32 -filetype=obj d.s -o d.32.o --defsym ELF32=1
+# RUN: ld.lld -shared -soname=d.32.so -o d.32.so d.32.o --fatal-warnings
+
 # GD64-RELA:      .rela.dyn {
 # GD64-RELA-NEXT:   0x2408 R_RISCV_TLSDESC - 0x7FF
 # GD64-RELA-NEXT:   0x23E8 R_RISCV_TLSDESC a 0x0
@@ -68,14 +76,14 @@
 # GD64-NEXT:         add     a0, a0, tp
 
 ## &.got[b]-. = 0x23e0+40 - 0x12f4 = 0x1114
-# GD64-NEXT:   12f4: auipc   a2, 0x1
+# GD64:        12f4: auipc   a2, 0x1
 # GD64-NEXT:         ld      a3, 0x114(a2)
 # GD64-NEXT:         addi    a0, a2, 0x114
 # GD64-NEXT:         jalr    t0, 0x0(a3)
 # GD64-NEXT:         add     a0, a0, tp
 
 ## &.got[c]-. = 0x23e0+24 - 0x1308 = 0x10f0
-# GD64-NEXT:   1308: auipc   a4, 0x1
+# GD64:        1308: auipc   a4, 0x1
 # GD64-NEXT:         ld      a5, 0xf0(a4)
 # GD64-NEXT:         addi    a0, a4, 0xf0
 # GD64-NEXT:         jalr    t0, 0x0(a5)
@@ -83,7 +91,7 @@
 
 # NOREL: no relocations
 
-# LE64-LABEL: <.text>:
+# LE64-LABEL: <.Ltlsdesc_hi0>:
 ## st_value(a) = 8
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:         addi    zero, zero, 0x0
@@ -91,12 +99,14 @@
 # LE64-NEXT:         addi    a0, zero, 0x8
 # LE64-NEXT:         add     a0, a0, tp
 ## st_value(b) = 2047
+# LE64-LABEL: <.Ltlsdesc_hi1>:
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:         addi    a0, zero, 0x7ff
 # LE64-NEXT:         add     a0, a0, tp
 ## st_value(c) = 2048
+# LE64-LABEL: <.Ltlsdesc_hi2>:
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:         addi    zero, zero, 0x0
 # LE64-NEXT:         lui     a0, 0x1
@@ -110,18 +120,20 @@
 # IE64:       .got     00000010 00000000000123a8
 
 ## a and b are optimized to use LE. c is optimized to IE.
-# IE64-LABEL: <.text>:
+# IE64-LABEL: <.Ltlsdesc_hi0>:
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    a0, zero, 0x8
 # IE64-NEXT:         add     a0, a0, tp
+# IE64-LABEL: <.Ltlsdesc_hi1>:
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    a0, zero, 0x7ff
 # IE64-NEXT:         add     a0, a0, tp
 ## &.got[c]-. = 0x123a8+8 - 0x112b8 = 0x10f8
+# IE64-LABEL: <.Ltlsdesc_hi2>:
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:         addi    zero, zero, 0x0
 # IE64-NEXT:  112b8: auipc   a0, 0x1
@@ -130,7 +142,7 @@
 
 # IE32:       .got     00000008 00012248
 
-# IE32-LABEL: <.text>:
+# IE32-LABEL: <.Ltlsdesc_hi0>:
 ## st_value(a) = 8
 # IE32-NEXT:         addi    zero, zero, 0x0
 # IE32-NEXT:         addi    zero, zero, 0x0
@@ -138,12 +150,14 @@
 # IE32-NEXT:         addi    a0, zero, 0x8
 # IE32-NEXT:         add     a0, a0, tp
 ## st_value(b) = 2047
+# IE32-LABEL: <.Ltlsdesc_hi1>:
 # IE32-NEXT:         addi    zero, zero, 0x0
 # IE32-NEXT:         addi    zero, zero, 0x0
 # IE32-NEXT:         addi    zero, zero, 0x0
 # IE32-NEXT:         addi    a0, zero, 0x7ff
 # IE32-NEXT:         add     a0, a0, tp
 ## &.got[c]-. = 0x12248+4 - 0x111cc = 0x1080
+# IE32-LABEL: <.Ltlsdesc_hi2>:
 # IE32-NEXT:         addi    zero, zero, 0x0
 # IE32-NEXT:         addi    zero, zero, 0x0
 # IE32-NEXT:  111cc: auipc   a0, 0x1
@@ -192,3 +206,19 @@ b:
 .tbss
 .globl c
 c: .zero 4
+
+#--- d.s
+.macro load dst, src
+.ifdef ELF32
+lw \dst, \src
+.else
+ld \dst, \src
+.endif
+.endm
+
+.Ltlsdesc_hi0:
+  auipc	a0, %tlsdesc_hi(foo)
+  load	a1, %tlsdesc_load_lo(.Ltlsdesc_hi0)(a0)
+  addi	a0, a0, %tlsdesc_add_lo(.Ltlsdesc_hi0)
+  jalr	t0, 0(a1), %tlsdesc_call(.Ltlsdesc_hi0)
+  add	a1, a0, tp
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
index 254a9a4bc0ef0..b8e0f3a867f40 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
@@ -207,8 +207,6 @@ void RISCVMCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
   case VK_RISCV_TLS_GOT_HI:
   case VK_RISCV_TLS_GD_HI:
   case VK_RISCV_TLSDESC_HI:
-  case VK_RISCV_TLSDESC_ADD_LO:
-  case VK_RISCV_TLSDESC_LOAD_LO:
     break;
   }
 
diff --git a/llvm/test/CodeGen/RISCV/tlsdesc-symbol.ll b/llvm/test/CodeGen/RISCV/tlsdesc-symbol.ll
new file mode 100644
index 0000000000000..23ba2ffb1ad76
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/tlsdesc-symbol.ll
@@ -0,0 +1,24 @@
+;; The test in this file do not appear in tls-models.ll because
+;; they are not auto-generated.
+; RUN: llc -mtriple=riscv64 -relocation-model=pic -enable-tlsdesc < %s \
+; RUN:     | llvm-mc -triple=riscv64 -filetype=obj -o - \
+; RUN:     | llvm-readelf --symbols - \
+; RUN:     | FileCheck %s
+
+; RUN: llc -mtriple=riscv32 -relocation-model=pic -enable-tlsdesc < %s \
+; RUN:     | llvm-mc -triple=riscv32 -filetype=obj -o - \
+; RUN:     | llvm-readelf --symbols - \
+; RUN:     | FileCheck %s
+
+; Check that TLS symbols are lowered correctly based on the specified
+; model. Make sure they're external to avoid them all being optimised to Local
+; Exec for the executable.
+
+ at unspecified = external thread_local global i32
+
+define ptr @f1() nounwind {
+entry:
+  ret ptr @unspecified
+  ; CHECK: Symbol table '.symtab' contains 7 entries:
+  ; CHECK: TLS {{.*}} unspecified
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/91678


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