[llvm-branch-commits] [lld] Fix handling of RISCV TLSDESC relocations (PR #85817)
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Tue Mar 19 09:43:12 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lld-elf
Author: Paul Kirth (ilovepi)
<details>
<summary>Changes</summary>
When adding fixups for RISCV_TLSDESC_ADD_LO and RISCV_TLSDESC_LOAD_LO,
the local label added for RISCV TLSDESC relocations have STT_TLS set,
which is incorrect. Instead, these labels should have `STT_NOTYPE`.
This patch stops adding such fixups and avoid setting the STT_TLS on
these symbols. Failing to do so can cause LLD to emit an error `has an
STT_TLS symbol but doesn't have an SHF_TLS section`. We additionally,
adjust how LLD services these relocations to avoid errors with
incompatible relocation and sybol types.
---
Full diff: https://github.com/llvm/llvm-project/pull/85817.diff
4 Files Affected:
- (modified) lld/ELF/Relocations.cpp (+7-2)
- (modified) lld/test/ELF/riscv-tlsdesc-relax.s (+8)
- (modified) lld/test/ELF/riscv-tlsdesc.s (+15-9)
- (modified) llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp (-2)
``````````diff
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 619fbaf5dc5452..241a5b82d35f4a 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -1280,7 +1280,6 @@ static unsigned handleTlsRelocation(RelType type, Symbol &sym,
if (config->emachine == EM_MIPS)
return handleMipsTlsRelocation(type, sym, c, offset, addend, expr);
bool isRISCV = config->emachine == EM_RISCV;
-
if (oneof<R_AARCH64_TLSDESC_PAGE, R_TLSDESC, R_TLSDESC_CALL, R_TLSDESC_PC,
R_TLSDESC_GOTPLT>(expr) &&
config->shared) {
@@ -1480,7 +1479,13 @@ 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()) {
+ if (sym.isTls() ||
+ // These RISCV TLSDESC relocations reference a local symbol that won't be
+ // a TLS symbol, but we need to process them in handleTlsRelocation the
+ // same as other TLS relocations.
+ (config->emachine == EM_RISCV &&
+ (type == R_RISCV_TLSDESC_CALL || type == R_RISCV_TLSDESC_LOAD_LO12 ||
+ type == R_RISCV_TLSDESC_ADD_LO12))) {
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 fb24317e6535ca..5718d4175be113 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 a893d098344d0a..b181f0e9a17a48 100644
--- a/lld/test/ELF/riscv-tlsdesc.s
+++ b/lld/test/ELF/riscv-tlsdesc.s
@@ -30,10 +30,10 @@
# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.32.ie | FileCheck %s --check-prefix=IE32
# RUN: llvm-mc -triple=riscv64 --position-independent -filetype=obj d.s -o d.64.o
-# RUN: not ld.lld -shared -soname=libd.64.so -o libd.64.so d.64.o 2>&1 | FileCheck %s --check-prefix=BADTLSLABEL
+# RUN: ld.lld -shared -soname=libd.64.so -o libd.64.so d.64.o 2>&1 | FileCheck %s --check-prefix=BADTLSLABEL --allow-empty
# RUN: llvm-mc -triple=riscv32 --position-independent -filetype=obj d.s -o d.32.o
-# RUN: not ld.lld -shared -soname=libd.32.so -o libd.32.so d.32.o 2>&1 | FileCheck %s --check-prefix=BADTLSLABEL
+# RUN: ld.lld -shared -soname=libd.32.so -o libd.32.so d.32.o 2>&1 | FileCheck %s --check-prefix=BADTLSLABEL --allow-empty
# GD64-RELA: .rela.dyn {
# GD64-RELA-NEXT: 0x2408 R_RISCV_TLSDESC - 0x7FF
@@ -74,14 +74,14 @@
# 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)
@@ -89,7 +89,7 @@
# 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
@@ -97,12 +97,14 @@
# 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
@@ -116,18 +118,20 @@
# 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
@@ -136,7 +140,7 @@
# 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
@@ -144,20 +148,22 @@
# 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
# IE32-NEXT: lw a0, 0x80(a0)
# IE32-NEXT: add a0, a0, tp
-## FIXME This should not pass, but the code MC layer needs a fix to prevent this.
-# BADTLSLABEL: error: d.{{.*}}.o has an STT_TLS symbol but doesn't have an SHF_TLS section
+# At one point the local TLSDESC labels would be marked STT_TLS, so make sure we don't regress
+# BADTLSLABEL-NOT: error: d.{{.*}}.o has an STT_TLS symbol but doesn't have an SHF_TLS section
#--- a.s
.macro load dst, src
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
index 254a9a4bc0ef0b..b8e0f3a867f402 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;
}
``````````
</details>
https://github.com/llvm/llvm-project/pull/85817
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