[Hexagon] Fix issue with non-preemptible STT_TLS symbols
A PC-relative relocation referencing a non-preemptible absolute symbol
(due to STT_TLS) is not representable in -pie/-shared mode.
Differential Revision: https://reviews.llvm.org/D77021
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 41a0cea..21fec6e 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -1334,7 +1334,10 @@
// stub type. It should be ignored if optimized to R_PC.
if (config->emachine == EM_PPC && expr == R_PPC32_PLTREL)
addend &= ~0x8000;
- expr = fromPlt(expr);
+ // R_HEX_GD_PLT_B22_PCREL (call a@GDPLT) is transformed into
+ // call __tls_get_addr even if the symbol is non-preemptible.
+ if (!(config->emachine == EM_HEXAGON && type == R_HEX_GD_PLT_B22_PCREL))
+ expr = fromPlt(expr);
}
}
diff --git a/lld/test/ELF/hexagon-tls-gd-nonpreemptible.s b/lld/test/ELF/hexagon-tls-gd-nonpreemptible.s
new file mode 100644
index 0000000..ba0eee9
--- /dev/null
+++ b/lld/test/ELF/hexagon-tls-gd-nonpreemptible.s
@@ -0,0 +1,39 @@
+
+# REQUIRES: hexagon
+# RUN: llvm-mc -filetype=obj -triple=hexagon-unknown-elf %s -o %t.o
+# RUN: ld.lld -shared %t.o -o %t.so
+# RUN: llvm-readobj -r %t.so | FileCheck --check-prefix=RELOC %s
+# RUN: llvm-objdump -d --no-show-raw-insn --print-imm-hex %t.so | FileCheck %s
+
+## Prior to D77021 lld would error "relocation R_HEX_GD_PLT_B22_PCREL cannot refer to absolute symbol".
+## A PC-relative relocation referencing a non-preemptible absolute symbol (due to STT_TLS) is not representable in -pie/-shared mode.
+## For this case we will actually patch the symbol to the external __tls_get_addr which is preemptible.
+
+.globl _start
+.type _start, @function
+
+# RELOC: Section ({{.*}}) .rela.plt {
+# RELOC-NEXT: R_HEX_JMP_SLOT - 0x0
+# RELOC-NEXT: R_HEX_JMP_SLOT __tls_get_addr 0x0
+# RELOC-NEXT: }
+
+# CHECK: { immext(#{{.*}})
+# CHECK-NEXT: r2 = add(pc,##{{.*}}) }
+# CHECK-NEXT: { immext(#{{.*}})
+# CHECK-NEXT: r0 = add(r2,##-{{.*}}) }
+# CHECK-NEXT: { call {{.*}} }
+# CHECK-NEXT: { r0 = memw(r0+#0x0) }
+
+_start:
+ r2 = add(pc,##_GLOBAL_OFFSET_TABLE_@PCREL)
+ r0 = add(r2,##a@GDGOT)
+ call a@GDPLT
+ r0 = memw(r0+#0)
+
+## a is non-preemptible due to STV_HIDDEN visibility.
+## We can achieve the same effect with -Bsymbolic.
+.section .tdata,"awT",@progbits
+.globl a
+.hidden a
+a:
+.word 1