Index: ELF/Config.h =================================================================== --- ELF/Config.h +++ ELF/Config.h @@ -158,6 +158,7 @@ bool OFormatBinary; bool Omagic; bool OptRemarksWithHotness; + bool PicThunk; bool Pie; bool PrintGcSections; bool PrintIcfSections; Index: ELF/Driver.cpp =================================================================== --- ELF/Driver.cpp +++ ELF/Driver.cpp @@ -1007,6 +1007,7 @@ Config->Endianness = Config->IsLE ? endianness::little : endianness::big; Config->IsMips64EL = (K == ELF64LEKind && M == EM_MIPS); Config->Pic = Config->Pie || Config->Shared; + Config->PicThunk = Args.hasArg(OPT_pic_thunk, Config->Pic); Config->Wordsize = Config->Is64 ? 8 : 4; // ELF defines two different ways to store relocation addends as shown below: Index: ELF/Options.td =================================================================== --- ELF/Options.td +++ ELF/Options.td @@ -255,6 +255,9 @@ "Use SHT_ANDROID_RELR / DT_ANDROID_RELR* tags instead of SHT_RELR / DT_RELR*", "Use SHT_RELR / DT_RELR* tags (default)">; +def pic_thunk: F<"pic-thunk">, + HelpText<"Always generate position independent thunks">; + defm pie: B<"pie", "Create a position independent executable", "Do not create a position independent executable (default)">; @@ -407,6 +410,7 @@ def: Flag<["-"], "N">, Alias, HelpText<"Alias for --omagic">; def: Joined<["--"], "output=">, Alias, HelpText<"Alias for -o">; def: Separate<["--"], "output">, Alias, HelpText<"Alias for -o">; +def: F<"pic-veneer">, Alias, HelpText<"Alias for --pic-thunk">; def: F<"pic-executable">, Alias, HelpText<"Alias for --pie">; def: Flag<["-"], "M">, Alias, HelpText<"Alias for --print-map">; def: Flag<["-"], "r">, Alias, HelpText<"Alias for --relocatable">; Index: ELF/Thunks.cpp =================================================================== --- ELF/Thunks.cpp +++ ELF/Thunks.cpp @@ -653,7 +653,7 @@ static Thunk *addThunkAArch64(RelType Type, Symbol &S) { if (Type != R_AARCH64_CALL26 && Type != R_AARCH64_JUMP26) fatal("unrecognized relocation type"); - if (Config->Pic) + if (Config->PicThunk) return make(S); return make(S); } @@ -670,7 +670,7 @@ case R_ARM_JUMP24: case R_ARM_CALL: case R_ARM_THM_CALL: - if (Config->Pic) + if (Config->PicThunk) return make(S); return make(S); } @@ -707,13 +707,13 @@ case R_ARM_PLT32: case R_ARM_JUMP24: case R_ARM_CALL: - if (Config->Pic) + if (Config->PicThunk) return make(S); return make(S); case R_ARM_THM_JUMP19: case R_ARM_THM_JUMP24: case R_ARM_THM_CALL: - if (Config->Pic) + if (Config->PicThunk) return make(S); return make(S); } @@ -733,7 +733,7 @@ if (S.isInPlt()) return make(S); - if (Config->Pic) + if (Config->PicThunk) return make(S); return make(S); Index: docs/ld.lld.1 =================================================================== --- docs/ld.lld.1 +++ docs/ld.lld.1 @@ -311,6 +311,8 @@ .Ar file . .It Fl -opt-remarks-with-hotness Include hotness information in the optimization remarks file. +.It Fl -pic-thunk +Always generate position independent thunks. .It Fl -pie Create a position independent executable. .It Fl -print-gc-sections Index: test/ELF/arm-force-pi-thunk.s =================================================================== --- /dev/null +++ test/ELF/arm-force-pi-thunk.s @@ -0,0 +1,89 @@ +// REQUIRES: arm +// RUN: llvm-mc -arm-add-build-attributes -filetype=obj -triple=armv7a-none-linux-gnueabi %s -o %t +// RUN: echo "SECTIONS { \ +// RUN: . = SIZEOF_HEADERS; \ +// RUN: .text_low : { *(.text_low) *(.text_low2) } \ +// RUN: .text_high 0x2000000 : { *(.text_high) *(.text_high2) } \ +// RUN: } " > %t.script +// RUN: ld.lld --pic-thunk --script %t.script %t -o %t2 2>&1 +// RUN: llvm-objdump -d -triple=thumbv7a-none-linux-gnueabi %t2 | FileCheck %s +// RUN: ld.lld --pic-veneer --script %t.script %t -o %t2v 2>&1 +// RUN: llvm-objdump -d -triple=thumbv7a-none-linux-gnueabi %t2v | FileCheck %s + +// Test that we can force generation of position independent thunks even when +// inputs are not pic. Also test command line alias --pic-veneer. + + .syntax unified + .section .text_low, "ax", %progbits + .thumb + .globl _start +_start: bx lr + .globl low_target + .type low_target, %function +low_target: + bl high_target + bl high_target2 + + .section .text_low2, "ax", %progbits + .thumb + .globl low_target2 + .type low_target2, %function +low_target2: + bl high_target + bl high_target2 + +// CHECK: Disassembly of section .text_low: +// CHECK-NEXT: _start: +// CHECK-NEXT: 94: 70 47 bx lr +// CHECK: low_target: +// CHECK-NEXT: 96: 00 f0 03 f8 bl #6 +// CHECK-NEXT: 9a: 00 f0 07 f8 bl #14 +// CHECK-NEXT: 9e: d4 d4 bmi #-88 +// CHECK: __ThumbV7PILongThunk_high_target: +// CHECK-NEXT: a0: 4f f6 55 7c movw r12, #65365 +// CHECK-NEXT: a4: c0 f2 ff 1c movt r12, #511 +// CHECK-NEXT: a8: fc 44 add r12, pc +// CHECK-NEXT: aa: 60 47 bx r12 +// CHECK: __ThumbV7PILongThunk_high_target2: +// CHECK-NEXT: ac: 4f f6 69 7c movw r12, #65385 +// CHECK-NEXT: b0: c0 f2 ff 1c movt r12, #511 +// CHECK-NEXT: b4: fc 44 add r12, pc +// CHECK-NEXT: b6: 60 47 bx r12 +// CHECK: low_target2: +// CHECK-NEXT: b8: ff f7 f2 ff bl #-28 +// CHECK-NEXT: bc: ff f7 f6 ff bl #-20 + + + .section .text_high, "ax", %progbits + .thumb + .globl high_target + .type high_target, %function +high_target: + bl low_target + bl low_target2 + + .section .text_high2, "ax", %progbits + .thumb + .globl high_target2 + .type high_target2, %function +high_target2: + bl low_target + bl low_target2 + +// CHECK: Disassembly of section .text_high: +// CHECK-NEXT: high_target: +// CHECK-NEXT: 2000000: 00 f0 02 f8 bl #4 +// CHECK-NEXT: 2000004: 00 f0 06 f8 bl #12 +// CHECK: __ThumbV7PILongThunk_low_target: +// CHECK-NEXT: 2000008: 40 f2 83 0c movw r12, #131 +// CHECK-NEXT: 200000c: cf f6 00 6c movt r12, #65024 +// CHECK-NEXT: 2000010: fc 44 add r12, pc +// CHECK-NEXT: 2000012: 60 47 bx r12 +// CHECK: __ThumbV7PILongThunk_low_target2: +// CHECK-NEXT: 2000014: 40 f2 99 0c movw r12, #153 +// CHECK-NEXT: 2000018: cf f6 00 6c movt r12, #65024 +// CHECK-NEXT: 200001c: fc 44 add r12, pc +// CHECK-NEXT: 200001e: 60 47 bx r12 +// CHECK: high_target2: +// CHECK-NEXT: 2000020: ff f7 f2 ff bl #-28 +// CHECK-NEXT: 2000024: ff f7 f6 ff bl #-20