[PATCH] LoongArch: Adapt R_LARCH_{PCALA, GOT, TLS_IE, TLS_DESC}64_* handling per psABI v2.30
mengqinggang
mengqinggang@loongson.cn
Tue Jan 16 06:38:32 GMT 2024
在 2024/1/15 下午8:44, Xi Ruoyao 写道:
> In LoongArch psABI v2.30, an offset (-8 for LO20 and -12 for HI12)
> should be applied on PC for these reloc types to avoid wrong relocation
> when the instruction sequence crosses a page boundary.
>
> The lld linker has already adapted the change. Make it for the bfd
> linker too.
>
> Link: https://github.com/loongson/la-abi-specs/releases/v2.30
> Link: https://github.com/loongson-community/discussions/issues/17
> Link: https://github.com/llvm/llvm-project/pull/73387
> Signed-off-by: Xi Ruoyao <xry111@xry111.site>
> ---
> bfd/elfnn-loongarch.c | 29 +++++++++++--------
> .../ld-loongarch-elf/ld-loongarch-elf.exp | 1 +
> ld/testsuite/ld-loongarch-elf/pcala64.d | 15 ++++++++++
> ld/testsuite/ld-loongarch-elf/pcala64.s | 8 +++++
> 4 files changed, 41 insertions(+), 12 deletions(-)
> create mode 100644 ld/testsuite/ld-loongarch-elf/pcala64.d
> create mode 100644 ld/testsuite/ld-loongarch-elf/pcala64.s
>
> diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
> index 3858a3179fd..e4f4da7a0dc 100644
> --- a/bfd/elfnn-loongarch.c
> +++ b/bfd/elfnn-loongarch.c
> @@ -3544,14 +3544,16 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
> }
> break;
>
> - case R_LARCH_PCALA64_LO20:
> case R_LARCH_PCALA64_HI12:
> + pc -= 4;
> + /* Fall through. */
> + case R_LARCH_PCALA64_LO20:
> if (h && h->plt.offset != MINUS_ONE)
> relocation = sec_addr (plt) + h->plt.offset;
> else
> relocation += rel->r_addend;
>
> - RELOCATE_CALC_PC64_HI32 (relocation, pc);
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 8);
The 'pc - 8' triggered an error because the pc parameter is not enclosed
in parentheses in macro definition.
/home/mengqinggang/toolchains/src/binutils-gdb/bfd/elfnn-loongarch.c:3546:51:
error: suggest parentheses around '-' in operand of '&'
[-Werror=parentheses]
3546 | RELOCATE_CALC_PC64_HI32 (relocation, pc - 8);
| ~~~^~~
/home/mengqinggang/toolchains/src/binutils-gdb/bfd/elfnn-loongarch.c:2532:22:
note: in definition of macro 'RELOCATE_CALC_PC64_HI32'
2532 | - (pc & ~(bfd_vma)0xfff); \
| ^~
>
> break;
>
> @@ -3678,9 +3680,10 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
> relocation = got_off + sec_addr (got);
> }
>
> - if (r_type == R_LARCH_GOT64_PC_HI12
> - || r_type == R_LARCH_GOT64_PC_LO20)
> - RELOCATE_CALC_PC64_HI32 (relocation, pc);
> + if (r_type == R_LARCH_GOT64_PC_HI12)
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 12);
> + else if (r_type == R_LARCH_GOT64_PC_LO20)
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 8);
>
> break;
>
> @@ -3881,13 +3884,14 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
> /* Use both TLS_GD and TLS_DESC. */
> if ((tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_GDESC))
> relocation += 2 * GOT_ENTRY_SIZE;
> - }
>
> - if (r_type == R_LARCH_TLS_DESC64_PC_LO20
> - || r_type == R_LARCH_TLS_DESC64_PC_HI12)
> - RELOCATE_CALC_PC64_HI32 (relocation, pc);
> + if (r_type == R_LARCH_TLS_DESC64_PC_LO20)
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 8);
> + else if (r_type == R_LARCH_TLS_DESC64_PC_HI12)
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 12);
>
> break;
> + }
>
> case R_LARCH_TLS_DESC_LD:
> case R_LARCH_TLS_DESC_CALL:
> @@ -3916,9 +3920,10 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
> else if (GOT_TLS_GD_ANY_P (tls_type) && (tls_type & GOT_TLS_IE))
> relocation += 2 * GOT_ENTRY_SIZE;
>
> - if (r_type == R_LARCH_TLS_IE64_PC_LO20
> - || r_type == R_LARCH_TLS_IE64_PC_HI12)
> - RELOCATE_CALC_PC64_HI32 (relocation, pc);
> + if (r_type == R_LARCH_TLS_IE64_PC_LO20)
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 8);
> + else if (r_type == R_LARCH_TLS_IE64_PC_HI12)
> + RELOCATE_CALC_PC64_HI32 (relocation, pc - 12);
>
> break;
>
> diff --git a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
> index 6ab87163039..2ff06d62236 100644
> --- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
> +++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
> @@ -26,6 +26,7 @@ if [istarget "loongarch64-*-*"] {
> run_dump_test "disas-jirl"
> run_dump_test "local-ifunc-reloc"
> run_dump_test "anno-sym"
> + run_dump_test "pcala64"
> }
>
> if [istarget "loongarch32-*-*"] {
> diff --git a/ld/testsuite/ld-loongarch-elf/pcala64.d b/ld/testsuite/ld-loongarch-elf/pcala64.d
> new file mode 100644
> index 00000000000..6b1411577db
> --- /dev/null
> +++ b/ld/testsuite/ld-loongarch-elf/pcala64.d
> @@ -0,0 +1,15 @@
> +#ld: -Ttext=0x180000ff8 -Tdata=0x1000000000 -shared
The test need to be disabled on loongarch*-elf target because -shared
option is not supported on loongarch*-elf target.
It can be disabled by adding a line "#skip: loongarch*-elf" after
"#objdump -d".
> +#objdump: -d
> +
> +.*:[ ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0000000180000ff8 <_start>:
> +[ ]+180000ff8:[ ]+1b000004[ ]+pcalau12i[ ]+\$a0,[ ]+-524288
> +[ ]+180000ffc:[ ]+02c0000c[ ]+li.d[ ]+\$t0,[ ]+0
> +[ ]+180001000:[ ]+160001ec[ ]+lu32i.d[ ]+\$t0,[ ]+15
> +[ ]+180001004:[ ]+0300018c[ ]+lu52i.d[ ]+\$t0,[ ]+\$t0,[ ]+0
> +[ ]+180001008:[ ]+0010b084[ ]+add.d[ ]+\$a0,[ ]+\$a0,[ ]+\$t0
> +[ ]+18000100c:[ ]+4c000020[ ]+ret
> diff --git a/ld/testsuite/ld-loongarch-elf/pcala64.s b/ld/testsuite/ld-loongarch-elf/pcala64.s
> new file mode 100644
> index 00000000000..dfef0e2b7b7
> --- /dev/null
> +++ b/ld/testsuite/ld-loongarch-elf/pcala64.s
> @@ -0,0 +1,8 @@
> +.text
> +.globl _start
> +_start:
> + la.pcrel $a0, $t0, sym
> + jr $ra
> +.data
> +sym:
> + .dword 0
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