Re: [PATCH v2 2/2] aarch64: Test DT_RELR with discarded sections

[Alan Modra <amodra@gmail.com>]

On Tue, Jun 04, 2024 at 06:41:45PM +0100, Szabolcs Nagy wrote:
> ---
>  ld/testsuite/ld-aarch64/aarch64-elf.exp       |  2 +
>  ld/testsuite/ld-aarch64/relr-discard-pie.d    | 15 +++++
>  ld/testsuite/ld-aarch64/relr-discard-shared.d | 15 +++++
>  ld/testsuite/ld-aarch64/relr-discard.ld       | 13 ++++
>  ld/testsuite/ld-aarch64/relr-discard.s        | 63 +++++++++++++++++++
>  5 files changed, 108 insertions(+)
>  create mode 100644 ld/testsuite/ld-aarch64/relr-discard-pie.d
>  create mode 100644 ld/testsuite/ld-aarch64/relr-discard-shared.d
>  create mode 100644 ld/testsuite/ld-aarch64/relr-discard.ld
>  create mode 100644 ld/testsuite/ld-aarch64/relr-discard.s
> 
> diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp
> index 38929ffc3c6..0e70ca3e028 100644
> --- a/ld/testsuite/ld-aarch64/aarch64-elf.exp
> +++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp
> @@ -475,6 +475,8 @@ run_dump_test_lp64 "relr-got-pie"
>  run_dump_test_lp64 "relr-got-shared"
>  run_dump_test_lp64 "relr-text-pie"
>  run_dump_test_lp64 "relr-text-shared"
> +run_dump_test_lp64 "relr-discard-pie"
> +run_dump_test_lp64 "relr-discard-shared"
>  
>  if { ![skip_sframe_tests] } {
>    run_dump_test "sframe-simple-1"
> diff --git a/ld/testsuite/ld-aarch64/relr-discard-pie.d b/ld/testsuite/ld-aarch64/relr-discard-pie.d
> new file mode 100644
> index 00000000000..b1d16e30bc9
> --- /dev/null
> +++ b/ld/testsuite/ld-aarch64/relr-discard-pie.d
> @@ -0,0 +1,15 @@
> +#source: relr-discard.s
> +#ld: -pie --no-apply-dynamic-relocs -z pack-relative-relocs -T relr-discard.ld
> +#readelf: -rW
> +
> +Relocation section '\.rela\.dyn' at offset 0x1.* contains 4 entries:
> +    Offset             Info             Type               Symbol's Value  Symbol's Name \+ Addend
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +

I must say I don't really like matching bad behaviour in a test, but I
guess this ensures you don't have both .rela.dyn and .relr.dyn relocs
against G_O_T, so OK.

> +Relocation section '\.relr\.dyn' at offset 0x1.* contains 2 entries which relocate 2 locations:
> +Index: Entry            Address           Symbolic Address
> +0000:  0000000000020008 0000000000020008  _GLOBAL_OFFSET_TABLE_ \+ 0x8
> +0001:  0000000000000003 0000000000020010  _GLOBAL_OFFSET_TABLE_ \+ 0x10
> diff --git a/ld/testsuite/ld-aarch64/relr-discard-shared.d b/ld/testsuite/ld-aarch64/relr-discard-shared.d
> new file mode 100644
> index 00000000000..b5f3ad87666
> --- /dev/null
> +++ b/ld/testsuite/ld-aarch64/relr-discard-shared.d
> @@ -0,0 +1,15 @@
> +#source: relr-discard.s
> +#ld: -shared --no-apply-dynamic-relocs -z pack-relative-relocs -T relr-discard.ld
> +#readelf: -rW
> +
> +Relocation section '\.rela\.dyn' at offset 0x1.* contains 5 entries:
> +    Offset             Info             Type               Symbol's Value  Symbol's Name \+ Addend
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000000000  0000000000000000 R_AARCH64_NONE                            0
> +0000000000020010  .*00000401 R_AARCH64_GLOB_DAT     000000000001000c sym_global \+ 0
> +
> +Relocation section '\.relr\.dyn' at offset 0x1.* contains 1 entry which relocates 1 location:
> +Index: Entry            Address           Symbolic Address
> +0000:  0000000000020008 0000000000020008  _GLOBAL_OFFSET_TABLE_ \+ 0x8
> diff --git a/ld/testsuite/ld-aarch64/relr-discard.ld b/ld/testsuite/ld-aarch64/relr-discard.ld
> new file mode 100644
> index 00000000000..288ba23e11c
> --- /dev/null
> +++ b/ld/testsuite/ld-aarch64/relr-discard.ld
> @@ -0,0 +1,13 @@
> +OUTPUT_ARCH(aarch64)
> +ENTRY(_start)
> +SECTIONS
> +{
> +  /DISCARD/ : { *(.discard.*) }
> +
> +  . = 0x10000;
> +  .text : { *(.text) }
> +  . = 0x20000;
> +  .got  : { *(.got) *(.got.plt)}
> +  . = 0x30000;
> +  .data : { *(.data) *(.data.*) }
> +}
> diff --git a/ld/testsuite/ld-aarch64/relr-discard.s b/ld/testsuite/ld-aarch64/relr-discard.s
> new file mode 100644
> index 00000000000..0ed9b4a9098
> --- /dev/null
> +++ b/ld/testsuite/ld-aarch64/relr-discard.s
> @@ -0,0 +1,63 @@
> +// Test DT_RELR with references in discarded sections.
> +
> +.text
> +.p2align 3
> +.global _start
> +_start:
> +	nop
> +
> +sym_local:
> +	nop
> +
> +.global sym_hidden
> +.hidden sym_hidden
> +sym_hidden:
> +	nop
> +
> +.global sym_global
> +sym_global:
> +	nop
> +
> +.global sym_global_abs
> +.set sym_global_abs, 42
> +
> +.global sym_weak_undef
> +.weak sym_weak_undef
> +
> +.section .discard.got_local,"ax"
> +	adrp	x0, :got:sym_local
> +	ldr	x0, [x0, :got_lo12:sym_local]
> +
> +.section .discard.got_global,"ax"
> +	adrp	x0, :got:sym_global
> +	ldr	x0, [x0, :got_lo12:sym_global]
> +
> +.section .discard.local,"a"
> +.p2align 1
> +discard_local:
> +.xword sym_local
> +
> +.section .discard.hidden,"a"
> +.p2align 1
> +discard_hidden:
> +.xword sym_hidden
> +
> +.section .discard.global,"a"
> +.p2align 1
> +discard_global:
> +.xword sym_global
> +
> +.section .discard.global_abs,"a"
> +.p2align 1
> +discard_global_abs:
> +.xword sym_global_abs
> +
> +.section .discard.weak_undef,"a"
> +.p2align 1
> +discard_weak_undef:
> +.xword sym_weak_undef
> +
> +.section .discard._DYNAMIC,"a"
> +.p2align 1
> +discard_DYNAMIC:
> +.xword _DYNAMIC
> -- 
> 2.25.1

-- 
Alan Modra