[PATCH v1] aarch64: Fix %dtprel relocations size.

[Alice Carlotti]

On Mon, Jul 06, 2026 at 09:49:39AM +0000, srinath.parvathaneni@arm.com wrote:
> From: Srinath Parvathaneni <srinath.parvathaneni@arm.com>
> 
> The AArch64 ELF ABI [1] requires DTPREL relocations to be
> 8 bytes wide, so added a check to reject %dtprel when used
> with anything other than .xword.
> 
> [1] https://github.com/ARM-software/abi-aa/pull/330
> 
> Regression tested on aarch64-linux-gnu and found no regressions.
> 
> Ok for master?
> 
> Regards,
> Srinath
> ---
>  gas/config/tc-aarch64.c                   | 7 +++++++
>  gas/testsuite/gas/aarch64/tls-debug-bad.d | 4 ++++
>  gas/testsuite/gas/aarch64/tls-debug-bad.l | 2 ++
>  gas/testsuite/gas/aarch64/tls-debug-bad.s | 7 +++++++
>  4 files changed, 20 insertions(+)
>  create mode 100644 gas/testsuite/gas/aarch64/tls-debug-bad.d
>  create mode 100644 gas/testsuite/gas/aarch64/tls-debug-bad.l
>  create mode 100644 gas/testsuite/gas/aarch64/tls-debug-bad.s
> 
> diff --git a/gas/config/tc-aarch64.c b/gas/config/tc-aarch64.c
> index 2da5139d8af..43baead03e7 100644
> --- a/gas/config/tc-aarch64.c
> +++ b/gas/config/tc-aarch64.c
> @@ -2234,6 +2234,13 @@ s_aarch64_cons (int nbytes)
>  
>  	      expression (&exp);
>  
> +	      if (nbytes != 8)
> +		{
> +		  as_bad (_("%%dtprel relocation requires .xword"));

.dword is also valid.  Some suggestions:
"%%dtprel relocation requires .xword or .dword"
"%%dtprel relocation produces 64-bit values"
"%%dtprel relocation requires 64-bit values"
"%%dtprel relocation requires 64-bit values (.xword or .dword)"

Ok to merge in 48 hours with any of those suggestions, unless someone comes up
with a better idea first.

Alice


> +		  ignore_rest_of_line ();
> +		  return;
> +		}
> +
>  	      /* Ensure we have a closing parenthesis */
>  	      if (*input_line_pointer == ')')
>  		input_line_pointer++;
> diff --git a/gas/testsuite/gas/aarch64/tls-debug-bad.d b/gas/testsuite/gas/aarch64/tls-debug-bad.d
> new file mode 100644
> index 00000000000..fb1af537d95
> --- /dev/null
> +++ b/gas/testsuite/gas/aarch64/tls-debug-bad.d
> @@ -0,0 +1,4 @@
> +#as:
> +#objdump: -r
> +#target: aarch64*-*-*
> +#error_output: tls-debug-bad.l
> diff --git a/gas/testsuite/gas/aarch64/tls-debug-bad.l b/gas/testsuite/gas/aarch64/tls-debug-bad.l
> new file mode 100644
> index 00000000000..34f24e3aa47
> --- /dev/null
> +++ b/gas/testsuite/gas/aarch64/tls-debug-bad.l
> @@ -0,0 +1,2 @@
> +[^ :]+: Assembler messages:
> +[^ :]+:[0-9]+: Error: %dtprel relocation requires \.xword
> diff --git a/gas/testsuite/gas/aarch64/tls-debug-bad.s b/gas/testsuite/gas/aarch64/tls-debug-bad.s
> new file mode 100644
> index 00000000000..c4987bc3260
> --- /dev/null
> +++ b/gas/testsuite/gas/aarch64/tls-debug-bad.s
> @@ -0,0 +1,7 @@
> +.section .tdata,"awT",@progbits
> +.globl var
> +var:
> +  .word 0
> +
> +.section        .debug_info,"",@progbits
> +  .word  %dtprel(var)
> -- 
> 2.43.0
>