On Sun, Nov 3, 2024 at 9:48 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
>
> When CONFIG_SATA_AHCI_PLATFORM=m, modpost outputs incorect MODULE_ALIAS()
> if the endianness of the target and the build machine do not match.
>
> When the endianness of the target kernel and the build machine match,
> the output is correct:
>
> $ grep 'MODULE_ALIAS("acpi' drivers/ata/ahci_platform.mod.c
> MODULE_ALIAS("acpi*:APMC0D33:*");
> MODULE_ALIAS("acpi*:010601:*");
>
> However, when building a little-endian kernel on a big-endian machine
> (or vice versa), the output is incorrect:
>
> $ grep 'MODULE_ALIAS("acpi' drivers/ata/ahci_platform.mod.c
> MODULE_ALIAS("acpi*:APMC0D33:*");
> MODULE_ALIAS("acpi*:0601??:*");
>
> The 'cls' and 'cls_msk' fields are 32-bit.
>
> DEF_FIELD() must be used instead of DEF_FIELD_ALIAS() to correctly handle
This is a typo:
DEF_FIELD_ALIAS() -> DEF_FIELD_ADDR()
> endianness of these 32-bit fields.
>
> The check 'if (cls)' was unnecessary; it never became NULL, as it was the
> pointer to 'symval' plus the offset to the 'cls' field.
>
> Fixes: 26095a01d359 ("ACPI / scan: Add support for ACPI _CLS device matching")
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> scripts/mod/file2alias.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
> index 99dce93a4188..16154449dde1 100644
> --- a/scripts/mod/file2alias.c
> +++ b/scripts/mod/file2alias.c
> @@ -567,12 +567,12 @@ static int do_acpi_entry(const char *filename,
> void *symval, char *alias)
> {
> DEF_FIELD_ADDR(symval, acpi_device_id, id);
> - DEF_FIELD_ADDR(symval, acpi_device_id, cls);
> - DEF_FIELD_ADDR(symval, acpi_device_id, cls_msk);
> + DEF_FIELD(symval, acpi_device_id, cls);
> + DEF_FIELD(symval, acpi_device_id, cls_msk);
>
> if (id && strlen((const char *)*id))
> sprintf(alias, "acpi*:%s:*", *id);
> - else if (cls) {
> + else {
> int i, byte_shift, cnt = 0;
> unsigned int msk;
>
> @@ -580,10 +580,10 @@ static int do_acpi_entry(const char *filename,
> cnt = 6;
> for (i = 1; i <= 3; i++) {
> byte_shift = 8 * (3-i);
> - msk = (*cls_msk >> byte_shift) & 0xFF;
> + msk = (cls_msk >> byte_shift) & 0xFF;
> if (msk)
> sprintf(&alias[cnt], "%02x",
> - (*cls >> byte_shift) & 0xFF);
> + (cls >> byte_shift) & 0xFF);
> else
> sprintf(&alias[cnt], "??");
> cnt += 2;
> --
> 2.43.0
>
--
Best Regards
Masahiro Yamada
