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modpost: fix acpi MODULE_DEVICE_TABLE built with mismatched endianness

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When CONFIG_SATA_AHCI_PLATFORM=m, modpost outputs incorect acpi
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_ADDR() to correctly handle
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: 26095a01d3 ("ACPI / scan: Add support for ACPI _CLS device matching")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2024-11-03 21:46:50 +09:00
parent d01661e1f4
commit 2e766a1f5f
1 changed files with 5 additions and 5 deletions
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10
scripts/mod/file2alias.c
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@ -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;