diff options
| author | Jessica Clarke <jrtc27@jrtc27.com> | 2021-12-22 17:21:25 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-12-27 17:01:28 +0100 |
| commit | ca25f92b72d25457653dbf2a81f322235804fb05 (patch) | |
| tree | f2f76e44ffbcc7e0c05e1a0adb4f04ee4b6f2a28 /drivers/acpi/acpica/exregion.c | |
| parent | f81bdeaf816142e0729eea0cc84c395ec9673151 (diff) | |
ACPICA: Use original data_table_region pointer for accesses
ACPICA commit d9eb82bd7515989f0b29d79deeeb758db4d6529c
Currently the pointer to the table is cast to acpi_physical_address and
later cast back to a pointer to be dereferenced. Whether or not this is
supported is implementation-defined.
On CHERI, and thus Arm's experimental Morello prototype architecture,
pointers are represented as capabilities, which are unforgeable bounded
pointers, providing always-on fine-grained spatial memory safety. This
means that any pointer cast to a plain integer will lose all its
associated metadata, and when cast back to a pointer it will give a
null-derived pointer (one that has the same metadata as null but an
address equal to the integer) that will trap on any dereference. As a
result, this is an implementation where acpi_physical_address cannot be
used as a hack to store real pointers.
Thus, add a new field to struct acpi_object_region to store the pointer for
table regions, and propagate it to acpi_ex_data_table_space_handler via the
region context, to use a more portable implementation that supports
CHERI.
Link: https://github.com/acpica/acpica/commit/d9eb82bd
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpica/exregion.c')
| -rw-r--r-- | drivers/acpi/acpica/exregion.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/acpi/acpica/exregion.c b/drivers/acpi/acpica/exregion.c index 82b713a9a193..48c19908fa4e 100644 --- a/drivers/acpi/acpica/exregion.c +++ b/drivers/acpi/acpica/exregion.c @@ -509,8 +509,15 @@ acpi_ex_data_table_space_handler(u32 function, u64 *value, void *handler_context, void *region_context) { + struct acpi_data_table_space_context *mapping; + char *pointer; + ACPI_FUNCTION_TRACE(ex_data_table_space_handler); + mapping = (struct acpi_data_table_space_context *) region_context; + pointer = ACPI_CAST_PTR(char, mapping->pointer) + + (address - ACPI_PTR_TO_PHYSADDR(mapping->pointer)); + /* * Perform the memory read or write. The bit_width was already * validated. @@ -518,14 +525,14 @@ acpi_ex_data_table_space_handler(u32 function, switch (function) { case ACPI_READ: - memcpy(ACPI_CAST_PTR(char, value), - ACPI_PHYSADDR_TO_PTR(address), ACPI_DIV_8(bit_width)); + memcpy(ACPI_CAST_PTR(char, value), pointer, + ACPI_DIV_8(bit_width)); break; case ACPI_WRITE: - memcpy(ACPI_PHYSADDR_TO_PTR(address), - ACPI_CAST_PTR(char, value), ACPI_DIV_8(bit_width)); + memcpy(pointer, ACPI_CAST_PTR(char, value), + ACPI_DIV_8(bit_width)); break; default: |