From: Jessica Clarke <jrtc27@xxxxxxxxxx> 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@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- drivers/acpi/acpica/acevents.h | 5 ++++ drivers/acpi/acpica/acobject.h | 1 + drivers/acpi/acpica/dsopcode.c | 1 + drivers/acpi/acpica/evhandler.c | 2 +- drivers/acpi/acpica/evrgnini.c | 52 +++++++++++++++++++++++++++++++++ drivers/acpi/acpica/excreate.c | 1 + drivers/acpi/acpica/exregion.c | 15 +++++++--- include/acpi/actypes.h | 4 +++ 8 files changed, 76 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/acpica/acevents.h b/drivers/acpi/acpica/acevents.h index 82a75964343b..b29ba436944a 100644 --- a/drivers/acpi/acpica/acevents.h +++ b/drivers/acpi/acpica/acevents.h @@ -223,6 +223,11 @@ acpi_ev_pci_bar_region_setup(acpi_handle handle, u32 function, void *handler_context, void **region_context); +acpi_status +acpi_ev_data_table_region_setup(acpi_handle handle, + u32 function, + void *handler_context, void **region_context); + acpi_status acpi_ev_default_region_setup(acpi_handle handle, u32 function, diff --git a/drivers/acpi/acpica/acobject.h b/drivers/acpi/acpica/acobject.h index 9db5ae0f79ea..0aa0d847cb25 100644 --- a/drivers/acpi/acpica/acobject.h +++ b/drivers/acpi/acpica/acobject.h @@ -138,6 +138,7 @@ struct acpi_object_region { union acpi_operand_object *next; acpi_physical_address address; u32 length; + void *pointer; /* Only for data table regions */ }; struct acpi_object_method { diff --git a/drivers/acpi/acpica/dsopcode.c b/drivers/acpi/acpica/dsopcode.c index 639635291ab7..44c448269861 100644 --- a/drivers/acpi/acpica/dsopcode.c +++ b/drivers/acpi/acpica/dsopcode.c @@ -531,6 +531,7 @@ acpi_ds_eval_table_region_operands(struct acpi_walk_state *walk_state, obj_desc->region.address = ACPI_PTR_TO_PHYSADDR(table); obj_desc->region.length = table->length; + obj_desc->region.pointer = table; ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "RgnObj %p Addr %8.8X%8.8X Len %X\n", obj_desc, diff --git a/drivers/acpi/acpica/evhandler.c b/drivers/acpi/acpica/evhandler.c index c0cd7147a5a3..8f43d38dc4ca 100644 --- a/drivers/acpi/acpica/evhandler.c +++ b/drivers/acpi/acpica/evhandler.c @@ -386,7 +386,7 @@ acpi_ev_install_space_handler(struct acpi_namespace_node *node, case ACPI_ADR_SPACE_DATA_TABLE: handler = acpi_ex_data_table_space_handler; - setup = NULL; + setup = acpi_ev_data_table_region_setup; break; default: diff --git a/drivers/acpi/acpica/evrgnini.c b/drivers/acpi/acpica/evrgnini.c index 984c172453bf..d28dee929e61 100644 --- a/drivers/acpi/acpica/evrgnini.c +++ b/drivers/acpi/acpica/evrgnini.c @@ -406,6 +406,58 @@ acpi_ev_cmos_region_setup(acpi_handle handle, return_ACPI_STATUS(AE_OK); } +/******************************************************************************* + * + * FUNCTION: acpi_ev_data_table_region_setup + * + * PARAMETERS: handle - Region we are interested in + * function - Start or stop + * handler_context - Address space handler context + * region_context - Region specific context + * + * RETURN: Status + * + * DESCRIPTION: Setup a data_table_region + * + * MUTEX: Assumes namespace is not locked + * + ******************************************************************************/ + +acpi_status +acpi_ev_data_table_region_setup(acpi_handle handle, + u32 function, + void *handler_context, void **region_context) +{ + union acpi_operand_object *region_desc = + (union acpi_operand_object *)handle; + struct acpi_data_table_space_context *local_region_context; + + ACPI_FUNCTION_TRACE(ev_data_table_region_setup); + + if (function == ACPI_REGION_DEACTIVATE) { + if (*region_context) { + ACPI_FREE(*region_context); + *region_context = NULL; + } + return_ACPI_STATUS(AE_OK); + } + + /* Create a new context */ + + local_region_context = + ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_data_table_space_context)); + if (!(local_region_context)) { + return_ACPI_STATUS(AE_NO_MEMORY); + } + + /* Save the data table pointer for use in the handler */ + + local_region_context->pointer = region_desc->region.pointer; + + *region_context = local_region_context; + return_ACPI_STATUS(AE_OK); +} + /******************************************************************************* * * FUNCTION: acpi_ev_default_region_setup diff --git a/drivers/acpi/acpica/excreate.c b/drivers/acpi/acpica/excreate.c index 80b52ad55775..deb3674ae726 100644 --- a/drivers/acpi/acpica/excreate.c +++ b/drivers/acpi/acpica/excreate.c @@ -279,6 +279,7 @@ acpi_ex_create_region(u8 * aml_start, obj_desc->region.space_id = space_id; obj_desc->region.address = 0; obj_desc->region.length = 0; + obj_desc->region.pointer = NULL; obj_desc->region.node = node; obj_desc->region.handler = NULL; obj_desc->common.flags &= 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: diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index 248242dca28d..700c2449e85a 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -1221,6 +1221,10 @@ struct acpi_mem_space_context { struct acpi_mem_mapping *first_mm; }; +struct acpi_data_table_space_context { + void *pointer; +}; + /* * struct acpi_memory_list is used only if the ACPICA local cache is enabled */ -- 2.26.2
