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platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated

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The purpose of this patch is to remove 128 bytes buffer limitation
imposed in bios_args structure.

A limiting factor discovered during this investigation was the struct
bios_args.data size restriction.  The data member size limits all
possible WMI commands to those requiring buffer size of 128 bytes or
less. Several WMI commands and queries require a buffer size larger
than 128 bytes hence limiting current and feature supported by the
driver. It is for this reason, struct bios_args.data changed and is
dynamically allocated.  hp_wmi_perform_query function changed to
handle the memory allocation and release of any required buffer size.

All changes were validated on a HP ZBook Workstation notebook,
HP EliteBook x360, and HP EliteBook 850 G8.  Additional
validation was included in the test process to ensure no other
commands were incorrectly handled.

Signed-off-by: Jorge Lopez <jorge.lopez2@hp.com>
Link: https://lore.kernel.org/r/20220310210853.28367-5-jorge.lopez2@hp.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Jorge Lopez 2022-03-10 15:08:53 -06:00 committed by Hans de Goede
parent be9d73e649
commit 4b4967cbd2
1 changed files with 33 additions and 21 deletions
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54
drivers/platform/x86/hp-wmi.c
View File

@ -82,12 +82,17 @@ enum hp_wmi_event_ids {
HPWMI_BATTERY_CHARGE_PERIOD = 0x10,
};
/*
* struct bios_args buffer is dynamically allocated. New WMI command types
* were introduced that exceeds 128-byte data size. Changes to handle
* the data size allocation scheme were kept in hp_wmi_perform_qurey function.
*/
struct bios_args {
u32 signature;
u32 command;
u32 commandtype;
u32 datasize;
u8 data[128];
u8 data[];
};
enum hp_wmi_commandtype {
@ -266,37 +271,43 @@ static inline int encode_outsize_for_pvsz(int outsize)
static int hp_wmi_perform_query(int query, enum hp_wmi_command command,
void *buffer, int insize, int outsize)
{
int mid;
struct acpi_buffer input, output = { ACPI_ALLOCATE_BUFFER, NULL };
struct bios_return *bios_return;
int actual_outsize;
union acpi_object *obj;
struct bios_args args = {
.signature = 0x55434553,
.command = command,
.commandtype = query,
.datasize = insize,
.data = { 0 },
};
struct acpi_buffer input = { sizeof(struct bios_args), &args };
struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
int ret = 0;
union acpi_object *obj = NULL;
struct bios_args *args = NULL;
int mid, actual_outsize, ret;
size_t bios_args_size;
mid = encode_outsize_for_pvsz(outsize);
if (WARN_ON(mid < 0))
return mid;
if (WARN_ON(insize > sizeof(args.data)))
return -EINVAL;
memcpy(&args.data[0], buffer, insize);
bios_args_size = struct_size(args, data, insize);
args = kmalloc(bios_args_size, GFP_KERNEL);
if (!args)
return -ENOMEM;
wmi_evaluate_method(HPWMI_BIOS_GUID, 0, mid, &input, &output);
input.length = bios_args_size;
input.pointer = args;
args->signature = 0x55434553;
args->command = command;
args->commandtype = query;
args->datasize = insize;
memcpy(args->data, buffer, flex_array_size(args, data, insize));
ret = wmi_evaluate_method(HPWMI_BIOS_GUID, 0, mid, &input, &output);
if (ret)
goto out_free;
obj = output.pointer;
if (!obj)
return -EINVAL;
if (!obj) {
ret = -EINVAL;
goto out_free;
}
if (obj->type != ACPI_TYPE_BUFFER) {
pr_warn("query 0x%x returned an invalid object 0x%x\n", query, ret);
ret = -EINVAL;
goto out_free;
}
@ -321,6 +332,7 @@ static int hp_wmi_perform_query(int query, enum hp_wmi_command command,
out_free:
kfree(obj);
kfree(args);
return ret;
}