It was <2023-11-05 nie 11:20>, when James Seo wrote: > The EliteDesk 800 G6 stores a raw WMI string within the ACPI object in its > BIOS corresponding to one instance of HPBIOS_PlatformEvents.Name. This is > evidently a valid way of representing a WMI data item as far as the Microsoft > ACPI-WMI mapper is concerned, but is preventing the driver from loading. > > This seems quite rare, but add support for such strings. Treating this as a > quirk pretty much means adding that support anyway. > > Also clean up an oversight in update_numeric_sensor_from_wobj() in which the > result of hp_wmi_strdup() was being used without error checking. > > Reported-by: Lukasz Stelmach <l.stelmach@xxxxxxxxxxx> > Closes: https://lore.kernel.org/linux-hwmon/7850a0bd-60e7-88f8-1d6c-0bb0e3234fdc@xxxxxxxxxxxx/ > Signed-off-by: James Seo <james@xxxxxxxxxx> > --- > > Changes v1->v2: > * Remove DMI-based workaround logic > * Add full support for raw WMI strings > - Improve UTF-16 validation and conversion for the general case > - Support such strings if they occur in HPBIOS_BIOSEvent objects > * Only use the result of hp_wmi_strdup() in update_numeric_sensor_from_wobj() > if the call succeeded > > History: > v1: https://lore.kernel.org/linux-hwmon/20231103181931.677796-1-james@xxxxxxxxxx/ > > --- > > drivers/hwmon/hp-wmi-sensors.c | 127 ++++++++++++++++++++++++++++----- > 1 file changed, 111 insertions(+), 16 deletions(-) > Tested-by: Lukasz Stelmach <l.stelmach@xxxxxxxxxxx> > diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c > index 17ae62f88bbf..bdd7ca163593 100644 > --- a/drivers/hwmon/hp-wmi-sensors.c > +++ b/drivers/hwmon/hp-wmi-sensors.c > @@ -17,6 +17,8 @@ > * Available: https://github.com/linuxhw/ACPI > * [4] P. Rohár, "bmfdec - Decompile binary MOF file (BMF) from WMI buffer", > * 2017. [Online]. Available: https://github.com/pali/bmfdec > + * [5] Microsoft Corporation, "Driver-Defined WMI Data Items", 2017. [Online]. > + * Available: https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/driver-defined-wmi-data-items > */ > > #include <linux/acpi.h> > @@ -24,6 +26,7 @@ > #include <linux/hwmon.h> > #include <linux/jiffies.h> > #include <linux/mutex.h> > +#include <linux/nls.h> > #include <linux/units.h> > #include <linux/wmi.h> > > @@ -395,6 +398,50 @@ struct hp_wmi_sensors { > struct mutex lock; /* Lock polling WMI and driver state changes. */ > }; > > +static bool is_raw_wmi_string(const u8 *pointer, u32 length) > +{ > + const u16 *ptr; > + u16 len; > + > + /* WMI strings are length-prefixed UTF-16 [5]. */ > + if (length <= sizeof(*ptr)) > + return false; > + > + length -= sizeof(*ptr); > + ptr = (const u16 *)pointer; > + len = *ptr; > + > + return len <= length && !(len & 1); > +} > + > +static char *convert_raw_wmi_string(const u8 *buf) > +{ > + const wchar_t *src; > + unsigned cps; > + unsigned len; > + char *dst; > + int i; > + > + src = (const wchar_t *)buf; > + > + /* Count UTF-16 code points. Exclude trailing null padding. */ > + cps = *src / sizeof(*src); > + while (cps && !src[cps]) > + cps--; > + > + /* Each code point becomes up to 3 UTF-8 characters. */ > + len = min(cps * 3, HP_WMI_MAX_STR_SIZE - 1); > + > + dst = kmalloc((len + 1) * sizeof(*dst), GFP_KERNEL); > + if (!dst) > + return NULL; > + > + i = utf16s_to_utf8s(++src, cps, UTF16_LITTLE_ENDIAN, dst, len); > + dst[i] = '\0'; > + > + return dst; > +} > + > /* hp_wmi_strdup - devm_kstrdup, but length-limited */ > static char *hp_wmi_strdup(struct device *dev, const char *src) > { > @@ -412,6 +459,23 @@ static char *hp_wmi_strdup(struct device *dev, const char *src) > return dst; > } > > +/* hp_wmi_wstrdup - hp_wmi_strdup, but for a raw WMI string */ > +static char *hp_wmi_wstrdup(struct device *dev, const u8 *buf) > +{ > + char *src; > + char *dst; > + > + src = convert_raw_wmi_string(buf); > + if (!src) > + return NULL; > + > + dst = hp_wmi_strdup(dev, strim(src)); /* Note: Copy is trimmed. */ > + > + kfree(src); > + > + return dst; > +} > + > /* > * hp_wmi_get_wobj - poll WMI for a WMI object instance > * @guid: WMI object GUID > @@ -462,8 +526,14 @@ static int check_wobj(const union acpi_object *wobj, > for (prop = 0; prop <= last_prop; prop++) { > type = elements[prop].type; > valid_type = property_map[prop]; > - if (type != valid_type) > + if (type != valid_type) { > + if (type == ACPI_TYPE_BUFFER && > + valid_type == ACPI_TYPE_STRING && > + is_raw_wmi_string(elements[prop].buffer.pointer, > + elements[prop].buffer.length)) > + continue; > return -EINVAL; > + } > } > > return 0; > @@ -480,7 +550,9 @@ static int extract_acpi_value(struct device *dev, > break; > > case ACPI_TYPE_STRING: > - *out_string = hp_wmi_strdup(dev, strim(element->string.pointer)); > + *out_string = element->type == ACPI_TYPE_BUFFER ? > + hp_wmi_wstrdup(dev, element->buffer.pointer) : > + hp_wmi_strdup(dev, strim(element->string.pointer)); > if (!*out_string) > return -ENOMEM; > break; > @@ -861,7 +933,9 @@ update_numeric_sensor_from_wobj(struct device *dev, > { > const union acpi_object *elements; > const union acpi_object *element; > - const char *string; > + const char *new_string; > + char *trimmed; > + char *string; > bool is_new; > int offset; > u8 size; > @@ -885,11 +959,21 @@ update_numeric_sensor_from_wobj(struct device *dev, > offset = is_new ? size - 1 : -2; > > element = &elements[HP_WMI_PROPERTY_CURRENT_STATE + offset]; > - string = strim(element->string.pointer); > - > - if (strcmp(string, nsensor->current_state)) { > - devm_kfree(dev, nsensor->current_state); > - nsensor->current_state = hp_wmi_strdup(dev, string); > + string = element->type == ACPI_TYPE_BUFFER ? > + convert_raw_wmi_string(element->buffer.pointer) : > + element->string.pointer; > + > + if (string) { > + trimmed = strim(string); > + if (strcmp(trimmed, nsensor->current_state)) { > + new_string = hp_wmi_strdup(dev, trimmed); > + if (new_string) { > + devm_kfree(dev, nsensor->current_state); > + nsensor->current_state = new_string; > + } > + } > + if (element->type == ACPI_TYPE_BUFFER) > + kfree(string); > } > > /* Old variant: -2 (not -1) because it lacks the Size property. */ > @@ -996,11 +1080,15 @@ static int check_event_wobj(const union acpi_object *wobj) > HP_WMI_EVENT_PROPERTY_STATUS); > } > > -static int populate_event_from_wobj(struct hp_wmi_event *event, > +static int populate_event_from_wobj(struct device *dev, > + struct hp_wmi_event *event, > union acpi_object *wobj) > { > int prop = HP_WMI_EVENT_PROPERTY_NAME; > union acpi_object *element; > + acpi_object_type type; > + char *string; > + u32 value; > int err; > > err = check_event_wobj(wobj); > @@ -1009,20 +1097,24 @@ static int populate_event_from_wobj(struct hp_wmi_event *event, > > element = wobj->package.elements; > > - /* Extracted strings are NOT device-managed copies. */ > - > for (; prop <= HP_WMI_EVENT_PROPERTY_CATEGORY; prop++, element++) { > + type = hp_wmi_event_property_map[prop]; > + > + err = extract_acpi_value(dev, element, type, &value, &string); > + if (err) > + return err; > + > switch (prop) { > case HP_WMI_EVENT_PROPERTY_NAME: > - event->name = strim(element->string.pointer); > + event->name = string; > break; > > case HP_WMI_EVENT_PROPERTY_DESCRIPTION: > - event->description = strim(element->string.pointer); > + event->description = string; > break; > > case HP_WMI_EVENT_PROPERTY_CATEGORY: > - event->category = element->integer.value; > + event->category = value; > break; > > default: > @@ -1511,8 +1603,8 @@ static void hp_wmi_notify(u32 value, void *context) > struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; > struct hp_wmi_sensors *state = context; > struct device *dev = &state->wdev->dev; > + struct hp_wmi_event event = {}; > struct hp_wmi_info *fan_info; > - struct hp_wmi_event event; > union acpi_object *wobj; > acpi_status err; > int event_type; > @@ -1546,7 +1638,7 @@ static void hp_wmi_notify(u32 value, void *context) > > wobj = out.pointer; > > - err = populate_event_from_wobj(&event, wobj); > + err = populate_event_from_wobj(dev, &event, wobj); > if (err) { > dev_warn(dev, "Bad event data (ACPI type %d)\n", wobj->type); > goto out_free_wobj; > @@ -1577,6 +1669,9 @@ static void hp_wmi_notify(u32 value, void *context) > out_free_wobj: > kfree(wobj); > > + devm_kfree(dev, event.name); > + devm_kfree(dev, event.description); > + > out_unlock: > mutex_unlock(&state->lock); > } > > base-commit: 0f564130e5c76f1e5cf0008924f6a6cd138929d9 -- Łukasz Stelmach Samsung R&D Institute Poland Samsung Electronics
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