[PATCH] x86: wmi: Remove private %pUL implementation

Rasmus Villemoes
2015-09-09T22:09:05Z

The work performed by wmi_gtoa is equivalent to simply sprintf(out,
"%pUL", in), so one could replace its body by this. However, most
users feed the result directly as a %s argument to some other function
which also understands the %p extensions (they all ultimately use
vsnprintf), so we can eliminate some stack buffers and quite a bit of
code by just using %pUL directly.

In wmi_dev_uevent I'm not sure whether there's room for a
nul-terminator in env->buf, so I've just replaced wmi_gtoa with the
equivalent sprintf call.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
Resending, hoping to get it picked up this time.

drivers/platform/x86/wmi.c | 51 ++++++----------------------------------------
1 file changed, 6 insertions(+), 45 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index aac47573f9ed..eb391a281833 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -194,34 +194,6 @@ static bool wmi_parse_guid(const u8 *src, u8 *dest)
return true;
}

-/*
- * Convert a raw GUID to the ACII string representation
- */
-static int wmi_gtoa(const char *in, char *out)
-{
- int i;
-
- for (i = 3; i >= 0; i--)
- out += sprintf(out, "%02X", in[i] & 0xFF);
-
- out += sprintf(out, "-");
- out += sprintf(out, "%02X", in[5] & 0xFF);
- out += sprintf(out, "%02X", in[4] & 0xFF);
- out += sprintf(out, "-");
- out += sprintf(out, "%02X", in[7] & 0xFF);
- out += sprintf(out, "%02X", in[6] & 0xFF);
- out += sprintf(out, "-");
- out += sprintf(out, "%02X", in[8] & 0xFF);
- out += sprintf(out, "%02X", in[9] & 0xFF);
- out += sprintf(out, "-");
-
- for (i = 10; i <= 15; i++)
- out += sprintf(out, "%02X", in[i] & 0xFF);
-
- *out = '\0';
- return 0;
-}
-
static bool find_guid(const char *guid_string, struct wmi_block **out)
{
char tmp[16], guid_input[16];
@@ -457,11 +429,7 @@ EXPORT_SYMBOL_GPL(wmi_set_block);

static void wmi_dump_wdg(const struct guid_block *g)
{
- char guid_string[37];
-
- wmi_gtoa(g->guid, guid_string);
-
- pr_info("%s:\n", guid_string);
+ pr_info("%pUL:\n", g->guid);
pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
pr_info("\tnotify_id: %02X\n", g->notify_id);
pr_info("\treserved: %02X\n", g->reserved);
@@ -661,7 +629,6 @@ EXPORT_SYMBOL_GPL(wmi_has_guid);
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
- char guid_string[37];
struct wmi_block *wblock;

wblock = dev_get_drvdata(dev);
@@ -670,9 +637,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
return strlen(buf);
}

- wmi_gtoa(wblock->gblock.guid, guid_string);
-
- return sprintf(buf, "wmi:%s\n", guid_string);
+ return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
}
static DEVICE_ATTR_RO(modalias);

@@ -695,7 +660,7 @@ static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
if (!wblock)
return -ENOMEM;

- wmi_gtoa(wblock->gblock.guid, guid_string);
+ sprintf(guid_string, "%pUL", wblock->gblock.guid);

strcpy(&env->buf[env->buflen - 1], "wmi:");
memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
@@ -721,12 +686,9 @@ static struct class wmi_class = {
static int wmi_create_device(const struct guid_block *gblock,
struct wmi_block *wblock, acpi_handle handle)
{
- char guid_string[37];
-
wblock->dev.class = &wmi_class;

- wmi_gtoa(gblock->guid, guid_string);
- dev_set_name(&wblock->dev, "%s", guid_string);
+ dev_set_name(&wblock->dev, "%pUL", gblock->guid);

dev_set_drvdata(&wblock->dev, wblock);

@@ -877,7 +839,6 @@ static void acpi_wmi_notify(struct acpi_device *device, u32 event)
struct guid_block *block;
struct wmi_block *wblock;
struct list_head *p;
- char guid_string[37];

list_for_each(p, &wmi_block_list) {
wblock = list_entry(p, struct wmi_block, list);
@@ -888,8 +849,8 @@ static void acpi_wmi_notify(struct acpi_device *device, u32 event)
if (wblock->handler)
wblock->handler(event, wblock->handler_data);
if (debug_event) {
- wmi_gtoa(wblock->gblock.guid, guid_string);
- pr_info("DEBUG Event GUID: %s\n", guid_string);
+ pr_info("DEBUG Event GUID: %pUL\n",
+ wblock->gblock.guid);
}

acpi_bus_generate_netlink_event(
--
2.1.3