[PATCH] mmc: slot-gpio: Allocate GPIO labels dynamically

[Linus Walleij]

The use of string pointers in the MMC slot GPIO context is
pretty dubious, allocating some 2*len extra bytes for each
label of the ro and wp pins.

Tidy this up using kasprintf() with dynamic allocation of
labels for these strings.

Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
 drivers/mmc/core/slot-gpio.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index ef05e0039378..c417801b366e 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -27,7 +27,7 @@ struct mmc_gpio {
     bool override_cd_active_level;
     irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id);
     char *ro_label;
-    char cd_label[0];
+    char *cd_label;
     u32 cd_debounce_delay_ms;
 };

@@ -47,13 +47,18 @@ int mmc_gpio_alloc(struct mmc_host *host)
 {
     size_t len =3D strlen(dev_name(host->parent)) + 4;
     struct mmc_gpio *ctx =3D devm_kzalloc(host->parent,
-                sizeof(*ctx) + 2 * len,    GFP_KERNEL);
+                        sizeof(*ctx), GFP_KERNEL);

     if (ctx) {
-        ctx->ro_label =3D ctx->cd_label + len;
         ctx->cd_debounce_delay_ms =3D 200;
-        snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
-        snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
+        ctx->cd_label =3D devm_kasprintf(host->parent, GFP_KERNEL,
+                "%s cd", dev_name(host->parent));
+        if (!ctx->cd_label)
+            return -ENOMEM;
+        ctx->ro_label =3D devm_kasprintf(host->parent, GFP_KERNEL,
+                "%s ro", dev_name(host->parent));
+        if (!ctx->ro_label)
+            return -ENOMEM;
         host->slot.handler_priv =3D ctx;
         host->slot.cd_irq =3D -EINVAL;
     }
--=20
2.17.0

I can send it as a separate patch if you like it.

Yours,
Linus Walleij