nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI

The Apple SPMI NVMEM driver previously cast regmap_bulk_read/write to
void * when assigning them to nvmem_config's reg_read/reg_write
function pointers.

This cast breaks the expected function signature of nvmem_reg_read_t
and nvmem_reg_write_t. With CFI enabled, indirect calls through
these pointers fail:

  CFI failure at nvmem_reg_write+0x194/0x1e4 (target: regmap_bulk_write+0x0/0x2c8; expected type: 0x83a189c3)
  ...
  Call trace:
   nvmem_reg_write+0x194/0x1e4 (P)
   __nvmem_cell_entry_write+0x298/0x2e8
   nvmem_cell_write+0x24/0x34
   macsmc_reboot_probe+0x1dc/0x454 [macsmc_reboot]
  ...

Introduce thin wrapper functions with the correct nvmem function
pointer types to satisfy the CFI checks.

Fixes: fe91c24a551c ("nvmem: Add apple-spmi-nvmem driver")
Signed-off-by: Aelin Reidel <aelin@mainlining.org>
Reported-by: Clayton Craft <craftyguy@postmarketos.org>
Tested-by: Clayton Craft <craftyguy@postmarketos.org>
Reviewed-by: Sven Peter <sven@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260724223404.629248-2-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/apple-spmi-nvmem.c b/drivers/nvmem/apple-spmi-nvmem.c
index 88614005d5ce1dc2d1cafcb89ac66d8376ffcc96..7acb0c07d6abe9e9984908f5ea2f4e2e9c10bb06 100644 (file)
--- a/drivers/nvmem/apple-spmi-nvmem.c
+++ b/drivers/nvmem/apple-spmi-nvmem.c
@@ -18,6 +18,22 @@ static const struct regmap_config apple_spmi_regmap_config = {
        .max_register   = 0xffff,
 };
 
+static int apple_spmi_nvmem_read(void *priv, unsigned int offset, void *val,
+                                size_t bytes)
+{
+       struct regmap *map = priv;
+
+       return regmap_bulk_read(map, offset, val, bytes);
+}
+
+static int apple_spmi_nvmem_write(void *priv, unsigned int offset, void *val,
+                                 size_t bytes)
+{
+       struct regmap *map = priv;
+
+       return regmap_bulk_write(map, offset, val, bytes);
+}
+
 static int apple_spmi_nvmem_probe(struct spmi_device *sdev)
 {
        struct regmap *regmap;
@@ -28,8 +44,8 @@ static int apple_spmi_nvmem_probe(struct spmi_device *sdev)
                .word_size = 1,
                .stride = 1,
                .size = 0xffff,
-               .reg_read = (void *)regmap_bulk_read,
-               .reg_write = (void *)regmap_bulk_write,
+               .reg_read = apple_spmi_nvmem_read,
+               .reg_write = apple_spmi_nvmem_write,
        };
 
        regmap = devm_regmap_init_spmi_ext(sdev, &apple_spmi_regmap_config);