platform/x86: dell-wmi-sysman: Clean up security buffer helpers

In calculate_security_buffer(), call strlen() once and use ALIGN() to
round up to an even size.

In populate_security_buffer(), also avoid recomputing strlen(), rename
the u32 pointer from 'seclen' to 'seclenp' to avoid confusion with the
new length variable, and drop the memcpy() guard since calling it with
size 0 is a no-op and therefore safe.

Use 'const char *' for the read-only source string in both helpers.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20260331160310.608857-3-thorsten.blum@linux.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h b/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
index 817ee7ba07ca08cfe286d8ff5a6f864991c6522d..5278a93fdaf796dcaaeacaed163f59e5c15a2f2f 100644 (file)
--- a/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
@@ -189,8 +189,8 @@ void exit_bios_attr_set_interface(void);
 int init_bios_attr_set_interface(void);
 int map_wmi_error(int error_code);
 size_t calculate_string_buffer(const char *str);
-size_t calculate_security_buffer(char *authentication);
-void populate_security_buffer(char *buffer, char *authentication);
+size_t calculate_security_buffer(const char *authentication);
+void populate_security_buffer(char *buffer, const char *authentication);
 ssize_t populate_string_buffer(char *buffer, size_t buffer_len, const char *str);
 int set_new_password(const char *password_type, const char *new);
 int init_bios_attr_pass_interface(void);

diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
index 069cf958a90d026ff70e363bdbf3eee25a40ec5e..353881353a04cced0757e9271ea9e357239ecf73 100644 (file)
--- a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
@@ -7,10 +7,12 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/align.h>
 #include <linux/fs.h>
 #include <linux/dmi.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/string.h>
 #include <linux/sysfs.h>
 #include <linux/wmi.h>
 #include "dell-wmi-sysman.h"
@@ -73,13 +75,9 @@ size_t calculate_string_buffer(const char *str)
  *
  * Currently only supported type is Admin password
  */
-size_t calculate_security_buffer(char *authentication)
+size_t calculate_security_buffer(const char *authentication)
 {
-       if (strlen(authentication) > 0) {
-               return (sizeof(u32) * 2) + strlen(authentication) +
-                       strlen(authentication) % 2;
-       }
-       return sizeof(u32) * 2;
+       return sizeof(u32) * 2 + ALIGN(strlen(authentication), 2);
 }
 
 /**
@@ -89,18 +87,18 @@ size_t calculate_security_buffer(char *authentication)
  *
  * Currently only supported type is PLAIN TEXT
  */
-void populate_security_buffer(char *buffer, char *authentication)
+void populate_security_buffer(char *buffer, const char *authentication)
 {
+       size_t seclen = strlen(authentication);
        char *auth = buffer + sizeof(u32) * 2;
        u32 *sectype = (u32 *) buffer;
-       u32 *seclen = sectype + 1;
+       u32 *seclenp = sectype + 1;
 
-       *sectype = strlen(authentication) > 0 ? 1 : 0;
-       *seclen = strlen(authentication);
+       *sectype = !!seclen;
+       *seclenp = seclen;
 
        /* plain text */
-       if (strlen(authentication) > 0)
-               memcpy(auth, authentication, *seclen);
+       memcpy(auth, authentication, seclen);
 }
 
 /**