UPSTREAM: console: Expand dummy functions for CFI

This expands the no-op dummy functions into full prototypes to avoid
indirect call mismatches when running under Control Flow Integrity
checking, like with Clang's -fsanitize=cfi.

Co-Developed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: If63cf04ad86b55afb1442ef4037b5f575457ea06
(cherry picked from commit c396a5bf457fb60159dcedbd4f48d53a62be030a)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

diff --git a/drivers/usb/misc/sisusbvga/sisusb_con.c b/drivers/usb/misc/sisusbvga/sisusb_con.c
index 78112f97d8c7ce95700ee194f2e10f00966ff7d6..dc45cfc8eb1016787dde88c5a60889bcff161245 100644 (file)
--- a/drivers/usb/misc/sisusbvga/sisusb_con.c
+++ b/drivers/usb/misc/sisusbvga/sisusb_con.c
@@ -1216,7 +1216,7 @@ font_op_error:
 /* Interface routine */
 static int
 sisusbcon_font_set(struct vc_data *c, struct console_font *font,
-                                                       unsigned flags)
+                  unsigned int flags)
 {
        struct sisusb_usb_data *sisusb;
        unsigned charcount = font->charcount;
@@ -1337,28 +1337,65 @@ static void sisusbdummycon_init(struct vc_data *vc, int init)
        vc_resize(vc, 80, 25);
 }
 
-static int sisusbdummycon_dummy(void)
+static void sisusbdummycon_deinit(struct vc_data *vc) { }
+static void sisusbdummycon_clear(struct vc_data *vc, int sy, int sx,
+                                int height, int width) { }
+static void sisusbdummycon_putc(struct vc_data *vc, int c, int ypos,
+                               int xpos) { }
+static void sisusbdummycon_putcs(struct vc_data *vc, const unsigned short *s,
+                                int count, int ypos, int xpos) { }
+static void sisusbdummycon_cursor(struct vc_data *vc, int mode) { }
+
+static bool sisusbdummycon_scroll(struct vc_data *vc, unsigned int top,
+                                 unsigned int bottom, enum con_scroll dir,
+                                 unsigned int lines)
 {
-    return 0;
+       return false;
 }
 
-#define SISUSBCONDUMMY (void *)sisusbdummycon_dummy
+static int sisusbdummycon_switch(struct vc_data *vc)
+{
+       return 0;
+}
+
+static int sisusbdummycon_blank(struct vc_data *vc, int blank, int mode_switch)
+{
+       return 0;
+}
+
+static int sisusbdummycon_font_set(struct vc_data *vc,
+                                  struct console_font *font,
+                                  unsigned int flags)
+{
+       return 0;
+}
+
+static int sisusbdummycon_font_default(struct vc_data *vc,
+                                      struct console_font *font, char *name)
+{
+       return 0;
+}
+
+static int sisusbdummycon_font_copy(struct vc_data *vc, int con)
+{
+       return 0;
+}
 
 static const struct consw sisusb_dummy_con = {
        .owner =                THIS_MODULE,
        .con_startup =          sisusbdummycon_startup,
        .con_init =             sisusbdummycon_init,
-       .con_deinit =           SISUSBCONDUMMY,
-       .con_clear =            SISUSBCONDUMMY,
-       .con_putc =             SISUSBCONDUMMY,
-       .con_putcs =            SISUSBCONDUMMY,
-       .con_cursor =           SISUSBCONDUMMY,
-       .con_scroll =           SISUSBCONDUMMY,
-       .con_switch =           SISUSBCONDUMMY,
-       .con_blank =            SISUSBCONDUMMY,
-       .con_font_set =         SISUSBCONDUMMY,
-       .con_font_default =     SISUSBCONDUMMY,
-       .con_font_copy =        SISUSBCONDUMMY,
+       .con_deinit =           sisusbdummycon_deinit,
+       .con_clear =            sisusbdummycon_clear,
+       .con_putc =             sisusbdummycon_putc,
+       .con_putcs =            sisusbdummycon_putcs,
+       .con_cursor =           sisusbdummycon_cursor,
+       .con_scroll =           sisusbdummycon_scroll,
+       .con_switch =           sisusbdummycon_switch,
+       .con_blank =            sisusbdummycon_blank,
+       .con_font_set =         sisusbdummycon_font_set,
+       .con_font_default =     sisusbdummycon_font_default,
+       .con_font_copy =        sisusbdummycon_font_copy,
 };
 
 int

diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index b90ef96e43d65a3ea18f74fdc6c9c9d702214595..f2eafe2ed98066866d6006f05f5019ead3fdae34 100644 (file)
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -41,12 +41,47 @@ static void dummycon_init(struct vc_data *vc, int init)
        vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
 }
 
-static int dummycon_dummy(void)
+static void dummycon_deinit(struct vc_data *vc) { }
+static void dummycon_clear(struct vc_data *vc, int sy, int sx, int height,
+                          int width) { }
+static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
+static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
+                          int count, int ypos, int xpos) { }
+static void dummycon_cursor(struct vc_data *vc, int mode) { }
+
+static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
+                           unsigned int bottom, enum con_scroll dir,
+                           unsigned int lines)
+{
+       return false;
+}
+
+static int dummycon_switch(struct vc_data *vc)
 {
-    return 0;
+       return 0;
 }
 
-#define DUMMY  (void *)dummycon_dummy
+static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
+{
+       return 0;
+}
+
+static int dummycon_font_set(struct vc_data *vc, struct console_font *font,
+                            unsigned int flags)
+{
+       return 0;
+}
+
+static int dummycon_font_default(struct vc_data *vc,
+                                struct console_font *font, char *name)
+{
+       return 0;
+}
+
+static int dummycon_font_copy(struct vc_data *vc, int con)
+{
+       return 0;
+}
 
 /*
  *  The console `switch' structure for the dummy console
@@ -55,19 +90,19 @@ static int dummycon_dummy(void)
  */
 
 const struct consw dummy_con = {
-    .owner =           THIS_MODULE,
-    .con_startup =     dummycon_startup,
-    .con_init =                dummycon_init,
-    .con_deinit =      DUMMY,
-    .con_clear =       DUMMY,
-    .con_putc =                DUMMY,
-    .con_putcs =       DUMMY,
-    .con_cursor =      DUMMY,
-    .con_scroll =      DUMMY,
-    .con_switch =      DUMMY,
-    .con_blank =       DUMMY,
-    .con_font_set =    DUMMY,
-    .con_font_default =        DUMMY,
-    .con_font_copy =   DUMMY,
+       .owner =                THIS_MODULE,
+       .con_startup =  dummycon_startup,
+       .con_init =             dummycon_init,
+       .con_deinit =   dummycon_deinit,
+       .con_clear =    dummycon_clear,
+       .con_putc =             dummycon_putc,
+       .con_putcs =    dummycon_putcs,
+       .con_cursor =   dummycon_cursor,
+       .con_scroll =   dummycon_scroll,
+       .con_switch =   dummycon_switch,
+       .con_blank =    dummycon_blank,
+       .con_font_set = dummycon_font_set,
+       .con_font_default =     dummycon_font_default,
+       .con_font_copy =        dummycon_font_copy,
 };
 EXPORT_SYMBOL_GPL(dummy_con);

diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 42d02a206059b55b198c797d5c8816dbe7c0a872..6897bd0fc00e7c6ae39e1ddcfd51b0283b940aea 100644 (file)
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -673,14 +673,14 @@ static bool newport_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
        return true;
 }
 
-static int newport_dummy(struct vc_data *c)
+static int newport_set_origin(struct vc_data *vc)
 {
        return 0;
 }
 
-#define DUMMY (void *) newport_dummy
+static void newport_save_screen(struct vc_data *vc) { }
 
-const struct consw newport_con = {
+static const struct consw newport_con = {
        .owner            = THIS_MODULE,
        .con_startup      = newport_startup,
        .con_init         = newport_init,
@@ -694,8 +694,8 @@ const struct consw newport_con = {
        .con_blank        = newport_blank,
        .con_font_set     = newport_font_set,
        .con_font_default = newport_font_default,
-       .con_set_origin   = DUMMY,
-       .con_save_screen  = DUMMY
+       .con_set_origin   = newport_set_origin,
+       .con_save_screen  = newport_save_screen
 };
 
 static int newport_probe(struct gio_device *dev,

diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index a17ba1465815f919444a83676517dc0f7e2bba16..f09e17b60e45ef611f51e2e21528432731fac8f0 100644 (file)
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1272,7 +1272,8 @@ static int vgacon_adjust_height(struct vc_data *vc, unsigned fontheight)
        return 0;
 }
 
-static int vgacon_font_set(struct vc_data *c, struct console_font *font, unsigned flags)
+static int vgacon_font_set(struct vc_data *c, struct console_font *font,
+                          unsigned int flags)
 {
        unsigned charcount = font->charcount;
        int rc;
@@ -1407,21 +1408,20 @@ static bool vgacon_scroll(struct vc_data *c, unsigned int t, unsigned int b,
  *  The console `switch' structure for the VGA based console
  */
 
-static int vgacon_dummy(struct vc_data *c)
-{
-       return 0;
-}
-
-#define DUMMY (void *) vgacon_dummy
+static void vgacon_clear(struct vc_data *vc, int sy, int sx, int height,
+                        int width) { }
+static void vgacon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
+static void vgacon_putcs(struct vc_data *vc, const unsigned short *s,
+                        int count, int ypos, int xpos) { }
 
 const struct consw vga_con = {
        .owner = THIS_MODULE,
        .con_startup = vgacon_startup,
        .con_init = vgacon_init,
        .con_deinit = vgacon_deinit,
-       .con_clear = DUMMY,
-       .con_putc = DUMMY,
-       .con_putcs = DUMMY,
+       .con_clear = vgacon_clear,
+       .con_putc = vgacon_putc,
+       .con_putcs = vgacon_putcs,
        .con_cursor = vgacon_cursor,
        .con_scroll = vgacon_scroll,
        .con_switch = vgacon_switch,

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 04612f938bab1fc3eecf457d070fe501b8a1a3de..235d549d5958564d307fa5cfaa1ff267e4b50849 100644 (file)
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2588,7 +2588,8 @@ static int fbcon_copy_font(struct vc_data *vc, int con)
  *  is ever implemented.
  */
 
-static int fbcon_set_font(struct vc_data *vc, struct console_font *font, unsigned flags)
+static int fbcon_set_font(struct vc_data *vc, struct console_font *font,
+                         unsigned int flags)
 {
        struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
        unsigned charcount = font->charcount;