This is a small series that cleans up struct consw a bit and prepares it for Control Flow Integrity checking (i.e. Clang's -fsanitize=cfi).
Thanks!
-Kees
As done in commit:
724ba8b30b04 ("console/dummy: leave .con_font_get set to NULL")
This drops the dummy .con_font_get(), as it could leave arguments uninitialized.
Cc: Thomas Winischhofer thomas@winischhofer.net Signed-off-by: Kees Cook keescook@chromium.org --- drivers/usb/misc/sisusbvga/sisusb_con.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/usb/misc/sisusbvga/sisusb_con.c b/drivers/usb/misc/sisusbvga/sisusb_con.c index 73f7bde78e11..998df891bdde 100644 --- a/drivers/usb/misc/sisusbvga/sisusb_con.c +++ b/drivers/usb/misc/sisusbvga/sisusb_con.c @@ -1358,7 +1358,6 @@ static const struct consw sisusb_dummy_con = { .con_switch = SISUSBCONDUMMY, .con_blank = SISUSBCONDUMMY, .con_font_set = SISUSBCONDUMMY, - .con_font_get = SISUSBCONDUMMY, .con_font_default = SISUSBCONDUMMY, .con_font_copy = SISUSBCONDUMMY, };
Reading the function declarations for the console callbacks lacks any hints as to what the arguments are. Instead of going and digging around in various implementations that may each only have a subset of the callbacks, name all the arguments in the declaration. This has no functional change.
Signed-off-by: Kees Cook keescook@chromium.org --- include/linux/console.h | 58 +++++++++++++++++++++++++++---------------------- 1 file changed, 32 insertions(+), 26 deletions(-)
diff --git a/include/linux/console.h b/include/linux/console.h index b8920a031a3e..dfd6b0e97855 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -46,46 +46,52 @@ enum con_scroll { struct consw { struct module *owner; const char *(*con_startup)(void); - void (*con_init)(struct vc_data *, int); - void (*con_deinit)(struct vc_data *); - void (*con_clear)(struct vc_data *, int, int, int, int); - void (*con_putc)(struct vc_data *, int, int, int); - void (*con_putcs)(struct vc_data *, const unsigned short *, int, int, int); - void (*con_cursor)(struct vc_data *, int); - bool (*con_scroll)(struct vc_data *, unsigned int top, + void (*con_init)(struct vc_data *vc, int init); + void (*con_deinit)(struct vc_data *vc); + void (*con_clear)(struct vc_data *vc, int sy, int sx, int height, + int width); + void (*con_putc)(struct vc_data *vc, int c, int ypos, int xpos); + void (*con_putcs)(struct vc_data *vc, const unsigned short *s, + int count, int ypos, int xpos); + void (*con_cursor)(struct vc_data *vc, int mode); + bool (*con_scroll)(struct vc_data *vc, unsigned int top, unsigned int bottom, enum con_scroll dir, unsigned int lines); - int (*con_switch)(struct vc_data *); - int (*con_blank)(struct vc_data *, int, int); - int (*con_font_set)(struct vc_data *, struct console_font *, unsigned); - int (*con_font_get)(struct vc_data *, struct console_font *); - int (*con_font_default)(struct vc_data *, struct console_font *, char *); - int (*con_font_copy)(struct vc_data *, int); - int (*con_resize)(struct vc_data *, unsigned int, unsigned int, - unsigned int); - void (*con_set_palette)(struct vc_data *, + int (*con_switch)(struct vc_data *vc); + int (*con_blank)(struct vc_data *vc, int blank, int mode_switch); + int (*con_font_set)(struct vc_data *vc, struct console_font *font, + unsigned int flags); + int (*con_font_get)(struct vc_data *vc, struct console_font *font); + int (*con_font_default)(struct vc_data *vc, + struct console_font *font, char *name); + int (*con_font_copy)(struct vc_data *vc, int con); + int (*con_resize)(struct vc_data *vc, unsigned int width, + unsigned int height, unsigned int user); + void (*con_set_palette)(struct vc_data *vc, const unsigned char *table); - void (*con_scrolldelta)(struct vc_data *, int lines); - int (*con_set_origin)(struct vc_data *); - void (*con_save_screen)(struct vc_data *); - u8 (*con_build_attr)(struct vc_data *, u8, u8, u8, u8, u8, u8); - void (*con_invert_region)(struct vc_data *, u16 *, int); - u16 *(*con_screen_pos)(struct vc_data *, int); - unsigned long (*con_getxy)(struct vc_data *, unsigned long, int *, int *); + void (*con_scrolldelta)(struct vc_data *vc, int lines); + int (*con_set_origin)(struct vc_data *vc); + void (*con_save_screen)(struct vc_data *vc); + u8 (*con_build_attr)(struct vc_data *vc, u8 color, u8 intensity, + u8 blink, u8 underline, u8 reverse, u8 italic); + void (*con_invert_region)(struct vc_data *vc, u16 *p, int count); + u16 *(*con_screen_pos)(struct vc_data *vc, int offset); + unsigned long (*con_getxy)(struct vc_data *vc, unsigned long position, + int *px, int *py); /* * Flush the video console driver's scrollback buffer */ - void (*con_flush_scrollback)(struct vc_data *); + void (*con_flush_scrollback)(struct vc_data *vc); /* * Prepare the console for the debugger. This includes, but is not * limited to, unblanking the console, loading an appropriate * palette, and allowing debugger generated output. */ - int (*con_debug_enter)(struct vc_data *); + int (*con_debug_enter)(struct vc_data *vc); /* * Restore the console to its pre-debug state as closely as possible. */ - int (*con_debug_leave)(struct vc_data *); + int (*con_debug_leave)(struct vc_data *vc); };
extern const struct consw *conswitchp;
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 --- drivers/usb/misc/sisusbvga/sisusb_con.c | 67 +++++++++++++++++++++++++------- drivers/video/console/dummycon.c | 69 +++++++++++++++++++++++++-------- drivers/video/console/newport_con.c | 10 ++--- drivers/video/console/vgacon.c | 20 +++++----- drivers/video/fbdev/core/fbcon.c | 3 +- 5 files changed, 121 insertions(+), 48 deletions(-)
diff --git a/drivers/usb/misc/sisusbvga/sisusb_con.c b/drivers/usb/misc/sisusbvga/sisusb_con.c index 998df891bdde..a0d6e0af957c 100644 --- a/drivers/usb/misc/sisusbvga/sisusb_con.c +++ b/drivers/usb/misc/sisusbvga/sisusb_con.c @@ -1217,7 +1217,7 @@ sisusbcon_do_font_op(struct sisusb_usb_data *sisusb, int set, int slot, /* 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; @@ -1338,28 +1338,65 @@ 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 b90ef96e43d6..f2eafe2ed980 100644 --- 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 42d02a206059..6897bd0fc00e 100644 --- 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 a17ba1465815..f09e17b60e45 100644 --- 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 5baf7bc054e1..3e330e0f56ed 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2595,7 +2595,8 @@ 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;
On Monday, February 26, 2018 04:04:17 PM Kees Cook wrote:
This is a small series that cleans up struct consw a bit and prepares it for Control Flow Integrity checking (i.e. Clang's -fsanitize=cfi).
for drivers/video/ parts:
Acked-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com
Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics
On Wednesday, February 28, 2018 04:09:47 PM Bartlomiej Zolnierkiewicz wrote:
On Monday, February 26, 2018 04:04:17 PM Kees Cook wrote:
This is a small series that cleans up struct consw a bit and prepares it for Control Flow Integrity checking (i.e. Clang's -fsanitize=cfi).
for drivers/video/ parts:
Acked-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com
also I'll be happy to merge all patches through fbdev tree (if Greg is fine with it and ACKs drivers/usb/ parts)
Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics
On Wed, Feb 28, 2018 at 04:14:38PM +0100, Bartlomiej Zolnierkiewicz wrote:
On Wednesday, February 28, 2018 04:09:47 PM Bartlomiej Zolnierkiewicz wrote:
On Monday, February 26, 2018 04:04:17 PM Kees Cook wrote:
This is a small series that cleans up struct consw a bit and prepares it for Control Flow Integrity checking (i.e. Clang's -fsanitize=cfi).
for drivers/video/ parts:
Acked-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com
also I'll be happy to merge all patches through fbdev tree (if Greg is fine with it and ACKs drivers/usb/ parts)
I've already taken this through the tty tree, sorry about that. Shouldn't cause any merge issues.
greg k-h
dri-devel@lists.freedesktop.org
-
Bartlomiej Zolnierkiewicz -
Greg Kroah-Hartman -
Kees Cook