[PATCH] fbdev: Constify struct sbus_mmap_map

From: Christophe JAILLET
Date: Sun Oct 13 2024 - 07:57:41 EST


'struct sbus_mmap_map' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increases overall security.

Update sbusfb_mmap_helper() accordingly.

On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
2452 536 16 3004 bbc drivers/video/fbdev/bw2.o

After:
=====
text data bss dec hex filename
2500 483 16 2999 bb7 drivers/video/fbdev/bw2.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Compile tested only with a cross compiler for sparc.
---
drivers/video/fbdev/bw2.c | 2 +-
drivers/video/fbdev/cg14.c | 2 +-
drivers/video/fbdev/cg3.c | 2 +-
drivers/video/fbdev/cg6.c | 2 +-
drivers/video/fbdev/ffb.c | 2 +-
drivers/video/fbdev/leo.c | 2 +-
drivers/video/fbdev/p9100.c | 2 +-
drivers/video/fbdev/sbuslib.c | 2 +-
drivers/video/fbdev/sbuslib.h | 2 +-
drivers/video/fbdev/tcx.c | 2 +-
10 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/video/fbdev/bw2.c b/drivers/video/fbdev/bw2.c
index 4a64940e0c00..e757462af0a6 100644
--- a/drivers/video/fbdev/bw2.c
+++ b/drivers/video/fbdev/bw2.c
@@ -147,7 +147,7 @@ bw2_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map bw2_mmap_map[] = {
+static const struct sbus_mmap_map bw2_mmap_map[] = {
{
.size = SBUS_MMAP_FBSIZE(1)
},
diff --git a/drivers/video/fbdev/cg14.c b/drivers/video/fbdev/cg14.c
index 430e1a7b352b..5389f8f07346 100644
--- a/drivers/video/fbdev/cg14.c
+++ b/drivers/video/fbdev/cg14.c
@@ -360,7 +360,7 @@ static void cg14_init_fix(struct fb_info *info, int linebytes,
info->fix.accel = FB_ACCEL_SUN_CG14;
}

-static struct sbus_mmap_map __cg14_mmap_map[CG14_MMAP_ENTRIES] = {
+static const struct sbus_mmap_map __cg14_mmap_map[CG14_MMAP_ENTRIES] = {
{
.voff = CG14_REGS,
.poff = 0x80000000,
diff --git a/drivers/video/fbdev/cg3.c b/drivers/video/fbdev/cg3.c
index e4c53c6632ba..a58a483014e6 100644
--- a/drivers/video/fbdev/cg3.c
+++ b/drivers/video/fbdev/cg3.c
@@ -209,7 +209,7 @@ static int cg3_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map cg3_mmap_map[] = {
+static const struct sbus_mmap_map cg3_mmap_map[] = {
{
.voff = CG3_MMAP_OFFSET,
.poff = CG3_RAM_OFFSET,
diff --git a/drivers/video/fbdev/cg6.c b/drivers/video/fbdev/cg6.c
index 0b60df51e7bc..56d74468040a 100644
--- a/drivers/video/fbdev/cg6.c
+++ b/drivers/video/fbdev/cg6.c
@@ -545,7 +545,7 @@ static int cg6_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map cg6_mmap_map[] = {
+static const struct sbus_mmap_map cg6_mmap_map[] = {
{
.voff = CG6_FBC,
.poff = CG6_FBC_OFFSET,
diff --git a/drivers/video/fbdev/ffb.c b/drivers/video/fbdev/ffb.c
index 0b7e7b38c05a..34b6abff9493 100644
--- a/drivers/video/fbdev/ffb.c
+++ b/drivers/video/fbdev/ffb.c
@@ -710,7 +710,7 @@ static int ffb_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map ffb_mmap_map[] = {
+static const struct sbus_mmap_map ffb_mmap_map[] = {
{
.voff = FFB_SFB8R_VOFF,
.poff = FFB_SFB8R_POFF,
diff --git a/drivers/video/fbdev/leo.c b/drivers/video/fbdev/leo.c
index 271e2e8c6a84..b9fb059df2c7 100644
--- a/drivers/video/fbdev/leo.c
+++ b/drivers/video/fbdev/leo.c
@@ -338,7 +338,7 @@ static int leo_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map leo_mmap_map[] = {
+static const struct sbus_mmap_map leo_mmap_map[] = {
{
.voff = LEO_SS0_MAP,
.poff = LEO_OFF_SS0,
diff --git a/drivers/video/fbdev/p9100.c b/drivers/video/fbdev/p9100.c
index 124468f0e9ef..0bc0f78fe4b9 100644
--- a/drivers/video/fbdev/p9100.c
+++ b/drivers/video/fbdev/p9100.c
@@ -206,7 +206,7 @@ p9100_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map p9100_mmap_map[] = {
+static const struct sbus_mmap_map p9100_mmap_map[] = {
{ CG3_MMAP_OFFSET, 0, SBUS_MMAP_FBSIZE(1) },
{ 0, 0, 0 }
};
diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
index 634e3d159452..4c79654bda30 100644
--- a/drivers/video/fbdev/sbuslib.c
+++ b/drivers/video/fbdev/sbuslib.c
@@ -38,7 +38,7 @@ static unsigned long sbusfb_mmapsize(long size, unsigned long fbsize)
return fbsize * (-size);
}

-int sbusfb_mmap_helper(struct sbus_mmap_map *map,
+int sbusfb_mmap_helper(const struct sbus_mmap_map *map,
unsigned long physbase,
unsigned long fbsize,
unsigned long iospace,
diff --git a/drivers/video/fbdev/sbuslib.h b/drivers/video/fbdev/sbuslib.h
index 6466b4cbcd7b..e9af2dc93f94 100644
--- a/drivers/video/fbdev/sbuslib.h
+++ b/drivers/video/fbdev/sbuslib.h
@@ -19,7 +19,7 @@ struct sbus_mmap_map {

extern void sbusfb_fill_var(struct fb_var_screeninfo *var,
struct device_node *dp, int bpp);
-extern int sbusfb_mmap_helper(struct sbus_mmap_map *map,
+extern int sbusfb_mmap_helper(const struct sbus_mmap_map *map,
unsigned long physbase, unsigned long fbsize,
unsigned long iospace,
struct vm_area_struct *vma);
diff --git a/drivers/video/fbdev/tcx.c b/drivers/video/fbdev/tcx.c
index 6eb8bb2e3501..f9a0085ad72b 100644
--- a/drivers/video/fbdev/tcx.c
+++ b/drivers/video/fbdev/tcx.c
@@ -236,7 +236,7 @@ tcx_blank(int blank, struct fb_info *info)
return 0;
}

-static struct sbus_mmap_map __tcx_mmap_map[TCX_MMAP_ENTRIES] = {
+static const struct sbus_mmap_map __tcx_mmap_map[TCX_MMAP_ENTRIES] = {
{
.voff = TCX_RAM8BIT,
.size = SBUS_MMAP_FBSIZE(1)
--
2.47.0