The patch titled
Video: fb, add true ref_count atomicity
has been added to the -mm tree. Its filename is
video-fb-add-true-ref_count-atomicity.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Video: fb, add true ref_count atomicity
From: Jiri Slaby <jirislaby@xxxxxxxxx>
Some of fb drivers uses atomic_t in bad manner, since there are still some
race-prone gaps. Use mutexes to protect open/close code sections with
ref_count testing and finally use simple uint.
Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
Acked-by: Denis Oliver Kropp <dok@xxxxxxxxxxxx>
Cc: James Simmons <jsimmons@xxxxxxxxxxxxx>
Cc: "Antonino A. Daplas" <adaplas@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/video/i810/i810.h | 3 ++-
drivers/video/i810/i810_main.c | 25 +++++++++++++++----------
drivers/video/neofb.c | 21 ++++++++++++++-------
drivers/video/riva/fbdev.c | 19 ++++++++++++-------
drivers/video/riva/rivafb.h | 3 ++-
drivers/video/vga16fb.c | 23 +++++++++++++++--------
include/video/neomagic.h | 3 ++-
7 files changed, 62 insertions(+), 35 deletions(-)
diff -puN drivers/video/i810/i810.h~video-fb-add-true-ref_count-atomicity drivers/video/i810/i810.h
--- a/drivers/video/i810/i810.h~video-fb-add-true-ref_count-atomicity
+++ a/drivers/video/i810/i810.h
@@ -264,7 +264,8 @@ struct i810fb_par {
struct heap_data cursor_heap;
struct vgastate state;
struct i810fb_i2c_chan chan[3];
- atomic_t use_count;
+ struct mutex open_lock;
+ unsigned int use_count;
u32 pseudo_palette[17];
unsigned long mmio_start_phys;
u8 __iomem *mmio_start_virtual;
diff -puN drivers/video/i810/i810_main.c~video-fb-add-true-ref_count-atomicity drivers/video/i810/i810_main.c
--- a/drivers/video/i810/i810_main.c~video-fb-add-true-ref_count-atomicity
+++ a/drivers/video/i810/i810_main.c
@@ -1235,9 +1235,9 @@ static int i810fb_getcolreg(u8 regno, u8
static int i810fb_open(struct fb_info *info, int user)
{
struct i810fb_par *par = info->par;
- u32 count = atomic_read(&par->use_count);
-
- if (count == 0) {
+
+ mutex_lock(&par->open_lock);
+ if (par->use_count == 0) {
memset(&par->state, 0, sizeof(struct vgastate));
par->state.flags = VGA_SAVE_CMAP;
par->state.vgabase = par->mmio_start_virtual;
@@ -1246,7 +1246,8 @@ static int i810fb_open(struct fb_info *i
i810_save_vga_state(par);
}
- atomic_inc(&par->use_count);
+ par->use_count++;
+ mutex_unlock(&par->open_lock);
return 0;
}
@@ -1254,18 +1255,20 @@ static int i810fb_open(struct fb_info *i
static int i810fb_release(struct fb_info *info, int user)
{
struct i810fb_par *par = info->par;
- u32 count;
-
- count = atomic_read(&par->use_count);
- if (count == 0)
+
+ mutex_lock(&par->open_lock);
+ if (par->use_count == 0) {
+ mutex_unlock(&par->open_lock);
return -EINVAL;
+ }
- if (count == 1) {
+ if (par->use_count == 1) {
i810_restore_vga_state(par);
restore_vga(&par->state);
}
- atomic_dec(&par->use_count);
+ par->use_count--;
+ mutex_unlock(&par->open_lock);
return 0;
}
@@ -1752,6 +1755,8 @@ static void __devinit i810_init_monspecs
static void __devinit i810_init_defaults(struct i810fb_par *par,
struct fb_info *info)
{
+ mutex_init(&par->open_lock);
+
if (voffset)
v_offset_default = voffset;
else if (par->aperture.size > 32 * 1024 * 1024)
diff -puN drivers/video/neofb.c~video-fb-add-true-ref_count-atomicity drivers/video/neofb.c
--- a/drivers/video/neofb.c~video-fb-add-true-ref_count-atomicity
+++ a/drivers/video/neofb.c
@@ -556,14 +556,16 @@ static int
neofb_open(struct fb_info *info, int user)
{
struct neofb_par *par = info->par;
- int cnt = atomic_read(&par->ref_count);
- if (!cnt) {
+ mutex_lock(&par->open_lock);
+ if (!par->ref_count) {
memset(&par->state, 0, sizeof(struct vgastate));
par->state.flags = VGA_SAVE_MODE | VGA_SAVE_FONTS;
save_vga(&par->state);
}
- atomic_inc(&par->ref_count);
+ par->ref_count++;
+ mutex_unlock(&par->open_lock);
+
return 0;
}
@@ -571,14 +573,18 @@ static int
neofb_release(struct fb_info *info, int user)
{
struct neofb_par *par = info->par;
- int cnt = atomic_read(&par->ref_count);
- if (!cnt)
+ mutex_lock(&par->open_lock);
+ if (!par->ref_count) {
+ mutex_unlock(&par->open_lock);
return -EINVAL;
- if (cnt == 1) {
+ }
+ if (par->ref_count == 1) {
restore_vga(&par->state);
}
- atomic_dec(&par->ref_count);
+ par->ref_count--;
+ mutex_unlock(&par->open_lock);
+
return 0;
}
@@ -2047,6 +2053,7 @@ static struct fb_info *__devinit neo_all
info->fix.accel = id->driver_data;
+ mutex_init(&par->open_lock);
par->pci_burst = !nopciburst;
par->lcd_stretch = !nostretch;
par->libretto = libretto;
diff -puN drivers/video/riva/fbdev.c~video-fb-add-true-ref_count-atomicity drivers/video/riva/fbdev.c
--- a/drivers/video/riva/fbdev.c~video-fb-add-true-ref_count-atomicity
+++ a/drivers/video/riva/fbdev.c
@@ -1100,10 +1100,10 @@ static int riva_get_cmap_len(const struc
static int rivafb_open(struct fb_info *info, int user)
{
struct riva_par *par = info->par;
- int cnt = atomic_read(&par->ref_count);
NVTRACE_ENTER();
- if (!cnt) {
+ mutex_lock(&par->open_lock);
+ if (!par->ref_count) {
#ifdef CONFIG_X86
memset(&par->state, 0, sizeof(struct vgastate));
par->state.flags = VGA_SAVE_MODE | VGA_SAVE_FONTS;
@@ -1118,7 +1118,8 @@ static int rivafb_open(struct fb_info *i
riva_save_state(par, &par->initial_state);
}
- atomic_inc(&par->ref_count);
+ par->ref_count++;
+ mutex_unlock(&par->open_lock);
NVTRACE_LEAVE();
return 0;
}
@@ -1126,12 +1127,14 @@ static int rivafb_open(struct fb_info *i
static int rivafb_release(struct fb_info *info, int user)
{
struct riva_par *par = info->par;
- int cnt = atomic_read(&par->ref_count);
NVTRACE_ENTER();
- if (!cnt)
+ mutex_lock(&par->open_lock);
+ if (!par->ref_count) {
+ mutex_unlock(&par->open_lock);
return -EINVAL;
- if (cnt == 1) {
+ }
+ if (par->ref_count == 1) {
par->riva.LockUnlock(&par->riva, 0);
par->riva.LoadStateExt(&par->riva, &par->initial_state.ext);
riva_load_state(par, &par->initial_state);
@@ -1140,7 +1143,8 @@ static int rivafb_release(struct fb_info
#endif
par->riva.LockUnlock(&par->riva, 1);
}
- atomic_dec(&par->ref_count);
+ par->ref_count--;
+ mutex_unlock(&par->open_lock);
NVTRACE_LEAVE();
return 0;
}
@@ -1998,6 +2002,7 @@ static int __devinit rivafb_probe(struct
goto err_disable_device;
}
+ mutex_init(&default_par->open_lock);
default_par->riva.Architecture = riva_get_arch(pd);
default_par->Chipset = (pd->vendor << 16) | pd->device;
diff -puN drivers/video/riva/rivafb.h~video-fb-add-true-ref_count-atomicity drivers/video/riva/rivafb.h
--- a/drivers/video/riva/rivafb.h~video-fb-add-true-ref_count-atomicity
+++ a/drivers/video/riva/rivafb.h
@@ -53,7 +53,8 @@ struct riva_par {
#ifdef CONFIG_X86
struct vgastate state;
#endif
- atomic_t ref_count;
+ struct mutex open_lock;
+ unsigned int ref_count;
unsigned char *EDID;
unsigned int Chipset;
int forceCRTC;
diff -puN drivers/video/vga16fb.c~video-fb-add-true-ref_count-atomicity drivers/video/vga16fb.c
--- a/drivers/video/vga16fb.c~video-fb-add-true-ref_count-atomicity
+++ a/drivers/video/vga16fb.c
@@ -70,7 +70,8 @@ struct vga16fb_par {
unsigned char ClockingMode; /* Seq-Controller:01h */
} vga_state;
struct vgastate state;
- atomic_t ref_count;
+ struct mutex open_lock;
+ unsigned int ref_count;
int palette_blanked, vesa_blanked, mode, isVGA;
u8 misc, pel_msk, vss, clkdiv;
u8 crtc[VGA_CRT_C];
@@ -300,28 +301,33 @@ static void vga16fb_clock_chip(struct vg
static int vga16fb_open(struct fb_info *info, int user)
{
struct vga16fb_par *par = info->par;
- int cnt = atomic_read(&par->ref_count);
- if (!cnt) {
+ mutex_lock(&par->open_lock);
+ if (!par->ref_count) {
memset(&par->state, 0, sizeof(struct vgastate));
par->state.flags = VGA_SAVE_FONTS | VGA_SAVE_MODE |
VGA_SAVE_CMAP;
save_vga(&par->state);
}
- atomic_inc(&par->ref_count);
+ par->ref_count++;
+ mutex_unlock(&par->open_lock);
+
return 0;
}
static int vga16fb_release(struct fb_info *info, int user)
{
struct vga16fb_par *par = info->par;
- int cnt = atomic_read(&par->ref_count);
- if (!cnt)
+ mutex_lock(&par->open_lock);
+ if (!par->ref_count) {
+ mutex_unlock(&par->open_lock);
return -EINVAL;
- if (cnt == 1)
+ }
+ if (par->ref_count == 1)
restore_vga(&par->state);
- atomic_dec(&par->ref_count);
+ par->ref_count--;
+ mutex_unlock(&par->open_lock);
return 0;
}
@@ -1357,6 +1363,7 @@ static int __init vga16fb_probe(struct p
printk(KERN_INFO "vga16fb: mapped to 0x%p\n", info->screen_base);
par = info->par;
+ mutex_init(&par->open_lock);
par->isVGA = ORIG_VIDEO_ISVGA;
par->palette_blanked = 0;
par->vesa_blanked = 0;
diff -puN include/video/neomagic.h~video-fb-add-true-ref_count-atomicity include/video/neomagic.h
--- a/include/video/neomagic.h~video-fb-add-true-ref_count-atomicity
+++ a/include/video/neomagic.h
@@ -140,7 +140,8 @@ typedef volatile struct {
struct neofb_par {
struct vgastate state;
- atomic_t ref_count;
+ struct mutex open_lock;
+ unsigned int ref_count;
unsigned char MiscOutReg; /* Misc */
unsigned char CRTC[25]; /* Crtc Controller */
_
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mxser-remove-ambiguous-redefinition-of-init_work.patch
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char-isicom-augment-card_reset.patch
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char-isicom-correct-probing-removing.patch
char-tty_wakeup-cleanup.patch
char-mxser_new-mark-init-functions.patch
char-mxser_new-remove-useless-spinlock.patch
char-serial167-cleanup.patch
char-n_r3964-cleanup.patch
char-mxser_new-remove-unused-stuff.patch
char-mxser-obsolete-old-nonexperimental-new.patch
char-mxser_new-remove-tty_wakeup-bottomhalf.patch
char-mxser_new-clean-request_irq-call.patch
doc-isicom-remove-reserved-ioctl-number.patch
char-mxser_new-alter-locking-in-isr.patch
char-mxser_new-header-file-cleanup.patch
char-mxser_new-less-loops-in-isr.patch
char-mxser_new-fix-twice-resource-releasing.patch
char-mxser_new-do-not-put-pdev.patch
char-mxser_new-upgrade-to-1915.patch
char-mxser_new-upgrade-to-1915-fix.patch
char-mxser_new-do-not-null-driver_data.patch
char-mxser_new-lock-count-and-flags.patch
char-mxser_new-fix-sparse-warning.patch
char-moxa-remove-unused-allocated-page.patch
char-moxa-do-not-initialize-global-static.patch
char-moxa-timers-cleanup.patch
char-moxa-remove-hangup-bottomhalf.patch
char-moxa-remove-unused-functions.patch
char-moxa-devids-cleanup.patch
char-moxa-use-pci_device.patch
char-moxa-eliminate-typedefs.patch
char-moxa-macros-cleanup.patch
char-moxa-use-del_timer_sync.patch
char-moxa-remove-moxa_pci_devinfo.patch
char-moxa-variables-cleanup.patch
char-moxa-remove-useless-vairables.patch
char-moxa-pci_probing-prepare.patch
char-moxa-pci-probing.patch
mxser-remove-useless-fields.patch
char-use-more-pci_device-macro.patch
char-cyclades-use-pci_device_id.patch
maintainers-remove-two-dead-e-mail.patch
video-fb-add-true-ref_count-atomicity.patch
video-fb-kzalloc-changes.patch
shrink_slab-handle-bad-shrinkers.patch
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