android_kernel_xiaomi_sm8350/drivers/video
Krzysztof Helt aef7db4bd5 fbdev: fix recursive notifier and locking when fbdev console is blanked
Fix infinite recursive notifier in the fbdev layer.  This causes recursive
locking.  Dmitry Baryshkov found the problem and confirmed that the patch
fixes the bug.

After doing
# echo 1 > /sys/class/graphics/fb0/blank
I got the following in my kernel log:

=============================================
[ INFO: possible recursive locking detected ]
2.6.27-rc6-00086-gda63874-dirty #97
---------------------------------------------
echo/1564 is trying to acquire lock:
 ((fb_notifier_list).rwsem){..--}, at: [<c005a384>] __blocking_notifier_call_chain+0x38/0x6c

but task is already holding lock:
 ((fb_notifier_list).rwsem){..--}, at: [<c005a384>] __blocking_notifier_call_chain+0x38/0x6c

other info that might help us debug this:
2 locks held by echo/1564:
 #0:  (&buffer->mutex){--..}, at: [<c00ddde0>] sysfs_write_file+0x30/0x80
 #1:  ((fb_notifier_list).rwsem){..--}, at: [<c005a384>] __blocking_notifier_call_chain+0x38/0x6c

stack backtrace:
[<c0029fe4>] (dump_stack+0x0/0x14) from [<c0060ce0>] (print_deadlock_bug+0xa4/0xd0)
[<c0060c3c>] (print_deadlock_bug+0x0/0xd0) from [<c0060e54>] (check_deadlock+0x148/0x17c)
 r6:c397a1e0 r5:c397a530 r4:c04fcf98
[<c0060d0c>] (check_deadlock+0x0/0x17c) from [<c00637e8>] (validate_chain+0x3c4/0x4f0)
[<c0063424>] (validate_chain+0x0/0x4f0) from [<c0063efc>] (__lock_acquire+0x5e8/0x6b4)
[<c0063914>] (__lock_acquire+0x0/0x6b4) from [<c006402c>] (lock_acquire+0x64/0x78)
[<c0063fc8>] (lock_acquire+0x0/0x78) from [<c0316ca8>] (down_read+0x4c/0x60)
 r7:00000009 r6:ffffffff r5:c0427a40 r4:c005a384
[<c0316c5c>] (down_read+0x0/0x60) from [<c005a384>] (__blocking_notifier_call_chain+0x38/0x6c)
 r5:c0427a40 r4:c0427a74
[<c005a34c>] (__blocking_notifier_call_chain+0x0/0x6c) from [<c005a3d8>] (blocking_notifier_call_chain+0x20/0x28)
 r8:00000009 r7:c086d640 r6:c3967940 r5:00000000 r4:c38984b8
[<c005a3b8>] (blocking_notifier_call_chain+0x0/0x28) from [<c014baa0>] (fb_notifier_call_chain+0x1c/0x24)
[<c014ba84>] (fb_notifier_call_chain+0x0/0x24) from [<c014c18c>] (fb_blank+0x64/0x70)
[<c014c128>] (fb_blank+0x0/0x70) from [<c0155978>] (fbcon_blank+0x114/0x1bc)
 r5:00000001 r4:c38984b8
[<c0155864>] (fbcon_blank+0x0/0x1bc) from [<c0170ea8>] (do_blank_screen+0x1e0/0x2a0)
[<c0170cc8>] (do_blank_screen+0x0/0x2a0) from [<c0154024>] (fbcon_fb_blanked+0x74/0x94)
 r5:c3967940 r4:00000001
[<c0153fb0>] (fbcon_fb_blanked+0x0/0x94) from [<c0154228>] (fbcon_event_notify+0x100/0x12c)
 r5:fffffffe r4:c39bc194
[<c0154128>] (fbcon_event_notify+0x0/0x12c) from [<c005a0d4>] (notifier_call_chain+0x38/0x7c)
[<c005a09c>] (notifier_call_chain+0x0/0x7c) from [<c005a3a0>] (__blocking_notifier_call_chain+0x54/0x6c)
 r8:c3b51ea0 r7:00000009 r6:ffffffff r5:c0427a40 r4:c0427a74
[<c005a34c>] (__blocking_notifier_call_chain+0x0/0x6c) from [<c005a3d8>] (blocking_notifier_call_chain+0x20/0x28)
 r8:00000001 r7:c3a7e000 r6:00000000 r5:00000000 r4:c38984b8
[<c005a3b8>] (blocking_notifier_call_chain+0x0/0x28) from [<c014baa0>] (fb_notifier_call_chain+0x1c/0x24)
[<c014ba84>] (fb_notifier_call_chain+0x0/0x24) from [<c014c18c>] (fb_blank+0x64/0x70)
[<c014c128>] (fb_blank+0x0/0x70) from [<c014e450>] (store_blank+0x54/0x7c)
 r5:c38984b8 r4:c3b51ec4
[<c014e3fc>] (store_blank+0x0/0x7c) from [<c017981c>] (dev_attr_store+0x28/0x2c)
 r8:00000001 r7:c042bf80 r6:c39eba10 r5:c3967c30 r4:c38e0140
[<c01797f4>] (dev_attr_store+0x0/0x2c) from [<c00ddaac>] (flush_write_buffer+0x54/0x68)
[<c00dda58>] (flush_write_buffer+0x0/0x68) from [<c00dde08>] (sysfs_write_file+0x58/0x80)
 r8:c3b51f78 r7:c3bcb070 r6:c39eba10 r5:00000001 r4:00000001
[<c00dddb0>] (sysfs_write_file+0x0/0x80) from [<c009de04>] (vfs_write+0xb8/0x148)
[<c009dd4c>] (vfs_write+0x0/0x148) from [<c009e384>] (sys_write+0x44/0x70)
 r7:00000004 r6:c3bcb070 r5:00000000 r4:00000000
[<c009e340>] (sys_write+0x0/0x70) from [<c0025d00>] (ret_fast_syscall+0x0/0x2c)
 r6:4001b000 r5:00000001 r4:401dc658

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Reported-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Testted-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-03 18:22:17 -07:00
..
aty radeonfb: fix accel engine hangs 2008-08-12 16:07:28 -07:00
backlight [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
console fbdev: fix recursive notifier and locking when fbdev console is blanked 2008-10-03 18:22:17 -07:00
display
geode lxfb: fix console blanking 2008-07-24 10:47:40 -07:00
i810
intelfb i2c: Let framebuffer drivers set their I2C bus class to DDC 2008-07-14 22:38:28 +02:00
kyro
logo
matrox matrox maven: convert to a new-style i2c driver 2008-08-12 16:07:29 -07:00
mbx
nvidia
omap [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
pnx4008 [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
riva
savage
sis video/sis/: remove compat code 2008-07-24 10:47:37 -07:00
vermilion removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
68328fb.c
acornfb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
acornfb.h
am200epd.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
amba-clcd.c
amifb.c drivers/video/amifb.c cleanups 2008-07-24 10:47:40 -07:00
arcfb.c
arkfb.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
asiliantfb.c
atafb_iplan2p2.c
atafb_iplan2p4.c
atafb_iplan2p8.c
atafb_mfb.c
atafb_utils.h
atafb.c atafb: test virtual screen range before subtraction on unsigned 2008-07-24 10:47:37 -07:00
atafb.h
atmel_lcdfb.c atmel_lcdfb: disable LCD and DMA engines when suspending 2008-09-13 14:41:52 -07:00
au1100fb.c
au1100fb.h
au1200fb.c
au1200fb.h
bf54x-lq043fb.c Blackfin arch: move include/asm-blackfin header files to arch/blackfin 2008-08-27 10:51:02 +08:00
bfin-t350mcqb-fb.c lcd: add lcd_device to check_fb() entry in lcd_ops 2008-07-24 10:47:40 -07:00
bt431.h
bt455.h
bw2.c
c2p.c export c2p 2008-07-20 17:24:39 -07:00
c2p.h
carminefb_regs.h fbdev: add the carmine FB driver 2008-07-24 10:47:34 -07:00
carminefb.c fbdev: add the carmine FB driver 2008-07-24 10:47:34 -07:00
carminefb.h fbdev: add the carmine FB driver 2008-07-24 10:47:34 -07:00
cfbcopyarea.c
cfbfillrect.c
cfbimgblt.c
cg3.c
cg6.c
cg14.c
chipsfb.c
cirrusfb.c cirrusfb: check_par fixes 2008-09-02 19:21:38 -07:00
clps711xfb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
cobalt_lcdfb.c fbdev: add new Cobalt LCD framebuffer driver 2008-07-24 10:47:40 -07:00
controlfb.c
controlfb.h
cyber2000fb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
cyber2000fb.h
cyblafb.c
dnfb.c
edid.h
efifb.c
epson1355fb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
fb_ddc.c i2c: Let framebuffer drivers set their I2C bus class to DDC 2008-07-14 22:38:28 +02:00
fb_defio.c fbdefio: add set_page_dirty handler to deferred IO FB 2008-08-20 15:40:32 -07:00
fb_draw.h
fb_notify.c
fb_sys_fops.c
fbcmap.c
fbcvt.c
fbmem.c fbdefio: add set_page_dirty handler to deferred IO FB 2008-08-20 15:40:32 -07:00
fbmon.c fbdev: width and height are unsigned 2008-07-24 10:47:39 -07:00
fbsysfs.c
ffb.c
fm2fb.c
fsl-diu-fb.c freescale DIU: bug fix: add sanity check for AOI position 2008-08-15 08:35:43 -07:00
fsl-diu-fb.h
g364fb.c
gbefb.c gbefb: cmap FIFO timeout 2008-07-30 09:41:47 -07:00
gxt4500.c
hecubafb.c
hgafb.c hgafb: convert to new platform driver API 2008-07-24 10:47:39 -07:00
hitfb.c video: Fix up hp6xx driver build regressions. 2008-07-30 02:16:12 +09:00
hpfb.c
igafb.c
imacfb.c
imsttfb.c
imxfb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
imxfb.h
Kconfig video: sh7760fb: SH7760/SH7763 LCDC framebuffer driver 2008-07-24 10:47:41 -07:00
leo.c
macfb.c make macfb_setup() static 2008-07-26 12:00:12 -07:00
macmodes.c
macmodes.h
Makefile video: Kill off leaked CONFIG_FB_SH7343VOU reference. 2008-07-29 06:39:26 +09:00
maxinefb.c
metronomefb.c
modedb.c
n411.c
neofb.c neofb: drop the xtimings structure 2008-07-24 10:47:41 -07:00
offb.c fbdev: Teaches offb about palette on radeon r5xx/r6xx 2008-07-22 10:39:36 +10:00
output.c
p9100.c
platinumfb.c
platinumfb.h
pm2fb.c pm2fb: free cmap memory on module remove 2008-08-20 15:40:31 -07:00
pm3fb.c
pmag-aa-fb.c
pmag-ba-fb.c
pmagb-b-fb.c
ps3fb.c powerpc/ps3: Add a sub-match id to ps3_system_bus 2008-07-22 10:39:33 +10:00
pvr2fb.c sh: More header path fixups for mach dir refactoring. 2008-07-29 22:10:01 +09:00
pxafb.c [ARM] pxafb: fix the warning of incorrect lccr when lcd_conn is specified 2008-08-16 16:39:16 +01:00
pxafb.h pxafb: convert ctrlr_sem in a mutex 2008-07-24 10:47:37 -07:00
q40fb.c
s1d13xxxfb.c
s3c2410fb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
s3c2410fb.h
s3fb.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
sa1100fb.c [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
sa1100fb.h sa1100fb: convert ctrlr_sem in a mutex 2008-07-24 10:47:37 -07:00
sbuslib.c
sbuslib.h
sgivwfb.c
sh7760fb.c sh7760fb: write colormap value to hardware 2008-07-28 16:30:21 -07:00
sh_mobile_lcdcfb.c video: export sh_mobile_lcdc panel size 2008-08-11 20:17:55 +09:00
skeletonfb.c skeletonfb: update to correct platform driver usage 2008-07-24 10:47:39 -07:00
sm501fb.c sm501: fixup allocation code to be 64bit resource compliant 2008-07-24 10:47:40 -07:00
sstfb.c
sticore.h video/console/stico{n,re}.c: make code static 2008-07-26 12:00:12 -07:00
stifb.c video/stifb.c: make 2 functions static 2008-07-26 12:00:12 -07:00
sunxvr500.c
sunxvr2500.c
svgalib.c
syscopyarea.c
sysfillrect.c
sysimgblt.c
tcx.c
tdfxfb.c tdfxfb: fix frame buffer name overrun 2008-09-02 19:21:39 -07:00
tgafb.c
tridentfb.c tridentfb: remove warning message that cyblafb driver should be used 2008-07-24 10:47:36 -07:00
uvesafb.c uvesafb: change mode parameter to mode_option 2008-07-24 10:47:37 -07:00
valkyriefb.c
valkyriefb.h
vesafb.c
vfb.c vfb: only enable if explicitly requested when compiled in 2008-07-24 10:47:39 -07:00
vga16fb.c vga16fb: source code improvement 2008-07-24 10:47:38 -07:00
vgastate.c
vt8623fb.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
w100fb.c
w100fb.h
xen-fbfront.c
xilinxfb.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00