forked from Minki/linux
aef7db4bd5
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> |
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| .. | ||
| aty | ||
| backlight | ||
| console | ||
| display | ||
| geode | ||
| i810 | ||
| intelfb | ||
| kyro | ||
| logo | ||
| matrox | ||
| mbx | ||
| nvidia | ||
| omap | ||
| pnx4008 | ||
| riva | ||
| savage | ||
| sis | ||
| vermilion | ||
| 68328fb.c | ||
| acornfb.c | ||
| acornfb.h | ||
| am200epd.c | ||
| amba-clcd.c | ||
| amifb.c | ||
| arcfb.c | ||
| arkfb.c | ||
| asiliantfb.c | ||
| atafb_iplan2p2.c | ||
| atafb_iplan2p4.c | ||
| atafb_iplan2p8.c | ||
| atafb_mfb.c | ||
| atafb_utils.h | ||
| atafb.c | ||
| atafb.h | ||
| atmel_lcdfb.c | ||
| au1100fb.c | ||
| au1100fb.h | ||
| au1200fb.c | ||
| au1200fb.h | ||
| bf54x-lq043fb.c | ||
| bfin-t350mcqb-fb.c | ||
| bt431.h | ||
| bt455.h | ||
| bw2.c | ||
| c2p.c | ||
| c2p.h | ||
| carminefb_regs.h | ||
| carminefb.c | ||
| carminefb.h | ||
| cfbcopyarea.c | ||
| cfbfillrect.c | ||
| cfbimgblt.c | ||
| cg3.c | ||
| cg6.c | ||
| cg14.c | ||
| chipsfb.c | ||
| cirrusfb.c | ||
| clps711xfb.c | ||
| cobalt_lcdfb.c | ||
| controlfb.c | ||
| controlfb.h | ||
| cyber2000fb.c | ||
| cyber2000fb.h | ||
| cyblafb.c | ||
| dnfb.c | ||
| edid.h | ||
| efifb.c | ||
| epson1355fb.c | ||
| fb_ddc.c | ||
| fb_defio.c | ||
| fb_draw.h | ||
| fb_notify.c | ||
| fb_sys_fops.c | ||
| fbcmap.c | ||
| fbcvt.c | ||
| fbmem.c | ||
| fbmon.c | ||
| fbsysfs.c | ||
| ffb.c | ||
| fm2fb.c | ||
| fsl-diu-fb.c | ||
| fsl-diu-fb.h | ||
| g364fb.c | ||
| gbefb.c | ||
| gxt4500.c | ||
| hecubafb.c | ||
| hgafb.c | ||
| hitfb.c | ||
| hpfb.c | ||
| igafb.c | ||
| imacfb.c | ||
| imsttfb.c | ||
| imxfb.c | ||
| imxfb.h | ||
| Kconfig | ||
| leo.c | ||
| macfb.c | ||
| macmodes.c | ||
| macmodes.h | ||
| Makefile | ||
| maxinefb.c | ||
| metronomefb.c | ||
| modedb.c | ||
| n411.c | ||
| neofb.c | ||
| offb.c | ||
| output.c | ||
| p9100.c | ||
| platinumfb.c | ||
| platinumfb.h | ||
| pm2fb.c | ||
| pm3fb.c | ||
| pmag-aa-fb.c | ||
| pmag-ba-fb.c | ||
| pmagb-b-fb.c | ||
| ps3fb.c | ||
| pvr2fb.c | ||
| pxafb.c | ||
| pxafb.h | ||
| q40fb.c | ||
| s1d13xxxfb.c | ||
| s3c2410fb.c | ||
| s3c2410fb.h | ||
| s3fb.c | ||
| sa1100fb.c | ||
| sa1100fb.h | ||
| sbuslib.c | ||
| sbuslib.h | ||
| sgivwfb.c | ||
| sh7760fb.c | ||
| sh_mobile_lcdcfb.c | ||
| skeletonfb.c | ||
| sm501fb.c | ||
| sstfb.c | ||
| sticore.h | ||
| stifb.c | ||
| sunxvr500.c | ||
| sunxvr2500.c | ||
| svgalib.c | ||
| syscopyarea.c | ||
| sysfillrect.c | ||
| sysimgblt.c | ||
| tcx.c | ||
| tdfxfb.c | ||
| tgafb.c | ||
| tridentfb.c | ||
| uvesafb.c | ||
| valkyriefb.c | ||
| valkyriefb.h | ||
| vesafb.c | ||
| vfb.c | ||
| vga16fb.c | ||
| vgastate.c | ||
| vt8623fb.c | ||
| w100fb.c | ||
| w100fb.h | ||
| xen-fbfront.c | ||
| xilinxfb.c | ||