Date: Tue, 17 Jul 2007 10:06:03 +0800 From: Ganbold <ganbold@micom.mng.net> To: Kostik Belousov <kostikbel@gmail.com> Cc: x11@freebsd.org Subject: Re: LOR when running google-earth Message-ID: <469C240B.4060201@micom.mng.net> In-Reply-To: <20070716105316.GT2200@deviant.kiev.zoral.com.ua> References: <469B17BB.9050305@micom.mng.net> <20070716105316.GT2200@deviant.kiev.zoral.com.ua>
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Hi, I have new LOR here after applying this patch: lock order reversal: (sleepable after non-sleepable) 1st 0xc3e3e4d8 drm device (drm device) @ /usr/src/sys/modules/drm/i915/../../../dev/drm/i915_dma.c:675 2nd 0xc42bb784 user map (user map) @ /usr/src/sys/vm/vm_map.c:1818 KDB: stack backtrace: db_trace_self_wrapper(c08a24a7,e6386a08,c066801e,c08a4988,c42bb784,...) at db_trace_self_wrapper+0x26 kdb_backtrace(c08a4988,c42bb784,c08bca1a,c08bca1a,c08bc9af,...) at kdb_backtrace+0x29 witness_checkorder(c42bb784,9,c08bc9af,71a,e6386a3c,...) at witness_checkorder+0x6de _sx_xlock(c42bb784,0,c08bc9af,71a,c3e3e400,...) at _sx_xlock+0x7d _vm_map_lock(c42bb740,c08bc9af,71a,e6386a84,c06677fc,...) at _vm_map_lock+0x51 vm_map_unwire(c42bb740,8570000,8571000,0,e6386b34,...) at vm_map_unwire+0x2d vsunlock(8570df8,30,c450171e,2a3,e6386b0c,...) at vsunlock+0x46 i915_cmdbuffer(c4358b00,8018644b,c3e1ae00,3,c3ef0000,...) at i915_cmdbuffer+0x5c8 drm_ioctl(c4358b00,8018644b,c3e1ae00,3,c3ef0000,...) at drm_ioctl+0x357 giant_ioctl(c4358b00,8018644b,c3e1ae00,3,c3ef0000,...) at giant_ioctl+0x56 devfs_ioctl_f(c4e10678,8018644b,c3e1ae00,c4359a00,c3ef0000,...) at devfs_ioctl_f+0xc9 kern_ioctl(c3ef0000,9,8018644b,c3e1ae00,386c4c,...) at kern_ioctl+0x243 ioctl(c3ef0000,e6386cfc,e6386c80,c4027e4a,c3ef0000,...) at ioctl+0x134 linux_ioctl_drm(c3ef0000,e6386cfc,c4035c45,a2f,c3ef0000,...) at linux_ioctl_drm+0x2f linux_ioctl(c3ef0000,e6386cfc,e6386cf8,e6386d1c,c4037dd0,...) at linux_ioctl+0xca syscall(e6386d38) at syscall+0x2b3 Xint0x80_syscall() at Xint0x80_syscall+0x20 --- syscall (54, Linux ELF, linux_ioctl), eip = 0x49ea95f4, esp = 0xbfbfdf0c, ebp = 0xbfbfdf2c --- KDB: enter: witness_checkorder [thread pid 991 tid 100083 ] Stopped at kdb_enter+0x32: leave db> bt Tracing pid 991 tid 100083 td 0xc3ef0000 kdb_enter(c085f570,c42bb784,c08bca1a,c08bca1a,c08bc9af,...) at kdb_enter+0x32 witness_checkorder(c42bb784,9,c08bc9af,71a,e6386a3c,...) at witness_checkorder+0x6f3 _sx_xlock(c42bb784,0,c08bc9af,71a,c3e3e400,...) at _sx_xlock+0x7d _vm_map_lock(c42bb740,c08bc9af,71a,e6386a84,c06677fc,...) at _vm_map_lock+0x51 vm_map_unwire(c42bb740,8570000,8571000,0,e6386b34,...) at vm_map_unwire+0x2d vsunlock(8570df8,30,c450171e,2a3,e6386b0c,...) at vsunlock+0x46 i915_cmdbuffer(c4358b00,8018644b,c3e1ae00,3,c3ef0000,...) at i915_cmdbuffer+0x5c8 drm_ioctl(c4358b00,8018644b,c3e1ae00,3,c3ef0000,...) at drm_ioctl+0x357 giant_ioctl(c4358b00,8018644b,c3e1ae00,3,c3ef0000,...) at giant_ioctl+0x56 devfs_ioctl_f(c4e10678,8018644b,c3e1ae00,c4359a00,c3ef0000,...) at devfs_ioctl_f+0xc9 kern_ioctl(c3ef0000,9,8018644b,c3e1ae00,386c4c,...) at kern_ioctl+0x243 ioctl(c3ef0000,e6386cfc,e6386c80,c4027e4a,c3ef0000,...) at ioctl+0x134 linux_ioctl_drm(c3ef0000,e6386cfc,c4035c45,a2f,c3ef0000,...) at linux_ioctl_drm+0x2f linux_ioctl(c3ef0000,e6386cfc,e6386cf8,e6386d1c,c4037dd0,...) at linux_ioctl+0xca syscall(e6386d38) at syscall+0x2b3 Xint0x80_syscall() at Xint0x80_syscall+0x20 --- syscall (54, Linux ELF, linux_ioctl), eip = 0x49ea95f4, esp = 0xbfbfdf0c, ebp = 0xbfbfdf2c --- db> Ganbold Kostik Belousov wrote: > [Redirected to x11@] > > On Mon, Jul 16, 2007 at 03:01:15PM +0800, Ganbold wrote: > >> Hi, >> >> I'm having LOR when I try to run google-earth. I have Intel 945GM >> graphic card. >> >> devil# uname -an >> FreeBSD devil.micom.mng.net 7.0-CURRENT FreeBSD 7.0-CURRENT #1: Tue Jul >> 10 10:44:42 ULAT 2007 >> root@devil.micom.mng.net:/usr/obj/usr/src/sys/DEVIL i386 >> devil# >> >> >> lock order reversal: (sleepable after non-sleepable) >> 1st 0xc3c06cd8 drm device (drm device) @ >> /usr/src/sys/modules/drm/drm/../../../dev/drm/drm_drv.c:907 >> 2nd 0xc3e6ea3c user map (user map) @ /usr/src/sys/vm/vm_glue.c:182 >> KDB: stack backtrace: >> db_trace_self_wrapper(c08a3fa4,e6450a44,c066992e,c08a6485,c3e6ea3c,...) >> at db_trace_self_wrapper+0x26 >> kdb_backtrace(c08a6485,c3e6ea3c,c08be517,c08be517,c08bdfed,...) at >> kdb_backtrace+0x29 >> witness_checkorder(c3e6ea3c,9,c08bdfed,b6,c435a000,...) at >> witness_checkorder+0x6de >> _sx_xlock(c3e6ea3c,0,c08bdfed,b6,e6450aa8,...) at _sx_xlock+0x7d >> _vm_map_lock_read(c3e6e9f8,c08bdfed,b6,c435a000,a60,...) at >> _vm_map_lock_read+0x50 >> useracc(4ce1ede8,8,1,f5,c09ce1bc,...) at useracc+0x65 >> i915_cmdbuffer(c3bf3800,8018644b,c43814a0,3,c435a000,...) at >> i915_cmdbuffer+0x10f >> drm_ioctl(c3bf3800,8018644b,c43814a0,3,c435a000,...) at drm_ioctl+0x357 >> giant_ioctl(c3bf3800,8018644b,c43814a0,3,c435a000,...) at giant_ioctl+0x56 >> devfs_ioctl_f(c4cdd1b0,8018644b,c43814a0,c4356700,c435a000,...) at >> devfs_ioctl_f+0xc9 >> kern_ioctl(c435a000,9,8018644b,c43814a0,450c4c,...) at kern_ioctl+0x243 >> ioctl(c435a000,e6450cfc,e6450c80,c4022e4a,c435a000,...) at ioctl+0x134 >> linux_ioctl_drm(c435a000,e6450cfc,c4030c45,a2f,c435a000,...) at >> linux_ioctl_drm+0x2f >> linux_ioctl(c435a000,e6450cfc,e6450cf8,e6450d1c,c4032dd0,...) at >> linux_ioctl+0xca >> syscall(e6450d38) at syscall+0x2b3 >> Xint0x80_syscall() at Xint0x80_syscall+0x20 >> --- syscall (54, Linux ELF, linux_ioctl), eip = 0x49ea95f4, esp = >> 0xbfbfdf44, ebp = 0xbfbfdf64 --- >> KDB: enter: witness_checkorder >> [thread pid 899 tid 100122 ] >> Stopped at kdb_enter+0x32: leave >> db> bt >> Tracing pid 899 tid 100122 td 0xc435a000 >> kdb_enter(c0861150,c3e6ea3c,c08be517,c08be517,c08bdfed,...) at >> kdb_enter+0x32 >> witness_checkorder(c3e6ea3c,9,c08bdfed,b6,c435a000,...) at >> witness_checkorder+0x6f3 >> _sx_xlock(c3e6ea3c,0,c08bdfed,b6,e6450aa8,...) at _sx_xlock+0x7d >> _vm_map_lock_read(c3e6e9f8,c08bdfed,b6,c435a000,a60,...) at >> _vm_map_lock_read+0x50 >> useracc(4ce1ede8,8,1,f5,c09ce1bc,...) at useracc+0x65 >> i915_cmdbuffer(c3bf3800,8018644b,c43814a0,3,c435a000,...) at >> i915_cmdbuffer+0x10f >> drm_ioctl(c3bf3800,8018644b,c43814a0,3,c435a000,...) at drm_ioctl+0x357 >> giant_ioctl(c3bf3800,8018644b,c43814a0,3,c435a000,...) at giant_ioctl+0x56 >> devfs_ioctl_f(c4cdd1b0,8018644b,c43814a0,c4356700,c435a000,...) at >> devfs_ioctl_f+0xc9 >> kern_ioctl(c435a000,9,8018644b,c43814a0,450c4c,...) at kern_ioctl+0x243 >> ioctl(c435a000,e6450cfc,e6450c80,c4022e4a,c435a000,...) at ioctl+0x134 >> linux_ioctl_drm(c435a000,e6450cfc,c4030c45,a2f,c435a000,...) at >> linux_ioctl_drm+0x2f >> linux_ioctl(c435a000,e6450cfc,e6450cf8,e6450d1c,c4032dd0,...) at >> linux_ioctl+0xca >> syscall(e6450d38) at syscall+0x2b3 >> Xint0x80_syscall() at Xint0x80_syscall+0x20 >> --- syscall (54, Linux ELF, linux_ioctl), eip = 0x49ea95f4, esp = >> 0xbfbfdf44, ebp = 0xbfbfdf64 --- >> db> c >> > > The use of useracc() seems to be racy and not complete. Below is the patch > that could fix the LOR and add missing checks, hopefully, in race free way. > Patch wires the ranges that are accessed under the drm lock with the help of > the vslock(). > > Patch was only compile-tested. > > diff --git a/sys/dev/drm/i915_dma.c b/sys/dev/drm/i915_dma.c > index dfaf334..431a2f9 100644 > --- a/sys/dev/drm/i915_dma.c > +++ b/sys/dev/drm/i915_dma.c > @@ -367,20 +367,14 @@ static int i915_emit_cmds(drm_device_t * dev, int __user * buffer, int dwords) > for (i = 0; i < dwords;) { > int cmd, sz; > > - if (DRM_COPY_FROM_USER_UNCHECKED(&cmd, &buffer[i], sizeof(cmd))) { > - > - return DRM_ERR(EINVAL); > - } > + cmd = buffer[i]; > if ((sz = validate_cmd(cmd)) == 0 || i + sz > dwords) > return DRM_ERR(EINVAL); > > OUT_RING(cmd); > > while (++i, --sz) { > - if (DRM_COPY_FROM_USER_UNCHECKED(&cmd, &buffer[i], > - sizeof(cmd))) { > - return DRM_ERR(EINVAL); > - } > + cmd = buffer[i]; > OUT_RING(cmd); > } > } > @@ -401,10 +395,7 @@ static int i915_emit_box(drm_device_t * dev, > drm_clip_rect_t box; > RING_LOCALS; > > - if (DRM_COPY_FROM_USER_UNCHECKED(&box, &boxes[i], sizeof(box))) { > - return EFAULT; > - } > - > + box = boxes[i]; > if (box.y2 <= box.y1 || box.x2 <= box.x1 || box.y2 <= 0 || box.x2 <= 0) { > DRM_ERROR("Bad box %d,%d..%d,%d\n", > box.x1, box.y1, box.x2, box.y2); > @@ -604,6 +595,7 @@ static int i915_batchbuffer(DRM_IOCTL_ARGS) > drm_i915_sarea_t *sarea_priv = (drm_i915_sarea_t *) > dev_priv->sarea_priv; > drm_i915_batchbuffer_t batch; > + size_t cliplen; > int ret; > > if (!dev_priv->allow_batchbuffer) { > @@ -619,12 +611,22 @@ static int i915_batchbuffer(DRM_IOCTL_ARGS) > > LOCK_TEST_WITH_RETURN(dev, filp); > > + DRM_UNLOCK(); > + cliplen = batch.num_cliprects * sizeof(drm_clip_rect_t); > if (batch.num_cliprects && DRM_VERIFYAREA_READ(batch.cliprects, > - batch.num_cliprects * > - sizeof(drm_clip_rect_t))) > + cliplen)) { > + DRM_LOCK(); > return DRM_ERR(EFAULT); > - > + } > + ret = vslock(batch.cliprects, cliplen); > + if (ret) { > + DRM_ERROR("Fault wiring cliprects\n"); > + DRM_LOCK(); > + return DRM_ERR(EFAULT); > + } > + DRM_LOCK(); > ret = i915_dispatch_batchbuffer(dev, &batch); > + vsunlock(batch.cliprects, cliplen); > > sarea_priv->last_dispatch = (int)hw_status[5]; > return ret; > @@ -638,6 +640,7 @@ static int i915_cmdbuffer(DRM_IOCTL_ARGS) > drm_i915_sarea_t *sarea_priv = (drm_i915_sarea_t *) > dev_priv->sarea_priv; > drm_i915_cmdbuffer_t cmdbuf; > + size_t cliplen; > int ret; > > DRM_COPY_FROM_USER_IOCTL(cmdbuf, (drm_i915_cmdbuffer_t __user *) data, > @@ -648,15 +651,31 @@ static int i915_cmdbuffer(DRM_IOCTL_ARGS) > > LOCK_TEST_WITH_RETURN(dev, filp); > > + DRM_UNLOCK(); > + cliplen = cmdbuf.num_cliprects * sizeof(drm_clip_rect_t); > if (cmdbuf.num_cliprects && > - DRM_VERIFYAREA_READ(cmdbuf.cliprects, > - cmdbuf.num_cliprects * > - sizeof(drm_clip_rect_t))) { > + DRM_VERIFYAREA_READ(cmdbuf.cliprects, cliplen)) { > DRM_ERROR("Fault accessing cliprects\n"); > + DRM_LOCK(); > return DRM_ERR(EFAULT); > } > - > + ret = vslock(cmdbuf.cliprects, cliplen); > + if (ret) { > + DRM_ERROR("Fault wiring cliprects\n"); > + DRM_LOCK(); > + return DRM_ERR(EFAULT); > + } > + ret = vslock(cmdbuf.buf, cmdbuf.sz); > + if (ret) { > + vsunlock(cmdbuf.cliprects, cliplen); > + DRM_ERROR("Fault wiring cmds\n"); > + DRM_LOCK(); > + return DRM_ERR(EFAULT); > + } > + DRM_LOCK(); > ret = i915_dispatch_cmdbuffer(dev, &cmdbuf); > + vsunlock(cmdbuf.buf, cmdbuf.sz); > + vsunlock(cmdbuf.cliprects, cliplen); > if (ret) { > DRM_ERROR("i915_dispatch_cmdbuffer failed\n"); > return ret; > -- Norm: Hey, everybody. All: [silence; everybody is mad at Norm for being rich.] Norm: [Carries on both sides of the conversation himself.] Norm! (Norman.) How are you feeling today, Norm? Rich and thirsty. Pour me a beer. -- Cheers, Tan 'n Wash Woody: What's the latest, Mr. Peterson? Norm: Zha-Zha marries a millionaire, Peterson drinks a beer. Film at eleven. -- Cheers, Knights of the Scimitar Woody: How are you today, Mr. Peterson? Norm: Never been better, Woody. ... Just once I'd like to be better. -- Cheers, Chambers vs. Malone
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