* Reading /proc/kcore causes a BUG() @ 2009-09-03 11:34 Nick Craig-Wood 2009-09-03 12:14 ` Pekka Enberg 0 siblings, 1 reply; 10+ messages in thread From: Nick Craig-Wood @ 2009-09-03 11:34 UTC (permalink / raw) To: linux-kernel Is a fix for this going to make 2.6.31? To replicate cat /proc/kcore >/dev/null See also http://bugzilla.kernel.org/show_bug.cgi?id=13850 To get BUG: unable to handle kernel paging request at eda08000 IP: [<c01a0e98>] read_kcore+0x27f/0x341 *pdpt = 0000000071809027 Oops: 0000 [#1] SMP last sysfs file: /sys/class/net/lo/operstate Pid: 2361, comm: cat Not tainted (2.6.31.git-x1 #1) EIP: 0061:[<c01a0e98>] EFLAGS: 00010286 CPU: 1 EIP is at read_kcore+0x27f/0x341 EAX: c04404fc EBX: 00001000 ECX: 00000400 EDX: eda09000 ESI: eda08000 EDI: ec129000 EBP: ec60bf48 ESP: ec60bf10 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0069 Process cat (pid: 2361, ti=ec60a000 task=ecf800b0 task.ti=ec60a000) Stack: 00001000 08051000 00000000 00001000 00000003 eda08000 ec129000 c04404fc <0> eda09000 00000000 00001000 ecd39380 fffffffb c01a0c19 ec60bf6c c019a907 <0> ec60bf98 00001000 08051000 eccbab00 eccbab00 c019a8af 00001000 ec60bf8c Call Trace: [<c01a0c19>] ? read_kcore+0x0/0x341 [<c019a907>] ? proc_reg_read+0x58/0x6c [<c019a8af>] ? proc_reg_read+0x0/0x6c [<c016905e>] ? vfs_read+0x87/0x110 [<c0169180>] ? sys_read+0x3b/0x60 [<c0106a4d>] ? syscall_call+0x7/0xb Code: d3 29 f3 89 f8 29 f0 39 d7 0f 46 d8 8d 0c 33 89 4d e8 29 5d ec 8b 45 e4 f6 40 0c 01 75 18 89 d9 c1 e9 02 89 f7 2b 7d dc 03 7d e0 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 55 e4 8b 12 89 55 e4 83 7d EIP: [<c01a0e98>] read_kcore+0x27f/0x341 SS:ESP 0069:ec60bf10 CR2: 00000000eda08000 ---[ end trace 4387f828fd1590eb ]--- I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) under Xen as a domU. The bugzilla report states it happens on non xen machines also. I know reading /proc/kcore isn't such a good idea, but badly written backup scripts are triggering this on our customer's servers :-( -- Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-03 11:34 Reading /proc/kcore causes a BUG() Nick Craig-Wood @ 2009-09-03 12:14 ` Pekka Enberg 2009-09-04 0:06 ` KAMEZAWA Hiroyuki 0 siblings, 1 reply; 10+ messages in thread From: Pekka Enberg @ 2009-09-03 12:14 UTC (permalink / raw) To: Nick Craig-Wood Cc: linux-kernel, KAMEZAWA Hiroyuki, Andrew Morton, Linus Torvalds On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > Is a fix for this going to make 2.6.31? > > To replicate > > cat /proc/kcore >/dev/null > > See also > > http://bugzilla.kernel.org/show_bug.cgi?id=13850 > > To get > > BUG: unable to handle kernel paging request at eda08000 > IP: [<c01a0e98>] read_kcore+0x27f/0x341 > *pdpt = 0000000071809027 > Oops: 0000 [#1] SMP > last sysfs file: /sys/class/net/lo/operstate > > Pid: 2361, comm: cat Not tainted (2.6.31.git-x1 #1) > EIP: 0061:[<c01a0e98>] EFLAGS: 00010286 CPU: 1 > EIP is at read_kcore+0x27f/0x341 > EAX: c04404fc EBX: 00001000 ECX: 00000400 EDX: eda09000 > ESI: eda08000 EDI: ec129000 EBP: ec60bf48 ESP: ec60bf10 > DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0069 > Process cat (pid: 2361, ti=ec60a000 task=ecf800b0 task.ti=ec60a000) > Stack: > 00001000 08051000 00000000 00001000 00000003 eda08000 ec129000 c04404fc > <0> eda09000 00000000 00001000 ecd39380 fffffffb c01a0c19 ec60bf6c c019a907 > <0> ec60bf98 00001000 08051000 eccbab00 eccbab00 c019a8af 00001000 ec60bf8c > Call Trace: > [<c01a0c19>] ? read_kcore+0x0/0x341 > [<c019a907>] ? proc_reg_read+0x58/0x6c > [<c019a8af>] ? proc_reg_read+0x0/0x6c > [<c016905e>] ? vfs_read+0x87/0x110 > [<c0169180>] ? sys_read+0x3b/0x60 > [<c0106a4d>] ? syscall_call+0x7/0xb > Code: d3 29 f3 89 f8 29 f0 39 d7 0f 46 d8 8d 0c 33 89 4d e8 29 5d ec 8b 45 e4 f6 40 0c 01 75 18 89 d9 c1 e9 02 89 f7 2b 7d dc 03 7d e0 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 55 e4 8b 12 89 55 e4 83 7d > EIP: [<c01a0e98>] read_kcore+0x27f/0x341 SS:ESP 0069:ec60bf10 > CR2: 00000000eda08000 > ---[ end trace 4387f828fd1590eb ]--- > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > under Xen as a domU. The bugzilla report states it happens on non xen > machines also. > > I know reading /proc/kcore isn't such a good idea, but badly written > backup scripts are triggering this on our customer's servers :-( AFAICT the bug was fixed but I can't seem to find the patches in Linus' git either. Lets CC Andrew and Hiroyuki-san. Pekka ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-03 12:14 ` Pekka Enberg @ 2009-09-04 0:06 ` KAMEZAWA Hiroyuki 2009-09-04 9:00 ` Nick Craig-Wood 0 siblings, 1 reply; 10+ messages in thread From: KAMEZAWA Hiroyuki @ 2009-09-04 0:06 UTC (permalink / raw) To: Pekka Enberg; +Cc: Nick Craig-Wood, linux-kernel, Andrew Morton, Linus Torvalds On Thu, 3 Sep 2009 15:14:55 +0300 Pekka Enberg <penberg@cs.helsinki.fi> wrote: > On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > > Is a fix for this going to make 2.6.31? > > > > To replicate > > > > cat /proc/kcore >/dev/null > > > > See also > > > > http://bugzilla.kernel.org/show_bug.cgi?id=13850 > > > > To get > > > > BUG: unable to handle kernel paging request at eda08000 > > IP: [<c01a0e98>] read_kcore+0x27f/0x341 > > *pdpt = 0000000071809027 > > Oops: 0000 [#1] SMP > > last sysfs file: /sys/class/net/lo/operstate > > > > Pid: 2361, comm: cat Not tainted (2.6.31.git-x1 #1) > > EIP: 0061:[<c01a0e98>] EFLAGS: 00010286 CPU: 1 > > EIP is at read_kcore+0x27f/0x341 > > EAX: c04404fc EBX: 00001000 ECX: 00000400 EDX: eda09000 > > ESI: eda08000 EDI: ec129000 EBP: ec60bf48 ESP: ec60bf10 > > DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0069 > > Process cat (pid: 2361, ti=ec60a000 task=ecf800b0 task.ti=ec60a000) > > Stack: > > 00001000 08051000 00000000 00001000 00000003 eda08000 ec129000 c04404fc > > <0> eda09000 00000000 00001000 ecd39380 fffffffb c01a0c19 ec60bf6c c019a907 > > <0> ec60bf98 00001000 08051000 eccbab00 eccbab00 c019a8af 00001000 ec60bf8c > > Call Trace: > > [<c01a0c19>] ? read_kcore+0x0/0x341 > > [<c019a907>] ? proc_reg_read+0x58/0x6c > > [<c019a8af>] ? proc_reg_read+0x0/0x6c > > [<c016905e>] ? vfs_read+0x87/0x110 > > [<c0169180>] ? sys_read+0x3b/0x60 > > [<c0106a4d>] ? syscall_call+0x7/0xb > > Code: d3 29 f3 89 f8 29 f0 39 d7 0f 46 d8 8d 0c 33 89 4d e8 29 5d ec 8b 45 e4 f6 40 0c 01 75 18 89 d9 c1 e9 02 89 f7 2b 7d dc 03 7d e0 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 55 e4 8b 12 89 55 e4 83 7d > > EIP: [<c01a0e98>] read_kcore+0x27f/0x341 SS:ESP 0069:ec60bf10 > > CR2: 00000000eda08000 > > ---[ end trace 4387f828fd1590eb ]--- > > > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > > under Xen as a domU. The bugzilla report states it happens on non xen > > machines also. > > > > I know reading /proc/kcore isn't such a good idea, but badly written > > backup scripts are triggering this on our customer's servers :-( > > AFAICT the bug was fixed but I can't seem to find the patches in > Linus' git either. Lets CC Andrew and Hiroyuki-san. > Ah, it's now tested under mmotm. please wait. Thanks, -Kame ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-04 0:06 ` KAMEZAWA Hiroyuki @ 2009-09-04 9:00 ` Nick Craig-Wood 2009-09-04 9:16 ` KAMEZAWA Hiroyuki 0 siblings, 1 reply; 10+ messages in thread From: Nick Craig-Wood @ 2009-09-04 9:00 UTC (permalink / raw) To: KAMEZAWA Hiroyuki Cc: Pekka Enberg, linux-kernel, Andrew Morton, Linus Torvalds On Fri, Sep 04, 2009 at 09:06:42AM +0900, KAMEZAWA Hiroyuki wrote: > On Thu, 3 Sep 2009 15:14:55 +0300 > Pekka Enberg <penberg@cs.helsinki.fi> wrote: > > On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > > > Is a fix for this going to make 2.6.31? > > > > > > To replicate > > > > > > cat /proc/kcore >/dev/null > > > > > > See also > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=13850 [snip] > > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > > > under Xen as a domU. The bugzilla report states it happens on non xen > > > machines also. > > > > > > I know reading /proc/kcore isn't such a good idea, but badly written > > > backup scripts are triggering this on our customer's servers :-( > > > > AFAICT the bug was fixed but I can't seem to find the patches in > > Linus' git either. Lets CC Andrew and Hiroyuki-san. > > Ah, it's now tested under mmotm. please wait. I tried mmotm but I couldn't get it to boot under Xen :-( If you send me a patch against latest git I'm willing to test it (I tried to extract the relevant patch from mmotm but failed dismally) Thanks Nick -- Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-04 9:00 ` Nick Craig-Wood @ 2009-09-04 9:16 ` KAMEZAWA Hiroyuki 2009-09-04 16:52 ` Nick Craig-Wood 2009-09-04 17:31 ` Andrew Morton 0 siblings, 2 replies; 10+ messages in thread From: KAMEZAWA Hiroyuki @ 2009-09-04 9:16 UTC (permalink / raw) To: Nick Craig-Wood; +Cc: Pekka Enberg, linux-kernel, Andrew Morton, Linus Torvalds On Fri, 4 Sep 2009 10:00:39 +0100 Nick Craig-Wood <nick@craig-wood.com> wrote: > On Fri, Sep 04, 2009 at 09:06:42AM +0900, KAMEZAWA Hiroyuki wrote: > > On Thu, 3 Sep 2009 15:14:55 +0300 > > Pekka Enberg <penberg@cs.helsinki.fi> wrote: > > > On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > > > > Is a fix for this going to make 2.6.31? > > > > > > > > To replicate > > > > > > > > cat /proc/kcore >/dev/null > > > > > > > > See also > > > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=13850 > [snip] > > > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > > > > under Xen as a domU. The bugzilla report states it happens on non xen > > > > machines also. > > > > > > > > I know reading /proc/kcore isn't such a good idea, but badly written > > > > backup scripts are triggering this on our customer's servers :-( > > > > > > AFAICT the bug was fixed but I can't seem to find the patches in > > > Linus' git either. Lets CC Andrew and Hiroyuki-san. > > > > Ah, it's now tested under mmotm. please wait. > > I tried mmotm but I couldn't get it to boot under Xen :-( > > If you send me a patch against latest git I'm willing to test it (I > tried to extract the relevant patch from mmotm but failed dismally) > > Thanks > If you already downloaded mmotm, use these patches. vmalloc-unmap-vmalloc-area-after-hiding-it.patch kcore-fix-vread-vwrite-to-be-aware-of-holes.patch kcore-fix-vread-vwrite-to-be-aware-of-holes-update.patch kcore-proc-kcore-should-use-vread.patch All I tested was x86-32/x86-64. then more tests are welcomed. -Kame > Nick > -- > Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-04 9:16 ` KAMEZAWA Hiroyuki @ 2009-09-04 16:52 ` Nick Craig-Wood 2009-09-04 17:31 ` Andrew Morton 1 sibling, 0 replies; 10+ messages in thread From: Nick Craig-Wood @ 2009-09-04 16:52 UTC (permalink / raw) To: KAMEZAWA Hiroyuki Cc: Pekka Enberg, linux-kernel, Andrew Morton, Linus Torvalds On Fri, Sep 04, 2009 at 06:16:45PM +0900, KAMEZAWA Hiroyuki wrote: > On Fri, 4 Sep 2009 10:00:39 +0100 > Nick Craig-Wood <nick@craig-wood.com> wrote: > > > On Fri, Sep 04, 2009 at 09:06:42AM +0900, KAMEZAWA Hiroyuki wrote: > > > On Thu, 3 Sep 2009 15:14:55 +0300 > > > Pekka Enberg <penberg@cs.helsinki.fi> wrote: > > > > On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > > > > > Is a fix for this going to make 2.6.31? > > > > > > > > > > To replicate > > > > > > > > > > cat /proc/kcore >/dev/null > > > > > > > > > > See also > > > > > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=13850 > > [snip] > > > > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > > > > > under Xen as a domU. The bugzilla report states it happens on non xen > > > > > machines also. > > > > > > > > > > I know reading /proc/kcore isn't such a good idea, but badly written > > > > > backup scripts are triggering this on our customer's servers :-( > > > > > > > > AFAICT the bug was fixed but I can't seem to find the patches in > > > > Linus' git either. Lets CC Andrew and Hiroyuki-san. > > > > > > Ah, it's now tested under mmotm. please wait. > > > > I tried mmotm but I couldn't get it to boot under Xen :-( > > > > If you send me a patch against latest git I'm willing to test it (I > > tried to extract the relevant patch from mmotm but failed dismally) > > If you already downloaded mmotm, use these patches. > > vmalloc-unmap-vmalloc-area-after-hiding-it.patch > kcore-fix-vread-vwrite-to-be-aware-of-holes.patch > kcore-fix-vread-vwrite-to-be-aware-of-holes-update.patch > kcore-proc-kcore-should-use-vread.patch > > All I tested was x86-32/x86-64. then more tests are welcomed. I can confirm that these patches fix the problem on x86-32 running under Xen DomU - thank you very much. -- Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-04 9:16 ` KAMEZAWA Hiroyuki 2009-09-04 16:52 ` Nick Craig-Wood @ 2009-09-04 17:31 ` Andrew Morton 2009-09-07 0:38 ` KAMEZAWA Hiroyuki 1 sibling, 1 reply; 10+ messages in thread From: Andrew Morton @ 2009-09-04 17:31 UTC (permalink / raw) To: KAMEZAWA Hiroyuki Cc: Nick Craig-Wood, Pekka Enberg, linux-kernel, Linus Torvalds On Fri, 4 Sep 2009 18:16:45 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > On Fri, 4 Sep 2009 10:00:39 +0100 > Nick Craig-Wood <nick@craig-wood.com> wrote: > > > On Fri, Sep 04, 2009 at 09:06:42AM +0900, KAMEZAWA Hiroyuki wrote: > > > On Thu, 3 Sep 2009 15:14:55 +0300 > > > Pekka Enberg <penberg@cs.helsinki.fi> wrote: > > > > On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > > > > > Is a fix for this going to make 2.6.31? > > > > > > > > > > To replicate > > > > > > > > > > __cat /proc/kcore >/dev/null > > > > > > > > > > See also > > > > > > > > > > __http://bugzilla.kernel.org/show_bug.cgi?id=13850 > > [snip] > > > > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > > > > > under Xen as a domU. __The bugzilla report states it happens on non xen > > > > > machines also. Is this a regression? I've lost track.. > > > > > I know reading /proc/kcore isn't such a good idea, but badly written > > > > > backup scripts are triggering this on our customer's servers :-( > > > > > > > > AFAICT the bug was fixed but I can't seem to find the patches in > > > > Linus' git either. Lets CC Andrew and Hiroyuki-san. > > > > > > Ah, it's now tested under mmotm. please wait. > > > > I tried mmotm but I couldn't get it to boot under Xen :-( > > > > If you send me a patch against latest git I'm willing to test it (I > > tried to extract the relevant patch from mmotm but failed dismally) > > > > Thanks > > > > If you already downloaded mmotm, use these patches. > > vmalloc-unmap-vmalloc-area-after-hiding-it.patch > kcore-fix-vread-vwrite-to-be-aware-of-holes.patch > kcore-fix-vread-vwrite-to-be-aware-of-holes-update.patch > kcore-proc-kcore-should-use-vread.patch > > All I tested was x86-32/x86-64. then more tests are welcomed. That's a lot of stuff for 2.6.31. Is there some simple quickfix we can do? ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-04 17:31 ` Andrew Morton @ 2009-09-07 0:38 ` KAMEZAWA Hiroyuki 2009-09-07 6:14 ` KAMEZAWA Hiroyuki 0 siblings, 1 reply; 10+ messages in thread From: KAMEZAWA Hiroyuki @ 2009-09-07 0:38 UTC (permalink / raw) To: Andrew Morton; +Cc: Nick Craig-Wood, Pekka Enberg, linux-kernel, Linus Torvalds On Fri, 4 Sep 2009 10:31:56 -0700 Andrew Morton <akpm@linux-foundation.org> wrote: > On Fri, 4 Sep 2009 18:16:45 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > > On Fri, 4 Sep 2009 10:00:39 +0100 > > Nick Craig-Wood <nick@craig-wood.com> wrote: > > > > > On Fri, Sep 04, 2009 at 09:06:42AM +0900, KAMEZAWA Hiroyuki wrote: > > > > On Thu, 3 Sep 2009 15:14:55 +0300 > > > > Pekka Enberg <penberg@cs.helsinki.fi> wrote: > > > > > On Thu, Sep 3, 2009 at 2:34 PM, Nick Craig-Wood<nick@craig-wood.com> wrote: > > > > > > Is a fix for this going to make 2.6.31? > > > > > > > > > > > > To replicate > > > > > > > > > > > > __cat /proc/kcore >/dev/null > > > > > > > > > > > > See also > > > > > > > > > > > > __http://bugzilla.kernel.org/show_bug.cgi?id=13850 > > > [snip] > > > > > > I tried this on the latest git checkout (as of 2009-09-03 11:00 GMT) > > > > > > under Xen as a domU. __The bugzilla report states it happens on non xen > > > > > > machines also. > > Is this a regression? I've lost track.. > regression. (this comes from new per-cpu area implemantation, which uses vmalloc area with memory holes.) > > > > > > I know reading /proc/kcore isn't such a good idea, but badly written > > > > > > backup scripts are triggering this on our customer's servers :-( > > > > > > > > > > AFAICT the bug was fixed but I can't seem to find the patches in > > > > > Linus' git either. Lets CC Andrew and Hiroyuki-san. > > > > > > > > Ah, it's now tested under mmotm. please wait. > > > > > > I tried mmotm but I couldn't get it to boot under Xen :-( > > > > > > If you send me a patch against latest git I'm willing to test it (I > > > tried to extract the relevant patch from mmotm but failed dismally) > > > > > > Thanks > > > > > > > If you already downloaded mmotm, use these patches. > > > > vmalloc-unmap-vmalloc-area-after-hiding-it.patch > > kcore-fix-vread-vwrite-to-be-aware-of-holes.patch > > kcore-fix-vread-vwrite-to-be-aware-of-holes-update.patch > > kcore-proc-kcore-should-use-vread.patch > > > > All I tested was x86-32/x86-64. then more tests are welcomed. > > That's a lot of stuff for 2.6.31. Is there some simple quickfix we can do? > I don't like this patch. But here, my 1st version which wasn't sent out. -Kame == /proc/kcore may access in memory holes in vmalloc area. skip it by using copy_from_user(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> --- fs/proc/kcore.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Index: linux-2.6.31-rc8/fs/proc/kcore.c =================================================================== --- linux-2.6.31-rc8.orig/fs/proc/kcore.c +++ linux-2.6.31-rc8/fs/proc/kcore.c @@ -361,7 +361,9 @@ read_kcore(struct file *file, char __use /* don't dump ioremap'd stuff! (TA) */ if (m->flags & VM_IOREMAP) continue; - memcpy(elf_buf + (vmstart - start), + /* we may access memory holes */ + __copy_from_user_inatomic( + elf_buf + (vmstart - start), (char *)vmstart, vmsize); } read_unlock(&vmlist_lock); ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-07 0:38 ` KAMEZAWA Hiroyuki @ 2009-09-07 6:14 ` KAMEZAWA Hiroyuki 2009-09-07 7:59 ` Nick Craig-Wood 0 siblings, 1 reply; 10+ messages in thread From: KAMEZAWA Hiroyuki @ 2009-09-07 6:14 UTC (permalink / raw) To: KAMEZAWA Hiroyuki Cc: Andrew Morton, Nick Craig-Wood, Pekka Enberg, linux-kernel, Linus Torvalds On Mon, 7 Sep 2009 09:38:56 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > That's a lot of stuff for 2.6.31. Is there some simple quickfix we can do? > > > I don't like this patch. But here, my 1st version which wasn't sent out. > -Kame Fixed warnings. (I confirmed this patch works well on x86-64.) == To access vmalloc area which may have memory holes, copy_from_user is useful. By this, # cat /proc/kcore > /dev/null will not panic. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> --- fs/proc/kcore.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) Index: linux-2.6.31-rc8/fs/proc/kcore.c =================================================================== --- linux-2.6.31-rc8.orig/fs/proc/kcore.c +++ linux-2.6.31-rc8/fs/proc/kcore.c @@ -361,7 +361,13 @@ read_kcore(struct file *file, char __use /* don't dump ioremap'd stuff! (TA) */ if (m->flags & VM_IOREMAP) continue; - memcpy(elf_buf + (vmstart - start), + /* + * we may access memory holes, then use + * ex_table. checking return value just for + * avoid warnings. + */ + vmsize = __copy_from_user_inatomic( + elf_buf + (vmstart - start), (char *)vmstart, vmsize); } read_unlock(&vmlist_lock); ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Reading /proc/kcore causes a BUG() 2009-09-07 6:14 ` KAMEZAWA Hiroyuki @ 2009-09-07 7:59 ` Nick Craig-Wood 0 siblings, 0 replies; 10+ messages in thread From: Nick Craig-Wood @ 2009-09-07 7:59 UTC (permalink / raw) To: KAMEZAWA Hiroyuki Cc: Andrew Morton, Pekka Enberg, linux-kernel, Linus Torvalds On Mon, Sep 07, 2009 at 03:14:22PM +0900, KAMEZAWA Hiroyuki wrote: > On Mon, 7 Sep 2009 09:38:56 +0900 > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > > That's a lot of stuff for 2.6.31. Is there some simple quickfix we can do? > > > > > I don't like this patch. But here, my 1st version which wasn't sent out. > > -Kame > > Fixed warnings. (I confirmed this patch works well on x86-64.) > == > To access vmalloc area which may have memory holes, copy_from_user is > useful. By this, > # cat /proc/kcore > /dev/null > will not panic. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > --- > fs/proc/kcore.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > Index: linux-2.6.31-rc8/fs/proc/kcore.c > =================================================================== > --- linux-2.6.31-rc8.orig/fs/proc/kcore.c > +++ linux-2.6.31-rc8/fs/proc/kcore.c > @@ -361,7 +361,13 @@ read_kcore(struct file *file, char __use > /* don't dump ioremap'd stuff! (TA) */ > if (m->flags & VM_IOREMAP) > continue; > - memcpy(elf_buf + (vmstart - start), > + /* > + * we may access memory holes, then use > + * ex_table. checking return value just for > + * avoid warnings. > + */ > + vmsize = __copy_from_user_inatomic( > + elf_buf + (vmstart - start), > (char *)vmstart, vmsize); > } > read_unlock(&vmlist_lock); I gave this patch a thrashing and it works fine for me too (Xen domU x86) It would be great if we could have this quick fix for 2.6.31. Perhaps it should also go out to 2.6.30-stable also? I can confirm that this patch applies to 2.6.30.5 and fixes the problem there too. -- Nick Craig-Wood <nick@craig-wood.com> -- http://www.craig-wood.com/nick ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2009-09-07 7:59 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2009-09-03 11:34 Reading /proc/kcore causes a BUG() Nick Craig-Wood 2009-09-03 12:14 ` Pekka Enberg 2009-09-04 0:06 ` KAMEZAWA Hiroyuki 2009-09-04 9:00 ` Nick Craig-Wood 2009-09-04 9:16 ` KAMEZAWA Hiroyuki 2009-09-04 16:52 ` Nick Craig-Wood 2009-09-04 17:31 ` Andrew Morton 2009-09-07 0:38 ` KAMEZAWA Hiroyuki 2009-09-07 6:14 ` KAMEZAWA Hiroyuki 2009-09-07 7:59 ` Nick Craig-Wood
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