Re: Linux 2.6.15-rc3

[Andrew Morton <akpm@osdl.org>]

Stephen Hemminger <shemminger@osdl.org> wrote:
>
> [  125.653485]  <1>Fixing recursive fault but reboot is needed!
>  [  125.653620] ----------- [cut here ] --------- [please bite here ] ---------
>  [  125.653622] Kernel BUG at mm/mmap.c:1956
>  [  125.653624] invalid operand: 0000 [727] SMP
>  [  125.653625] CPU 0
>  [  125.653627] Modules linked in:
>  [  125.653629] Pid: 746, comm: hotplug Not tainted 2.6.15-rc3 #1
>  [  125.653631] RIP: 0010:[<ffffffff8016cecb>] <ffffffff8016cecb>{exit_mmap+235}
>  [  125.653636] RSP: 0018:ffff81007ebcfeb8  EFLAGS: 00010202
>  [  125.653639] RAX: 0000000000000000 RBX: ffff810002c0e3e0 RCX: 00000000000005b4
>  [  125.653642] RDX: 000000000000000f RSI: ffff81007fc2ead8 RDI: ffff81007ff5ca80
>  [  125.653645] RBP: 0000000000000000 R08: ffff81007ff2c920 R09: 0000000000000000
>  [  125.653647] R10: 0000000000000000 R11: 0000000000000246 R12: ffff81007eb785c0
>  [  125.653649] R13: 0000000000000001 R14: 0000000000000100 R15: 0000000000000000
>  [  125.653653] FS:  0000000000587850(0000) GS:ffffffff805c6800(0000) knlGS:0000000000000000
>  [  125.653655] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  [  125.653658] CR2: 000000000040a9b0 CR3: 0000000000101000 CR4: 00000000000006e0
>  [  125.653661] Process hotplug (pid: 746, threadinfo ffff81007ebce000, task ffff81007ebcafa0)
>  [  125.653663] Stack: 000000000000003c ffff810002c0e3e0 ffff81007eb785c0 ffff81007eb78638
>  [  125.653668]        ffff81007ebcafa0 ffffffff80130d61 0000000000000100 0000000000000100
>  [  125.653672]        ffff81007ebcb5e4 ffffffff80135bb2
>  [  125.653675] Call Trace:<ffffffff80130d61>{mmput+49} <ffffffff80135bb2>{do_exit+578}
>  [  125.653682]        <ffffffff8024f961>{__up_write+49} <ffffffff801366b8>{do_group_exit+248}
>  [  125.653687]        <ffffffff8010dcee>{system_call+126}
>  [  125.653691]
>  [  125.653692] Code: 0f 0b 68 de 7e 3e 80 c2 a4 07 48 83 c4 10 5b 5d 41 5c c3 66
>  [  125.653700] RIP <ffffffff8016cecb>{exit_mmap+235} RSP <ffff81007ebcfeb8>
>  [  125.653704]  <1>Fixing recursive fault but reboot is needed!
>  [  125.653841] ----------- [cut here ] --------- [please bite here ] ---------
>  [  125.653843] Kernel BUG at mm/mmap.c:1956

That's

        BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);

It's hard to see how this is caused by a USB patch.

Are you using the very latest Linus tree?  You should...

This might help, dunno.

diff -puN mm/memory.c~mm-get_locked_pte-fix mm/memory.c
--- 25/mm/memory.c~mm-get_locked_pte-fix	2005-11-29 16:05:05.000000000 -0800
+++ 25-akpm/mm/memory.c	2005-11-29 16:05:24.000000000 -0800
@@ -1151,7 +1151,7 @@ pte_t *get_locked_pte(struct mm_struct *
 	pgd_t * pgd = pgd_offset(mm, addr);
 	pud_t * pud = pud_alloc(mm, pgd, addr);
 	if (pud) {
-		pmd_t * pmd = pmd_alloc(mm, pgd, addr);
+		pmd_t * pmd = pmd_alloc(mm, pud, addr);
 		if (pmd)
 			return pte_alloc_map_lock(mm, pmd, addr, ptl);
 	}
_