Would be nice to get the fix below into -rc1 as well, it triggers
rather easily on bootup when CONFIG_CPUMASK_OFFSTACK is turned on.
Ingo
---------------------->
>From 59b28833ae328e2206865fb25e61917e738d9696 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Sat, 28 May 2011 08:22:15 +0200
Subject: [PATCH] mm: Fix boot crash in mm_alloc()
Fix CONFIG_CPUMASK_OFFSTACK=y boot crash:
[ 12.598405] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 12.600012] IP: [<c11ae035>] find_next_bit+0x55/0xb0
[ 12.600012] *pdpt = 0000000000000000 *pde = f000e81af000e81a
[ 12.600012] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 12.600012] Modules linked in:
[ 12.600012]
[ 12.600012] Pid: 1, comm: swapper Not tainted 2.6.39-05707-gde03c72-dirty #130523 System manufacturer System Product Name/A8N-E
[ 12.600012] EIP: 0060:[<c11ae035>] EFLAGS: 00010202 CPU: 0
[ 12.600012] EIP is at find_next_bit+0x55/0xb0
[ 12.600012] EAX: 00000000 EBX: 00000002 ECX: 00000000 EDX: 00000000
[ 12.600012] ESI: 00000000 EDI: f59a4000 EBP: f6479e78 ESP: f6479e70
[ 12.600012] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 12.600012] Process swapper (pid: 1, ti=f6478000 task=f6470000 task.ti=f6478000)
[ 12.600012] Stack:
[ 12.600012] 00000000 00000000 f6479e8c c11addda 00000000 f59a4000 f5939000 f6479e98
[ 12.600012] c102396b 35937001 f6479eac c1022705 00000001 f5939008 f59a4000 f6479ed8
[ 12.600012] c10227ba f5939000 f59a4000 f5939000 f5937000 f5938000 f593c000 f59a4000
[ 12.600012] Call Trace:
[ 12.600012] [<c11addda>] cpumask_any_but+0x2a/0x70
[ 12.600012] [<c102396b>] flush_tlb_mm+0x2b/0x80
[ 12.600012] [<c1022705>] pud_populate+0x35/0x50
[ 12.600012] [<c10227ba>] pgd_alloc+0x9a/0xf0
[ 12.600012] [<c103a3fc>] mm_init+0xec/0x120
[ 12.600012] [<c103a7a3>] mm_alloc+0x53/0xd0
[ 12.600012] [<c10f9220>] bprm_mm_init+0x20/0x1b0
[ 12.600012] [<c10370bf>] ? sched_exec+0x7f/0xb0
[ 12.600012] [<c10f96b9>] do_execve+0xb9/0x270
[ 12.600012] [<c100aec7>] sys_execve+0x37/0x70
[ 12.600012] [<c13d60a2>] ptregs_execve+0x12/0x18
[ 12.600012] [<c13d5299>] ? syscall_call+0x7/0xb
[ 12.600012] [<c1006840>] ? kernel_execve+0x20/0x30
[ 12.600012] [<c16086af>] ? start_kernel+0x2de/0x2de
[ 12.600012] [<c13c9ea2>] ? run_init_process+0x1c/0x1e
[ 12.600012] [<c13c9f2d>] ? init_post+0x89/0xb3
[ 12.600012] [<c16087d1>] ? kernel_init+0x122/0x122
[ 12.600012] [<c13d657a>] ? kernel_thread_helper+0x6/0x10
Caused by:
de03c72: mm: convert mm->cpu_vm_cpumask into cpumask_var_t
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/fork.c | 6 +-----
1 files changed, 1 insertions(+), 5 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index ca406d9..7b0669f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -538,17 +538,13 @@ struct mm_struct * mm_alloc(void)
return NULL;
memset(mm, 0, sizeof(*mm));
- mm = mm_init(mm, current);
- if (!mm)
- return NULL;
if (mm_init_cpumask(mm, NULL)) {
- mm_free_pgd(mm);
free_mm(mm);
return NULL;
}
- return mm;
+ return mm_init(mm, current);
}
/*
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