diff options
| author | Ani Sinha | 2015-12-18 02:15:10 +0100 |
|---|---|---|
| committer | Paul E. McKenney | 2015-12-30 01:29:18 +0100 |
| commit | 984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b (patch) | |
| tree | f768f851c8eb20e10537f3c47216547b8b116162 /init | |
| parent | Merge branches 'doc.2015.12.05a', 'exp.2015.12.07a', 'fixes.2015.12.07a', 'li... (diff) | |
| download | kernel-qcow2-linux-984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b.tar.gz kernel-qcow2-linux-984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b.tar.xz kernel-qcow2-linux-984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b.zip | |
sysrq: Fix warning in sysrq generated crash.
Commit 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") replaced
spin_lock_irqsave() calls with rcu_read_lock() calls in sysrq. Since
rcu_read_lock() does not disable preemption, faulthandler_disabled() in
__do_page_fault() in x86/fault.c returns false. When the code later calls
might_sleep() in the pagefault handler, we get the following warning:
BUG: sleeping function called from invalid context at ../arch/x86/mm/fault.c:1187
in_atomic(): 0, irqs_disabled(): 0, pid: 4706, name: bash
Preemption disabled at:[<ffffffff81484339>] printk+0x48/0x4a
To fix this, we release the RCU read lock before we crash.
Tested this patch on linux 3.18 by booting off one of our boards.
Fixes: 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq")
Signed-off-by: Ani Sinha <ani@arista.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions