diff options
author | Breno Leitao <leitao@debian.org> | 2018-11-08 15:12:42 -0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-26 09:38:33 +0100 |
commit | 8117508a9c4b38c941c0fe0d2cdeacf54cd317c7 (patch) | |
tree | 190ddd5d6dcd9eae5a2c252fe8c16e070fa21dba /drivers | |
parent | fffdbf586866e9500b53c9d4b061d3983720375a (diff) |
powerpc/xmon: Fix invocation inside lock region
[ Upstream commit 8d4a862276a9c30a269d368d324fb56529e6d5fd ]
Currently xmon needs to get devtree_lock (through rtas_token()) during its
invocation (at crash time). If there is a crash while devtree_lock is being
held, then xmon tries to get the lock but spins forever and never get into
the interactive debugger, as in the following case:
int *ptr = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
*ptr = 0xdeadbeef;
This patch avoids calling rtas_token(), thus trying to get the same lock,
at crash time. This new mechanism proposes getting the token at
initialization time (xmon_init()) and just consuming it at crash time.
This would allow xmon to be possible invoked independent of devtree_lock
being held or not.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions