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SubjectRe: [PATCH] pseries/le: Fix endiannes issue in RTAS call from xmon
On 15/01/2015 05:25, Michael Ellerman wrote:
> On Mon, 2014-11-24 at 15:07 +0100, Laurent Dufour wrote:
>> On pseries system (LPAR) xmon failed to enter when running in LE mode, system
>> is hunging. Inititating xmon will lead to such an output on the console:
>>
>> SysRq : Entering xmon
>> cpu 0x15: Vector: 0 at [c0000003f39ffb10]
>> pc: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70
>> lr: c00000000007ed7c: sysrq_handle_xmon+0x5c/0x70
>> sp: c0000003f39ffc70
>> msr: 8000000000009033
>> current = 0xc0000003fafa7180
>> paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01
>> pid = 14617, comm = bash
>> Bad kernel stack pointer fafb4b0 at eca7cc4
>> cpu 0x15: Vector: 300 (Data Access) at [c000000007f07d40]
>> pc: 000000000eca7cc4
>> lr: 000000000eca7c44
>> sp: fafb4b0
>> msr: 8000000000001000
>> dar: 10000000
>> dsisr: 42000000
>> current = 0xc0000003fafa7180
>> paca = 0xc000000007d75e80 softe: 0 irq_happened: 0x01
>> pid = 14617, comm = bash
>> cpu 0x15: Exception 300 (Data Access) in xmon, returning to main loop
>> xmon: WARNING: bad recursive fault on cpu 0x15
>>
>> The root cause is that xmon is calling RTAS to turn off the surveillance
>> when entering xmon, and RTAS is requiring big endian parameters.
>>
>> This patch is byte swapping the RTAS arguments when running in LE mode.
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/xmon/xmon.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
>> index b988b5addf86..c8efbb37d6e0 100644
>> --- a/arch/powerpc/xmon/xmon.c
>> +++ b/arch/powerpc/xmon/xmon.c
>> @@ -293,10 +293,10 @@ static inline void disable_surveillance(void)
>> args.token = rtas_token("set-indicator");
>> if (args.token == RTAS_UNKNOWN_SERVICE)
>> return;
>
> I just noticed we're not handling the token correctly here. It is be32 also.

Ouch, my mistake :(

I will drop a new patch to complete this one.

Cheers.

> cheers
>
>



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