| Message ID | 1416838073-16642-1-git-send-email-ldufour@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 3b8a3c01096925a824ed3272601082289d9c23a5 |
| Delegated to: | Michael Ellerman |
| Headers | show |
On Mon, 2014-24-11 at 14:07:53 UTC, 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: OK. You say "LPAR", by which you mean "under phyp" I think. I haven't seen this under KVM, and it looks like KVM doesn't implement "set-indicator" so that would explain that. I'll take this as a bug fix and CC it to stable. cheers
On 26/11/2014 04:31, Michael Ellerman wrote: > OK. You say "LPAR", by which you mean "under phyp" I think. I haven't seen this > under KVM, and it looks like KVM doesn't implement "set-indicator" so that > would explain that. Yes LPAR implies phyp, and KVM don't implement "set-indicator" so this doesn't happen in that case. > I'll take this as a bug fix and CC it to stable. That's a good point. Thanks, Laurent.
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. cheers
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 > >
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; - args.nargs = 3; - args.nret = 1; + args.nargs = cpu_to_be32(3); + args.nret = cpu_to_be32(1); args.rets = &args.args[3]; - args.args[0] = SURVEILLANCE_TOKEN; + args.args[0] = cpu_to_be32(SURVEILLANCE_TOKEN); args.args[1] = 0; args.args[2] = 0; enter_rtas(__pa(&args));
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(-)