Re: [PATCH AUTOSEL 4.4 07/32] cpupower: Fix coredump on VMWare

Greg KH
2018-11-12T13:32:47Z

On Mon, Nov 12, 2018 at 08:29:27AM -0200, Rafael David Tinoco wrote:
> On 10/31/18 9:11 PM, Sasha Levin wrote:
> > From: Prarit Bhargava <prarit@redhat.com>
> >
> > [ Upstream commit f69ffc5d3db8f1f03fd6d1df5930f9a1fbd787b6 ]
> >
> > cpupower crashes on VMWare guests. The guests have the AMD PStateDef MSR
> > (0xC0010064 + state number) set to zero. As a result fid and did are zero
> > and the crash occurs because of a divide by zero (cof = fid/did). This
> > can be prevented by checking the enable bit in the PStateDef MSR before
> > calculating cof. By doing this the value of pstate[i] remains zero and
> > the value can be tested before displaying the active Pstates.
> >
> > Check the enable bit in the PstateDef register for all supported families
> > and only print out enabled Pstates.
> >
> > Signed-off-by: Prarit Bhargava <prarit@redhat.com>
> > Cc: Shuah Khan <shuah@kernel.org>
> > Cc: Stafford Horne <shorne@gmail.com>
> > Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
> > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > ---
> > tools/power/cpupower/utils/cpufreq-info.c | 2 ++
> > tools/power/cpupower/utils/helpers/amd.c | 5 +++++
> > 2 files changed, 7 insertions(+)
> >
> > diff --git a/tools/power/cpupower/utils/cpufreq-info.c b/tools/power/cpupower/utils/cpufreq-info.c
> > index 0e6764330241..f9b064ac8d94 100644
> > --- a/tools/power/cpupower/utils/cpufreq-info.c
> > +++ b/tools/power/cpupower/utils/cpufreq-info.c
> > @@ -200,6 +200,8 @@ static int get_boost_mode(unsigned int cpu)
> > printf(_(" Boost States: %d\n"), b_states);
> > printf(_(" Total States: %d\n"), pstate_no);
> > for (i = 0; i < pstate_no; i++) {
> > + if (!pstates[i])
> > + continue;
> > if (i < b_states)
> > printf(_(" Pstate-Pb%d: %luMHz (boost state)"
> > "\n"), i, pstates[i]);
> > diff --git a/tools/power/cpupower/utils/helpers/amd.c b/tools/power/cpupower/utils/helpers/amd.c
> > index 6437ef39aeea..82adfb33d7a5 100644
> > --- a/tools/power/cpupower/utils/helpers/amd.c
> > +++ b/tools/power/cpupower/utils/helpers/amd.c
> > @@ -103,6 +103,11 @@ int decode_pstates(unsigned int cpu, unsigned int cpu_family,
> > }
> > if (read_msr(cpu, MSR_AMD_PSTATE + i, &pstate.val))
> > return -1;
> > + if ((cpu_family == 0x17) && (!pstate.fam17h_bits.en))
> > + continue;
> > + else if (!pstate.bits.en)
> > + continue;
> > +
> > pstates[i] = get_cof(cpu_family, pstate);
> > }
> > *no = i;
> >
>
> Sasha,
>
> This commit is causing:
>
> $ make V=1 -C tools/power/cpupower all
>
> gcc -fPIC -DVERSION=\"4.4.163.99.g0d9e7b\" -DPACKAGE=\"cpupower\"
> -DPACKAGE_BUGREPORT=\"linux-pm@vger.kernel.org\" -D_GNU_SOURCE -pipe -DNLS
> -Wall -Wchar-subscripts -Wpointer-arith -Wsign-compare -Wno-pointer-sign
> -Wdeclaration-after-statement -Wshadow -O1 -g -DDEBUG -I./lib -I ./utils -o
> utils/helpers/amd.o -c utils/helpers/amd.c
> utils/helpers/amd.c: In function ‘decode_pstates’:
> utils/helpers/amd.c:106:39: error: ‘union msr_pstate’ has no member named
> ‘fam17h_bits’
> if ((cpu_family == 0x17) && (!pstate.fam17h_bits.en))
>
> I think it should be dropped from v4.4 and v4.9 RCs, since this is a fix for
> a CPU that isn't supported for those 2.

Now dropped from both queues now. Thanks for testing and finding these.

greg k-h