From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Prarit Bhargava , Shuah Khan , Stafford Horne , Sasha Levin Subject: [PATCH 4.19 068/361] cpupower: Fix coredump on VMWare Date: Sun, 11 Nov 2018 14:16:55 -0800 Message-Id: <20181111221629.611668869@linuxfoundation.org> In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Prarit Bhargava [ 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 Cc: Shuah Khan Cc: Stafford Horne Signed-off-by: Shuah Khan (Samsung OSG) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- tools/power/cpupower/utils/cpufreq-info.c | 2 ++ tools/power/cpupower/utils/helpers/amd.c | 5 +++++ 2 files changed, 7 insertions(+) --- 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 c 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]); --- a/tools/power/cpupower/utils/helpers/amd.c +++ b/tools/power/cpupower/utils/helpers/amd.c @@ -119,6 +119,11 @@ int decode_pstates(unsigned int cpu, uns } 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;