diff options
Diffstat (limited to '0007-x86-MCE-AMD-Do-not-use-rdmsr_safe_on_cpu-in-smca_configure.patch')
| -rw-r--r-- | 0007-x86-MCE-AMD-Do-not-use-rdmsr_safe_on_cpu-in-smca_configure.patch | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/0007-x86-MCE-AMD-Do-not-use-rdmsr_safe_on_cpu-in-smca_configure.patch b/0007-x86-MCE-AMD-Do-not-use-rdmsr_safe_on_cpu-in-smca_configure.patch new file mode 100644 index 0000000..659a1dd --- /dev/null +++ b/0007-x86-MCE-AMD-Do-not-use-rdmsr_safe_on_cpu-in-smca_configure.patch @@ -0,0 +1,72 @@ +From 1a95a3417bdadb0528e16745802688c393aa0afd Mon Sep 17 00:00:00 2001 +From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> +Date: Thu, 31 Oct 2019 16:04:48 +0300 +Subject: x86/MCE/AMD: Do not use rdmsr_safe_on_cpu() in smca_configure() + +... because interrupts are disabled that early and sending IPIs can +deadlock: + + BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 + in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 + no locks held by swapper/1/0. + irq event stamp: 0 + hardirqs last enabled at (0): [<0000000000000000>] 0x0 + hardirqs last disabled at (0): [<ffffffff8106dda9>] copy_process+0x8b9/0x1ca0 + softirqs last enabled at (0): [<ffffffff8106dda9>] copy_process+0x8b9/0x1ca0 + softirqs last disabled at (0): [<0000000000000000>] 0x0 + Preemption disabled at: + [<ffffffff8104703b>] start_secondary+0x3b/0x190 + CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-rc2+ #1 + Hardware name: GIGABYTE MZ01-CE1-00/MZ01-CE1-00, BIOS F02 08/29/2018 + Call Trace: + dump_stack + ___might_sleep.cold.92 + wait_for_completion + ? generic_exec_single + rdmsr_safe_on_cpu + ? wrmsr_on_cpus + mce_amd_feature_init + mcheck_cpu_init + identify_cpu + identify_secondary_cpu + smp_store_cpu_info + start_secondary + secondary_startup_64 + +The function smca_configure() is called only on the current CPU anyway, +therefore replace rdmsr_safe_on_cpu() with atomic rdmsr_safe() and avoid +the IPI. + + [ bp: Update commit message. ] + +Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> +Signed-off-by: Borislav Petkov <bp@suse.de> +Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com> +Cc: "H. Peter Anvin" <hpa@zytor.com> +Cc: Ingo Molnar <mingo@redhat.com> +Cc: linux-edac <linux-edac@vger.kernel.org> +Cc: <stable@vger.kernel.org> +Cc: Thomas Gleixner <tglx@linutronix.de> +Cc: Tony Luck <tony.luck@intel.com> +Cc: x86-ml <x86@kernel.org> +Link: https://lkml.kernel.org/r/157252708836.3876.4604398213417262402.stgit@buzz +--- + arch/x86/kernel/cpu/mce/amd.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c +index 6ea7fdc82f3c..c7ab0d38af79 100644 +--- a/arch/x86/kernel/cpu/mce/amd.c ++++ b/arch/x86/kernel/cpu/mce/amd.c +@@ -269,7 +269,7 @@ static void smca_configure(unsigned int bank, unsigned int cpu) + if (smca_banks[bank].hwid) + return; + +- if (rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) { ++ if (rdmsr_safe(MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) { + pr_warn("Failed to read MCA_IPID for bank %d\n", bank); + return; + } +-- +cgit v1.2.1-1-g437b + |