From 274920a3ecd5f43af0cc380bc0a9ee73a52b9f8a Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 10 Jan 2018 23:49:12 +1100 Subject: [PATCH 1/6] powerpc/xmon: Add RFI flush related fields to paca dump Signed-off-by: Michael Ellerman --- arch/powerpc/xmon/xmon.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index cab24f549e7c..b3bb5beec54a 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2375,6 +2375,10 @@ static void dump_one_paca(int cpu) DUMP(p, slb_cache_ptr, "x"); for (i = 0; i < SLB_CACHE_ENTRIES; i++) printf(" slb_cache[%d]: = 0x%016lx\n", i, p->slb_cache[i]); + + DUMP(p, rfi_flush_fallback_area, "px"); + DUMP(p, l1d_flush_congruence, "llx"); + DUMP(p, l1d_flush_sets, "llx"); #endif DUMP(p, dscr_default, "llx"); #ifdef CONFIG_PPC_BOOK3E From 2248fade965a5f1ba2a8e6e63f84df696b2d2780 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Thu, 11 Jan 2018 01:17:24 +1100 Subject: [PATCH 2/6] powerpc/xmon: Don't print hashed pointers in paca dump Remember when the biggest problem we had to worry about was hashed pointers, those were the days. These were missed in my earlier patch because they don't match "%p", but the macro is hiding a "%p", so these all end up being hashed, which is not what we want in xmon. Convert them to "%px". Signed-off-by: Michael Ellerman --- arch/powerpc/xmon/xmon.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index b3bb5beec54a..0ddc7ac6c5f1 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2344,10 +2344,10 @@ static void dump_one_paca(int cpu) DUMP(p, kernel_toc, "lx"); DUMP(p, kernelbase, "lx"); DUMP(p, kernel_msr, "lx"); - DUMP(p, emergency_sp, "p"); + DUMP(p, emergency_sp, "px"); #ifdef CONFIG_PPC_BOOK3S_64 - DUMP(p, nmi_emergency_sp, "p"); - DUMP(p, mc_emergency_sp, "p"); + DUMP(p, nmi_emergency_sp, "px"); + DUMP(p, mc_emergency_sp, "px"); DUMP(p, in_nmi, "x"); DUMP(p, in_mce, "x"); DUMP(p, hmi_event_available, "x"); @@ -2382,14 +2382,14 @@ static void dump_one_paca(int cpu) #endif DUMP(p, dscr_default, "llx"); #ifdef CONFIG_PPC_BOOK3E - DUMP(p, pgd, "p"); - DUMP(p, kernel_pgd, "p"); - DUMP(p, tcd_ptr, "p"); - DUMP(p, mc_kstack, "p"); - DUMP(p, crit_kstack, "p"); - DUMP(p, dbg_kstack, "p"); + DUMP(p, pgd, "px"); + DUMP(p, kernel_pgd, "px"); + DUMP(p, tcd_ptr, "px"); + DUMP(p, mc_kstack, "px"); + DUMP(p, crit_kstack, "px"); + DUMP(p, dbg_kstack, "px"); #endif - DUMP(p, __current, "p"); + DUMP(p, __current, "px"); DUMP(p, kstack, "lx"); printf(" kstack_base = 0x%016lx\n", p->kstack & ~(THREAD_SIZE - 1)); DUMP(p, stab_rr, "lx"); @@ -2407,7 +2407,7 @@ static void dump_one_paca(int cpu) #endif #ifdef CONFIG_PPC_POWERNV - DUMP(p, core_idle_state_ptr, "p"); + DUMP(p, core_idle_state_ptr, "px"); DUMP(p, thread_idle_state, "x"); DUMP(p, thread_mask, "x"); DUMP(p, subcore_sibling_mask, "x"); From 349524bc0da698ec77f2057cf4a4948eb6349265 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 10 Jan 2018 17:10:12 +1100 Subject: [PATCH 3/6] powerpc: Don't preempt_disable() in show_cpuinfo() This causes warnings from cpufreq mutex code. This is also rather unnecessary and ineffective. If we really want to prevent concurrent unplug, we could take the unplug read lock but I don't see this being critical. Fixes: cd77b5ce208c ("powerpc/powernv/cpufreq: Fix the frequency read by /proc/cpuinfo") Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/setup-common.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 9d213542a48b..8fd3a70047f1 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -242,14 +242,6 @@ static int show_cpuinfo(struct seq_file *m, void *v) unsigned short maj; unsigned short min; - /* We only show online cpus: disable preempt (overzealous, I - * knew) to prevent cpu going down. */ - preempt_disable(); - if (!cpu_online(cpu_id)) { - preempt_enable(); - return 0; - } - #ifdef CONFIG_SMP pvr = per_cpu(cpu_pvr, cpu_id); #else @@ -358,9 +350,6 @@ static int show_cpuinfo(struct seq_file *m, void *v) #ifdef CONFIG_SMP seq_printf(m, "\n"); #endif - - preempt_enable(); - /* If this is the last cpu, print the summary */ if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids) show_cpuinfo_summary(m); From fd6e440f20b1a4304553775fc55938848ff617c9 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 16 Jan 2018 21:20:05 +1100 Subject: [PATCH 4/6] powerpc/64s: Wire up cpu_show_meltdown() The recent commit 87590ce6e373 ("sysfs/cpu: Add vulnerability folder") added a generic folder and set of files for reporting information on CPU vulnerabilities. One of those was for meltdown: /sys/devices/system/cpu/vulnerabilities/meltdown This commit wires up that file for 64-bit Book3S powerpc. For now we default to "Vulnerable" unless the RFI flush is enabled. That may not actually be true on all hardware, further patches will refine the reporting based on the CPU/platform etc. But for now we default to being pessimists. Signed-off-by: Michael Ellerman --- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/setup_64.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c51e6ce42e7a..2ed525a44734 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -166,6 +166,7 @@ config PPC select GENERIC_CLOCKEVENTS_BROADCAST if SMP select GENERIC_CMOS_UPDATE select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_VULNERABILITIES if PPC_BOOK3S_64 select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL select GENERIC_SMP_IDLE_THREAD diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 491be4179ddd..624d2a62d05d 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -901,4 +901,12 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) if (!no_rfi_flush) rfi_flush_enable(enable); } + +ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) +{ + if (rfi_flush) + return sprintf(buf, "Mitigation: RFI Flush\n"); + + return sprintf(buf, "Vulnerable\n"); +} #endif /* CONFIG_PPC_BOOK3S_64 */ From 236003e6b5443c45c18e613d2b0d776a9f87540e Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 16 Jan 2018 22:17:18 +1100 Subject: [PATCH 5/6] powerpc/64s: Allow control of RFI flush via debugfs Expose the state of the RFI flush (enabled/disabled) via debugfs, and allow it to be enabled/disabled at runtime. eg: $ cat /sys/kernel/debug/powerpc/rfi_flush 1 $ echo 0 > /sys/kernel/debug/powerpc/rfi_flush $ cat /sys/kernel/debug/powerpc/rfi_flush 0 Signed-off-by: Michael Ellerman Reviewed-by: Nicholas Piggin --- arch/powerpc/kernel/setup_64.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 624d2a62d05d..e67413f4a8f0 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -38,6 +38,7 @@ #include #include +#include #include #include #include @@ -902,6 +903,35 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) rfi_flush_enable(enable); } +#ifdef CONFIG_DEBUG_FS +static int rfi_flush_set(void *data, u64 val) +{ + if (val == 1) + rfi_flush_enable(true); + else if (val == 0) + rfi_flush_enable(false); + else + return -EINVAL; + + return 0; +} + +static int rfi_flush_get(void *data, u64 *val) +{ + *val = rfi_flush ? 1 : 0; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n"); + +static __init int rfi_flush_debugfs_init(void) +{ + debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush); + return 0; +} +device_initcall(rfi_flush_debugfs_init); +#endif + ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) { if (rfi_flush) From 1b689a95ce7427075f9ac9fb4aea1af530742b7f Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Mon, 15 Jan 2018 14:30:03 +0100 Subject: [PATCH 6/6] powerpc/pseries: include linux/types.h in asm/hvcall.h Commit 6e032b350cd1 ("powerpc/powernv: Check device-tree for RFI flush settings") uses u64 in asm/hvcall.h without including linux/types.h This breaks hvcall.h users that do not include the header themselves. Fixes: 6e032b350cd1 ("powerpc/powernv: Check device-tree for RFI flush settings") Signed-off-by: Michal Suchanek Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/hvcall.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index f0461618bf7b..eca3f9c68907 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -353,6 +353,7 @@ #define PROC_TABLE_GTSE 0x01 #ifndef __ASSEMBLY__ +#include /** * plpar_hcall_norets: - Make a pseries hypervisor call with no return arguments