136 lines
3.9 KiB
Diff
136 lines
3.9 KiB
Diff
From 73351c9e7f3de7f398e6257ffbd46c886aca1bc4 Mon Sep 17 00:00:00 2001
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From: Peter Zijlstra <peterz@infradead.org>
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Date: Mon, 20 Mar 2017 12:26:55 +0100
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Subject: [PATCH 004/365] lockdep: Fix per-cpu static objects
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Since commit 383776fa7527 ("locking/lockdep: Handle statically initialized
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PER_CPU locks properly") we try to collapse per-cpu locks into a single
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class by giving them all the same key. For this key we choose the canonical
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address of the per-cpu object, which would be the offset into the per-cpu
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area.
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This has two problems:
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- there is a case where we run !0 lock->key through static_obj() and
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expect this to pass; it doesn't for canonical pointers.
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- 0 is a valid canonical address.
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Cure both issues by redefining the canonical address as the address of the
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per-cpu variable on the boot CPU.
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Since I didn't want to rely on CPU0 being the boot-cpu, or even existing at
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all, track the boot CPU in a variable.
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Fixes: 383776fa7527 ("locking/lockdep: Handle statically initialized PER_CPU locks properly")
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Reported-by: kernel test robot <fengguang.wu@intel.com>
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Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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Tested-by: Borislav Petkov <bp@suse.de>
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Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Cc: linux-mm@kvack.org
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Cc: wfg@linux.intel.com
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Cc: kernel test robot <fengguang.wu@intel.com>
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Cc: LKP <lkp@01.org>
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Link: http://lkml.kernel.org/r/20170320114108.kbvcsuepem45j5cr@hirez.programming.kicks-ass.net
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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include/linux/smp.h | 12 ++++++++++++
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kernel/cpu.c | 6 ++++++
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kernel/module.c | 6 +++++-
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mm/percpu.c | 5 ++++-
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4 files changed, 27 insertions(+), 2 deletions(-)
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diff --git a/include/linux/smp.h b/include/linux/smp.h
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index 8e0cb7a0f836..68123c1fe549 100644
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--- a/include/linux/smp.h
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+++ b/include/linux/smp.h
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@@ -120,6 +120,13 @@ extern unsigned int setup_max_cpus;
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extern void __init setup_nr_cpu_ids(void);
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extern void __init smp_init(void);
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+extern int __boot_cpu_id;
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+
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+static inline int get_boot_cpu_id(void)
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+{
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+ return __boot_cpu_id;
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+}
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+
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#else /* !SMP */
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static inline void smp_send_stop(void) { }
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@@ -158,6 +165,11 @@ static inline void smp_init(void) { up_late_init(); }
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static inline void smp_init(void) { }
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#endif
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+static inline int get_boot_cpu_id(void)
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+{
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+ return 0;
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+}
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+
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#endif /* !SMP */
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/*
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diff --git a/kernel/cpu.c b/kernel/cpu.c
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index 41dd49aa526d..c135d54a50bb 100644
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--- a/kernel/cpu.c
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+++ b/kernel/cpu.c
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@@ -1396,6 +1396,8 @@ core_initcall(cpu_hotplug_pm_sync_init);
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#endif /* CONFIG_PM_SLEEP_SMP */
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+int __boot_cpu_id;
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+
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#endif /* CONFIG_SMP */
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/* Boot processor state steps */
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@@ -2245,6 +2247,10 @@ void __init boot_cpu_init(void)
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set_cpu_active(cpu, true);
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set_cpu_present(cpu, true);
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set_cpu_possible(cpu, true);
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+
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+#ifdef CONFIG_SMP
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+ __boot_cpu_id = cpu;
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+#endif
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}
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/*
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diff --git a/kernel/module.c b/kernel/module.c
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index a7da7fae0c70..3d9df85fece8 100644
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--- a/kernel/module.c
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+++ b/kernel/module.c
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@@ -677,8 +677,12 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
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void *va = (void *)addr;
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if (va >= start && va < start + mod->percpu_size) {
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- if (can_addr)
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+ if (can_addr) {
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*can_addr = (unsigned long) (va - start);
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+ *can_addr += (unsigned long)
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+ per_cpu_ptr(mod->percpu,
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+ get_boot_cpu_id());
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+ }
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preempt_enable();
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return true;
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}
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diff --git a/mm/percpu.c b/mm/percpu.c
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index 16bb5f561e53..39b329891d27 100644
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--- a/mm/percpu.c
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+++ b/mm/percpu.c
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@@ -1296,8 +1296,11 @@ bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr)
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void *va = (void *)addr;
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if (va >= start && va < start + static_size) {
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- if (can_addr)
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+ if (can_addr) {
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*can_addr = (unsigned long) (va - start);
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+ *can_addr += (unsigned long)
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+ per_cpu_ptr(base, get_boot_cpu_id());
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+ }
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return true;
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}
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}
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--
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2.28.0
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