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| author | Peter Zijlstra <peterz@infradead.org> | 2017-03-20 14:26:55 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-03-26 16:09:45 +0300 |
| commit | 8ce371f9846ef1e8b3cc8f6865766cb5c1f17e40 (patch) | |
| tree | ae7406dc794c7cf642b9c37bf85408e3a38c5dca /kernel/module.c | |
| parent | 56222b212e8edb1cf51f5dd73ff645809b082b40 (diff) | |
| download | linux-8ce371f9846ef1e8b3cc8f6865766cb5c1f17e40.tar.xz | |
lockdep: Fix per-cpu static objects
Since commit 383776fa7527 ("locking/lockdep: Handle statically initialized
PER_CPU locks properly") we try to collapse per-cpu locks into a single
class by giving them all the same key. For this key we choose the canonical
address of the per-cpu object, which would be the offset into the per-cpu
area.
This has two problems:
- there is a case where we run !0 lock->key through static_obj() and
expect this to pass; it doesn't for canonical pointers.
- 0 is a valid canonical address.
Cure both issues by redefining the canonical address as the address of the
per-cpu variable on the boot CPU.
Since I didn't want to rely on CPU0 being the boot-cpu, or even existing at
all, track the boot CPU in a variable.
Fixes: 383776fa7527 ("locking/lockdep: Handle statically initialized PER_CPU locks properly")
Reported-by: kernel test robot <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-mm@kvack.org
Cc: wfg@linux.intel.com
Cc: kernel test robot <fengguang.wu@intel.com>
Cc: LKP <lkp@01.org>
Link: http://lkml.kernel.org/r/20170320114108.kbvcsuepem45j5cr@hirez.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/module.c b/kernel/module.c index 5ef618133849..6d9988031c5b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -682,8 +682,12 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) void *va = (void *)addr; if (va >= start && va < start + mod->percpu_size) { - if (can_addr) + if (can_addr) { *can_addr = (unsigned long) (va - start); + *can_addr += (unsigned long) + per_cpu_ptr(mod->percpu, + get_boot_cpu_id()); + } preempt_enable(); return true; } |