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authorKevin Hilman <khilman@baylibre.com>2016-04-22 09:45:53 -0700
committerKevin Hilman <khilman@baylibre.com>2016-04-22 09:45:53 -0700
commitc0e309138be2e4ba1551dde76f7fa2479cd9198d (patch)
tree81d7681547f8717c5a5416315110050f1a2a4962 /kernel/locking
parentMerge tag 'v4.6-soc-fixes' of https://github.com/mbgg/linux-mediatek into fixes (diff)
parentRevert "ARM: OMAP: Catch callers of revision information prior to it being populated" (diff)
Merge tag 'omap-for-v4.6/fixes-rc2-v2-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Merge "omap fixes against v4.6-rc2" from Tony Lindgren Fixes for omaps against v4.6-rc2, mostly to fix suspend for beagle-x15 that broke when we added runtime based SoC revision detection earlier. It seems suspend worked earlier as things were only partially initialized, while now we initialize things properly for dra7. Note that the "ARM: OMAP: Catch callers of revision information prior to it being populated" had to be reverted as it caused bogus warnings for other SoCs because omap initcalls bail out based on revision being set to 0 for other SoCs. These initcalls will mostly just disappear when we drop support for omap3 legacy booting. Also included is a fix for dra7 sys_32k_ck clock source that is not enabled on boot making system fall back to using emulated clock. * tag 'omap-for-v4.6/fixes-rc2-v2-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (198 commits) Revert "ARM: OMAP: Catch callers of revision information prior to it being populated" ARM: OMAP: Catch callers of revision information prior to it being populated ARM: dts: dra7: Correct clock tree for sys_32k_ck ARM: OMAP: DRA7: Provide proper class to omap2_set_globals_tap ARM: OMAP: DRA7: wakeupgen: Skip SAR save for wakeupgen Linux 4.6-rc2 v4l2-mc: avoid warning about unused variable Convert straggling drivers to new six-argument get_user_pages() .mailmap: add Christophe Ricard Make CONFIG_FHANDLE default y mm/page_isolation.c: fix the function comments oom, oom_reaper: do not enqueue task if it is on the oom_reaper_list head mm/page_isolation: fix tracepoint to mirror check function behavior mm/rmap: batched invalidations should use existing api x86/mm: TLB_REMOTE_SEND_IPI should count pages mm: fix invalid node in alloc_migrate_target() include/linux/huge_mm.h: return NULL instead of false for pmd_trans_huge_lock() mm, kasan: fix compilation for CONFIG_SLAB MAINTAINERS: orangefs mailing list is subscribers-only net: mvneta: fix changing MTU when using per-cpu processing ...
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/lockdep.c79
1 files changed, 77 insertions, 2 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 53ab2f85d77e..2324ba5310db 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2000,6 +2000,77 @@ static inline int get_first_held_lock(struct task_struct *curr,
}
/*
+ * Returns the next chain_key iteration
+ */
+static u64 print_chain_key_iteration(int class_idx, u64 chain_key)
+{
+ u64 new_chain_key = iterate_chain_key(chain_key, class_idx);
+
+ printk(" class_idx:%d -> chain_key:%016Lx",
+ class_idx,
+ (unsigned long long)new_chain_key);
+ return new_chain_key;
+}
+
+static void
+print_chain_keys_held_locks(struct task_struct *curr, struct held_lock *hlock_next)
+{
+ struct held_lock *hlock;
+ u64 chain_key = 0;
+ int depth = curr->lockdep_depth;
+ int i;
+
+ printk("depth: %u\n", depth + 1);
+ for (i = get_first_held_lock(curr, hlock_next); i < depth; i++) {
+ hlock = curr->held_locks + i;
+ chain_key = print_chain_key_iteration(hlock->class_idx, chain_key);
+
+ print_lock(hlock);
+ }
+
+ print_chain_key_iteration(hlock_next->class_idx, chain_key);
+ print_lock(hlock_next);
+}
+
+static void print_chain_keys_chain(struct lock_chain *chain)
+{
+ int i;
+ u64 chain_key = 0;
+ int class_id;
+
+ printk("depth: %u\n", chain->depth);
+ for (i = 0; i < chain->depth; i++) {
+ class_id = chain_hlocks[chain->base + i];
+ chain_key = print_chain_key_iteration(class_id + 1, chain_key);
+
+ print_lock_name(lock_classes + class_id);
+ printk("\n");
+ }
+}
+
+static void print_collision(struct task_struct *curr,
+ struct held_lock *hlock_next,
+ struct lock_chain *chain)
+{
+ printk("\n");
+ printk("======================\n");
+ printk("[chain_key collision ]\n");
+ print_kernel_ident();
+ printk("----------------------\n");
+ printk("%s/%d: ", current->comm, task_pid_nr(current));
+ printk("Hash chain already cached but the contents don't match!\n");
+
+ printk("Held locks:");
+ print_chain_keys_held_locks(curr, hlock_next);
+
+ printk("Locks in cached chain:");
+ print_chain_keys_chain(chain);
+
+ printk("\nstack backtrace:\n");
+ dump_stack();
+}
+
+/*
* Checks whether the chain and the current held locks are consistent
* in depth and also in content. If they are not it most likely means
* that there was a collision during the calculation of the chain_key.
@@ -2014,14 +2085,18 @@ static int check_no_collision(struct task_struct *curr,
i = get_first_held_lock(curr, hlock);
- if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1)))
+ if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1))) {
+ print_collision(curr, hlock, chain);
return 0;
+ }
for (j = 0; j < chain->depth - 1; j++, i++) {
id = curr->held_locks[i].class_idx - 1;
- if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id))
+ if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) {
+ print_collision(curr, hlock, chain);
return 0;
+ }
}
#endif
return 1;