diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index fb186b9ddf519159d866fcaa8fc187328820f2bf..31c90fec415899bfb40927bbbcc8ad29657317ab 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1925,8 +1925,16 @@ ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) * when we are adding another op to the rec or removing the * current one. Thus, if the op is being added, we can * ignore it because it hasn't attached itself to the rec - * yet. That means we just need to find the op that has a - * trampoline and is not beeing added. + * yet. + * + * If an ops is being modified (hooking to different functions) + * then we don't care about the new functions that are being + * added, just the old ones (that are probably being removed). + * + * If we are adding an ops to a function that already is using + * a trampoline, it needs to be removed (trampolines are only + * for single ops connected), then an ops that is not being + * modified also needs to be checked. */ do_for_each_ftrace_op(op, ftrace_ops_list) { @@ -1940,17 +1948,23 @@ ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) if (op->flags & FTRACE_OPS_FL_ADDING) continue; + /* - * If the ops is not being added and has a trampoline, - * then it must be the one that we want! + * If the ops is being modified and is in the old + * hash, then it is probably being removed from this + * function. */ - if (hash_contains_ip(ip, op->func_hash)) - return op; - - /* If the ops is being modified, it may be in the old hash. */ if ((op->flags & FTRACE_OPS_FL_MODIFYING) && hash_contains_ip(ip, &op->old_hash)) return op; + /* + * If the ops is not being added or modified, and it's + * in its normal filter hash, then this must be the one + * we want! + */ + if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && + hash_contains_ip(ip, op->func_hash)) + return op; } while_for_each_ftrace_op(op); @@ -2293,10 +2307,13 @@ static void ftrace_run_update_code(int command) FTRACE_WARN_ON(ret); } -static void ftrace_run_modify_code(struct ftrace_ops *ops, int command) +static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, + struct ftrace_hash *old_hash) { ops->flags |= FTRACE_OPS_FL_MODIFYING; + ops->old_hash.filter_hash = old_hash; ftrace_run_update_code(command); + ops->old_hash.filter_hash = NULL; ops->flags &= ~FTRACE_OPS_FL_MODIFYING; } @@ -3340,7 +3357,7 @@ static struct ftrace_ops trace_probe_ops __read_mostly = static int ftrace_probe_registered; -static void __enable_ftrace_function_probe(void) +static void __enable_ftrace_function_probe(struct ftrace_hash *old_hash) { int ret; int i; @@ -3348,7 +3365,8 @@ static void __enable_ftrace_function_probe(void) if (ftrace_probe_registered) { /* still need to update the function call sites */ if (ftrace_enabled) - ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS); + ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, + old_hash); return; } @@ -3477,13 +3495,14 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, } while_for_each_ftrace_rec(); ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); + + __enable_ftrace_function_probe(old_hash); + if (!ret) free_ftrace_hash_rcu(old_hash); else count = ret; - __enable_ftrace_function_probe(); - out_unlock: mutex_unlock(&ftrace_lock); out: @@ -3764,10 +3783,11 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) return add_hash_entry(hash, ip); } -static void ftrace_ops_update_code(struct ftrace_ops *ops) +static void ftrace_ops_update_code(struct ftrace_ops *ops, + struct ftrace_hash *old_hash) { if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled) - ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS); + ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); } static int @@ -3813,7 +3833,7 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, old_hash = *orig_hash; ret = ftrace_hash_move(ops, enable, orig_hash, hash); if (!ret) { - ftrace_ops_update_code(ops); + ftrace_ops_update_code(ops, old_hash); free_ftrace_hash_rcu(old_hash); } mutex_unlock(&ftrace_lock); @@ -4058,7 +4078,7 @@ int ftrace_regex_release(struct inode *inode, struct file *file) ret = ftrace_hash_move(iter->ops, filter_hash, orig_hash, iter->hash); if (!ret) { - ftrace_ops_update_code(iter->ops); + ftrace_ops_update_code(iter->ops, old_hash); free_ftrace_hash_rcu(old_hash); } mutex_unlock(&ftrace_lock);