From 558df6c8f74ac4a0b9026ef85b0028280f364d96 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 7 Jul 2009 13:54:48 +0800 Subject: [PATCH] ksym_tracer: Fix memory leak - When remove a filter, we leak entry->ksym_hbp->info.name. - With CONFIG_FTRAC_SELFTEST enabled, we leak ->info.name: # echo ksym_tracer > current_tracer # echo 'ksym_selftest_dummy:rw-' > ksym_trace_filter # echo nop > current_tracer Signed-off-by: Li Zefan Acked-by: Frederic Weisbecker Cc: "K.Prasad" Cc: Alan Stern Cc: Steven Rostedt LKML-Reference: <4A52E328.8010200@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_ksym.c | 61 +++++++++++++++++++++-------------------------- 1 file changed, 27 insertions(+), 34 deletions(-) diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index 891e3b8..7d349d3 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -179,7 +179,7 @@ static int parse_ksym_trace_str(char *input_string, char **ksymname, int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) { struct trace_ksym *entry; - int ret; + int ret = -ENOMEM; if (ksym_filter_entry_count >= KSYM_TRACER_MAX) { printk(KERN_ERR "ksym_tracer: Maximum limit:(%d) reached. No" @@ -193,12 +193,13 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) return -ENOMEM; entry->ksym_hbp = kzalloc(sizeof(struct hw_breakpoint), GFP_KERNEL); - if (!entry->ksym_hbp) { - kfree(entry); - return -ENOMEM; - } + if (!entry->ksym_hbp) + goto err; + + entry->ksym_hbp->info.name = kstrdup(ksymname, GFP_KERNEL); + if (!entry->ksym_hbp->info.name) + goto err; - entry->ksym_hbp->info.name = ksymname; entry->ksym_hbp->info.type = op; entry->ksym_addr = entry->ksym_hbp->info.address = addr; #ifdef CONFIG_X86 @@ -210,14 +211,18 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) if (ret < 0) { printk(KERN_INFO "ksym_tracer request failed. Try again" " later!!\n"); - kfree(entry->ksym_hbp); - kfree(entry); - return -EAGAIN; + ret = -EAGAIN; + goto err; } hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); ksym_filter_entry_count++; - return 0; +err: + if (entry->ksym_hbp) + kfree(entry->ksym_hbp->info.name); + kfree(entry->ksym_hbp); + kfree(entry); + return ret; } static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, @@ -289,7 +294,7 @@ static ssize_t ksym_trace_filter_write(struct file *file, if (entry->ksym_hbp->info.type != op) changed = 1; else - goto err_ret; + goto out; break; } } @@ -298,34 +303,29 @@ static ssize_t ksym_trace_filter_write(struct file *file, entry->ksym_hbp->info.type = op; if (op > 0) { ret = register_kernel_hw_breakpoint(entry->ksym_hbp); - if (ret == 0) { - ret = count; - goto unlock_ret_path; - } - } else - ret = count; + if (ret == 0) + goto out; + } ksym_filter_entry_count--; hlist_del_rcu(&(entry->ksym_hlist)); synchronize_rcu(); + kfree(entry->ksym_hbp->info.name); kfree(entry->ksym_hbp); kfree(entry); - goto err_ret; + goto out; } else { /* Check for malformed request: (4) */ if (op == 0) - goto err_ret; + goto out; ret = process_new_ksym_entry(ksymname, op, ksym_addr); - if (ret) - goto err_ret; } - ret = count; - goto unlock_ret_path; +out: + mutex_unlock(&ksym_tracer_mutex); -err_ret: kfree(input_string); -unlock_ret_path: - mutex_unlock(&ksym_tracer_mutex); + if (!ret) + ret = count; return ret; } @@ -349,14 +349,7 @@ static void ksym_trace_reset(struct trace_array *tr) ksym_filter_entry_count--; hlist_del_rcu(&(entry->ksym_hlist)); synchronize_rcu(); - /* Free the 'input_string' only if reset - * after startup self-test - */ -#ifdef CONFIG_FTRACE_SELFTEST - if (strncmp(entry->ksym_hbp->info.name, KSYM_SELFTEST_ENTRY, - strlen(KSYM_SELFTEST_ENTRY)) != 0) -#endif /* CONFIG_FTRACE_SELFTEST*/ - kfree(entry->ksym_hbp->info.name); + kfree(entry->ksym_hbp->info.name); kfree(entry->ksym_hbp); kfree(entry); } -- 2.7.4