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ksym_tracer: Fix memory leak

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- 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 <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A52E328.8010200@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Li Zefan 2009-07-07 13:54:48 +08:00 committed by Ingo Molnar
parent 0d109c8f70
commit 558df6c8f7
1 changed files with 27 additions and 34 deletions
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61
kernel/trace/trace_ksym.c
View file

@ -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);
}