2022-07-01 11:41:11

by XueBing Chen

[permalink] [raw]
Subject: [PATCH] ftrace: use strscpy to replace strlcpy


The strlcpy should not be used because it doesn't limit the source
length. Preferred is strscpy.

Signed-off-by: XueBing Chen <[email protected]>
---
kernel/trace/ftrace.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 601ccf1b2f09..8d2ad1472fcb 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5902,7 +5902,7 @@ bool ftrace_filter_param __initdata;
static int __init set_ftrace_notrace(char *str)
{
ftrace_filter_param = true;
- strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+ strscpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
return 1;
}
__setup("ftrace_notrace=", set_ftrace_notrace);
@@ -5910,7 +5910,7 @@ __setup("ftrace_notrace=", set_ftrace_notrace);
static int __init set_ftrace_filter(char *str)
{
ftrace_filter_param = true;
- strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+ strscpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
return 1;
}
__setup("ftrace_filter=", set_ftrace_filter);
@@ -5922,14 +5922,14 @@ static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);

static int __init set_graph_function(char *str)
{
- strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
+ strscpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
return 1;
}
__setup("ftrace_graph_filter=", set_graph_function);

static int __init set_graph_notrace_function(char *str)
{
- strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
+ strscpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
return 1;
}
__setup("ftrace_graph_notrace=", set_graph_notrace_function);
@@ -6714,8 +6714,8 @@ static int ftrace_get_trampoline_kallsym(unsigned int symnum,
continue;
*value = op->trampoline;
*type = 't';
- strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
- strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
+ strscpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
+ strscpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
*exported = 0;
return 0;
}
@@ -7046,7 +7046,7 @@ ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
if (off)
*off = addr - found_func->ip;
if (sym)
- strlcpy(sym, found_func->name, KSYM_NAME_LEN);
+ strscpy(sym, found_func->name, KSYM_NAME_LEN);

return found_func->name;
}
@@ -7100,8 +7100,8 @@ int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,

*value = mod_func->ip;
*type = 'T';
- strlcpy(name, mod_func->name, KSYM_NAME_LEN);
- strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
+ strscpy(name, mod_func->name, KSYM_NAME_LEN);
+ strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
*exported = 1;
preempt_enable();
return 0;
--
2.25.1



2022-07-01 15:31:24

by Steven Rostedt

[permalink] [raw]
Subject: Re: [PATCH] ftrace: use strscpy to replace strlcpy

On Fri, 1 Jul 2022 19:09:15 +0800 (GMT+08:00)
"XueBing Chen" <[email protected]> wrote:

> The strlcpy should not be used because it doesn't limit the source
> length. Preferred is strscpy.
>
> Signed-off-by: XueBing Chen <[email protected]>
> ---
> kernel/trace/ftrace.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 601ccf1b2f09..8d2ad1472fcb 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -5902,7 +5902,7 @@ bool ftrace_filter_param __initdata;
> static int __init set_ftrace_notrace(char *str)
> {
> ftrace_filter_param = true;
> - strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
> + strscpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
> return 1;
> }
> __setup("ftrace_notrace=", set_ftrace_notrace);
> @@ -5910,7 +5910,7 @@ __setup("ftrace_notrace=", set_ftrace_notrace);
> static int __init set_ftrace_filter(char *str)
> {
> ftrace_filter_param = true;
> - strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
> + strscpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
> return 1;
> }
> __setup("ftrace_filter=", set_ftrace_filter);
> @@ -5922,14 +5922,14 @@ static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
>
> static int __init set_graph_function(char *str)
> {
> - strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
> + strscpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
> return 1;
> }
> __setup("ftrace_graph_filter=", set_graph_function);
>
> static int __init set_graph_notrace_function(char *str)
> {
> - strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
> + strscpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
> return 1;
> }


No need for strscpy() in init functions that simply read the kernel command
line.

> __setup("ftrace_graph_notrace=", set_graph_notrace_function);
> @@ -6714,8 +6714,8 @@ static int ftrace_get_trampoline_kallsym(unsigned int symnum,
> continue;
> *value = op->trampoline;
> *type = 't';
> - strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
> - strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
> + strscpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
> + strscpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);

The source is a macro, no need for strscpy() here.


> *exported = 0;
> return 0;
> }
> @@ -7046,7 +7046,7 @@ ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
> if (off)
> *off = addr - found_func->ip;
> if (sym)
> - strlcpy(sym, found_func->name, KSYM_NAME_LEN);
> + strscpy(sym, found_func->name, KSYM_NAME_LEN);

The name can not be bigger than KSYM_NAME_LEN, no need for strscpy() here.

>
> return found_func->name;
> }
> @@ -7100,8 +7100,8 @@ int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
>
> *value = mod_func->ip;
> *type = 'T';
> - strlcpy(name, mod_func->name, KSYM_NAME_LEN);
> - strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
> + strscpy(name, mod_func->name, KSYM_NAME_LEN);
> + strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);

Same for this.

I don't see how converting any of these to strscpy() is helpful.

NAK.

-- Steve

> *exported = 1;
> preempt_enable();
> return 0;