On Thu, Oct 31, 2024 at 6:55 PM Maíra Canal <mcanal@xxxxxxxxxx> wrote: > > Hi Barry, > > On 30/10/24 20:07, Barry Song wrote: > > On Thu, Oct 31, 2024 at 2:03 AM Maíra Canal <mcanal@xxxxxxxxxx> wrote: > >> > >> Replace strcpy() with strscpy() in mm/huge_memory.c > >> > >> strcpy() has been deprecated because it is generally unsafe, so help to > >> eliminate it from the kernel source. > >> > >> Link: https://github.com/KSPP/linux/issues/88 > >> Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx> > >> --- > >> mm/huge_memory.c | 4 ++-- > >> 1 file changed, 2 insertions(+), 2 deletions(-) > >> > >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c > >> index f92068864469..8f41a694433c 100644 > >> --- a/mm/huge_memory.c > >> +++ b/mm/huge_memory.c > >> @@ -989,7 +989,7 @@ static int __init setup_thp_anon(char *str) > >> > >> if (!str || strlen(str) + 1 > PAGE_SIZE) > >> goto err; > >> - strcpy(str_dup, str); > >> + strscpy(str_dup, str); > > > > What is the difference between strcpy and strscpy without a size parameter? > > > > we have already a check and goto err. strcpy() is entirely safe. > > if (!str || strlen(str) + 1 > PAGE_SIZE) > > goto err; > > > > My understanding is that we don't need this patch. > > strcpy() is a deprecated interface [1]. From the GitHub issue I linked > in the commit description, Kees states: "A lot of kernel code is still > using strcpy(). While the CONFIG_FORTIFY_SOURCE wrapper macros tend to > make its use mostly safe, it would be nice to eliminate the function > from the kernel entirely." I don't see any value added here since strscpy() has no size parameter and we have checked strlen(str) + 1 > PAGE_SIZE to avoid parsing any pointless bootcmd longer than PAGE_SIZE. But I have no objection to this patch if other people like it. > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy > > Best Regards, > - Maíra > > > > >> > >> always = huge_anon_orders_always; > >> madvise = huge_anon_orders_madvise; > >> @@ -4175,7 +4175,7 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, > >> > >> tok = strsep(&buf, ","); > >> if (tok) { > >> - strcpy(file_path, tok); > >> + strscpy(file_path, tok); > >> } else { > >> ret = -EINVAL; > >> goto out; > >> -- > >> 2.46.2 > >> > > Thanks barry
