| Message ID | ZxxmLngMg3iNjOfK@mail.google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [next] um: Malloc just enough space for fitting pid file | expand |
On Sat, 2024-10-26 at 16:46 +1300, Paulo Miguel Almeida wrote: > umid is already generated during make_umid_init __initcall so there is > no need to allocate UMID_LEN bytes to accommodate the max possible name > for the umid segment of the filepath > > This patch replaces UMID_LEN occurences in which it's redundant OK, I guess that's maybe all true, but can you say _why_ in the commit log? johannes
On Sat, Oct 26, 2024 at 09:44:53AM +0200, Johannes Berg wrote: Hi! > On Sat, 2024-10-26 at 16:46 +1300, Paulo Miguel Almeida wrote: > > umid is already generated during make_umid_init __initcall so there is > > no need to allocate UMID_LEN bytes to accommodate the max possible name > > for the umid segment of the filepath > > > > This patch replaces UMID_LEN occurences in which it's redundant > > OK, I guess that's maybe all true, but can you say _why_ in the commit > log? > > johannes > thanks for taking the time to review this patch. :-) when I said that "umid is already generated during make_umid_init __initcall", from my humble point of view, I was explaining the 'why' using UMID_LEN for calculation buffer sizes was redundant. Then again, once we know the size of char* umid, we can use strlen(umid) instead. I'm happy to amend the commit message to a better one but I'm not sure if I got 100% what I'm missing. - Paulo
On Sat, 2024-10-26 at 20:59 +1300, Paulo Miguel Almeida wrote: > > when I said that "umid is already generated during make_umid_init > __initcall", from my humble point of view, I was explaining the 'why' > using UMID_LEN for calculation buffer sizes was redundant. Then again, > once we know the size of char* umid, we can use strlen(umid) instead. That's not "why am I changing it" though, that's "why does it work". The only reasonable explanation I could come up with is that you're trying to save memory ... but why go to the trouble for a function that's called exactly once? johannes
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c index eb523ab1e218..513a2cce38db 100644 --- a/arch/um/os-Linux/umid.c +++ b/arch/um/os-Linux/umid.c @@ -212,7 +212,7 @@ static void __init create_pid_file(void) char pid[sizeof("nnnnnnnnn")], *file; int fd, n; - n = strlen(uml_dir) + UMID_LEN + sizeof("/pid"); + n = strlen(uml_dir) + strlen(umid) + sizeof("/pid"); file = malloc(n); if (!file) return; @@ -394,7 +394,7 @@ static void remove_umid_dir(void) { char *dir, err; - dir = malloc(strlen(uml_dir) + UMID_LEN + 1); + dir = malloc(strlen(uml_dir) + strlen(umid) + 1); if (!dir) return;
umid is already generated during make_umid_init __initcall so there is no need to allocate UMID_LEN bytes to accommodate the max possible name for the umid segment of the filepath This patch replaces UMID_LEN occurences in which it's redundant Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com> --- arch/um/os-Linux/umid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)