2023-01-12 08:11:28

by Jiri Slaby

Subject: [PATCH 04/11] tty: vt: use sizeof(*variable) where possible

Instead of sizeof(type), use sizeof(*variable) which is preferred. We
are going to remove the unicode's char32_t typedef, so this makes the
switch easier.

Signed-off-by: Jiri Slaby (SUSE) <[email protected]>
---
drivers/tty/vt/vt.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 561c82e120cf..3ae0212f1aa7 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -330,11 +330,11 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
{
struct uni_screen *uniscr;
void *p;
- unsigned int memsize, i;
+ unsigned int memsize, i, col_size = cols * sizeof(**uniscr->lines);

/* allocate everything in one go */
- memsize = cols * rows * sizeof(char32_t);
- memsize += rows * sizeof(char32_t *);
+ memsize = col_size * rows;
+ memsize += rows * sizeof(*uniscr->lines);
p = vzalloc(memsize);
if (!p)
return NULL;
@@ -344,7 +344,7 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
p = uniscr->lines + rows;
for (i = 0; i < rows; i++) {
uniscr->lines[i] = p;
- p += cols * sizeof(char32_t);
+ p += col_size;
}
return uniscr;
}
@@ -469,7 +469,7 @@ static void vc_uniscr_copy_area(struct uni_screen *dst,
char32_t *src_line = src->lines[src_top_row];
char32_t *dst_line = dst->lines[dst_row];

- memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
+ memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
if (dst_cols - src_cols)
memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
src_top_row++;
--
2.39.0

2023-01-12 09:10:34

by Ilpo Järvinen

Subject: Re: [PATCH 04/11] tty: vt: use sizeof(*variable) where possible

On Thu, 12 Jan 2023, Jiri Slaby (SUSE) wrote:

> Instead of sizeof(type), use sizeof(*variable) which is preferred. We
> are going to remove the unicode's char32_t typedef, so this makes the
> switch easier.
>
> Signed-off-by: Jiri Slaby (SUSE) <[email protected]>
> ---
> drivers/tty/vt/vt.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index 561c82e120cf..3ae0212f1aa7 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -330,11 +330,11 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
> {
> struct uni_screen *uniscr;
> void *p;
> - unsigned int memsize, i;
> + unsigned int memsize, i, col_size = cols * sizeof(**uniscr->lines);
>
> /* allocate everything in one go */
> - memsize = cols * rows * sizeof(char32_t);
> - memsize += rows * sizeof(char32_t *);
> + memsize = col_size * rows;
> + memsize += rows * sizeof(*uniscr->lines);

Wouldn't something from linux/overflow.h be more appropriate for these?

--
i.

> p = vzalloc(memsize);
> if (!p)
> return NULL;
> @@ -344,7 +344,7 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
> p = uniscr->lines + rows;
> for (i = 0; i < rows; i++) {
> uniscr->lines[i] = p;
> - p += cols * sizeof(char32_t);
> + p += col_size;
> }
> return uniscr;
> }
> @@ -469,7 +469,7 @@ static void vc_uniscr_copy_area(struct uni_screen *dst,
> char32_t *src_line = src->lines[src_top_row];
> char32_t *dst_line = dst->lines[dst_row];
>
> - memcpy(dst_line, src_line, src_cols * sizeof(char32_t));
> + memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
> if (dst_cols - src_cols)
> memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
> src_top_row++;
>