| Message ID | 20210505211047.1496765-19-philmd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | misc: Remove variable-length arrays on the stack | expand |
On 5/5/21 2:10 PM, Philippe Mathieu-Daudé wrote: > We know 'pf.bytes_per_pixel' will be at most 'VNC_SERVER_FB_BYTES' > (which is actually 4 bytes for 32bpp). Instead of having the compiler > use variable-length array, use this 'small' maximum length and > autofree to allocate the buffer on the heap. > > Signed-off-by: Philippe Mathieu-Daudé<philmd@redhat.com> > --- > ui/vnc-enc-hextile-template.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Wait, you know the value is small (max 4), and you don't want to allocate a constant 1k on the stack? r~
diff --git a/ui/vnc-enc-hextile-template.h b/ui/vnc-enc-hextile-template.h index 0c56262afff..85e67bd9d88 100644 --- a/ui/vnc-enc-hextile-template.h +++ b/ui/vnc-enc-hextile-template.h @@ -25,10 +25,11 @@ static void CONCAT(send_hextile_tile_, NAME)(VncState *vs, int bg_count = 0; int fg_count = 0; int flags = 0; - uint8_t data[(vs->client_pf.bytes_per_pixel + 2) * 16 * 16]; + g_autofree uint8_t *data = g_malloc((VNC_SERVER_FB_BYTES + 2) * 16 * 16); int n_data = 0; int n_subtiles = 0; + assert(vs->client_pf.bytes_per_pixel <= VNC_SERVER_FB_BYTES); for (j = 0; j < h; j++) { for (i = 0; i < w; i++) { switch (n_colors) {
We know 'pf.bytes_per_pixel' will be at most 'VNC_SERVER_FB_BYTES' (which is actually 4 bytes for 32bpp). Instead of having the compiler use variable-length array, use this 'small' maximum length and autofree to allocate the buffer on the heap. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> --- ui/vnc-enc-hextile-template.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)