[media] drivers/media/pci: use memmove for overlapping regions

Change several memcpy() to memmove() in cases when the regions are
definitely overlapping; memcpy() of overlapping regions is undefined
behavior in C and can produce different results depending on the compiler,
the memcpy implementation, etc.

Cc: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/pci/bt8xx/dst_ca.c b/drivers/media/pci/bt8xx/dst_ca.c
index 7d96fab..0e788fc 100644 (file)
--- a/drivers/media/pci/bt8xx/dst_ca.c
+++ b/drivers/media/pci/bt8xx/dst_ca.c
@@ -180,11 +180,11 @@ static int ca_get_app_info(struct dst_state *state)
        put_command_and_length(&state->messages[0], CA_APP_INFO, length);
 
        // Copy application_type, application_manufacturer and manufacturer_code
-       memcpy(&state->messages[4], &state->messages[7], 5);
+       memmove(&state->messages[4], &state->messages[7], 5);
 
        // Set string length and copy string
        state->messages[9] = str_length;
-       memcpy(&state->messages[10], &state->messages[12], str_length);
+       memmove(&state->messages[10], &state->messages[12], str_length);
 
        return 0;
 }

diff --git a/drivers/media/pci/cx18/cx18-vbi.c b/drivers/media/pci/cx18/cx18-vbi.c
index 6d3121f..add9964 100644 (file)
--- a/drivers/media/pci/cx18/cx18-vbi.c
+++ b/drivers/media/pci/cx18/cx18-vbi.c
@@ -84,7 +84,7 @@ static void copy_vbi_data(struct cx18 *cx, int lines, u32 pts_stamp)
                   (the max size of the VBI data is 36 * 43 + 4 bytes).
                   So in this case we use the magic number 'ITV0'. */
                memcpy(dst + sd, "ITV0", 4);
-               memcpy(dst + sd + 4, dst + sd + 12, line * 43);
+               memmove(dst + sd + 4, dst + sd + 12, line * 43);
                size = 4 + ((43 * line + 3) & ~3);
        } else {
                memcpy(dst + sd, "itv0", 4);

diff --git a/drivers/media/pci/ivtv/ivtv-vbi.c b/drivers/media/pci/ivtv/ivtv-vbi.c
index 293db80..3c156bc 100644 (file)
--- a/drivers/media/pci/ivtv/ivtv-vbi.c
+++ b/drivers/media/pci/ivtv/ivtv-vbi.c
@@ -224,7 +224,7 @@ static void copy_vbi_data(struct ivtv *itv, int lines, u32 pts_stamp)
                   (the max size of the VBI data is 36 * 43 + 4 bytes).
                   So in this case we use the magic number 'ITV0'. */
                memcpy(dst + sd, "ITV0", 4);
-               memcpy(dst + sd + 4, dst + sd + 12, line * 43);
+               memmove(dst + sd + 4, dst + sd + 12, line * 43);
                size = 4 + ((43 * line + 3) & ~3);
        } else {
                memcpy(dst + sd, "itv0", 4);
@@ -532,7 +532,7 @@ void ivtv_vbi_work_handler(struct ivtv *itv)
                while (vi->cc_payload_idx) {
                        cc = vi->cc_payload[0];
 
-                       memcpy(vi->cc_payload, vi->cc_payload + 1,
+                       memmove(vi->cc_payload, vi->cc_payload + 1,
                                        sizeof(vi->cc_payload) - sizeof(vi->cc_payload[0]));
                        vi->cc_payload_idx--;
                        if (vi->cc_payload_idx && cc.odd[0] == 0x80 && cc.odd[1] == 0x80)