virtio-console: avoid DMA from stack
put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com>
This commit is contained in:
parent
f889491380
commit
c4baad5029
|
@ -1136,6 +1136,8 @@ static int put_chars(u32 vtermno, const char *buf, int count)
|
||||||
{
|
{
|
||||||
struct port *port;
|
struct port *port;
|
||||||
struct scatterlist sg[1];
|
struct scatterlist sg[1];
|
||||||
|
void *data;
|
||||||
|
int ret;
|
||||||
|
|
||||||
if (unlikely(early_put_chars))
|
if (unlikely(early_put_chars))
|
||||||
return early_put_chars(vtermno, buf, count);
|
return early_put_chars(vtermno, buf, count);
|
||||||
|
@ -1144,8 +1146,14 @@ static int put_chars(u32 vtermno, const char *buf, int count)
|
||||||
if (!port)
|
if (!port)
|
||||||
return -EPIPE;
|
return -EPIPE;
|
||||||
|
|
||||||
sg_init_one(sg, buf, count);
|
data = kmemdup(buf, count, GFP_ATOMIC);
|
||||||
return __send_to_port(port, sg, 1, count, (void *)buf, false);
|
if (!data)
|
||||||
|
return -ENOMEM;
|
||||||
|
|
||||||
|
sg_init_one(sg, data, count);
|
||||||
|
ret = __send_to_port(port, sg, 1, count, data, false);
|
||||||
|
kfree(data);
|
||||||
|
return ret;
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
|
Loading…
Reference in a new issue