于 2012年11月29日 21:41, Alan Cox 写道: > On Thu, 29 Nov 2012 13:07:28 +0800 > Chen Gang <gang.c...@asianux.com> wrote: > >> Hello Greg Kroah-Hartman: >> >> for MAX_ASYNC_BUFFER_SIZE: >> it is defined as 4096; >> but for the max buffer size which it processes, is 65535. >> so suggest to #define MAX_ASYNC_BUFFER_SIZE 0x10000 (better than 0xffff) > > I don't see the need to change this. Possibly some of the old synclink > drivers need to check more carefully for overflows if configured for very > large frame sizes ? >
I am just through code review (so it is only a suggestion), I will try to perform test. also welcome another members to help testing. this issue has effect with 4 synclink drivers (most of source code are the same). drivers/char/pcmcia/synclink_cs.c:213: char flag_buf[MAX_ASYNC_BUFFER_SIZE]; drivers/tty/synclink_gt.c:320: char flag_buf[MAX_ASYNC_BUFFER_SIZE]; drivers/tty/synclink.c:294: char flag_buf[MAX_ASYNC_BUFFER_SIZE]; drivers/tty/synclinkmp.c:265: char flag_buf[MAX_ASYNC_BUFFER_SIZE]; for the char_buf, has already useless (can be removed) drivers/tty/synclink_gt.c:321: char char_buf[MAX_ASYNC_BUFFER_SIZE]; drivers/tty/synclink.c:295: char char_buf[MAX_ASYNC_BUFFER_SIZE]; drivers/tty/synclinkmp.c:266: char char_buf[MAX_ASYNC_BUFFER_SIZE]; >> >> --------------------------------------------------------------------------------- >> Step 3: >> >> one sample in drivers/tty/n_gsm.c (same for another implementation) >> >> receive_buf is a function ptr which may be gsmld_receive_buf at line 2819. >> it does not check the length of count whether larger than >> MAX_ASYNC_BUFFER_SIZE. >> if count is larger than MAX_ASYNC_BUFFER_SIZE, will cause issue. > > Why should it - MAX_ASYNC_BUFFER_SIZE is an internal detail of the > synclink drivers. > > Alan > > no, not need. (excuse me, my English is not quite well, maybe you misunderstand what I said) at least, currently: the caller should be sure that the buffer length is enough (it seems not, I need test it). the internal has no duty to check it. -- Chen Gang Asianux Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/