Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 25 Feb 2003 15:46:46 -0800 | Subject | Invalid compilation without -fno-strict-aliasing | From | Jean Tourrilhes <> |
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Hi,
It looks like a compiler bug to me... Some users have complained that when the following code is compiled without the -fno-strict-aliasing, the order of the write and memcpy is inverted (which mean a bogus len is mem-copied into the stream). Code (from linux/include/net/iw_handler.h) : -------------------------------------------- static inline char * iwe_stream_add_event(char * stream, /* Stream of events */ char * ends, /* End of stream */ struct iw_event *iwe, /* Payload */ int event_len) /* Real size of payload */ { /* Check if it's possible */ if((stream + event_len) < ends) { iwe->len = event_len; memcpy(stream, (char *) iwe, event_len); stream += event_len; } return stream; } -------------------------------------------- IMHO, the compiler should have enough context to know that the reordering is dangerous. Any suggestion to make this simple code more bullet proof is welcomed.
Have fun...
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