On Mon, Jan 20, 2014 at 10:01:37AM +0800, Gu Zheng wrote: > Hi Dan, > Variable length array(vla) is allowed in ISO C99, and as an extension GCC > accepts it in C89 mode. > http://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Variable-Length.html > On my box, gcc does not give any warning to this, and it works very well. > So I can not understand why Sparse gave this warning. Or this usage(vla) > is forbidden in kernel source? If it is true, we must fix it. But, AFAIK, > there are not these strict provisions. >
The kernel has a 2 PAGE_SIZE stack so we need to make sure that orphan_blocks is very small. If any individual function uses over 1K stack then it's considered a bug unless the call tree is carefully audited. The stack size limit has security implications so orphan_blocks has to be something which is easy to audit. regards, dan carpenter _______________________________________________ kbuild mailing list kbuild@lists.01.org https://lists.01.org/mailman/listinfo/kbuild
