Wed, Jun 03, 2009 at 01:54:30PM +0400, Eygene Ryabinkin wrote: > KTR's case seems to be wrong for PCPU_NAME_LEN larger than 24 bytes. > Just now we won't be able to reach this with the current definition > for PCPU_NAME_LEN, but some day (N - (PCPU_NAME_LEN + 7)/8) can > become negative and that's bad. And while I am here: definition for PCPU_NAME_LEN seems to be wrong. It is intended to fit ("CPU %d", cpuid) where cpuid <= MAXCPU. If this is correct, then (sys/sys/pcpu.h, line 57) 1. sizeof(__XSTRING(MAXCPU) + 1) is a typo: typeof(__XSTRING(...) + 1) is 'char *', so sizeof() will return the size of the pointer, not the size of the string contents. The proper expression should be 'sizeof(__XSTRING(MAXCPU)) + 1'. 2. one should not add one, but substract it: sizeof() accounts for the trailing '\0' and we have two sizeof's, so the size of one '\0' should be substracted -- this will give the maximal string buffer length for CPU with its number, no less, no more. Does the attached patch looks sane? -- Eygene _ ___ _.--. # \`.|\..----...-'` `-._.-'_.-'` # Remember that it is hard / ' ` , __.--' # to read the on-line manual )/' _/ \ `-_, / # while single-stepping the kernel. `-'" `"\_ ,_.-;_.-\_ ', fsc/as # _.-'_./ {_.' ; / # -- FreeBSD Developers handbook {_.-``-' {_/ #
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