On 10/23/2014 01:55 PM, Jakub Jelinek wrote: > On Thu, Oct 23, 2014 at 01:51:12PM +0400, Andrey Ryabinin wrote: >> IMO we don't need different versions of __asan_load* and >> __asan_load*_noabort, because >> -fno-sanitize-recover=kernel-address will never work with the linux kernel. >> >> I already said this before, and repeat this once again: >> There is few places in kernel where we validly touch poisoned memory, >> so we need to disable error reporting in runtime for such memory accesses. >> I use per-thread flag which is raised before the valid access to poisoned >> memory. >> This flag checked in __asan_report*() function. If it raised then we >> shouldn't print any error message, >> just silently exit from report. > > Can't you just use __attribute__((no_sanitize_address)) on the functions > that have such a code? Or you could use special macros for those accesses > (which could e.g. call function to read memory or write memory, implemented > in assembly or in __attribute__((no_sanitize_address)) function), or
Those are quite generic functions used from a lot of places. So we want to instrument them in general, but there are few call sites which use those functions for poisoned memory. > temporarily unpoison and poison again. > That's a bit tricky. State of shadow memory is unknown, so we would need to store shadow somewhere before unpoisoning to restore it later. > Jakub >
