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From: Greg P. <gp...@us...> - 2005-02-15 02:07:32
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Jeremy Fitzhardinge writes: > Come to think of it, if there are only a small number of superpages, > then just mprotecting them on entry/exit to generated code would be > pretty cheap (since you'd only have to do the Valgrind one(s), which is > at most one mprotect per superblock, and fewer if they're contiguous). > It might get expensive if there are lots of syscalls, but it would save > on extra code per memory reference... You mean mprotect the superblock itself when moving in and out of Valgrind? That won't work because part of the generated code needs to read and write things like the shadow memory and the ThreadState. The generated simulation can't touch them, but the generated instrumentation and scaffolding must. -- Greg Parker gp...@us... |