Messages in this thread | | | Date | Fri, 30 Jun 2017 15:24:39 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 0/1] expand_downwards: don't require the gap if !vm_prev |
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On Wed 28-06-17 16:26:33, Linus Torvalds wrote: [...] > In fact, I'd even be quite open to adding a kernel warning about badly > behaved binaries that grow their stack by a big amount in one go. Not > only is it bad taste (and we really should encourage compilers to do > probing every page when growing the stack), but it migth be a sign of > an attempted attack.
FWIW our gcc guys shown an interest in having something to tell the kernel how much the stack can grow at once. They want it for testing of the new stack probing alloca implementation. I have something preliminary with /proc/<pid>/stack_expand_limit for the internal testing purpose but maybe there will be more interest for this. I didn't plan to post it public because it basically duplicates the stack_gap but it is also true that it can help some applications which won't use the proposed __save_alloca (or whatever it will be) without increasing stack_gap too much.
What do you think? -- Michal Hocko SUSE Labs
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