Re: [RFC, PATCHv2 29/29] mm, x86: introduce RLIMIT_VADDR
From: Kirill A. Shutemov <hidden>
Date: 2017-01-05 20:12:06
Also in:
linux-arch, linux-mm, lkml
On Thu, Jan 05, 2017 at 11:39:16AM -0800, Dave Hansen wrote:
On 01/05/2017 11:29 AM, Kirill A. Shutemov wrote:quoted
On Thu, Jan 05, 2017 at 11:13:57AM -0800, Dave Hansen wrote:quoted
On 12/26/2016 05:54 PM, Kirill A. Shutemov wrote:quoted
MM would use min(RLIMIT_VADDR, TASK_SIZE) as upper limit of virtual address available to map by userspace.What happens to existing mappings above the limit when this upper limit is dropped?Nothing: we only prevent creating new mappings. All existing are not affected. The semantics here the same as with other resource limits.quoted
Similarly, why do we do with an application running with something incompatible with the larger address space that tries to raise the limit? Say, legacy MPX.It has to know what it does. Yes, it can change limit to the point where application is unusable. But you can to the same with other limits.I'm not sure I'm comfortable with this. Do other rlimit changes cause silent data corruption? I'm pretty sure doing this to MPX would.
Maybe it's too ugly, but MPX can set rlim_max to rlim_cur on enabling. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>