[PATCH v1 1/4] syscalls: Restore address limit after a syscall

Russell King - ARM Linux
2017-03-08T21:58:15Z

On Wed, Mar 08, 2017 at 01:38:41PM -0800, Thomas Garnier wrote:
> This patch prevents a syscall to modify the address limit of the
> caller. The address limit is kept by the syscall wrapper and restored
> just after the syscall ends.

I would much rather architectures were given the opportunity to code up
checks like this efficiently (iow, inline in the exit path assembly),
rather than having to unconditionally call an additional function on
every syscall, with its register saving overheads.

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