Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH] m68k: Implement "current_stack_pointer" | Date | Thu, 24 Feb 2022 09:54:04 +0000 |
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From: Geert Uytterhoeven <geert@linux-m68k.org> > Sent: 24 February 2022 09:17 > > On Thu, Feb 24, 2022 at 10:12 AM David Laight <David.Laight@aculab.com> wrote: > > From: Geert Uytterhoeven > > > Sent: 24 February 2022 08:59 > > ... > > > > +register unsigned long current_stack_pointer __asm__("sp"); > > > > > > I don't know what HARDENED_USERCOPY does, so I don't know if you need > > > "usp" (see rdusp()) or "sp"? > > > > HARDENED_USERCOPY significantly slows down some systems calls > > (especially things like sendmsg()) by trying to run-time verify > > that the kernel buffer doesn't overrun a stack frame or kmalloc()ed > > Kernel stack frame of user stack frame?
Kernel, the kernel doesn't care if the user stack gets trashed.
David
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