On Fri, 2015-09-11 at 15:45 +0100, Julien Grall wrote: > On 11/09/15 15:29, Ian Campbell wrote: > > On Fri, 2015-09-11 at 15:16 +0100, Julien Grall wrote: > > > When Xen is copyin data to/from the guest it will check if the kernel > > > > "copying" > > > > > has the right to do the access. If not, the hypercall will return an > > > error. > > > > > > After the commit a5e090acbf545c0a3b04080f8a488b17ec41fe02 "ARM: > > > software-based priviledged-no-access support", the kernel can't > > > access > > > > "privileged" > > > > > anymore the user space by default. This will result to fail on every > > > > "any more" (or "any longer") > > > > > hypercall made by the userspace (i.e via privcmd). > > > > > > We have to enable the userspace access and then restore the correct > > > permission everytime the privmcd is used to made an hypercall. > > > > "every time" and "privcmd" > > > > > HYPERCALL1(tmem_op); > > > HYPERCALL2(multicall); > > > > > > -ENTRY(privcmd_call) > > > +ENTRY(__privcmd_call) > > > > arch/arm/include/asm/assembler.h seems to contain uaccess_* macros > > which > > could be used right here directly I think? That would be preferable to > > wrapping I think. > > Looking to the uaccess_save macro:
I was thinking more about uaccess_enable/disable. Ian. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
