On 02/09/2020 17:48, Dave Martin wrote: > On Fri, Aug 28, 2020 at 02:16:02PM +0100, Boyan Karatotev wrote: >> Pointer Authentication (PAuth) is a security feature introduced in ARMv8.3. >> It introduces instructions to sign addresses and later check for potential >> corruption using a second modifier value and one of a set of keys. The >> signature, in the form of the Pointer Authentication Code (PAC), is stored >> in some of the top unused bits of the virtual address (e.g. [54: 49] if >> TBID0 is enabled and TnSZ is set to use a 48 bit VA space). A set of >> controls are present to enable/disable groups of instructions (which use >> certain keys) for compatibility with libraries that do not utilize the >> feature. PAuth is used to verify the integrity of return addresses on the >> stack with less memory than the stack canary. >> >> This patchset adds kselftests to verify the kernel's configuration of the >> feature and its runtime behaviour. There are 7 tests which verify that: >> * an authentication failure leads to a SIGSEGV >> * the data/instruction instruction groups are enabled >> * the generic instructions are enabled >> * all 5 keys are unique for a single thread >> * exec() changes all keys to new unique ones >> * context switching preserves the 4 data/instruction keys >> * context switching preserves the generic keys >> >> The tests have been verified to work on qemu without a working PAUTH >> Implementation and on ARM's FVP with a full or partial PAuth >> implementation. >> >> Note: This patchset is only verified for ARMv8.3 and there will be some >> changes required for ARMv8.6. More details can be found here [1]. Once >> ARMv8.6 PAuth is merged the first test in this series will required to be >> updated. > > Nit: is it worth running checkpatch over this series? > > Although this is not kernel code, there are a number of formatting > weirdnesses and surplus blank lines etc. that checkpatch would probably > warn about. > I ran it through checkpatch and it came out clean except for some MAINTAINERS warnings. I see that when I add --strict it does complain about multiple blank lines which I can fix for the next version. Are there any other flags I should be running checkpatch with? > [...] > > Cheers > ---Dave > -- Regards, Boyan
