On Wed, Apr 24, 2019 at 11:25:00AM -0400, Mathieu Desnoyers wrote: > Handle compiling with -mbig-endian on aarch64, which generates binaries > with mixed code vs data endianness (little endian code, big endian > data). > > Else mismatch between code endianness for the generated signatures and > data endianness for the RSEQ_SIG parameter passed to the rseq > registration will trigger application segmentation faults when the > kernel try to abort rseq critical sections. > > Signed-off-by: Mathieu Desnoyers <[email protected]> > CC: Peter Zijlstra <[email protected]> > CC: Thomas Gleixner <[email protected]> > CC: Joel Fernandes <[email protected]> > CC: Catalin Marinas <[email protected]> > CC: Dave Watson <[email protected]> > CC: Will Deacon <[email protected]> > CC: Shuah Khan <[email protected]> > CC: Andi Kleen <[email protected]> > CC: [email protected] > CC: "H . Peter Anvin" <[email protected]> > CC: Chris Lameter <[email protected]> > CC: Russell King <[email protected]> > CC: Michael Kerrisk <[email protected]> > CC: "Paul E . McKenney" <[email protected]> > CC: Paul Turner <[email protected]> > CC: Boqun Feng <[email protected]> > CC: Josh Triplett <[email protected]> > CC: Steven Rostedt <[email protected]> > CC: Ben Maurer <[email protected]> > CC: [email protected] > CC: Andy Lutomirski <[email protected]> > CC: Andrew Morton <[email protected]> > CC: Linus Torvalds <[email protected]> > --- > tools/testing/selftests/rseq/rseq-arm64.h | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/rseq/rseq-arm64.h > b/tools/testing/selftests/rseq/rseq-arm64.h > index b41a2a48e965..200dae9e4208 100644 > --- a/tools/testing/selftests/rseq/rseq-arm64.h > +++ b/tools/testing/selftests/rseq/rseq-arm64.h > @@ -6,7 +6,20 @@ > * (C) Copyright 2018 - Will Deacon <[email protected]> > */ > > -#define RSEQ_SIG 0xd428bc00 /* BRK #0x45E0 */ > +/* > + * aarch64 -mbig-endian generates mixed endianness code vs data: > + * little-endian code and big-endian data. Ensure the RSEQ_SIG signature > + * matches code endianness. > + */ > +#define RSEQ_SIG_CODE 0xd428bc00 /* BRK #0x45E0. */ > + > +#ifdef __AARCH64EB__ > +#define RSEQ_SIG_DATA 0x00bc28d4 /* BRK #0x45E0. */
It would be neater to implement swab32 and use that with RSEQ_SIG_CODE, but either way: Acked-by: Will Deacon <[email protected]> Will
