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 <mathieu.desnoyers@xxxxxxxxxxxx> > CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > CC: Joel Fernandes <joelaf@xxxxxxxxxx> > CC: Catalin Marinas <catalin.marinas@xxxxxxx> > CC: Dave Watson <davejwatson@xxxxxx> > CC: Will Deacon <will.deacon@xxxxxxx> > CC: Shuah Khan <shuah@xxxxxxxxxx> > CC: Andi Kleen <andi@xxxxxxxxxxxxxx> > CC: linux-kselftest@xxxxxxxxxxxxxxx > CC: "H . Peter Anvin" <hpa@xxxxxxxxx> > CC: Chris Lameter <cl@xxxxxxxxx> > CC: Russell King <linux@xxxxxxxxxxxxxxxx> > CC: Michael Kerrisk <mtk.manpages@xxxxxxxxx> > CC: "Paul E . McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> > CC: Paul Turner <pjt@xxxxxxxxxx> > CC: Boqun Feng <boqun.feng@xxxxxxxxx> > CC: Josh Triplett <josh@xxxxxxxxxxxxxxxx> > CC: Steven Rostedt <rostedt@xxxxxxxxxxx> > CC: Ben Maurer <bmaurer@xxxxxx> > CC: linux-api@xxxxxxxxxxxxxxx > CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > --- > 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 <will.deacon@xxxxxxx> > */ > > -#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 <will.deacon@xxxxxxx> Will
