From 7cd4ce2e466f56ae92930adbded675a4e326a59e Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 29 Apr 2019 11:28:00 -0400 Subject: rseq/selftests: aarch64 code signature: handle big-endian environment 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 Acked-by: Will Deacon CC: Peter Zijlstra CC: Thomas Gleixner CC: Joel Fernandes CC: Catalin Marinas CC: Dave Watson CC: Will Deacon CC: Shuah Khan CC: Andi Kleen CC: linux-kselftest@vger.kernel.org CC: "H . Peter Anvin" CC: Chris Lameter CC: Russell King CC: Michael Kerrisk CC: "Paul E . McKenney" CC: Paul Turner CC: Boqun Feng CC: Josh Triplett CC: Steven Rostedt CC: Ben Maurer CC: linux-api@vger.kernel.org CC: Andy Lutomirski CC: Andrew Morton CC: Linus Torvalds Signed-off-by: Shuah Khan --- tools/testing/selftests/rseq/rseq-arm64.h | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'tools/testing') 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 */ -#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. */ +#else +#define RSEQ_SIG_DATA RSEQ_SIG_CODE +#endif + +#define RSEQ_SIG RSEQ_SIG_DATA #define rseq_smp_mb() __asm__ __volatile__ ("dmb ish" ::: "memory") #define rseq_smp_rmb() __asm__ __volatile__ ("dmb ishld" ::: "memory") @@ -121,7 +134,7 @@ do { \ #define RSEQ_ASM_DEFINE_ABORT(label, abort_label) \ " b 222f\n" \ - " .inst " __rseq_str(RSEQ_SIG) "\n" \ + " .inst " __rseq_str(RSEQ_SIG_CODE) "\n" \ __rseq_str(label) ":\n" \ " b %l[" __rseq_str(abort_label) "]\n" \ "222:\n" -- cgit v1.2.3-59-g8ed1b