Wire up the rseq system call on 32-bit ARM. This provides an ABI improving the speed of a user-space getcpu operation on ARM by skipping the getcpu system call on the fast path, as well as improving the speed of user-space operations on per-cpu data compared to using load-linked/store-conditional.
Signed-off-by: Mathieu Desnoyers <[email protected]> CC: Russell King <[email protected]> CC: Catalin Marinas <[email protected]> CC: Will Deacon <[email protected]> CC: Thomas Gleixner <[email protected]> CC: Paul Turner <[email protected]> CC: Andrew Hunter <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Andy Lutomirski <[email protected]> CC: Andi Kleen <[email protected]> CC: Dave Watson <[email protected]> CC: Chris Lameter <[email protected]> CC: Ingo Molnar <[email protected]> CC: Ben Maurer <[email protected]> CC: Steven Rostedt <[email protected]> CC: "Paul E. McKenney" <[email protected]> CC: Josh Triplett <[email protected]> CC: Linus Torvalds <[email protected]> CC: Andrew Morton <[email protected]> CC: Boqun Feng <[email protected]> CC: [email protected] --- arch/arm/include/uapi/asm/unistd.h | 1 + arch/arm/kernel/calls.S | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/arm/include/uapi/asm/unistd.h b/arch/arm/include/uapi/asm/unistd.h index 2cb9dc7..8f61c79 100644 --- a/arch/arm/include/uapi/asm/unistd.h +++ b/arch/arm/include/uapi/asm/unistd.h @@ -420,6 +420,7 @@ #define __NR_copy_file_range (__NR_SYSCALL_BASE+391) #define __NR_preadv2 (__NR_SYSCALL_BASE+392) #define __NR_pwritev2 (__NR_SYSCALL_BASE+393) +#define __NR_rseq (__NR_SYSCALL_BASE+394) /* * The following SWIs are ARM private. diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index 703fa0f..0865c04 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -403,6 +403,7 @@ CALL(sys_copy_file_range) CALL(sys_preadv2) CALL(sys_pwritev2) + CALL(sys_rseq) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted -- 2.1.4
