arm64: rseq: Implement backend rseq calls and select HAVE_RSEQ

Implement calls to rseq_signal_deliver, rseq_handle_notify_resume
and rseq_syscall so that we can select HAVE_RSEQ on arm64.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2e7609e..f4157d4 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -138,6 +138,7 @@ config ARM64
        select HAVE_PERF_USER_STACK_DUMP
        select HAVE_REGS_AND_STACK_ACCESS_API
        select HAVE_RCU_TABLE_FREE
+       select HAVE_RSEQ
        select HAVE_STACKPROTECTOR
        select HAVE_SYSCALL_TRACEPOINTS
        select HAVE_KPROBES

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index a0baa9a..e0d0f5b 100644 (file)
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -43,7 +43,7 @@
 #define __ARM_NR_compat_cacheflush     (__ARM_NR_COMPAT_BASE+2)
 #define __ARM_NR_compat_set_tls                (__ARM_NR_COMPAT_BASE+5)
 
-#define __NR_compat_syscalls           398
+#define __NR_compat_syscalls           399
 #endif
 
 #define __ARCH_WANT_SYS_CLONE

diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index ef29216..0fdc7ef 100644 (file)
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -817,6 +817,8 @@ __SYSCALL(__NR_pkey_alloc, sys_pkey_alloc)
 __SYSCALL(__NR_pkey_free, sys_pkey_free)
 #define __NR_statx 397
 __SYSCALL(__NR_statx, sys_statx)
+#define __NR_rseq 398
+__SYSCALL(__NR_rseq, sys_rseq)
 
 /*
  * Please add new compat syscalls above this comment and update

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 28ad879..1eda9e1 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -904,6 +904,7 @@ ENDPROC(el0_error)
 ret_fast_syscall:
        disable_daif
        str     x0, [sp, #S_X0]                 // returned x0
+#ifndef CONFIG_DEBUG_RSEQ
        ldr     x1, [tsk, #TSK_TI_FLAGS]        // re-check for syscall tracing
        and     x2, x1, #_TIF_SYSCALL_WORK
        cbnz    x2, ret_fast_syscall_trace
@@ -911,6 +912,7 @@ ret_fast_syscall:
        cbnz    x2, work_pending
        enable_step_tsk x1, x2
        kernel_exit 0
+#endif
 ret_fast_syscall_trace:
        enable_daif
        b       __sys_trace_return_skipped      // we already saved x0

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 42ff28a..489db36 100644 (file)
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1658,6 +1658,8 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 
        if (test_thread_flag(TIF_SYSCALL_TRACE))
                tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
+
+       rseq_syscall(regs);
 }
 
 /*

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 511af13..e3b1d1b 100644 (file)
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -802,6 +802,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
        int usig = ksig->sig;
        int ret;
 
+       rseq_signal_deliver(ksig, regs);
+
        /*
         * Set up the stack frame
         */
@@ -940,6 +942,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
                        if (thread_flags & _TIF_NOTIFY_RESUME) {
                                clear_thread_flag(TIF_NOTIFY_RESUME);
                                tracehook_notify_resume(regs);
+                               rseq_handle_notify_resume(NULL, regs);
                        }
 
                        if (thread_flags & _TIF_FOREIGN_FPSTATE)