entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume()

Invoke rseq_handle_notify_resume() from tracehook_notify_resume() now
that the two function are always called back-to-back by architectures
that have rseq.  The rseq helper is stubbed out for architectures that
don't support rseq, i.e. this is a nop across the board.

Note, tracehook_notify_resume() is horribly named and arguably does not
belong in tracehook.h as literally every line of code in it has nothing
to do with tracing.  But, that's been true since commit a42c6ded827d
("move key_repace_session_keyring() into tracehook_notify_resume()")
first usurped tracehook_notify_resume() back in 2012.  Punt cleaning that
mess up to future patches.

No functional change intended.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210901203030.1292304-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index d0a800b..a41e27a 100644 (file)
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -628,7 +628,6 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
                                uprobe_notify_resume(regs);
                        } else {
                                tracehook_notify_resume(regs);
-                               rseq_handle_notify_resume(NULL, regs);
                        }
                }
                local_irq_disable();

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 9fe70b1..c287b94 100644 (file)
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -940,10 +940,8 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags)
                        if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
                                do_signal(regs);
 
-                       if (thread_flags & _TIF_NOTIFY_RESUME) {
+                       if (thread_flags & _TIF_NOTIFY_RESUME)
                                tracehook_notify_resume(regs);
-                               rseq_handle_notify_resume(NULL, regs);
-                       }
 
                        if (thread_flags & _TIF_FOREIGN_FPSTATE)
                                fpsimd_restore_current_state();

diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
index 312f046..bc4238b 100644 (file)
--- a/arch/csky/kernel/signal.c
+++ b/arch/csky/kernel/signal.c
@@ -260,8 +260,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
        if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
                do_signal(regs);
 
-       if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+       if (thread_info_flags & _TIF_NOTIFY_RESUME)
                tracehook_notify_resume(regs);
-               rseq_handle_notify_resume(NULL, regs);
-       }
 }

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index f1e9851..c9b2a75 100644 (file)
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -906,10 +906,8 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
        if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
                do_signal(regs);
 
-       if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+       if (thread_info_flags & _TIF_NOTIFY_RESUME)
                tracehook_notify_resume(regs);
-               rseq_handle_notify_resume(NULL, regs);
-       }
 
        user_enter();
 }

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index e600764..b93b87d 100644 (file)
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -293,10 +293,8 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
                do_signal(current);
        }
 
-       if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+       if (thread_info_flags & _TIF_NOTIFY_RESUME)
                tracehook_notify_resume(regs);
-               rseq_handle_notify_resume(NULL, regs);
-       }
 }
 
 static unsigned long get_tm_stackpointer(struct task_struct *tsk)

diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 3e80c4b..2564b74 100644 (file)
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -197,6 +197,8 @@ static inline void tracehook_notify_resume(struct pt_regs *regs)
 
        mem_cgroup_handle_over_high();
        blkcg_maybe_throttle_current();
+
+       rseq_handle_notify_resume(NULL, regs);
 }
 
 /*

diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index bf16395..d5a61d5 100644 (file)
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -171,10 +171,8 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
                if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
                        handle_signal_work(regs, ti_work);
 
-               if (ti_work & _TIF_NOTIFY_RESUME) {
+               if (ti_work & _TIF_NOTIFY_RESUME)
                        tracehook_notify_resume(regs);
-                       rseq_handle_notify_resume(NULL, regs);
-               }
 
                /* Architecture specific TIF work */
                arch_exit_to_user_mode_work(regs, ti_work);

diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
index 049fd06..49972ee 100644 (file)
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/kvm.c
@@ -19,10 +19,8 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
                if (ti_work & _TIF_NEED_RESCHED)
                        schedule();
 
-               if (ti_work & _TIF_NOTIFY_RESUME) {
+               if (ti_work & _TIF_NOTIFY_RESUME)
                        tracehook_notify_resume(NULL);
-                       rseq_handle_notify_resume(NULL, NULL);
-               }
 
                ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
                if (ret)