The generic entry syscall_trace_enter() use the input syscall
work flag and syscall number.

In preparation for moving arm64 over to the generic entry code, refactor
syscall_trace_enter() to also pass syscall number and thread flags,
by using syscall_get_nr() helper.

No functional changes.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/arm64/include/asm/syscall.h |  2 +-
 arch/arm64/kernel/ptrace.c       | 20 ++++++++++++++------
 arch/arm64/kernel/syscall.c      |  2 +-
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index ab8e14b96f68..6b71d335c224 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -85,7 +85,7 @@ static inline int syscall_get_arch(struct task_struct *task)
 	return AUDIT_ARCH_AARCH64;
 }
 
-int syscall_trace_enter(struct pt_regs *regs);
+int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags);
 void syscall_trace_exit(struct pt_regs *regs);
 
 #endif	/* __ASM_SYSCALL_H */
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index d0d801a4094a..48bb813e0ef6 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -2353,10 +2353,8 @@ static void report_syscall_exit(struct pt_regs *regs)
 	}
 }
 
-int syscall_trace_enter(struct pt_regs *regs)
+int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags)
 {
-	unsigned long flags = read_thread_flags();
-
 	if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
 		report_syscall_enter(regs);
 		if (flags & _TIF_SYSCALL_EMU)
@@ -2367,10 +2365,20 @@ int syscall_trace_enter(struct pt_regs *regs)
 	if (secure_computing() == -1)
 		return NO_SYSCALL;
 
-	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-		trace_sys_enter(regs, regs->syscallno);
+	/* Either of the above might have changed the syscall number */
+	syscall = syscall_get_nr(current, regs);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) {
+		trace_sys_enter(regs, syscall);
+
+		/*
+		 * Probes or BPF hooks in the tracepoint may have changed the
+		 * system call number as well.
+		 */
+		 syscall = syscall_get_nr(current, regs);
+	}
 
-	audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
+	audit_syscall_entry(syscall, regs->orig_x0, regs->regs[1],
 			    regs->regs[2], regs->regs[3]);
 
 	return regs->syscallno;
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index c442fcec6b9e..eb328ee1423c 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -124,7 +124,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 		 */
 		if (scno == NO_SYSCALL)
 			syscall_set_return_value(current, regs, -ENOSYS, 0);
-		scno = syscall_trace_enter(regs);
+		scno = syscall_trace_enter(regs, regs->syscallno, flags);
 		if (scno == NO_SYSCALL)
 			goto trace_exit;
 	}
-- 
2.34.1