From: Philippe Gerum <rpm@xenomai.org>
Date: Fri, 29 Dec 2017 04:20:08 +0000 (-0800)
Subject: ARM64: ipipe: intercept syscalls
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0990fba891d3cacb93bffced6f6b6de27e204acf;p=platform%2Fkernel%2Flinux-exynos.git

ARM64: ipipe: intercept syscalls
---

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index a0baa9af5487..90e64fd5e50b 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -53,3 +53,5 @@
 #endif
 
 #define NR_syscalls (__NR_syscalls)
+
+#define __ARM_ipipe_syscall	0x10000000
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index b8d001d430cd..ea207e98060c 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -789,7 +789,7 @@ el0_sys:
 	mov	x0, x25
 	mov	x1, sp
 	bl	do_sysinstr
-	b	ret_to_user
+	b	ret_from_exception
 el0_dbg:
 	/*
 	 * Debug exception handling
@@ -864,9 +864,7 @@ ret_fast_syscall_trace:
 work_pending:
 	mov	x0, sp				// 'regs'
 	bl	do_notify_resume
-#ifdef CONFIG_TRACE_IRQFLAGS
-	bl	trace_hardirqs_on		// enabled while in userspace
-#endif
+	TRACE_IRQSON
 	ldr	x1, [tsk, #TSK_TI_FLAGS]	// re-check for single-step
 	b	finish_ret_to_user
 /*
@@ -894,6 +892,57 @@ el0_svc:
 el0_svc_naked:					// compat entry point
 	stp	x0, xscno, [sp, #S_ORIG_X0]	// save the original x0 and syscall number
 	enable_dbg_and_irq
+
+#ifdef CONFIG_IPIPE
+	ldr     x16, [tsk, #TSK_TI_IPIPE]
+	tst     wscno, __ARM_ipipe_syscall
+	b.eq    fastcall_bypass
+	tst     x16, #_TIP_HEAD
+	b.eq    fastcall_bypass
+	mov     x0, sp
+	bl      ipipe_fastcall_hook
+	cmp     w0, #0
+	b.lt    no_fastcall
+	ldr     x16, [tsk, #TSK_TI_IPIPE]
+	tst     x16, #_TIP_HEAD
+	b.ne    fastcall_exit
+	bl      __ipipe_root_sync
+fastcall_tail:
+	ldr     x0, [sp, #S_X0]
+	b       ret_fast_syscall
+fastcall_exit:
+	tst     x16, #_TIP_MAYDAY
+	b.eq    fastcall_notail
+	mov     x0, sp
+	bl      __ipipe_call_mayday
+fastcall_notail:
+	ldr     x0, [sp, #S_X0]
+	disable_irq
+	ldr     x1, [tsk, #TSK_TI_FLAGS]
+	enable_step_tsk x1, x2
+	kernel_exit 0
+no_fastcall:
+	ldr     x16, [tsk, #TSK_TI_IPIPE]
+fastcall_bypass:
+	tst     x16, #_TIP_NOTIFY
+	b.ne    syscall_pipeline
+	tst     wscno, __ARM_ipipe_syscall
+	b.eq    regular_syscall
+syscall_pipeline:
+	mov     x0, sp
+	bl      __ipipe_notify_syscall
+	ldr     x16, [tsk, #TSK_TI_IPIPE]
+	tst     x16, #_TIP_HEAD
+	b.ne    fastcall_notail
+	cmp     w0, #0
+	b.ne    fastcall_tail
+regular_syscall:
+	ldp     x0, x1, [sp, #S_X0]
+	ldp     x2, x3, [sp, #S_X2]
+	ldp     x4, x5, [sp, #S_X4]
+	ldp     x6, x7, [sp, #S_X6]
+#endif /* CONFIG_IPIPE */
+
 	ct_user_exit 1
 
 	ldr	x16, [tsk, #TSK_TI_FLAGS]	// check for syscall hooks