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From: shijie.huang@arm.com (Huang Shijie)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/9] arm64: entry: only restore the syscall registers once
Date: Mon, 30 May 2016 10:52:26 +0800	[thread overview]
Message-ID: <1464576750-25160-6-git-send-email-shijie.huang@arm.com> (raw)
In-Reply-To: <1464576750-25160-1-git-send-email-shijie.huang@arm.com>

There are two pachs which will restore the syscall registers (x0 - x7)
separately: the hardirq trace code and the context tracking code.

This patch makes the code to restore the syscall registers only once.

Signed-off-by: Huang Shijie <shijie.huang@arm.com>
---
 arch/arm64/kernel/entry.S | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 102fd8b..98d8dd1 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -46,12 +46,9 @@
  * Context tracking subsystem.  Used to instrument transitions
  * between user and kernel mode.
  */
-	.macro ct_user_exit, syscall = 0
+	.macro ct_user_exit
 #ifdef CONFIG_CONTEXT_TRACKING
 	bl	context_tracking_user_exit
-	.if \syscall == 1
-	restore_syscall_regs
-	.endif
 #endif
 	.endm
 
@@ -729,12 +726,12 @@ el0_svc:
 	uxtw	scno, w26			// syscall number in w8
 	mov	sc_nr, #__NR_syscalls
 el0_svc_naked:					// compat entry point
-#ifdef CONFIG_TRACE_IRQFLAGS
-	restore_syscall_regs
-#endif
 	stp	x19, scno, [sp, #S_ORIG_X0]	// save the original x0 and syscall number
 	enable_dbg_and_irq
-	ct_user_exit 1
+	ct_user_exit
+#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
+	restore_syscall_regs
+#endif
 
 	ldr	x16, [tsk, #TI_FLAGS]		// check for syscall hooks
 	tst	x16, #_TIF_SYSCALL_WORK
-- 
2.5.5

  parent reply	other threads:[~2016-05-30  2:52 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-30  2:52 [PATCH 0/9] arm64: add more accurate code for tracing the hardirq flags changes Huang Shijie
2016-05-30  2:52 ` [PATCH 1/9] arm64: entry: use the callee-saved registers to save some registers Huang Shijie
2016-05-30  2:52 ` [PATCH 2/9] arm64: entry: add a new macro to restore the registers for syscall Huang Shijie
2016-05-30  2:52 ` [PATCH 3/9] arm64: entry: record the hardirq changes on the entry/exit code Huang Shijie
2016-05-30  2:52 ` [PATCH 4/9] arm64: entry: remove the duplicated code for tracing the IRQ flags Huang Shijie
2016-05-30  2:52 ` Huang Shijie [this message]
2016-05-30  2:52 ` [PATCH 6/9] arm64: entry: adjust el1_sync so that a function can be called Huang Shijie
2016-05-30  2:52 ` [PATCH 7/9] arm64: entry: save the x0 back into the stack before disabling the interrupt Huang Shijie
2016-05-30  2:52 ` [PATCH 8/9] arm64: add the hardirq flags trace code for irq macros Huang Shijie
2016-05-30  2:52 ` [PATCH 9/9] arm64: entry: remove the duplicated hardirq flags trace code Huang Shijie

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