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From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, will.deacon@arm.com
Cc: catalin.marinas@arm.com, dave.martin@arm.com, hch@infradead.org,
	james.morse@arm.com, linux@dominikbrodowski.net,
	linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com,
	mark.rutland@arm.com, viro@zeniv.linux.org.uk
Subject: [PATCHv5 11/21] arm64: don't restore GPRs when context tracking
Date: Wed, 11 Jul 2018 14:56:46 +0100	[thread overview]
Message-ID: <20180711135656.20670-12-mark.rutland@arm.com> (raw)
In-Reply-To: <20180711135656.20670-1-mark.rutland@arm.com>

Now that syscalls are invoked with pt_regs, we no longer need to ensure
that the argument regsiters are live in the entry assembly, and it's
fine to not restore them after context_tracking_user_exit() has
corrupted them.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/entry.S | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 156c4e3fd1a4..c41b84d06644 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -41,19 +41,9 @@
  * 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
-	/*
-	 * Save/restore needed during syscalls.  Restore syscall arguments from
-	 * the values already saved on stack during kernel_entry.
-	 */
-	ldp	x0, x1, [sp]
-	ldp	x2, x3, [sp, #S_X2]
-	ldp	x4, x5, [sp, #S_X4]
-	ldp	x6, x7, [sp, #S_X6]
-	.endif
 #endif
 	.endm
 
-- 
2.11.0


WARNING: multiple messages have this Message-ID (diff)
From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv5 11/21] arm64: don't restore GPRs when context tracking
Date: Wed, 11 Jul 2018 14:56:46 +0100	[thread overview]
Message-ID: <20180711135656.20670-12-mark.rutland@arm.com> (raw)
In-Reply-To: <20180711135656.20670-1-mark.rutland@arm.com>

Now that syscalls are invoked with pt_regs, we no longer need to ensure
that the argument regsiters are live in the entry assembly, and it's
fine to not restore them after context_tracking_user_exit() has
corrupted them.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/entry.S | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 156c4e3fd1a4..c41b84d06644 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -41,19 +41,9 @@
  * 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
-	/*
-	 * Save/restore needed during syscalls.  Restore syscall arguments from
-	 * the values already saved on stack during kernel_entry.
-	 */
-	ldp	x0, x1, [sp]
-	ldp	x2, x3, [sp, #S_X2]
-	ldp	x4, x5, [sp, #S_X4]
-	ldp	x6, x7, [sp, #S_X6]
-	.endif
 #endif
 	.endm
 
-- 
2.11.0

  parent reply	other threads:[~2018-07-11 13:58 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-11 13:56 [PATCHv5 00/21] arm64: invoke syscalls with pt_regs Mark Rutland
2018-07-11 13:56 ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 01/21] arm64: consistently use unsigned long for thread flags Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 02/21] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> Mark Rutland
2018-07-11 13:56   ` [PATCHv5 02/21] arm64: move SCTLR_EL{1, 2} " Mark Rutland
2018-07-11 13:56 ` [PATCHv5 03/21] arm64: kill config_sctlr_el1() Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 04/21] arm64: kill change_cpacr() Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 05/21] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> Mark Rutland
2018-07-11 13:56   ` [PATCHv5 05/21] arm64: move sve_user_{enable, disable} " Mark Rutland
2018-07-11 13:56 ` [PATCHv5 06/21] arm64: remove sigreturn wrappers Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 07/21] arm64: introduce syscall_fn_t Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 08/21] arm64: convert raw syscall invocation to C Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 09/21] arm64: convert syscall trace logic " Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 10/21] arm64: convert native/compat syscall entry " Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` Mark Rutland [this message]
2018-07-11 13:56   ` [PATCHv5 11/21] arm64: don't restore GPRs when context tracking Mark Rutland
2018-07-11 13:56 ` [PATCHv5 12/21] arm64: don't reload GPRs after apply_ssbd Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 13/21] arm64: zero GPRs upon entry from EL0 Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 14/21] arm64: drop alignment from syscall tables Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 15/21] kernel: add ksys_personality() Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 16/21] kernel: add kcompat_sys_{f,}statfs64() Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 17/21] arm64: remove in-kernel call to sys_personality() Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 18/21] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 19/21] arm64: use SYSCALL_DEFINE6() for mmap Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 20/21] arm64: convert compat wrappers to C Mark Rutland
2018-07-11 13:56   ` Mark Rutland
2018-07-11 13:56 ` [PATCHv5 21/21] arm64: implement syscall wrappers Mark Rutland
2018-07-11 13:56   ` Mark Rutland

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