[V3,05/13] x86/entry: Consolidate check_user_regs()

Message ID	20200716185424.442693273@linutronix.de (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=rfeS=A3=vger.kernel.org=kvm-owner@kernel.org> Message-Id: <20200716185424.442693273@linutronix.de> Date: Thu, 16 Jul 2020 20:22:13 +0200 From: Thomas Gleixner <tglx@linutronix.de> To: LKML <linux-kernel@vger.kernel.org> Cc: x86@kernel.org, linux-arch@vger.kernel.org, Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Mark Rutland <mark.rutland@arm.com>, Kees Cook <keescook@chromium.org>, Keno Fischer <keno@juliacomputing.com>, Paolo Bonzini <pbonzini@redhat.com>, kvm@vger.kernel.org Subject: [patch V3 05/13] x86/entry: Consolidate check_user_regs() References: <20200716182208.180916541@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Sender: kvm-owner@vger.kernel.org Precedence: bulk
Series	entry, x86, kvm: Generic entry/exit functionality for host and guest \| expand [V3,00/13] entry, x86, kvm: Generic entry/exit functionality for host and guest [V3,01/13] entry: Provide generic syscall entry functionality [V3,02/13] entry: Provide generic syscall exit function [V3,03/13] entry: Provide generic interrupt entry/exit code [V3,04/13] entry: Provide infrastructure for work before exiting to guest mode [V3,05/13] x86/entry: Consolidate check_user_regs() [V3,06/13] x86/entry: Consolidate 32/64 bit syscall entry [V3,07/13] x86/ptrace: Provide pt_regs helpers for entry/exit [V3,08/13] x86/entry: Use generic syscall entry function [V3,09/13] x86/entry: Use generic syscall exit functionality [V3,10/13] x86/entry: Cleanup idtentry_entry/exit_user [V3,11/13] x86/entry: Use generic interrupt entry/exit code [V3,12/13] x86/entry: Cleanup idtentry_enter/exit [V3,13/13] x86/kvm: Use generic exit to guest work function

Message ID

20200716185424.442693273@linutronix.de (mailing list archive)

State

New, archived

Headers

Message-Id: <20200716185424.442693273@linutronix.de>
Date: Thu, 16 Jul 2020 20:22:13 +0200
From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, linux-arch@vger.kernel.org,
        Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
        Mark Rutland <mark.rutland@arm.com>,
        Kees Cook <keescook@chromium.org>,
        Keno Fischer <keno@juliacomputing.com>,
        Paolo Bonzini <pbonzini@redhat.com>, kvm@vger.kernel.org
Subject: [patch V3 05/13] x86/entry: Consolidate check_user_regs()
References: <20200716182208.180916541@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-transfer-encoding: 8-bit
Sender: kvm-owner@vger.kernel.org
Precedence: bulk

Series

entry, x86, kvm: Generic entry/exit functionality for host and guest | expand

Commit Message

Thomas Gleixner July 16, 2020, 6:22 p.m. UTC

The user register sanity check is sprinkled all over the place. Move it
into enter_from_user_mode().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/entry/common.c |   24 +++++++++---------------
 1 file changed, 9 insertions(+), 15 deletions(-)

Comments

Kees Cook July 16, 2020, 8:56 p.m. UTC | #1

On Thu, Jul 16, 2020 at 08:22:13PM +0200, Thomas Gleixner wrote:
> The user register sanity check is sprinkled all over the place. Move it
> into enter_from_user_mode().
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Reviewed-by: Kees Cook <keescook@chromium.org>

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -82,10 +82,11 @@  static noinstr void check_user_regs(stru
  * 2) Invoke context tracking if enabled to reactivate RCU
  * 3) Trace interrupts off state
  */
-static noinstr void enter_from_user_mode(void)
+static noinstr void enter_from_user_mode(struct pt_regs *regs)
 {
 	enum ctx_state state = ct_state();
 
+	check_user_regs(regs);
 	lockdep_hardirqs_off(CALLER_ADDR0);
 	user_exit_irqoff();
 
@@ -95,8 +96,9 @@  static noinstr void enter_from_user_mode
 	instrumentation_end();
 }
 #else
-static __always_inline void enter_from_user_mode(void)
+static __always_inline void enter_from_user_mode(struct pt_regs *regs)
 {
+	check_user_regs(regs);
 	lockdep_hardirqs_off(CALLER_ADDR0);
 	instrumentation_begin();
 	trace_hardirqs_off_finish();
@@ -369,9 +371,7 @@  static void __syscall_return_slowpath(st
 {
 	struct thread_info *ti;
 
-	check_user_regs(regs);
-
-	enter_from_user_mode();
+	enter_from_user_mode(regs);
 	instrumentation_begin();
 
 	local_irq_enable();
@@ -434,9 +434,7 @@  static void do_syscall_32_irqs_on(struct
 /* Handles int $0x80 */
 __visible noinstr void do_int80_syscall_32(struct pt_regs *regs)
 {
-	check_user_regs(regs);
-
-	enter_from_user_mode();
+	enter_from_user_mode(regs);
 	instrumentation_begin();
 
 	local_irq_enable();
@@ -487,8 +485,6 @@  static bool __do_fast_syscall_32(struct
 					vdso_image_32.sym_int80_landing_pad;
 	bool success;
 
-	check_user_regs(regs);
-
 	/*
 	 * SYSENTER loses EIP, and even SYSCALL32 needs us to skip forward
 	 * so that 'regs->ip -= 2' lands back on an int $0x80 instruction.
@@ -496,7 +492,7 @@  static bool __do_fast_syscall_32(struct
 	 */
 	regs->ip = landing_pad;
 
-	enter_from_user_mode();
+	enter_from_user_mode(regs);
 	instrumentation_begin();
 
 	local_irq_enable();
@@ -599,8 +595,7 @@  idtentry_state_t noinstr idtentry_enter(
 	};
 
 	if (user_mode(regs)) {
-		check_user_regs(regs);
-		enter_from_user_mode();
+		enter_from_user_mode(regs);
 		return ret;
 	}
 
@@ -733,8 +728,7 @@  void noinstr idtentry_exit(struct pt_reg
  */
 void noinstr idtentry_enter_user(struct pt_regs *regs)
 {
-	check_user_regs(regs);
-	enter_from_user_mode();
+	enter_from_user_mode(regs);
 }
 
 /**

[V3,05/13] x86/entry: Consolidate check_user_regs()

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