All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peng Liang <liangpeng10@huawei.com>
To: <kvmarm@lists.cs.columbia.edu>
Cc: zhang.zhanghailiang@huawei.com, kvm@vger.kernel.org,
	maz@kernel.org, will@kernel.org
Subject: [RFC v2 4/7] kvm: arm64: introduce check_user
Date: Thu, 17 Sep 2020 20:00:58 +0800	[thread overview]
Message-ID: <20200917120101.3438389-5-liangpeng10@huawei.com> (raw)
In-Reply-To: <20200917120101.3438389-1-liangpeng10@huawei.com>

Currently, if we need to check the value of the register defined by user
space, we should check it in set_user.  However, some system registers
may use the same set_user (for example, almost all ID registers), which
make it difficult to validate the value defined by user space.

Introduce check_user to solve the problem.  And apply check_user before
set_user to make sure that the value of register is valid.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Peng Liang <liangpeng10@huawei.com>
---
 arch/arm64/kvm/sys_regs.c | 7 +++++++
 arch/arm64/kvm/sys_regs.h | 6 ++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2b0fa8d5ac62..86ebb8093c3c 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2684,6 +2684,7 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 {
 	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	int err;
 
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_set(reg->id, uaddr);
@@ -2699,6 +2700,12 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (sysreg_hidden_from_user(vcpu, r))
 		return -ENOENT;
 
+	if (r->check_user) {
+		err = (r->check_user)(vcpu, r, reg, uaddr);
+		if (err)
+			return err;
+	}
+
 	if (r->set_user)
 		return (r->set_user)(vcpu, r, reg, uaddr);
 
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index 5a6fc30f5989..9bce5e9a3490 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -53,6 +53,12 @@ struct sys_reg_desc {
 			const struct kvm_one_reg *reg, void __user *uaddr);
 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 			const struct kvm_one_reg *reg, void __user *uaddr);
+	/*
+	 * Check the value userspace passed.  It should return 0 on success and
+	 * otherwise on failure.
+	 */
+	int (*check_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+			  const struct kvm_one_reg *reg, void __user *uaddr);
 
 	/* Return mask of REG_* runtime visibility overrides */
 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
-- 
2.26.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Peng Liang <liangpeng10@huawei.com>
To: <kvmarm@lists.cs.columbia.edu>
Cc: <kvm@vger.kernel.org>, <maz@kernel.org>, <will@kernel.org>,
	<drjones@redhat.com>, <zhang.zhanghailiang@huawei.com>,
	<xiexiangyou@huawei.com>, Peng Liang <liangpeng10@huawei.com>
Subject: [RFC v2 4/7] kvm: arm64: introduce check_user
Date: Thu, 17 Sep 2020 20:00:58 +0800	[thread overview]
Message-ID: <20200917120101.3438389-5-liangpeng10@huawei.com> (raw)
In-Reply-To: <20200917120101.3438389-1-liangpeng10@huawei.com>

Currently, if we need to check the value of the register defined by user
space, we should check it in set_user.  However, some system registers
may use the same set_user (for example, almost all ID registers), which
make it difficult to validate the value defined by user space.

Introduce check_user to solve the problem.  And apply check_user before
set_user to make sure that the value of register is valid.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Peng Liang <liangpeng10@huawei.com>
---
 arch/arm64/kvm/sys_regs.c | 7 +++++++
 arch/arm64/kvm/sys_regs.h | 6 ++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2b0fa8d5ac62..86ebb8093c3c 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2684,6 +2684,7 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 {
 	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	int err;
 
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_set(reg->id, uaddr);
@@ -2699,6 +2700,12 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (sysreg_hidden_from_user(vcpu, r))
 		return -ENOENT;
 
+	if (r->check_user) {
+		err = (r->check_user)(vcpu, r, reg, uaddr);
+		if (err)
+			return err;
+	}
+
 	if (r->set_user)
 		return (r->set_user)(vcpu, r, reg, uaddr);
 
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index 5a6fc30f5989..9bce5e9a3490 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -53,6 +53,12 @@ struct sys_reg_desc {
 			const struct kvm_one_reg *reg, void __user *uaddr);
 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 			const struct kvm_one_reg *reg, void __user *uaddr);
+	/*
+	 * Check the value userspace passed.  It should return 0 on success and
+	 * otherwise on failure.
+	 */
+	int (*check_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+			  const struct kvm_one_reg *reg, void __user *uaddr);
 
 	/* Return mask of REG_* runtime visibility overrides */
 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
-- 
2.26.2


  parent reply	other threads:[~2020-09-17 12:09 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-17 12:00 [RFC v2 0/7] kvm: arm64: emulate ID registers Peng Liang
2020-09-17 12:00 ` Peng Liang
2020-09-17 12:00 ` [RFC v2 1/7] arm64: add a helper function to traverse arm64_ftr_regs Peng Liang
2020-09-17 12:00   ` Peng Liang
2020-09-18  7:18   ` Andrew Jones
2020-09-18  7:18     ` Andrew Jones
2020-09-18  9:24     ` Peng Liang
2020-09-18  9:24       ` Peng Liang
2020-09-18 10:28       ` Andrew Jones
2020-09-18 10:28         ` Andrew Jones
2020-09-18 11:58         ` Peng Liang
2020-09-18 11:58           ` Peng Liang
2020-09-17 12:00 ` [RFC v2 2/7] arm64: introduce check_features Peng Liang
2020-09-17 12:00   ` Peng Liang
2020-09-18  7:30   ` Andrew Jones
2020-09-18  7:30     ` Andrew Jones
2020-09-18  9:25     ` Peng Liang
2020-09-18  9:25       ` Peng Liang
2020-09-17 12:00 ` [RFC v2 3/7] kvm: arm64: save ID registers to sys_regs file Peng Liang
2020-09-17 12:00   ` Peng Liang
2020-09-18  7:34   ` Andrew Jones
2020-09-18  7:34     ` Andrew Jones
2020-09-17 12:00 ` Peng Liang [this message]
2020-09-17 12:00   ` [RFC v2 4/7] kvm: arm64: introduce check_user Peng Liang
2020-09-18  7:41   ` Andrew Jones
2020-09-18  7:41     ` Andrew Jones
2020-09-18  9:25     ` Peng Liang
2020-09-18  9:25       ` Peng Liang
2020-09-17 12:00 ` [RFC v2 5/7] kvm: arm64: implement check_user for ID registers Peng Liang
2020-09-17 12:00   ` Peng Liang
2020-09-18  7:46   ` Andrew Jones
2020-09-18  7:46     ` Andrew Jones
2020-09-18  9:26     ` Peng Liang
2020-09-18  9:26       ` Peng Liang
2020-09-17 12:01 ` [RFC v2 6/7] kvm: arm64: make ID registers configurable Peng Liang
2020-09-17 12:01   ` Peng Liang
2020-09-18  7:50   ` Andrew Jones
2020-09-18  7:50     ` Andrew Jones
2020-09-18  9:26     ` Peng Liang
2020-09-18  9:26       ` Peng Liang
2020-09-17 12:01 ` [RFC v2 7/7] kvm: arm64: add KVM_CAP_ARM_CPU_FEATURE extension Peng Liang
2020-09-17 12:01   ` Peng Liang
2020-09-18  7:55   ` Andrew Jones
2020-09-18  7:55     ` Andrew Jones
2020-09-18  9:26     ` Peng Liang
2020-09-18  9:26       ` Peng Liang
2020-09-18  8:01 ` [RFC v2 0/7] kvm: arm64: emulate ID registers Andrew Jones
2020-09-18  8:01   ` Andrew Jones
2020-09-18  9:51   ` Peng Liang
2020-09-18  9:51     ` Peng Liang
2020-09-18 10:20     ` Andrew Jones
2020-09-18 10:20       ` Andrew Jones

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200917120101.3438389-5-liangpeng10@huawei.com \
    --to=liangpeng10@huawei.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=maz@kernel.org \
    --cc=will@kernel.org \
    --cc=zhang.zhanghailiang@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.