All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joerg Roedel <joro@8bytes.org>
To: x86@kernel.org
Cc: Joerg Roedel <joro@8bytes.org>, Joerg Roedel <jroedel@suse.de>,
	hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Jiri Slaby <jslaby@suse.cz>,
	Dan Williams <dan.j.williams@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Juergen Gross <jgross@suse.com>,
	Kees Cook <keescook@chromium.org>,
	David Rientjes <rientjes@google.com>,
	Cfir Cohen <cfir@google.com>, Erdem Aktas <erdemaktas@google.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Mike Stunes <mstunes@vmware.com>,
	Sean Christopherson <seanjc@google.com>,
	Martin Radev <martin.b.radev@gmail.com>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: [PATCH v4 4/6] x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip()
Date: Thu, 10 Jun 2021 11:11:39 +0200	[thread overview]
Message-ID: <20210610091141.30322-5-joro@8bytes.org> (raw)
In-Reply-To: <20210610091141.30322-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

In theory 0 is a valid value for the instruction pointer, so don't use
it as the error return value from insn_get_effective_ip().

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/lib/insn-eval.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index a67afd74232c..4eecb9c7c6a0 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -1417,7 +1417,7 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs)
 	}
 }
 
-static unsigned long insn_get_effective_ip(struct pt_regs *regs)
+static int insn_get_effective_ip(struct pt_regs *regs, unsigned long *ip)
 {
 	unsigned long seg_base = 0;
 
@@ -1430,10 +1430,12 @@ static unsigned long insn_get_effective_ip(struct pt_regs *regs)
 	if (!user_64bit_mode(regs)) {
 		seg_base = insn_get_seg_base(regs, INAT_SEG_REG_CS);
 		if (seg_base == -1L)
-			return 0;
+			return -EINVAL;
 	}
 
-	return seg_base + regs->ip;
+	*ip = seg_base + regs->ip;
+
+	return 0;
 }
 
 /**
@@ -1455,8 +1457,7 @@ int insn_fetch_from_user(struct pt_regs *regs, unsigned char buf[MAX_INSN_SIZE])
 	unsigned long ip;
 	int not_copied;
 
-	ip = insn_get_effective_ip(regs);
-	if (!ip)
+	if (insn_get_effective_ip(regs, &ip))
 		return 0;
 
 	not_copied = copy_from_user(buf, (void __user *)ip, MAX_INSN_SIZE);
@@ -1484,8 +1485,7 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
 	unsigned long ip;
 	int not_copied;
 
-	ip = insn_get_effective_ip(regs);
-	if (!ip)
+	if (insn_get_effective_ip(regs, &ip))
 		return 0;
 
 	not_copied = __copy_from_user_inatomic(buf, (void __user *)ip, MAX_INSN_SIZE);
-- 
2.31.1


WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: x86@kernel.org
Cc: kvm@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	virtualization@lists.linux-foundation.org,
	Arvind Sankar <nivedita@alum.mit.edu>,
	hpa@zytor.com, Jiri Slaby <jslaby@suse.cz>,
	Joerg Roedel <joro@8bytes.org>,
	David Rientjes <rientjes@google.com>,
	Martin Radev <martin.b.radev@gmail.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Joerg Roedel <jroedel@suse.de>, Kees Cook <keescook@chromium.org>,
	Cfir Cohen <cfir@google.com>,
	linux-coco@lists.linux.dev, Andy Lutomirski <luto@kernel.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Juergen Gross <jgross@suse.com>, Mike Stunes <mstunes@vmware.com>,
	Sean Christopherson <seanjc@google.com>,
	linux-kernel@vger.kernel.org,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Erdem Aktas <erdemaktas@google.com>
Subject: [PATCH v4 4/6] x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip()
Date: Thu, 10 Jun 2021 11:11:39 +0200	[thread overview]
Message-ID: <20210610091141.30322-5-joro@8bytes.org> (raw)
In-Reply-To: <20210610091141.30322-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

In theory 0 is a valid value for the instruction pointer, so don't use
it as the error return value from insn_get_effective_ip().

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/lib/insn-eval.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index a67afd74232c..4eecb9c7c6a0 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -1417,7 +1417,7 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs)
 	}
 }
 
-static unsigned long insn_get_effective_ip(struct pt_regs *regs)
+static int insn_get_effective_ip(struct pt_regs *regs, unsigned long *ip)
 {
 	unsigned long seg_base = 0;
 
@@ -1430,10 +1430,12 @@ static unsigned long insn_get_effective_ip(struct pt_regs *regs)
 	if (!user_64bit_mode(regs)) {
 		seg_base = insn_get_seg_base(regs, INAT_SEG_REG_CS);
 		if (seg_base == -1L)
-			return 0;
+			return -EINVAL;
 	}
 
-	return seg_base + regs->ip;
+	*ip = seg_base + regs->ip;
+
+	return 0;
 }
 
 /**
@@ -1455,8 +1457,7 @@ int insn_fetch_from_user(struct pt_regs *regs, unsigned char buf[MAX_INSN_SIZE])
 	unsigned long ip;
 	int not_copied;
 
-	ip = insn_get_effective_ip(regs);
-	if (!ip)
+	if (insn_get_effective_ip(regs, &ip))
 		return 0;
 
 	not_copied = copy_from_user(buf, (void __user *)ip, MAX_INSN_SIZE);
@@ -1484,8 +1485,7 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
 	unsigned long ip;
 	int not_copied;
 
-	ip = insn_get_effective_ip(regs);
-	if (!ip)
+	if (insn_get_effective_ip(regs, &ip))
 		return 0;
 
 	not_copied = __copy_from_user_inatomic(buf, (void __user *)ip, MAX_INSN_SIZE);
-- 
2.31.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

  parent reply	other threads:[~2021-06-10  9:12 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-10  9:11 [PATCH v4 0/6] x86/sev-es: Fixes for SEV-ES Guest Support Joerg Roedel
2021-06-10  9:11 ` Joerg Roedel
2021-06-10  9:11 ` [PATCH v4 1/6] x86/sev-es: Fix error message in runtime #VC handler Joerg Roedel
2021-06-10  9:11   ` Joerg Roedel
2021-06-10  9:11 ` [PATCH v4 2/6] x86/sev-es: Disable IRQs while GHCB is active Joerg Roedel
2021-06-10  9:11   ` Joerg Roedel
2021-06-11 14:05   ` Borislav Petkov
2021-06-11 14:05     ` Borislav Petkov
2021-06-11 14:20     ` Joerg Roedel
2021-06-11 14:20       ` Joerg Roedel
2021-06-11 14:34       ` Borislav Petkov
2021-06-11 14:34         ` Borislav Petkov
2021-06-10  9:11 ` [PATCH v4 3/6] x86/sev-es: Split up runtime #VC handler for correct state tracking Joerg Roedel
2021-06-10  9:11   ` Joerg Roedel
2021-06-10 10:19   ` Peter Zijlstra
2021-06-10 10:19     ` Peter Zijlstra
2021-06-10 11:30     ` Joerg Roedel
2021-06-10 11:30       ` Joerg Roedel
2021-06-10  9:11 ` Joerg Roedel [this message]
2021-06-10  9:11   ` [PATCH v4 4/6] x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip() Joerg Roedel
2021-06-10  9:11 ` [PATCH v4 5/6] x86/insn: Extend error reporting from insn_fetch_from_user[_inatomic]() Joerg Roedel
2021-06-10  9:11   ` Joerg Roedel
2021-06-10  9:11 ` [PATCH v4 6/6] x86/sev-es: Propagate #GP if getting linear instruction address failed Joerg Roedel
2021-06-10  9:11   ` Joerg Roedel

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=20210610091141.30322-5-joro@8bytes.org \
    --to=joro@8bytes.org \
    --cc=cfir@google.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=erdemaktas@google.com \
    --cc=hpa@zytor.com \
    --cc=jgross@suse.com \
    --cc=jroedel@suse.de \
    --cc=jslaby@suse.cz \
    --cc=keescook@chromium.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-coco@lists.linux.dev \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=martin.b.radev@gmail.com \
    --cc=mhiramat@kernel.org \
    --cc=mstunes@vmware.com \
    --cc=nivedita@alum.mit.edu \
    --cc=peterz@infradead.org \
    --cc=rientjes@google.com \
    --cc=seanjc@google.com \
    --cc=thomas.lendacky@amd.com \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=x86@kernel.org \
    /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.