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 v5 4/6] x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip()
Date: Mon, 14 Jun 2021 15:53:25 +0200 [thread overview]
Message-ID: <20210614135327.9921-5-joro@8bytes.org> (raw)
In-Reply-To: <20210614135327.9921-1-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
next prev parent reply other threads:[~2021-06-14 13:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-14 13:53 [PATCH v5 0/6] x86/sev-es: Fixes for SEV-ES Guest Support Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 1/6] x86/sev-es: Fix error message in runtime #VC handler Joerg Roedel
2021-06-15 10:51 ` [tip: x86/sev] x86/sev: " tip-bot2 for Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 2/6] x86/sev-es: Make sure IRQs are disabled while GHCB is active Joerg Roedel
2021-06-14 16:25 ` Borislav Petkov
2021-06-14 16:30 ` Borislav Petkov
2021-06-15 9:37 ` Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 3/6] x86/sev-es: Split up runtime #VC handler for correct state tracking Joerg Roedel
2021-06-16 16:04 ` Peter Zijlstra
2021-06-16 19:01 ` Joerg Roedel
2021-06-14 13:53 ` Joerg Roedel [this message]
2021-06-15 10:51 ` [tip: x86/sev] x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip() tip-bot2 for Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 5/6] x86/insn: Extend error reporting from insn_fetch_from_user[_inatomic]() Joerg Roedel
2021-06-15 10:51 ` [tip: x86/sev] " tip-bot2 for Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 6/6] x86/sev-es: Propagate #GP if getting linear instruction address failed Joerg Roedel
2021-06-15 10:51 ` [tip: x86/sev] x86/sev: " tip-bot2 for Joerg Roedel
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