From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, Borislav Petkov <bp@alien8.de>,
Brian Gerst <brgerst@gmail.com>,
David Laight <David.Laight@aculab.com>,
Kees Cook <keescook@chromium.org>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>
Subject: [PATCH PTI v3 06/10] x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode
Date: Tue, 12 Dec 2017 07:56:41 -0800 [thread overview]
Message-ID: <d583ed9f2d2d9c5399b92c8c3c48eaefb8a1e8c0.1513035461.git.luto@kernel.org> (raw)
In-Reply-To: <24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.org>
In-Reply-To: <cover.1513035461.git.luto@kernel.org>
If something goes wrong with pagetable setup, vsyscall=native will
accidentally fall back to emulation. Make it warn and fail so that
we notice.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index bc88a0540347..a06f2ae09ad6 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -138,6 +138,10 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
WARN_ON_ONCE(address != regs->ip);
+ /* This should be unreachable in NATIVE mode. */
+ if (WARN_ON(vsyscall_mode == NATIVE))
+ return false;
+
if (vsyscall_mode == NONE) {
warn_bad_vsyscall(KERN_INFO, regs,
"vsyscall attempted with vsyscall=none");
--
2.13.6
next prev parent reply other threads:[~2017-12-12 15:57 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-11 23:40 [PATCH PTI v3 00/10] Clean up pgd handling and fix VSYSCALL and LDT Andy Lutomirski
2017-12-12 10:09 ` Ingo Molnar
2017-12-12 15:58 ` Andy Lutomirski
2017-12-12 16:13 ` Borislav Petkov
2017-12-12 16:14 ` Juergen Gross
2017-12-12 16:20 ` Borislav Petkov
2017-12-12 15:56 ` [PATCH PTI v3 01/10] x86/espfix/64: Fix espfix double-fault handling on 5-level systems Andy Lutomirski
2017-12-12 17:18 ` Kirill A. Shutemov
2017-12-15 18:34 ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 02/10] x86/pti: Vastly simplify pgd synchronization Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 03/10] x86/pti/64: Fix ESPFIX64 user mapping Andy Lutomirski
2017-12-13 13:12 ` Kirill A. Shutemov
2017-12-13 17:01 ` Andy Lutomirski
2017-12-14 14:10 ` Kirill A. Shutemov
2017-12-14 16:18 ` Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 04/10] Revert "x86/mm/pti: Disable native VSYSCALL" Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 05/10] x86/vsyscall/64: Explicitly set _PAGE_USER in the pagetable hierarchy Andy Lutomirski
2017-12-12 15:56 ` Andy Lutomirski [this message]
2017-12-12 15:56 ` [PATCH PTI v3 07/10] x86/pti: Map the vsyscall page if needed Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 08/10] x86/mm/64: Improve the memory map documentation Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 09/10] x86/mm/64: Make a full PGD-entry size hole in the memory map Andy Lutomirski
2017-12-13 13:17 ` Kirill A. Shutemov
2017-12-13 17:04 ` Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 10/10] x86/pti: Put the LDT in its own PGD if PTI is on Andy Lutomirski
2017-12-15 22:54 ` Thomas Gleixner
2017-12-16 0:39 ` Thomas Gleixner
2017-12-16 6:41 ` Andy Lutomirski
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