[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20171004212003.28296-7-thgarnie@google.com>
Date: Wed, 4 Oct 2017 14:19:42 -0700
From: Thomas Garnier <thgarnie@...gle.com>
To: Herbert Xu <herbert@...dor.apana.org.au>,
"David S . Miller" <davem@...emloft.net>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H . Peter Anvin" <hpa@...or.com>,
Peter Zijlstra <peterz@...radead.org>,
Josh Poimboeuf <jpoimboe@...hat.com>,
Thomas Garnier <thgarnie@...gle.com>,
Arnd Bergmann <arnd@...db.de>,
Kees Cook <keescook@...omium.org>,
Matthias Kaehlcke <mka@...omium.org>,
Tom Lendacky <thomas.lendacky@....com>,
Andy Lutomirski <luto@...nel.org>,
"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
Borislav Petkov <bp@...e.de>,
"Rafael J . Wysocki" <rjw@...ysocki.net>,
Len Brown <len.brown@...el.com>,
Pavel Machek <pavel@....cz>,
Juergen Gross <jgross@...e.com>,
Chris Wright <chrisw@...s-sol.org>,
Alok Kataria <akataria@...are.com>,
Rusty Russell <rusty@...tcorp.com.au>,
Tejun Heo <tj@...nel.org>,
Christoph Lameter <cl@...ux.com>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>,
Alexey Dobriyan <adobriyan@...il.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Paul Gortmaker <paul.gortmaker@...driver.com>,
Chris Metcalf <cmetcalf@...lanox.com>,
"Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>,
Nicolas Pitre <nicolas.pitre@...aro.org>,
Borislav Petkov <bp@...en8.de>,
"Luis R . Rodriguez" <mcgrof@...nel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Christopher Li <sparse@...isli.org>,
Steven Rostedt <rostedt@...dmis.org>,
Jason Baron <jbaron@...mai.com>,
Dou Liyang <douly.fnst@...fujitsu.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
Lukas Wunner <lukas@...ner.de>,
Masahiro Yamada <yamada.masahiro@...ionext.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Markus Trippelsdorf <markus@...ppelsdorf.de>,
Paolo Bonzini <pbonzini@...hat.com>,
Radim Krčmář <rkrcmar@...hat.com>,
Joerg Roedel <joro@...tes.org>,
Rik van Riel <riel@...hat.com>,
David Howells <dhowells@...hat.com>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Waiman Long <longman@...hat.com>,
Kyle Huey <me@...ehuey.com>,
Andrey Ryabinin <aryabinin@...tuozzo.com>,
Jonathan Corbet <corbet@....net>,
Matthew Wilcox <mawilcox@...rosoft.com>,
Michal Hocko <mhocko@...e.com>,
Peter Foley <pefoley2@...oley.com>,
Paul Bolle <pebolle@...cali.nl>,
Jiri Kosina <jkosina@...e.cz>,
Rob Landley <rob@...dley.net>,
"H . J . Lu" <hjl.tools@...il.com>,
Baoquan He <bhe@...hat.com>,
Jan H . Schönherr <jschoenh@...zon.de>,
Daniel Micay <danielmicay@...il.com>
Cc: x86@...nel.org,
linux-crypto@...r.kernel.org,
linux-kernel@...r.kernel.org,
linux-pm@...r.kernel.org,
virtualization@...ts.linux-foundation.org,
xen-devel@...ts.xenproject.org,
linux-arch@...r.kernel.org,
linux-sparse@...r.kernel.org,
kvm@...r.kernel.org,
linux-doc@...r.kernel.org,
kernel-hardening@...ts.openwall.com
Subject: [RFC v3 06/27] x86/entry/64: Adapt assembly for PIE support
Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.
Position Independent Executable (PIE) support will allow to extended the
KASLR randomization range below the -2G memory limit.
Signed-off-by: Thomas Garnier <thgarnie@...gle.com>
---
arch/x86/entry/entry_64.S | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 49167258d587..15bd5530d2ae 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -194,12 +194,15 @@ entry_SYSCALL_64_fastpath:
ja 1f /* return -ENOSYS (already in pt_regs->ax) */
movq %r10, %rcx
+ /* Ensures the call is position independent */
+ leaq sys_call_table(%rip), %r11
+
/*
* This call instruction is handled specially in stub_ptregs_64.
* It might end up jumping to the slow path. If it jumps, RAX
* and all argument registers are clobbered.
*/
- call *sys_call_table(, %rax, 8)
+ call *(%r11, %rax, 8)
.Lentry_SYSCALL_64_after_fastpath_call:
movq %rax, RAX(%rsp)
@@ -334,7 +337,8 @@ ENTRY(stub_ptregs_64)
* RAX stores a pointer to the C function implementing the syscall.
* IRQs are on.
*/
- cmpq $.Lentry_SYSCALL_64_after_fastpath_call, (%rsp)
+ leaq .Lentry_SYSCALL_64_after_fastpath_call(%rip), %r11
+ cmpq %r11, (%rsp)
jne 1f
/*
@@ -1172,7 +1176,8 @@ ENTRY(error_entry)
movl %ecx, %eax /* zero extend */
cmpq %rax, RIP+8(%rsp)
je .Lbstep_iret
- cmpq $.Lgs_change, RIP+8(%rsp)
+ leaq .Lgs_change(%rip), %rcx
+ cmpq %rcx, RIP+8(%rsp)
jne .Lerror_entry_done
/*
@@ -1383,10 +1388,10 @@ ENTRY(nmi)
* resume the outer NMI.
*/
- movq $repeat_nmi, %rdx
+ leaq repeat_nmi(%rip), %rdx
cmpq 8(%rsp), %rdx
ja 1f
- movq $end_repeat_nmi, %rdx
+ leaq end_repeat_nmi(%rip), %rdx
cmpq 8(%rsp), %rdx
ja nested_nmi_out
1:
@@ -1440,7 +1445,8 @@ nested_nmi:
pushq %rdx
pushfq
pushq $__KERNEL_CS
- pushq $repeat_nmi
+ leaq repeat_nmi(%rip), %rdx
+ pushq %rdx
/* Put stack back */
addq $(6*8), %rsp
@@ -1479,7 +1485,9 @@ first_nmi:
addq $8, (%rsp) /* Fix up RSP */
pushfq /* RFLAGS */
pushq $__KERNEL_CS /* CS */
- pushq $1f /* RIP */
+ pushq %rax /* Support Position Independent Code */
+ leaq 1f(%rip), %rax /* RIP */
+ xchgq %rax, (%rsp) /* Restore RAX, put 1f */
INTERRUPT_RETURN /* continues at repeat_nmi below */
UNWIND_HINT_IRET_REGS
1:
--
2.14.2.920.gcf0c67979c-goog
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
