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>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Kees Cook <keescook@chromium.org>,
Andy Lutomirski <luto@kernel.org>
Subject: [RFC 17/17] x86/traps: Use a new on_thread_stack() helper to clean up an assertion
Date: Wed, 6 Sep 2017 14:37:02 -0700 [thread overview]
Message-ID: <eabfbaaf295473e4d6fda700bb346af766fcee80.1504733277.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1504733277.git.luto@kernel.org>
In-Reply-To: <cover.1504733277.git.luto@kernel.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/processor.h | 17 +++++++++++++++++
arch/x86/include/asm/thread_info.h | 11 -----------
arch/x86/kernel/traps.c | 3 +--
3 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 4c137472f530..b6f8dc11c222 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -534,6 +534,23 @@ static inline unsigned long current_top_of_stack(void)
#endif
}
+static inline unsigned long current_stack_pointer(void)
+{
+ unsigned long sp;
+#ifdef CONFIG_X86_64
+ asm("mov %%rsp,%0" : "=g" (sp));
+#else
+ asm("mov %%esp,%0" : "=g" (sp));
+#endif
+ return sp;
+}
+
+static inline bool on_thread_stack(void)
+{
+ return (unsigned long)(current_top_of_stack() -
+ current_stack_pointer()) < THREAD_SIZE;
+}
+
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index e00e1bd6e7b3..90e1f9b84534 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -155,17 +155,6 @@ struct thread_info {
*/
#ifndef __ASSEMBLY__
-static inline unsigned long current_stack_pointer(void)
-{
- unsigned long sp;
-#ifdef CONFIG_X86_64
- asm("mov %%rsp,%0" : "=g" (sp));
-#else
- asm("mov %%esp,%0" : "=g" (sp));
-#endif
- return sp;
-}
-
/*
* Walks up the stack frames to make sure that the specified object is
* entirely contained by a single stack frame.
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index bf54309b85da..0347ed41c92d 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -153,8 +153,7 @@ void ist_begin_non_atomic(struct pt_regs *regs)
* will catch asm bugs and any attempt to use ist_preempt_enable
* from double_fault.
*/
- BUG_ON((unsigned long)(current_top_of_stack() -
- current_stack_pointer()) >= THREAD_SIZE);
+ BUG_ON(!on_thread_stack());
preempt_enable_no_resched();
}
--
2.13.5
next prev parent reply other threads:[~2017-09-06 21:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-06 21:36 [RFC 00/17] Pile o' entry stack changes Andy Lutomirski
2017-09-06 21:36 ` [RFC 01/17] x86/asm/64: Remove the restore_c_regs_and_iret label Andy Lutomirski
2017-09-07 9:40 ` Borislav Petkov
2017-09-07 9:46 ` Ingo Molnar
2017-09-07 9:49 ` Ingo Molnar
2017-09-07 9:57 ` Borislav Petkov
2017-09-07 10:29 ` Ingo Molnar
2017-09-06 21:36 ` [RFC 02/17] x86/asm/64: Split the iret-to-user and iret-to-kernel paths Andy Lutomirski
2017-09-06 21:36 ` [RFC 03/17] x86/asm/64: Move SWAPGS into the common iret-to-usermode path Andy Lutomirski
2017-09-06 21:36 ` [RFC 04/17] x86/asm/64: Simplify reg restore code in the standard IRET paths Andy Lutomirski
2017-09-12 20:05 ` Josh Poimboeuf
2017-09-06 21:36 ` [RFC 05/17] x86/asm/64: Shrink paranoid_exit_restore and make labels local Andy Lutomirski
2017-09-06 21:36 ` [RFC 06/17] x86/asm/64: Use pop instead of movq in syscall_return_via_sysret Andy Lutomirski
2017-09-06 21:36 ` [RFC 07/17] x86/asm/64: Merge the fast and slow SYSRET paths Andy Lutomirski
2017-09-06 21:36 ` [RFC 08/17] x86/asm/64: De-Xen-ify our NMI code Andy Lutomirski
2017-09-07 9:34 ` Juergen Gross
2017-09-07 18:38 ` Andy Lutomirski
2017-09-08 4:26 ` Juergen Gross
2017-09-06 21:36 ` [RFC 09/17] x86/asm/32: Pull MSR_IA32_SYSENTER_CS update code out of native_load_sp0() Andy Lutomirski
2017-09-12 20:06 ` Josh Poimboeuf
2017-09-06 21:36 ` [RFC 10/17] x86/asm/64: Pass sp0 directly to load_sp0() Andy Lutomirski
2017-09-06 21:36 ` [RFC 11/17] x86/asm: Add task_top_of_stack() to find the top of a task's stack Andy Lutomirski
2017-09-06 21:36 ` [RFC 12/17] x86/xen/64: Clean up SP code in cpu_initialize_context() Andy Lutomirski
2017-09-12 20:09 ` Josh Poimboeuf
2017-09-06 21:36 ` [RFC 13/17] x86/boot/64: Stop initializing TSS.sp0 at boot Andy Lutomirski
2017-09-06 21:36 ` [RFC 14/17] x86/asm/64: Remove all remaining direct thread_struct::sp0 reads Andy Lutomirski
2017-09-06 21:37 ` [RFC 15/17] x86/boot/32: Fix cpu_current_top_of_stack initialization at boot Andy Lutomirski
2017-09-06 21:37 ` [RFC 16/17] x86/asm/64: Remove thread_struct::sp0 Andy Lutomirski
2017-09-06 21:37 ` Andy Lutomirski [this message]
2017-09-12 20:11 ` [RFC 17/17] x86/traps: Use a new on_thread_stack() helper to clean up an assertion Josh Poimboeuf
2017-09-12 20:25 ` Andrew Cooper
2017-09-06 22:16 ` [RFC 00/17] Pile o' entry stack changes Andi Kleen
2017-09-07 0:01 ` Andy Lutomirski
2017-09-07 7:04 ` Ingo Molnar
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