* Re: [PATCH] x86: simplify task_pt_regs() macro definition
2015-03-13 14:09 [PATCH] x86: simplify task_pt_regs() macro definition Denys Vlasenko
@ 2015-03-13 18:26 ` Steven Rostedt
2015-03-16 12:09 ` [tip:x86/asm] x86/asm/entry: Simplify " tip-bot for Denys Vlasenko
2015-03-17 8:46 ` tip-bot for Denys Vlasenko
2 siblings, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2015-03-13 18:26 UTC (permalink / raw)
To: Denys Vlasenko
Cc: Andy Lutomirski, Linus Torvalds, Ingo Molnar, Borislav Petkov,
H. Peter Anvin, Oleg Nesterov, Frederic Weisbecker,
Alexei Starovoitov, Will Drewry, Kees Cook, x86, linux-kernel
On Fri, 13 Mar 2015 15:09:03 +0100
Denys Vlasenko <dvlasenk@redhat.com> wrote:
> Before this change, task_pt_regs() was using KSTK_TOP(),
> and it was the only use of that macro. In turn, KSTK_TOP used
> THREAD_SIZE_LONGS, and it was the only use of that macro too.
>
> Fold these macros into task_pt_regs(). Tweak comment
> about "- 8" - we now use a symbolic constant, not literal 8.
I wonder if we should mention "8" at all?
As for the patch, from what I can tell, it keeps the same logic.
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
-- Steve
> Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
> CC: Linus Torvalds <torvalds@linux-foundation.org>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Ingo Molnar <mingo@kernel.org>
> CC: Borislav Petkov <bp@alien8.de>
> CC: "H. Peter Anvin" <hpa@zytor.com>
> CC: Andy Lutomirski <luto@amacapital.net>
> CC: Oleg Nesterov <oleg@redhat.com>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Alexei Starovoitov <ast@plumgrid.com>
> CC: Will Drewry <wad@chromium.org>
> CC: Kees Cook <keescook@chromium.org>
> CC: x86@kernel.org
> CC: linux-kernel@vger.kernel.org
> ---
> arch/x86/include/asm/processor.h | 20 ++++++--------------
> 1 file changed, 6 insertions(+), 14 deletions(-)
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:x86/asm] x86/asm/entry: Simplify task_pt_regs() macro definition
2015-03-13 14:09 [PATCH] x86: simplify task_pt_regs() macro definition Denys Vlasenko
2015-03-13 18:26 ` Steven Rostedt
@ 2015-03-16 12:09 ` tip-bot for Denys Vlasenko
2015-03-17 8:46 ` tip-bot for Denys Vlasenko
2 siblings, 0 replies; 4+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-03-16 12:09 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, rostedt, oleg, tglx, keescook, dvlasenk, wad, torvalds, bp,
ast, mingo, linux-kernel, fweisbec, luto
Commit-ID: 42503341cde213c5928a19f7c6e1eb8c85f2df3d
Gitweb: http://git.kernel.org/tip/42503341cde213c5928a19f7c6e1eb8c85f2df3d
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Fri, 13 Mar 2015 15:09:03 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 16 Mar 2015 11:05:36 +0100
x86/asm/entry: Simplify task_pt_regs() macro definition
Before this change, task_pt_regs() was using KSTK_TOP(),
and it was the only use of that macro. In turn, KSTK_TOP used
THREAD_SIZE_LONGS, and it was the only use of that macro too.
Fold these macros into task_pt_regs(). Tweak comment
about "- 8" - we now use a symbolic constant, not literal 8.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426255743-5394-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/processor.h | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c3a037b..d157f94 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -846,15 +846,8 @@ static inline void spin_lock_prefetch(const void *x)
extern unsigned long thread_saved_pc(struct task_struct *tsk);
-#define THREAD_SIZE_LONGS (THREAD_SIZE/sizeof(unsigned long))
-#define KSTK_TOP(info) \
-({ \
- unsigned long *__ptr = (unsigned long *)(info); \
- (unsigned long)(&__ptr[THREAD_SIZE_LONGS]); \
-})
-
/*
- * The below -8 is to reserve 8 bytes on top of the ring0 stack.
+ * TOP_OF_KERNEL_STACK_PADDING reserves 8 bytes on top of the ring0 stack.
* This is necessary to guarantee that the entire "struct pt_regs"
* is accessible even if the CPU haven't stored the SS/ESP registers
* on the stack (interrupt gate does not save these registers
@@ -863,12 +856,11 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
* "struct pt_regs" is possible, but they may contain the
* completely wrong values.
*/
-#define task_pt_regs(task) \
-({ \
- struct pt_regs *__regs__; \
- __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task)) - \
- TOP_OF_KERNEL_STACK_PADDING); \
- __regs__ - 1; \
+#define task_pt_regs(task) \
+({ \
+ unsigned long __ptr = (unsigned long)task_stack_page(task); \
+ __ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; \
+ ((struct pt_regs *)__ptr) - 1; \
})
#define KSTK_ESP(task) (task_pt_regs(task)->sp)
^ permalink raw reply [flat|nested] 4+ messages in thread* [tip:x86/asm] x86/asm/entry: Simplify task_pt_regs() macro definition
2015-03-13 14:09 [PATCH] x86: simplify task_pt_regs() macro definition Denys Vlasenko
2015-03-13 18:26 ` Steven Rostedt
2015-03-16 12:09 ` [tip:x86/asm] x86/asm/entry: Simplify " tip-bot for Denys Vlasenko
@ 2015-03-17 8:46 ` tip-bot for Denys Vlasenko
2 siblings, 0 replies; 4+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-03-17 8:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: dvlasenk, keescook, hpa, rostedt, mingo, wad, linux-kernel, oleg,
fweisbec, torvalds, ast, bp, luto, tglx
Commit-ID: 5c39403e004bec75ce0c549541be5479595d6ad0
Gitweb: http://git.kernel.org/tip/5c39403e004bec75ce0c549541be5479595d6ad0
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Fri, 13 Mar 2015 15:09:03 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 17 Mar 2015 09:25:28 +0100
x86/asm/entry: Simplify task_pt_regs() macro definition
Before this change, task_pt_regs() was using KSTK_TOP(),
and it was the only use of that macro. In turn, KSTK_TOP used
THREAD_SIZE_LONGS, and it was the only use of that macro too.
Fold these macros into task_pt_regs(). Tweak comment
about "- 8" - we now use a symbolic constant, not literal 8.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426255743-5394-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/processor.h | 20 ++++++--------------
1 file changed, 6 insertions(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index b262089..6a5c0ec 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -847,15 +847,8 @@ static inline void spin_lock_prefetch(const void *x)
extern unsigned long thread_saved_pc(struct task_struct *tsk);
-#define THREAD_SIZE_LONGS (THREAD_SIZE/sizeof(unsigned long))
-#define KSTK_TOP(info) \
-({ \
- unsigned long *__ptr = (unsigned long *)(info); \
- (unsigned long)(&__ptr[THREAD_SIZE_LONGS]); \
-})
-
/*
- * The below -8 is to reserve 8 bytes on top of the ring0 stack.
+ * TOP_OF_KERNEL_STACK_PADDING reserves 8 bytes on top of the ring0 stack.
* This is necessary to guarantee that the entire "struct pt_regs"
* is accessible even if the CPU haven't stored the SS/ESP registers
* on the stack (interrupt gate does not save these registers
@@ -864,12 +857,11 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
* "struct pt_regs" is possible, but they may contain the
* completely wrong values.
*/
-#define task_pt_regs(task) \
-({ \
- struct pt_regs *__regs__; \
- __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task)) - \
- TOP_OF_KERNEL_STACK_PADDING); \
- __regs__ - 1; \
+#define task_pt_regs(task) \
+({ \
+ unsigned long __ptr = (unsigned long)task_stack_page(task); \
+ __ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; \
+ ((struct pt_regs *)__ptr) - 1; \
})
#define KSTK_ESP(task) (task_pt_regs(task)->sp)
^ permalink raw reply [flat|nested] 4+ messages in thread