* Re: [PATCH] x86/signal: fix restart_syscall number for x32 tasks
@ 2015-12-07 23:22 Andy Lutomirski
2015-12-13 3:44 ` Dmitry V. Levin
0 siblings, 1 reply; 9+ messages in thread
From: Andy Lutomirski @ 2015-12-07 23:22 UTC (permalink / raw)
To: X86 ML, linux-kernel, Dmitry V. Levin, lvira Khabirova
[not real reply because I'm using a bad internet connection right now
and I'm not set up with my usual Gmane reply hack right now]
The new code is (whitespace-damaged):
static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
{
#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
return __NR_restart_syscall;
#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
__NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
}
This is IMO awful. This use of TIF_IA32 is wrong, and this is
otherwise gross. Can we do it for real:
if (is_ia32_task())
return __NR_ia32_restart_syscall;
else
return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
/* preserve x32 bit */
I'd send the patch myself, but you apparently have a good test case
for this, and I don't.
(this isn't a regression, and I'm not suggesting any change for 4.4 or
for stable. But for 4.5, can we do it right, please?)
And yes, I'll send a patch to rename is_ia32_task, but that's orthogonal.
--Andy
P.S. I'm still hoping to kill TIF_IA32 entirely some time soon.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] x86/signal: fix restart_syscall number for x32 tasks
2015-12-07 23:22 [PATCH] x86/signal: fix restart_syscall number for x32 tasks Andy Lutomirski
@ 2015-12-13 3:44 ` Dmitry V. Levin
2015-12-17 20:27 ` Andy Lutomirski
0 siblings, 1 reply; 9+ messages in thread
From: Dmitry V. Levin @ 2015-12-13 3:44 UTC (permalink / raw)
To: Andy Lutomirski; +Cc: X86 ML, linux-kernel, Elvira Khabirova
On Mon, Dec 07, 2015 at 03:22:06PM -0800, Andy Lutomirski wrote:
> [not real reply because I'm using a bad internet connection right now
> and I'm not set up with my usual Gmane reply hack right now]
>
> The new code is (whitespace-damaged):
>
> static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
> {
> #if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
> return __NR_restart_syscall;
> #else /* !CONFIG_X86_32 && CONFIG_X86_64 */
> return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
> __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
> #endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
> }
>
> This is IMO awful. This use of TIF_IA32 is wrong, and this is
> otherwise gross. Can we do it for real:
>
> if (is_ia32_task())
> return __NR_ia32_restart_syscall;
> else
> return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
> /* preserve x32 bit */
>
> I'd send the patch myself, but you apparently have a good test case
> for this, and I don't.
Unfortunately, this won't compile on CONFIG_X86_32 because
__NR_ia32_restart_syscall is defined for CONFIG_X86_64 only.
Something like this should work:
static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
{
#ifdef CONFIG_X86_64
if (is_ia32_task())
return __NR_ia32_restart_syscall;
# ifdef CONFIG_X86_X32_ABI
if (regs->orig_ax & __X32_SYSCALL_BIT)
return __NR_restart_syscall | __X32_SYSCALL_BIT;
# endif
#endif
return __NR_restart_syscall;
}
I don't see any way to avoid ifdefs here, sorry.
--
ldv
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] x86/signal: fix restart_syscall number for x32 tasks
2015-12-13 3:44 ` Dmitry V. Levin
@ 2015-12-17 20:27 ` Andy Lutomirski
2015-12-18 23:37 ` [PATCH] x86/signal: Cleanup get_nr_restart_syscall Dmitry V. Levin
0 siblings, 1 reply; 9+ messages in thread
From: Andy Lutomirski @ 2015-12-17 20:27 UTC (permalink / raw)
To: Dmitry V. Levin; +Cc: X86 ML, linux-kernel, Elvira Khabirova
On Sat, Dec 12, 2015 at 7:44 PM, Dmitry V. Levin <ldv@altlinux.org> wrote:
> On Mon, Dec 07, 2015 at 03:22:06PM -0800, Andy Lutomirski wrote:
>> [not real reply because I'm using a bad internet connection right now
>> and I'm not set up with my usual Gmane reply hack right now]
>>
>> The new code is (whitespace-damaged):
>>
>> static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
>> {
>> #if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
>> return __NR_restart_syscall;
>> #else /* !CONFIG_X86_32 && CONFIG_X86_64 */
>> return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
>> __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
>> #endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
>> }
>>
>> This is IMO awful. This use of TIF_IA32 is wrong, and this is
>> otherwise gross. Can we do it for real:
>>
>> if (is_ia32_task())
>> return __NR_ia32_restart_syscall;
>> else
>> return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
>> /* preserve x32 bit */
>>
>> I'd send the patch myself, but you apparently have a good test case
>> for this, and I don't.
>
> Unfortunately, this won't compile on CONFIG_X86_32 because
> __NR_ia32_restart_syscall is defined for CONFIG_X86_64 only.
>
> Something like this should work:
>
> static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
> {
> #ifdef CONFIG_X86_64
> if (is_ia32_task())
> return __NR_ia32_restart_syscall;
> # ifdef CONFIG_X86_X32_ABI
> if (regs->orig_ax & __X32_SYSCALL_BIT)
> return __NR_restart_syscall | __X32_SYSCALL_BIT;
> # endif
> #endif
> return __NR_restart_syscall;
> }
Looks good to me. Want to send a patch?
--Andy
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] x86/signal: Cleanup get_nr_restart_syscall
2015-12-17 20:27 ` Andy Lutomirski
@ 2015-12-18 23:37 ` Dmitry V. Levin
2015-12-19 6:34 ` H. Peter Anvin
0 siblings, 1 reply; 9+ messages in thread
From: Dmitry V. Levin @ 2015-12-18 23:37 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, H. Peter Anvin, Andy Lutomirski
Cc: Elvira Khabirova, X86 ML, linux-kernel
Check for TS_COMPAT instead of TIF_IA32 to distinguish ia32 tasks
from 64-bit tasks.
Check for __X32_SYSCALL_BIT only if CONFIG_X86_X32_ABI is defined.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/kernel/signal.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index cb6282c..ff7dedc 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -692,12 +692,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
{
-#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
+#ifdef CONFIG_X86_64
+ if (is_ia32_task())
+ return __NR_ia32_restart_syscall;
+# ifdef CONFIG_X86_X32_ABI
+ if (regs->orig_ax & __X32_SYSCALL_BIT)
+ return __NR_restart_syscall | __X32_SYSCALL_BIT;
+# endif
+#endif
return __NR_restart_syscall;
-#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
- return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
- __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
-#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
}
/*
--
ldv
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] x86/signal: Cleanup get_nr_restart_syscall
2015-12-18 23:37 ` [PATCH] x86/signal: Cleanup get_nr_restart_syscall Dmitry V. Levin
@ 2015-12-19 6:34 ` H. Peter Anvin
2015-12-19 14:43 ` [PATCH v2] " Dmitry V. Levin
0 siblings, 1 reply; 9+ messages in thread
From: H. Peter Anvin @ 2015-12-19 6:34 UTC (permalink / raw)
To: Dmitry V. Levin, Thomas Gleixner, Ingo Molnar, Andy Lutomirski
Cc: Elvira Khabirova, X86 ML, linux-kernel
On 12/18/15 15:37, Dmitry V. Levin wrote:
> Check for TS_COMPAT instead of TIF_IA32 to distinguish ia32 tasks
> from 64-bit tasks.
> Check for __X32_SYSCALL_BIT only if CONFIG_X86_X32_ABI is defined.
>
> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> Cc: Elvira Khabirova <lineprinter0@gmail.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> ---
> arch/x86/kernel/signal.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
> index cb6282c..ff7dedc 100644
> --- a/arch/x86/kernel/signal.c
> +++ b/arch/x86/kernel/signal.c
> @@ -692,12 +692,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
>
> static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
> {
> -#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
> +#ifdef CONFIG_X86_64
> + if (is_ia32_task())
> + return __NR_ia32_restart_syscall;
> +# ifdef CONFIG_X86_X32_ABI
> + if (regs->orig_ax & __X32_SYSCALL_BIT)
> + return __NR_restart_syscall | __X32_SYSCALL_BIT;
> +# endif
> +#endif
> return __NR_restart_syscall;
> -#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
> - return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
> - __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
> -#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
> }
>
> /*
>
I bet you actually made the code slower.
-hpa
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v2] x86/signal: Cleanup get_nr_restart_syscall
2015-12-19 6:34 ` H. Peter Anvin
@ 2015-12-19 14:43 ` Dmitry V. Levin
2015-12-19 20:48 ` Andy Lutomirski
0 siblings, 1 reply; 9+ messages in thread
From: Dmitry V. Levin @ 2015-12-19 14:43 UTC (permalink / raw)
To: H. Peter Anvin, Thomas Gleixner, Ingo Molnar, Andy Lutomirski
Cc: Elvira Khabirova, X86 ML, linux-kernel
Check for TS_COMPAT instead of TIF_IA32 to distinguish ia32 tasks
from 64-bit tasks.
Check for __X32_SYSCALL_BIT iff CONFIG_X86_X32_ABI is defined.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
---
v2: reintroduced __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT)
arch/x86/kernel/signal.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index cb6282c..c07ff5d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -692,12 +692,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
{
-#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
+#ifdef CONFIG_X86_64
+ if (is_ia32_task())
+ return __NR_ia32_restart_syscall;
+#endif
+#ifdef CONFIG_X86_X32_ABI
+ return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
+#else
return __NR_restart_syscall;
-#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
- return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
- __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
-#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
+#endif
}
/*
--
ldv
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v2] x86/signal: Cleanup get_nr_restart_syscall
2015-12-19 14:43 ` [PATCH v2] " Dmitry V. Levin
@ 2015-12-19 20:48 ` Andy Lutomirski
2016-01-11 14:55 ` [RESEND PATCH " Dmitry V. Levin
0 siblings, 1 reply; 9+ messages in thread
From: Andy Lutomirski @ 2015-12-19 20:48 UTC (permalink / raw)
To: Dmitry V. Levin
Cc: H. Peter Anvin, Thomas Gleixner, Ingo Molnar, Andy Lutomirski,
Elvira Khabirova, X86 ML, linux-kernel
On Sat, Dec 19, 2015 at 6:43 AM, Dmitry V. Levin <ldv@altlinux.org> wrote:
> Check for TS_COMPAT instead of TIF_IA32 to distinguish ia32 tasks
> from 64-bit tasks.
> Check for __X32_SYSCALL_BIT iff CONFIG_X86_X32_ABI is defined.
LGTM.
--Andy
^ permalink raw reply [flat|nested] 9+ messages in thread
* [RESEND PATCH v2] x86/signal: Cleanup get_nr_restart_syscall
2015-12-19 20:48 ` Andy Lutomirski
@ 2016-01-11 14:55 ` Dmitry V. Levin
2016-01-19 13:39 ` [tip:x86/asm] x86/signal: Cleanup get_nr_restart_syscall() tip-bot for Dmitry V. Levin
0 siblings, 1 reply; 9+ messages in thread
From: Dmitry V. Levin @ 2016-01-11 14:55 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, H. Peter Anvin
Cc: Andy Lutomirski, Elvira Khabirova, X86 ML, linux-kernel
Date: Thu Dec 17 23:56:52 2015 +0000
Check for TS_COMPAT instead of TIF_IA32 to distinguish ia32 tasks
from 64-bit tasks.
Check for __X32_SYSCALL_BIT iff CONFIG_X86_X32_ABI is defined.
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
---
v2: reintroduced __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT)
arch/x86/kernel/signal.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index cb6282c..c07ff5d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -692,12 +692,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
{
-#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
+#ifdef CONFIG_X86_64
+ if (is_ia32_task())
+ return __NR_ia32_restart_syscall;
+#endif
+#ifdef CONFIG_X86_X32_ABI
+ return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
+#else
return __NR_restart_syscall;
-#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
- return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
- __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
-#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
+#endif
}
/*
--
ldv
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [tip:x86/asm] x86/signal: Cleanup get_nr_restart_syscall()
2016-01-11 14:55 ` [RESEND PATCH " Dmitry V. Levin
@ 2016-01-19 13:39 ` tip-bot for Dmitry V. Levin
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot for Dmitry V. Levin @ 2016-01-19 13:39 UTC (permalink / raw)
To: linux-tip-commits
Cc: dvlasenk, hpa, luto, ldv, linux-kernel, peterz, torvalds,
lineprinter0, luto, brgerst, tglx, mingo, bp
Commit-ID: 95d97adb2bb85d964bae4538e0574e742e522dda
Gitweb: http://git.kernel.org/tip/95d97adb2bb85d964bae4538e0574e742e522dda
Author: Dmitry V. Levin <ldv@altlinux.org>
AuthorDate: Thu, 17 Dec 2015 23:56:52 +0000
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 19 Jan 2016 12:55:47 +0100
x86/signal: Cleanup get_nr_restart_syscall()
Check for TS_COMPAT instead of TIF_IA32 to distinguish ia32
tasks from 64-bit tasks.
Check for __X32_SYSCALL_BIT iff CONFIG_X86_X32_ABI is defined.
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160111145515.GB29007@altlinux.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/signal.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index cb6282c..c07ff5d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -692,12 +692,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
{
-#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
+#ifdef CONFIG_X86_64
+ if (is_ia32_task())
+ return __NR_ia32_restart_syscall;
+#endif
+#ifdef CONFIG_X86_X32_ABI
+ return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
+#else
return __NR_restart_syscall;
-#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
- return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
- __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
-#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
+#endif
}
/*
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2016-01-19 13:40 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-12-07 23:22 [PATCH] x86/signal: fix restart_syscall number for x32 tasks Andy Lutomirski
2015-12-13 3:44 ` Dmitry V. Levin
2015-12-17 20:27 ` Andy Lutomirski
2015-12-18 23:37 ` [PATCH] x86/signal: Cleanup get_nr_restart_syscall Dmitry V. Levin
2015-12-19 6:34 ` H. Peter Anvin
2015-12-19 14:43 ` [PATCH v2] " Dmitry V. Levin
2015-12-19 20:48 ` Andy Lutomirski
2016-01-11 14:55 ` [RESEND PATCH " Dmitry V. Levin
2016-01-19 13:39 ` [tip:x86/asm] x86/signal: Cleanup get_nr_restart_syscall() tip-bot for Dmitry V. Levin
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