* [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-17 1:54 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-17 1:54 UTC (permalink / raw)
To: linux-mips, linux-kernel; +Cc: Ralf Baechle
We can't trust in the caller(userspace) to give signed-extend
parameter, thus futex-wait may fail in some special case.
For example, if 'val' is too big and bit-31 is 1,
the caller may enter endless loop at:
futex_wait_setup()
{
...
if (uval != val) {
queue_unlock(q, *hb);
ret = -EWOULDBLOCK;
...
}
Below assembler code will make it more easy to understand how
the patch take effect :)
Dump of assembler code for function SyS_32_futex:
0xffffffff811b6fe8 <+0>: sll a1,a1,0x0
0xffffffff811b6fec <+4>: sll a2,a2,0x0
0xffffffff811b6ff0 <+8>: j 0xffffffff8121a240 <compat_sys_futex>
0xffffffff811b6ff4 <+12>: sll a5,a5,0x0
Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/kernel/linux32.c | 7 +++++++
arch/mips/kernel/scall64-n32.S | 2 +-
arch/mips/kernel/scall64-o32.S | 2 +-
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 876a75c..922a554 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -349,3 +349,10 @@ SYSCALL_DEFINE6(32_fanotify_mark, int, fanotify_fd, unsigned int, flags,
return sys_fanotify_mark(fanotify_fd, flags, merge_64(a3, a4),
dfd, pathname);
}
+
+SYSCALL_DEFINE6(32_futex, u32 __user *, uaddr, int, op, u32, val,
+ struct compat_timespec __user *, utime, u32 __user *, uaddr2,
+ u32, val3)
+{
+ return compat_sys_futex(uaddr, op, val, utime, uaddr2, val3);
+}
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index b85842f..c956cc9 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -315,7 +315,7 @@ EXPORT(sysn32_call_table)
PTR sys_fremovexattr
PTR sys_tkill
PTR sys_ni_syscall
- PTR compat_sys_futex
+ PTR sys_32_futex
PTR compat_sys_sched_setaffinity /* 6195 */
PTR compat_sys_sched_getaffinity
PTR sys_cacheflush
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 46c4763..f48b18e 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -441,7 +441,7 @@ sys_call_table:
PTR sys_fremovexattr /* 4235 */
PTR sys_tkill
PTR sys_sendfile64
- PTR compat_sys_futex
+ PTR sys_32_futex
PTR compat_sys_sched_setaffinity
PTR compat_sys_sched_getaffinity /* 4240 */
PTR compat_sys_io_setup
--
1.7.4.1
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-17 1:54 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-17 1:54 UTC (permalink / raw)
To: linux-mips, linux-kernel; +Cc: Ralf Baechle
We can't trust in the caller(userspace) to give signed-extend
parameter, thus futex-wait may fail in some special case.
For example, if 'val' is too big and bit-31 is 1,
the caller may enter endless loop at:
futex_wait_setup()
{
...
if (uval != val) {
queue_unlock(q, *hb);
ret = -EWOULDBLOCK;
...
}
Below assembler code will make it more easy to understand how
the patch take effect :)
Dump of assembler code for function SyS_32_futex:
0xffffffff811b6fe8 <+0>: sll a1,a1,0x0
0xffffffff811b6fec <+4>: sll a2,a2,0x0
0xffffffff811b6ff0 <+8>: j 0xffffffff8121a240 <compat_sys_futex>
0xffffffff811b6ff4 <+12>: sll a5,a5,0x0
Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/kernel/linux32.c | 7 +++++++
arch/mips/kernel/scall64-n32.S | 2 +-
arch/mips/kernel/scall64-o32.S | 2 +-
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 876a75c..922a554 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -349,3 +349,10 @@ SYSCALL_DEFINE6(32_fanotify_mark, int, fanotify_fd, unsigned int, flags,
return sys_fanotify_mark(fanotify_fd, flags, merge_64(a3, a4),
dfd, pathname);
}
+
+SYSCALL_DEFINE6(32_futex, u32 __user *, uaddr, int, op, u32, val,
+ struct compat_timespec __user *, utime, u32 __user *, uaddr2,
+ u32, val3)
+{
+ return compat_sys_futex(uaddr, op, val, utime, uaddr2, val3);
+}
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index b85842f..c956cc9 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -315,7 +315,7 @@ EXPORT(sysn32_call_table)
PTR sys_fremovexattr
PTR sys_tkill
PTR sys_ni_syscall
- PTR compat_sys_futex
+ PTR sys_32_futex
PTR compat_sys_sched_setaffinity /* 6195 */
PTR compat_sys_sched_getaffinity
PTR sys_cacheflush
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 46c4763..f48b18e 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -441,7 +441,7 @@ sys_call_table:
PTR sys_fremovexattr /* 4235 */
PTR sys_tkill
PTR sys_sendfile64
- PTR compat_sys_futex
+ PTR sys_32_futex
PTR compat_sys_sched_setaffinity
PTR compat_sys_sched_getaffinity /* 4240 */
PTR compat_sys_io_setup
--
1.7.4.1
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
2011-08-17 1:54 ` Yong Zhang
(?)
@ 2011-08-17 12:43 ` Ralf Baechle
-1 siblings, 0 replies; 16+ messages in thread
From: Ralf Baechle @ 2011-08-17 12:43 UTC (permalink / raw)
To: Yong Zhang; +Cc: linux-mips, linux-kernel
Applied. Thanks Yong!
Ralf
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
2011-08-17 1:54 ` Yong Zhang
(?)
(?)
@ 2011-08-17 17:17 ` David Daney
2011-08-18 2:32 ` Yong Zhang
` (2 more replies)
-1 siblings, 3 replies; 16+ messages in thread
From: David Daney @ 2011-08-17 17:17 UTC (permalink / raw)
To: Yong Zhang; +Cc: linux-mips, linux-kernel, Ralf Baechle
On 08/16/2011 06:54 PM, Yong Zhang wrote:
> We can't trust in the caller(userspace) to give signed-extend
> parameter, thus futex-wait may fail in some special case.
>
> For example, if 'val' is too big and bit-31 is 1,
> the caller may enter endless loop at:
> futex_wait_setup()
> {
> ...
>
> if (uval != val) {
> queue_unlock(q, *hb);
> ret = -EWOULDBLOCK;
>
> ...
> }
>
> Below assembler code will make it more easy to understand how
> the patch take effect :)
>
> Dump of assembler code for function SyS_32_futex:
> 0xffffffff811b6fe8<+0>: sll a1,a1,0x0
> 0xffffffff811b6fec<+4>: sll a2,a2,0x0
> 0xffffffff811b6ff0<+8>: j 0xffffffff8121a240<compat_sys_futex>
> 0xffffffff811b6ff4<+12>: sll a5,a5,0x0
>
> Signed-off-by: Yong Zhang<yong.zhang@windriver.com>
> Cc: Ralf Baechle<ralf@linux-mips.org>
> ---
> arch/mips/kernel/linux32.c | 7 +++++++
> arch/mips/kernel/scall64-n32.S | 2 +-
> arch/mips/kernel/scall64-o32.S | 2 +-
> 3 files changed, 9 insertions(+), 2 deletions(-)
[...]
> diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
> index 876a75c..922a554 100644
> --- a/arch/mips/kernel/linux32.c
> +++ b/arch/mips/kernel/linux32.c
> @@ -349,3 +349,10 @@ SYSCALL_DEFINE6(32_fanotify_mark, int, fanotify_fd, unsigned int, flags,
> return sys_fanotify_mark(fanotify_fd, flags, merge_64(a3, a4),
> dfd, pathname);
> }
> +
> +SYSCALL_DEFINE6(32_futex, u32 __user *, uaddr, int, op, u32, val,
> + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> + u32, val3)
> +{
> + return compat_sys_futex(uaddr, op, val, utime, uaddr2, val3);
> +}
> diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
> index b85842f..c956cc9 100644
> --- a/arch/mips/kernel/scall64-n32.S
> +++ b/arch/mips/kernel/scall64-n32.S
> @@ -315,7 +315,7 @@ EXPORT(sysn32_call_table)
> PTR sys_fremovexattr
> PTR sys_tkill
> PTR sys_ni_syscall
> - PTR compat_sys_futex
> + PTR sys_32_futex
> PTR compat_sys_sched_setaffinity /* 6195 */
> PTR compat_sys_sched_getaffinity
> PTR sys_cacheflush
> diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> index 46c4763..f48b18e 100644
> --- a/arch/mips/kernel/scall64-o32.S
> +++ b/arch/mips/kernel/scall64-o32.S
> @@ -441,7 +441,7 @@ sys_call_table:
> PTR sys_fremovexattr /* 4235 */
> PTR sys_tkill
> PTR sys_sendfile64
> - PTR compat_sys_futex
> + PTR sys_32_futex
This change is redundant, scall64-o32.S already does the right thing
so additional zero extending is not needed and is just extra
instructions to execute for no reason.
> PTR compat_sys_sched_setaffinity
> PTR compat_sys_sched_getaffinity /* 4240 */
> PTR compat_sys_io_setup
But really I think this patch fixes things at the wrong level. Each
architecture potentially needs a similar patch. What would happen if
we did something like:
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 5f9e689..74ada65 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -180,9 +180,9 @@ err_unlock:
return ret;
}
-asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
- struct compat_timespec __user *utime, u32 __user *uaddr2,
- u32 val3)
+SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
+ struct compat_timespec __user *, utime, u32 __user *, uaddr2,
+ u32, val3)
{
struct timespec ts;
ktime_t t, *tp = NULL;
Obviously the function name is wrong, but a varient of
SYSCALL_DEFINE*() could be created so the proper function names are
produced.
David Daney
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-18 2:32 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-18 2:32 UTC (permalink / raw)
To: David Daney; +Cc: linux-mips, linux-kernel, Ralf Baechle
On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> >diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> >index 46c4763..f48b18e 100644
> >--- a/arch/mips/kernel/scall64-o32.S
> >+++ b/arch/mips/kernel/scall64-o32.S
> >@@ -441,7 +441,7 @@ sys_call_table:
> > PTR sys_fremovexattr /* 4235 */
> > PTR sys_tkill
> > PTR sys_sendfile64
> >- PTR compat_sys_futex
> >+ PTR sys_32_futex
>
> This change is redundant, scall64-o32.S already does the right thing
My first virsion(not sent out) doesn't include scall64-o32.S either.
> so additional zero extending is not needed and is just extra
> instructions to execute for no reason.
Why I'm adding it here is for:
1)code consistent, otherwise we must move SYSCALL_DEFINE6(32_futex,...)
under CONFIG_MIPS32_N32;
2)I'm afraid there may be some other way to touch the high 32-bit of a
register, so touching scall64-o32.S is also for safety(due to unknown
reason, fix me if I'm wrong).
Thanks,
Yong
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-18 2:32 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-18 2:32 UTC (permalink / raw)
To: David Daney; +Cc: linux-mips, linux-kernel, Ralf Baechle
On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> >diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> >index 46c4763..f48b18e 100644
> >--- a/arch/mips/kernel/scall64-o32.S
> >+++ b/arch/mips/kernel/scall64-o32.S
> >@@ -441,7 +441,7 @@ sys_call_table:
> > PTR sys_fremovexattr /* 4235 */
> > PTR sys_tkill
> > PTR sys_sendfile64
> >- PTR compat_sys_futex
> >+ PTR sys_32_futex
>
> This change is redundant, scall64-o32.S already does the right thing
My first virsion(not sent out) doesn't include scall64-o32.S either.
> so additional zero extending is not needed and is just extra
> instructions to execute for no reason.
Why I'm adding it here is for:
1)code consistent, otherwise we must move SYSCALL_DEFINE6(32_futex,...)
under CONFIG_MIPS32_N32;
2)I'm afraid there may be some other way to touch the high 32-bit of a
register, so touching scall64-o32.S is also for safety(due to unknown
reason, fix me if I'm wrong).
Thanks,
Yong
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-18 2:44 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-18 2:44 UTC (permalink / raw)
To: David Daney; +Cc: linux-mips, linux-kernel, Ralf Baechle
On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> > PTR compat_sys_sched_setaffinity
> > PTR compat_sys_sched_getaffinity /* 4240 */
> > PTR compat_sys_io_setup
>
> But really I think this patch fixes things at the wrong level. Each
> architecture potentially needs a similar patch. What would happen if
> we did something like:
I have thought about it but finally I decide to keep it under arch code;
because sparc64 and s390 have the same issue and they all smooth the
concern by themselves.
For sparc64:
arch/sparc/kernel/sys32.S:
91: SIGN3(sys32_futex, compat_sys_futex, %o1, %o2, %o5)
For s390:
arch/s390/kernel/compat_wrapper.S
ENTRY(compat_sys_futex_wrapper)
llgtr %r2,%r2 # u32 *
lgfr %r3,%r3 # int
lgfr %r4,%r4 # int
llgtr %r5,%r5 # struct compat_timespec *
llgtr %r6,%r6 # u32 *
lgf %r0,164(%r15) # int
stg %r0,160(%r15)
jg compat_sys_futex # branch to system call
Maybe we can consolidate all of this like your patch in the future,
but it's a different issue.
Thanks,
Yong
>
>
> diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
> index 5f9e689..74ada65 100644
> --- a/kernel/futex_compat.c
> +++ b/kernel/futex_compat.c
> @@ -180,9 +180,9 @@ err_unlock:
> return ret;
> }
>
> -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> - struct compat_timespec __user *utime, u32 __user *uaddr2,
> - u32 val3)
> +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> + u32, val3)
> {
> struct timespec ts;
> ktime_t t, *tp = NULL;
>
> Obviously the function name is wrong, but a varient of
> SYSCALL_DEFINE*() could be created so the proper function names are
> produced.
>
> David Daney
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-18 2:44 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-18 2:44 UTC (permalink / raw)
To: David Daney; +Cc: linux-mips, linux-kernel, Ralf Baechle
On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> > PTR compat_sys_sched_setaffinity
> > PTR compat_sys_sched_getaffinity /* 4240 */
> > PTR compat_sys_io_setup
>
> But really I think this patch fixes things at the wrong level. Each
> architecture potentially needs a similar patch. What would happen if
> we did something like:
I have thought about it but finally I decide to keep it under arch code;
because sparc64 and s390 have the same issue and they all smooth the
concern by themselves.
For sparc64:
arch/sparc/kernel/sys32.S:
91: SIGN3(sys32_futex, compat_sys_futex, %o1, %o2, %o5)
For s390:
arch/s390/kernel/compat_wrapper.S
ENTRY(compat_sys_futex_wrapper)
llgtr %r2,%r2 # u32 *
lgfr %r3,%r3 # int
lgfr %r4,%r4 # int
llgtr %r5,%r5 # struct compat_timespec *
llgtr %r6,%r6 # u32 *
lgf %r0,164(%r15) # int
stg %r0,160(%r15)
jg compat_sys_futex # branch to system call
Maybe we can consolidate all of this like your patch in the future,
but it's a different issue.
Thanks,
Yong
>
>
> diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
> index 5f9e689..74ada65 100644
> --- a/kernel/futex_compat.c
> +++ b/kernel/futex_compat.c
> @@ -180,9 +180,9 @@ err_unlock:
> return ret;
> }
>
> -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> - struct compat_timespec __user *utime, u32 __user *uaddr2,
> - u32 val3)
> +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> + u32, val3)
> {
> struct timespec ts;
> ktime_t t, *tp = NULL;
>
> Obviously the function name is wrong, but a varient of
> SYSCALL_DEFINE*() could be created so the proper function names are
> produced.
>
> David Daney
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
2011-08-18 2:32 ` Yong Zhang
(?)
@ 2011-08-18 16:23 ` David Daney
2011-08-19 1:56 ` Yong Zhang
-1 siblings, 1 reply; 16+ messages in thread
From: David Daney @ 2011-08-18 16:23 UTC (permalink / raw)
To: Yong Zhang; +Cc: linux-mips, linux-kernel, Ralf Baechle
On 08/17/2011 07:32 PM, Yong Zhang wrote:
> On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
>>> diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
>>> index 46c4763..f48b18e 100644
>>> --- a/arch/mips/kernel/scall64-o32.S
>>> +++ b/arch/mips/kernel/scall64-o32.S
>>> @@ -441,7 +441,7 @@ sys_call_table:
>>> PTR sys_fremovexattr /* 4235 */
>>> PTR sys_tkill
>>> PTR sys_sendfile64
>>> - PTR compat_sys_futex
>>> + PTR sys_32_futex
>>
>> This change is redundant, scall64-o32.S already does the right thing
>
> My first virsion(not sent out) doesn't include scall64-o32.S either.
>
>> so additional zero extending is not needed and is just extra
>> instructions to execute for no reason.
>
> Why I'm adding it here is for:
> 1)code consistent, otherwise we must move SYSCALL_DEFINE6(32_futex,...)
> under CONFIG_MIPS32_N32;
No, you don't have to move it. Just don't call it.
> 2)I'm afraid there may be some other way to touch the high 32-bit of a
> register, so touching scall64-o32.S is also for safety(due to unknown
> reason, fix me if I'm wrong).
OK: You are mistaken. You claim you don't understand what the code
does. That is really a poor justification for modifying it.
David Daney
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
2011-08-17 17:17 ` David Daney
2011-08-18 2:32 ` Yong Zhang
2011-08-18 2:44 ` Yong Zhang
@ 2011-08-18 20:19 ` Ralf Baechle
2011-08-19 3:49 ` Yong Zhang
2 siblings, 1 reply; 16+ messages in thread
From: Ralf Baechle @ 2011-08-18 20:19 UTC (permalink / raw)
To: David Daney; +Cc: Yong Zhang, linux-mips, linux-kernel
On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> >diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> >index 46c4763..f48b18e 100644
> >--- a/arch/mips/kernel/scall64-o32.S
> >+++ b/arch/mips/kernel/scall64-o32.S
> >@@ -441,7 +441,7 @@ sys_call_table:
> > PTR sys_fremovexattr /* 4235 */
> > PTR sys_tkill
> > PTR sys_sendfile64
> >- PTR compat_sys_futex
> >+ PTR sys_32_futex
>
> This change is redundant, scall64-o32.S already does the right thing
> so additional zero extending is not needed and is just extra
> instructions to execute for no reason.
Compat_sys_futex is a syscall entry point and for some configurations
such as CONFIG_FTRACE_SYSCALLS SYSCALL_DEFINE*() will do additional work
beyond cleaning up the arguments. The 3 unnecessary shifts are the
overhead we just gotta live with.
> > PTR compat_sys_sched_setaffinity
> > PTR compat_sys_sched_getaffinity /* 4240 */
> > PTR compat_sys_io_setup
>
> But really I think this patch fixes things at the wrong level. Each
> architecture potentially needs a similar patch. What would happen if
> we did something like:
> +++ b/kernel/futex_compat.c
> @@ -180,9 +180,9 @@ err_unlock:
> return ret;
> }
>
> -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> - struct compat_timespec __user *utime, u32 __user *uaddr2,
> - u32 val3)
> +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> + u32, val3)
> {
> struct timespec ts;
> ktime_t t, *tp = NULL;
>
> Obviously the function name is wrong, but a varient of
> SYSCALL_DEFINE*() could be created so the proper function names are
> produced.
Right now none of the the generic compat_ functions is wrapped in
SYSCALL_DEFINE* because for some architectures a further wrapper function
is needed. It seems some architectures call compat_ calls directly
without SYSCALL_DEFINE* which with CONFIG_FTRACE_SYSCALLS is a bug ...
Ralf
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-19 1:56 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-19 1:56 UTC (permalink / raw)
To: David Daney; +Cc: linux-mips, linux-kernel, Ralf Baechle
On Thu, Aug 18, 2011 at 09:23:41AM -0700, David Daney wrote:
> On 08/17/2011 07:32 PM, Yong Zhang wrote:
> >On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> >>>diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> >>>index 46c4763..f48b18e 100644
> >>>--- a/arch/mips/kernel/scall64-o32.S
> >>>+++ b/arch/mips/kernel/scall64-o32.S
> >>>@@ -441,7 +441,7 @@ sys_call_table:
> >>> PTR sys_fremovexattr /* 4235 */
> >>> PTR sys_tkill
> >>> PTR sys_sendfile64
> >>>- PTR compat_sys_futex
> >>>+ PTR sys_32_futex
> >>
> >>This change is redundant, scall64-o32.S already does the right thing
> >
> >My first virsion(not sent out) doesn't include scall64-o32.S either.
> >
> >>so additional zero extending is not needed and is just extra
> >>instructions to execute for no reason.
> >
> >Why I'm adding it here is for:
> >1)code consistent, otherwise we must move SYSCALL_DEFINE6(32_futex,...)
> > under CONFIG_MIPS32_N32;
>
> No, you don't have to move it. Just don't call it.
>
>
> >2)I'm afraid there may be some other way to touch the high 32-bit of a
> > register, so touching scall64-o32.S is also for safety(due to unknown
> > reason, fix me if I'm wrong).
>
> OK: You are mistaken. You claim you don't understand what the code
> does. That is really a poor justification for modifying it.
If you don't like it and you are sure there is no potential security problem,
just make a patch to remove it. Go ahead.
Thanks,
Yong
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex
@ 2011-08-19 1:56 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-19 1:56 UTC (permalink / raw)
To: David Daney; +Cc: linux-mips, linux-kernel, Ralf Baechle
On Thu, Aug 18, 2011 at 09:23:41AM -0700, David Daney wrote:
> On 08/17/2011 07:32 PM, Yong Zhang wrote:
> >On Wed, Aug 17, 2011 at 10:17:52AM -0700, David Daney wrote:
> >>>diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> >>>index 46c4763..f48b18e 100644
> >>>--- a/arch/mips/kernel/scall64-o32.S
> >>>+++ b/arch/mips/kernel/scall64-o32.S
> >>>@@ -441,7 +441,7 @@ sys_call_table:
> >>> PTR sys_fremovexattr /* 4235 */
> >>> PTR sys_tkill
> >>> PTR sys_sendfile64
> >>>- PTR compat_sys_futex
> >>>+ PTR sys_32_futex
> >>
> >>This change is redundant, scall64-o32.S already does the right thing
> >
> >My first virsion(not sent out) doesn't include scall64-o32.S either.
> >
> >>so additional zero extending is not needed and is just extra
> >>instructions to execute for no reason.
> >
> >Why I'm adding it here is for:
> >1)code consistent, otherwise we must move SYSCALL_DEFINE6(32_futex,...)
> > under CONFIG_MIPS32_N32;
>
> No, you don't have to move it. Just don't call it.
>
>
> >2)I'm afraid there may be some other way to touch the high 32-bit of a
> > register, so touching scall64-o32.S is also for safety(due to unknown
> > reason, fix me if I'm wrong).
>
> OK: You are mistaken. You claim you don't understand what the code
> does. That is really a poor justification for modifying it.
If you don't like it and you are sure there is no potential security problem,
just make a patch to remove it. Go ahead.
Thanks,
Yong
^ permalink raw reply [flat|nested] 16+ messages in thread
* How to trace compat syscalls? [Was Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex]
2011-08-18 20:19 ` Ralf Baechle
@ 2011-08-19 3:49 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-19 3:49 UTC (permalink / raw)
To: Ralf Baechle
Cc: David Daney, linux-mips, linux-kernel, linux-arch, Yong Zhang,
Steven Rostedt, Frederic Weisbecker, Ingo Molnar,
Martin Schwidefsky, David S. Miller, Thomas Gleixner,
Andrew Morton
Cc'ing more people.
On Thu, Aug 18, 2011 at 09:19:11PM +0100, Ralf Baechle wrote:
> > But really I think this patch fixes things at the wrong level. Each
> > architecture potentially needs a similar patch. What would happen if
> > we did something like:
>
> > +++ b/kernel/futex_compat.c
> > @@ -180,9 +180,9 @@ err_unlock:
> > return ret;
> > }
> >
> > -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> > - struct compat_timespec __user *utime, u32 __user *uaddr2,
> > - u32 val3)
> > +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> > + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> > + u32, val3)
> > {
> > struct timespec ts;
> > ktime_t t, *tp = NULL;
> >
> > Obviously the function name is wrong, but a varient of
> > SYSCALL_DEFINE*() could be created so the proper function names are
> > produced.
>
> Right now none of the the generic compat_ functions is wrapped in
> SYSCALL_DEFINE* because for some architectures a further wrapper function
> is needed. It seems some architectures call compat_ calls directly
> without SYSCALL_DEFINE* which with CONFIG_FTRACE_SYSCALLS is a bug ...
Just checked some archs which have HAVE_SYSCALL_TRACEPOINTS=y and could
call compat_* syscalls when run 32bit process on 64bit kernel, I don't
find any special code against FTRACE_SYSCALLS. So that means we could
not trace compat syscalls even if we want to(Am I missing something?).
So I think if we want to trace it, the easy way is just like what we have
done on normal syscalls, IOW, we could SYSCALL_DEFINE all of the compat
syscalls.
Thought?
BTW, I have make a trival patch to introduce COMPAT_SYSCALL_DEFINE, it's just
for calling of inspiration(no test no build, and I leave SYSCALL_METADATA
etc untouched.)
Thanks,
Yong
---
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 8c03b98..e79027f 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -221,26 +221,38 @@ extern struct trace_event_functions exit_syscall_print_funcs;
__SC_STR_ADECL##x(__VA_ARGS__) \
}; \
SYSCALL_METADATA(sname, x); \
- __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+ __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
+
+#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
+ static const char *types_compat_##sname[] = { \
+ __SC_STR_TDECL##x(__VA_ARGS__) \
+ }; \
+ static const char *args_compat_##sname[] = { \
+ __SC_STR_ADECL##x(__VA_ARGS__) \
+ }; \
+ SYSCALL_METADATA(compat, sname, x); \
+ __SYSCALL_DEFINEx(cmopat_, x, sname, __VA_ARGS__)
#else
#define SYSCALL_DEFINEx(x, sname, ...) \
- __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+ __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
+ __SYSCALL_DEFINEx(compat_, x, sname, __VA_ARGS__)
#endif
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
-#define SYSCALL_DEFINE(name) static inline long SYSC_##name
+#define SYSCALL_DEFINE(compat, name) static inline long compat##SYSC_##name
-#define __SYSCALL_DEFINEx(x, name, ...) \
- asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__)); \
- static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__)); \
- asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__)) \
+#define __SYSCALL_DEFINEx(compat, x, name, ...) \
+ asmlinkage long compat##sys##name(__SC_DECL##x(__VA_ARGS__)); \
+ static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__));\
+ asmlinkage long compat##SyS##name(__SC_LONG##x(__VA_ARGS__)) \
{ \
__SC_TEST##x(__VA_ARGS__); \
- return (long) SYSC##name(__SC_CAST##x(__VA_ARGS__)); \
+ return (long) compat##SYSC##name(__SC_CAST##x(__VA_ARGS__));\
} \
- SYSCALL_ALIAS(sys##name, SyS##name); \
- static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__))
+ SYSCALL_ALIAS(compat##sys##name, compat##SyS##name); \
+ static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__))
#else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
^ permalink raw reply related [flat|nested] 16+ messages in thread
* How to trace compat syscalls? [Was Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex]
@ 2011-08-19 3:49 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-19 3:49 UTC (permalink / raw)
To: Ralf Baechle
Cc: David Daney, linux-mips, linux-kernel, linux-arch, Yong Zhang,
Steven Rostedt, Frederic Weisbecker, Ingo Molnar,
Martin Schwidefsky, David S. Miller, Thomas Gleixner,
Andrew Morton
Cc'ing more people.
On Thu, Aug 18, 2011 at 09:19:11PM +0100, Ralf Baechle wrote:
> > But really I think this patch fixes things at the wrong level. Each
> > architecture potentially needs a similar patch. What would happen if
> > we did something like:
>
> > +++ b/kernel/futex_compat.c
> > @@ -180,9 +180,9 @@ err_unlock:
> > return ret;
> > }
> >
> > -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> > - struct compat_timespec __user *utime, u32 __user *uaddr2,
> > - u32 val3)
> > +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> > + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> > + u32, val3)
> > {
> > struct timespec ts;
> > ktime_t t, *tp = NULL;
> >
> > Obviously the function name is wrong, but a varient of
> > SYSCALL_DEFINE*() could be created so the proper function names are
> > produced.
>
> Right now none of the the generic compat_ functions is wrapped in
> SYSCALL_DEFINE* because for some architectures a further wrapper function
> is needed. It seems some architectures call compat_ calls directly
> without SYSCALL_DEFINE* which with CONFIG_FTRACE_SYSCALLS is a bug ...
Just checked some archs which have HAVE_SYSCALL_TRACEPOINTS=y and could
call compat_* syscalls when run 32bit process on 64bit kernel, I don't
find any special code against FTRACE_SYSCALLS. So that means we could
not trace compat syscalls even if we want to(Am I missing something?).
So I think if we want to trace it, the easy way is just like what we have
done on normal syscalls, IOW, we could SYSCALL_DEFINE all of the compat
syscalls.
Thought?
BTW, I have make a trival patch to introduce COMPAT_SYSCALL_DEFINE, it's just
for calling of inspiration(no test no build, and I leave SYSCALL_METADATA
etc untouched.)
Thanks,
Yong
---
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 8c03b98..e79027f 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -221,26 +221,38 @@ extern struct trace_event_functions exit_syscall_print_funcs;
__SC_STR_ADECL##x(__VA_ARGS__) \
}; \
SYSCALL_METADATA(sname, x); \
- __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+ __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
+
+#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
+ static const char *types_compat_##sname[] = { \
+ __SC_STR_TDECL##x(__VA_ARGS__) \
+ }; \
+ static const char *args_compat_##sname[] = { \
+ __SC_STR_ADECL##x(__VA_ARGS__) \
+ }; \
+ SYSCALL_METADATA(compat, sname, x); \
+ __SYSCALL_DEFINEx(cmopat_, x, sname, __VA_ARGS__)
#else
#define SYSCALL_DEFINEx(x, sname, ...) \
- __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+ __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
+ __SYSCALL_DEFINEx(compat_, x, sname, __VA_ARGS__)
#endif
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
-#define SYSCALL_DEFINE(name) static inline long SYSC_##name
+#define SYSCALL_DEFINE(compat, name) static inline long compat##SYSC_##name
-#define __SYSCALL_DEFINEx(x, name, ...) \
- asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__)); \
- static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__)); \
- asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__)) \
+#define __SYSCALL_DEFINEx(compat, x, name, ...) \
+ asmlinkage long compat##sys##name(__SC_DECL##x(__VA_ARGS__)); \
+ static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__));\
+ asmlinkage long compat##SyS##name(__SC_LONG##x(__VA_ARGS__)) \
{ \
__SC_TEST##x(__VA_ARGS__); \
- return (long) SYSC##name(__SC_CAST##x(__VA_ARGS__)); \
+ return (long) compat##SYSC##name(__SC_CAST##x(__VA_ARGS__));\
} \
- SYSCALL_ALIAS(sys##name, SyS##name); \
- static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__))
+ SYSCALL_ALIAS(compat##sys##name, compat##SyS##name); \
+ static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__))
#else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: How to trace compat syscalls? [Was Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex]
2011-08-19 3:49 ` Yong Zhang
@ 2011-08-19 4:15 ` Yong Zhang
-1 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-19 4:15 UTC (permalink / raw)
To: Ralf Baechle
Cc: David Daney, linux-mips, linux-kernel, linux-arch, Yong Zhang,
Steven Rostedt, Frederic Weisbecker, Ingo Molnar,
Martin Schwidefsky, David S. Miller, Thomas Gleixner,
Andrew Morton
On Fri, Aug 19, 2011 at 11:49:50AM +0800, Yong Zhang wrote:
> Cc'ing more people.
>
> On Thu, Aug 18, 2011 at 09:19:11PM +0100, Ralf Baechle wrote:
> > > But really I think this patch fixes things at the wrong level. Each
> > > architecture potentially needs a similar patch. What would happen if
> > > we did something like:
> >
> > > +++ b/kernel/futex_compat.c
> > > @@ -180,9 +180,9 @@ err_unlock:
> > > return ret;
> > > }
> > >
> > > -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> > > - struct compat_timespec __user *utime, u32 __user *uaddr2,
> > > - u32 val3)
> > > +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> > > + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> > > + u32, val3)
> > > {
> > > struct timespec ts;
> > > ktime_t t, *tp = NULL;
> > >
> > > Obviously the function name is wrong, but a varient of
> > > SYSCALL_DEFINE*() could be created so the proper function names are
> > > produced.
> >
> > Right now none of the the generic compat_ functions is wrapped in
> > SYSCALL_DEFINE* because for some architectures a further wrapper function
> > is needed. It seems some architectures call compat_ calls directly
> > without SYSCALL_DEFINE* which with CONFIG_FTRACE_SYSCALLS is a bug ...
>
> Just checked some archs which have HAVE_SYSCALL_TRACEPOINTS=y and could
> call compat_* syscalls when run 32bit process on 64bit kernel, I don't
> find any special code against FTRACE_SYSCALLS. So that means we could
> not trace compat syscalls even if we want to(Am I missing something?).
> So I think if we want to trace it, the easy way is just like what we have
> done on normal syscalls, IOW, we could SYSCALL_DEFINE all of the compat
> syscalls.
Except the ones which call sys_* finally, :)
>
> Thought?
>
> BTW, I have make a trival patch to introduce COMPAT_SYSCALL_DEFINE, it's just
> for calling of inspiration(no test no build, and I leave SYSCALL_METADATA
> etc untouched.)
>
> Thanks,
> Yong
>
> ---
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index 8c03b98..e79027f 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -221,26 +221,38 @@ extern struct trace_event_functions exit_syscall_print_funcs;
> __SC_STR_ADECL##x(__VA_ARGS__) \
> }; \
> SYSCALL_METADATA(sname, x); \
> - __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
> + __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
> +
> +#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
> + static const char *types_compat_##sname[] = { \
> + __SC_STR_TDECL##x(__VA_ARGS__) \
> + }; \
> + static const char *args_compat_##sname[] = { \
> + __SC_STR_ADECL##x(__VA_ARGS__) \
> + }; \
> + SYSCALL_METADATA(compat, sname, x); \
> + __SYSCALL_DEFINEx(cmopat_, x, sname, __VA_ARGS__)
> #else
> #define SYSCALL_DEFINEx(x, sname, ...) \
> - __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
> + __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
> +#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
> + __SYSCALL_DEFINEx(compat_, x, sname, __VA_ARGS__)
> #endif
>
> #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
>
> -#define SYSCALL_DEFINE(name) static inline long SYSC_##name
> +#define SYSCALL_DEFINE(compat, name) static inline long compat##SYSC_##name
>
> -#define __SYSCALL_DEFINEx(x, name, ...) \
> - asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__)); \
> - static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__)); \
> - asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__)) \
> +#define __SYSCALL_DEFINEx(compat, x, name, ...) \
> + asmlinkage long compat##sys##name(__SC_DECL##x(__VA_ARGS__)); \
> + static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__));\
> + asmlinkage long compat##SyS##name(__SC_LONG##x(__VA_ARGS__)) \
> { \
> __SC_TEST##x(__VA_ARGS__); \
> - return (long) SYSC##name(__SC_CAST##x(__VA_ARGS__)); \
> + return (long) compat##SYSC##name(__SC_CAST##x(__VA_ARGS__));\
> } \
> - SYSCALL_ALIAS(sys##name, SyS##name); \
> - static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__))
> + SYSCALL_ALIAS(compat##sys##name, compat##SyS##name); \
> + static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__))
>
> #else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: How to trace compat syscalls? [Was Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex]
@ 2011-08-19 4:15 ` Yong Zhang
0 siblings, 0 replies; 16+ messages in thread
From: Yong Zhang @ 2011-08-19 4:15 UTC (permalink / raw)
To: Ralf Baechle
Cc: David Daney, linux-mips, linux-kernel, linux-arch, Yong Zhang,
Steven Rostedt, Frederic Weisbecker, Ingo Molnar,
Martin Schwidefsky, David S. Miller, Thomas Gleixner,
Andrew Morton
On Fri, Aug 19, 2011 at 11:49:50AM +0800, Yong Zhang wrote:
> Cc'ing more people.
>
> On Thu, Aug 18, 2011 at 09:19:11PM +0100, Ralf Baechle wrote:
> > > But really I think this patch fixes things at the wrong level. Each
> > > architecture potentially needs a similar patch. What would happen if
> > > we did something like:
> >
> > > +++ b/kernel/futex_compat.c
> > > @@ -180,9 +180,9 @@ err_unlock:
> > > return ret;
> > > }
> > >
> > > -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> > > - struct compat_timespec __user *utime, u32 __user *uaddr2,
> > > - u32 val3)
> > > +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> > > + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> > > + u32, val3)
> > > {
> > > struct timespec ts;
> > > ktime_t t, *tp = NULL;
> > >
> > > Obviously the function name is wrong, but a varient of
> > > SYSCALL_DEFINE*() could be created so the proper function names are
> > > produced.
> >
> > Right now none of the the generic compat_ functions is wrapped in
> > SYSCALL_DEFINE* because for some architectures a further wrapper function
> > is needed. It seems some architectures call compat_ calls directly
> > without SYSCALL_DEFINE* which with CONFIG_FTRACE_SYSCALLS is a bug ...
>
> Just checked some archs which have HAVE_SYSCALL_TRACEPOINTS=y and could
> call compat_* syscalls when run 32bit process on 64bit kernel, I don't
> find any special code against FTRACE_SYSCALLS. So that means we could
> not trace compat syscalls even if we want to(Am I missing something?).
> So I think if we want to trace it, the easy way is just like what we have
> done on normal syscalls, IOW, we could SYSCALL_DEFINE all of the compat
> syscalls.
Except the ones which call sys_* finally, :)
>
> Thought?
>
> BTW, I have make a trival patch to introduce COMPAT_SYSCALL_DEFINE, it's just
> for calling of inspiration(no test no build, and I leave SYSCALL_METADATA
> etc untouched.)
>
> Thanks,
> Yong
>
> ---
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index 8c03b98..e79027f 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -221,26 +221,38 @@ extern struct trace_event_functions exit_syscall_print_funcs;
> __SC_STR_ADECL##x(__VA_ARGS__) \
> }; \
> SYSCALL_METADATA(sname, x); \
> - __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
> + __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
> +
> +#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
> + static const char *types_compat_##sname[] = { \
> + __SC_STR_TDECL##x(__VA_ARGS__) \
> + }; \
> + static const char *args_compat_##sname[] = { \
> + __SC_STR_ADECL##x(__VA_ARGS__) \
> + }; \
> + SYSCALL_METADATA(compat, sname, x); \
> + __SYSCALL_DEFINEx(cmopat_, x, sname, __VA_ARGS__)
> #else
> #define SYSCALL_DEFINEx(x, sname, ...) \
> - __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
> + __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
> +#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
> + __SYSCALL_DEFINEx(compat_, x, sname, __VA_ARGS__)
> #endif
>
> #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
>
> -#define SYSCALL_DEFINE(name) static inline long SYSC_##name
> +#define SYSCALL_DEFINE(compat, name) static inline long compat##SYSC_##name
>
> -#define __SYSCALL_DEFINEx(x, name, ...) \
> - asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__)); \
> - static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__)); \
> - asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__)) \
> +#define __SYSCALL_DEFINEx(compat, x, name, ...) \
> + asmlinkage long compat##sys##name(__SC_DECL##x(__VA_ARGS__)); \
> + static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__));\
> + asmlinkage long compat##SyS##name(__SC_LONG##x(__VA_ARGS__)) \
> { \
> __SC_TEST##x(__VA_ARGS__); \
> - return (long) SYSC##name(__SC_CAST##x(__VA_ARGS__)); \
> + return (long) compat##SYSC##name(__SC_CAST##x(__VA_ARGS__));\
> } \
> - SYSCALL_ALIAS(sys##name, SyS##name); \
> - static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__))
> + SYSCALL_ALIAS(compat##sys##name, compat##SyS##name); \
> + static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__))
>
> #else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
>
^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2011-08-19 4:16 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-08-17 1:54 [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex Yong Zhang
2011-08-17 1:54 ` Yong Zhang
2011-08-17 12:43 ` Ralf Baechle
2011-08-17 17:17 ` David Daney
2011-08-18 2:32 ` Yong Zhang
2011-08-18 2:32 ` Yong Zhang
2011-08-18 16:23 ` David Daney
2011-08-19 1:56 ` Yong Zhang
2011-08-19 1:56 ` Yong Zhang
2011-08-18 2:44 ` Yong Zhang
2011-08-18 2:44 ` Yong Zhang
2011-08-18 20:19 ` Ralf Baechle
2011-08-19 3:49 ` How to trace compat syscalls? [Was Re: [PATCH] MIPS: use 32-bit wrapper for compat_sys_futex] Yong Zhang
2011-08-19 3:49 ` Yong Zhang
2011-08-19 4:15 ` Yong Zhang
2011-08-19 4:15 ` Yong Zhang
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.