Re: [PATCH 49/50] mars: generic pre-patch for mars

Thomas Schoebel-Theuer
2014-07-02T07:19:35Z

I will prepare a new version ASAP.

Is the asmlinkage one of the reasons?

If so, some additional wrappers like vfs_* or kernel_* would have to be
written. This would also complicate portability between the out-of-tree
and the in-tree version of MARS (which I have to maintain in parallel at
least for some years).

It would be great if I just could make the exports of sys_* explicitly.

Thanks and cheers,

Thomas

On 07/02/2014 12:36 AM, Greg KH wrote:
> On Tue, Jul 01, 2014 at 11:47:29PM +0200, Thomas Schoebel-Theuer wrote:
>> From: Thomas Schoebel-Theuer <schoebel@bell.site>
>>
>> Mostly introduces missing EXPORT_SYMBOL().
>> Should have no impact onto the kernel.
>>
>> This is the generic version which exports all sys_*() system
>> calls. This should not introduce any additional maintenance pain
>> because that interfaces has to be stable anyway due to POSIX etc.
>>
>> Signed-off-by: Thomas Schoebel-Theuer <schoebel@bell.site>
>> ---
>> fs/open.c | 1 -
>> fs/utimes.c | 2 ++
>> include/linux/syscalls.h | 3 +++
>> include/uapi/linux/major.h | 1 +
>> mm/page_alloc.c | 3 +++
>> 5 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/open.c b/fs/open.c
>> index 36662d0..3b21b76 100644
>> --- a/fs/open.c
>> +++ b/fs/open.c
>> @@ -1064,7 +1064,6 @@ SYSCALL_DEFINE1(close, unsigned int, fd)
>>
>> return retval;
>> }
>> -EXPORT_SYMBOL(sys_close);
>>
>> /*
>> * This routine simulates a hangup on the tty, to arrange that users
>> diff --git a/fs/utimes.c b/fs/utimes.c
>> index aa138d6..4a1f4a8 100644
>> --- a/fs/utimes.c
>> +++ b/fs/utimes.c
>> @@ -1,3 +1,4 @@
>> +#include <linux/module.h>
>> #include <linux/compiler.h>
>> #include <linux/file.h>
>> #include <linux/fs.h>
>> @@ -181,6 +182,7 @@ retry:
>> out:
>> return error;
>> }
>> +EXPORT_SYMBOL(do_utimes);
>>
>> SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
>> struct timespec __user *, utimes, int, flags)
>> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
>> index b0881a0..c674309 100644
>> --- a/include/linux/syscalls.h
>> +++ b/include/linux/syscalls.h
>> @@ -75,6 +75,7 @@ struct sigaltstack;
>> #include <linux/sem.h>
>> #include <asm/siginfo.h>
>> #include <linux/unistd.h>
>> +#include <linux/export.h>
>> #include <linux/quota.h>
>> #include <linux/key.h>
>> #include <trace/syscall.h>
>> @@ -176,6 +177,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
>>
>> #define SYSCALL_DEFINE0(sname) \
>> SYSCALL_METADATA(_##sname, 0); \
>> + EXPORT_SYMBOL(sys_##sname); \
>> asmlinkage long sys_##sname(void)
>>
>> #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
>> @@ -202,6 +204,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
>> __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
>> return ret; \
>> } \
>> + EXPORT_SYMBOL(sys##name); \
>> static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
>>
> Heh, nice try, but no, we aren't going to export all syscalls, that's
> crazy. And wrong on many levels, sorry.
>
> Be explicit with your exports, and justify _why_ you need them.
>
> thanks,
>
> greg k-h
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