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

From: Greg KH
Date: Tue Jul 01 2014 - 18:43:41 EST


On Tue, Jul 01, 2014 at 11:47:29PM +0200, Thomas Schoebel-Theuer wrote:
> From: Thomas Schoebel-Theuer <schoebel@xxxxxxxxx>
>
> 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@xxxxxxxxx>
> ---
> 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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