compat: let architectures define __ARCH_WANT_COMPAT_SYS_GETDENTS64
For architecture dependent compat syscalls in common code an architecture
must define something like __ARCH_WANT_<WHATEVER> if it wants to use the
code.
This however is not true for compat_sys_getdents64 for which architectures
must define __ARCH_OMIT_COMPAT_SYS_GETDENTS64 if they do not want the code.
This leads to the situation where all architectures, except mips, get the
compat code but only x86_64, arm64 and the generic syscall architectures
actually use it.
So invert the logic, so that architectures actively must do something to
get the compat code.
This way a couple of architectures get rid of otherwise dead code.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 82ce217..a4654c6 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -14,6 +14,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef CONFIG_COMPAT
+#define __ARCH_WANT_COMPAT_SYS_GETDENTS64
#define __ARCH_WANT_COMPAT_STAT64
#define __ARCH_WANT_SYS_GETHOSTNAME
#define __ARCH_WANT_SYS_PAUSE
diff --git a/arch/mips/include/asm/unistd.h b/arch/mips/include/asm/unistd.h
index 4d3b928..413d6c6 100644
--- a/arch/mips/include/asm/unistd.h
+++ b/arch/mips/include/asm/unistd.h
@@ -24,7 +24,6 @@
#ifndef __ASSEMBLY__
-#define __ARCH_OMIT_COMPAT_SYS_GETDENTS64
#define __ARCH_WANT_OLD_READDIR
#define __ARCH_WANT_SYS_ALARM
#define __ARCH_WANT_SYS_GETHOSTNAME
diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index c2a4813..f4b5795 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -23,6 +23,7 @@
# include <asm/unistd_64.h>
# include <asm/unistd_64_x32.h>
# define __ARCH_WANT_COMPAT_SYS_TIME
+# define __ARCH_WANT_COMPAT_SYS_GETDENTS64
# endif
diff --git a/fs/compat.c b/fs/compat.c
index 6af20de..0095a69 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -981,7 +981,7 @@
return error;
}
-#ifndef __ARCH_OMIT_COMPAT_SYS_GETDENTS64
+#ifdef __ARCH_WANT_COMPAT_SYS_GETDENTS64
struct compat_getdents_callback64 {
struct dir_context ctx;
@@ -1066,7 +1066,7 @@
fdput(f);
return error;
}
-#endif /* ! __ARCH_OMIT_COMPAT_SYS_GETDENTS64 */
+#endif /* __ARCH_WANT_COMPAT_SYS_GETDENTS64 */
/*
* Exactly like fs/open.c:sys_open(), except that it doesn't set the
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 3f448c6..beded18 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -502,9 +502,11 @@
asmlinkage long compat_sys_getdents(unsigned int fd,
struct compat_linux_dirent __user *dirent,
unsigned int count);
+#ifdef __ARCH_WANT_COMPAT_SYS_GETDENTS64
asmlinkage long compat_sys_getdents64(unsigned int fd,
struct linux_dirent64 __user *dirent,
unsigned int count);
+#endif
asmlinkage long compat_sys_vmsplice(int fd, const struct compat_iovec __user *,
unsigned int nr_segs, unsigned int flags);
asmlinkage long compat_sys_open(const char __user *filename, int flags,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index dde8041..6db6678 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -191,6 +191,7 @@
/* fs/readdir.c */
#define __NR_getdents64 61
+#define __ARCH_WANT_COMPAT_SYS_GETDENTS64
__SC_COMP(__NR_getdents64, sys_getdents64, compat_sys_getdents64)
/* fs/read_write.c */
