[PATCH 11/14] y2038: utimes: Rework #ifdef guards for compat syscalls

From: Arnd Bergmann
Date: Mon Aug 27 2018 - 15:46:22 EST


After changing over to 64-bit time_t syscalls, many architectures will
want compat_sys_utimensat() but not respective handlers for utime(),
utimes() and futimesat(). This adds a new __ARCH_WANT_SYS_UTIME32 to
complement __ARCH_WANT_SYS_UTIME. For now, all 64-bit architectures that
support CONFIG_COMPAT set it, but future 64-bit architectures will not
(tile would not have needed it either, but got removed).

As older 32-bit architectures get converted to using CONFIG_64BIT_TIME,
they will have to use __ARCH_WANT_SYS_UTIME32 instead of
__ARCH_WANT_SYS_UTIME. Architectures using the generic syscall ABI don't
need either of them as they never had a utime syscall.

Since the compat_utimbuf structure is now required outside of
CONFIG_COMPAT, I'm moving it into compat_time.h.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
changed from last version:
- renamed __ARCH_WANT_COMPAT_SYS_UTIME to __ARCH_WANT_SYS_UTIME32
---
arch/arm64/include/asm/unistd.h | 1 +
arch/mips/include/asm/unistd.h | 1 +
arch/parisc/include/asm/unistd.h | 1 +
arch/powerpc/include/asm/unistd.h | 1 +
arch/s390/include/asm/unistd.h | 1 +
arch/sparc/include/asm/unistd.h | 1 +
arch/x86/include/asm/unistd.h | 1 +
fs/utimes.c | 8 ++++++--
include/linux/compat.h | 7 +------
include/linux/time32.h | 5 +++++
10 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 2af308f13463..b13ca091f833 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -22,6 +22,7 @@
#define __ARCH_WANT_SYS_SIGPENDING
#define __ARCH_WANT_SYS_SIGPROCMASK
#define __ARCH_WANT_COMPAT_SYS_SENDFILE
+#define __ARCH_WANT_SYS_UTIME32
#define __ARCH_WANT_SYS_FORK
#define __ARCH_WANT_SYS_VFORK

diff --git a/arch/mips/include/asm/unistd.h b/arch/mips/include/asm/unistd.h
index c2174b80e50e..c68b8ae3efcb 100644
--- a/arch/mips/include/asm/unistd.h
+++ b/arch/mips/include/asm/unistd.h
@@ -31,6 +31,7 @@
#define __ARCH_WANT_SYS_IPC
#define __ARCH_WANT_SYS_PAUSE
#define __ARCH_WANT_SYS_UTIME
+#define __ARCH_WANT_SYS_UTIME32
#define __ARCH_WANT_SYS_WAITPID
#define __ARCH_WANT_SYS_SOCKETCALL
#define __ARCH_WANT_SYS_GETPGRP
diff --git a/arch/parisc/include/asm/unistd.h b/arch/parisc/include/asm/unistd.h
index a0c38374fff0..bc37a4953eaa 100644
--- a/arch/parisc/include/asm/unistd.h
+++ b/arch/parisc/include/asm/unistd.h
@@ -152,6 +152,7 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5) \
#define __ARCH_WANT_COMPAT_SYS_TIME
#define __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL
#define __ARCH_WANT_SYS_UTIME
+#define __ARCH_WANT_SYS_UTIME32
#define __ARCH_WANT_SYS_WAITPID
#define __ARCH_WANT_SYS_SOCKETCALL
#define __ARCH_WANT_SYS_FADVISE64
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 9326c9133516..b0de85b477e1 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -47,6 +47,7 @@
#endif
#ifdef CONFIG_PPC64
#define __ARCH_WANT_COMPAT_SYS_TIME
+#define __ARCH_WANT_SYS_UTIME32
#define __ARCH_WANT_SYS_NEWFSTATAT
#define __ARCH_WANT_COMPAT_SYS_SENDFILE
#endif
diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index a2d583ea526d..a1fbf15d53aa 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -34,6 +34,7 @@
#define __ARCH_WANT_SYS_SIGPROCMASK
# ifdef CONFIG_COMPAT
# define __ARCH_WANT_COMPAT_SYS_TIME
+# define __ARCH_WANT_SYS_UTIME32
# endif
#define __ARCH_WANT_SYS_FORK
#define __ARCH_WANT_SYS_VFORK
diff --git a/arch/sparc/include/asm/unistd.h b/arch/sparc/include/asm/unistd.h
index f7514d3eae7b..00f87dbd0b17 100644
--- a/arch/sparc/include/asm/unistd.h
+++ b/arch/sparc/include/asm/unistd.h
@@ -42,6 +42,7 @@
#define __ARCH_WANT_SYS_IPC
#else
#define __ARCH_WANT_COMPAT_SYS_TIME
+#define __ARCH_WANT_SYS_UTIME32
#define __ARCH_WANT_COMPAT_SYS_SENDFILE
#endif

diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index 153d2a5e6b02..dc4ed8bc2382 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -24,6 +24,7 @@
# include <asm/unistd_64.h>
# include <asm/unistd_64_x32.h>
# define __ARCH_WANT_COMPAT_SYS_TIME
+# define __ARCH_WANT_SYS_UTIME32
# define __ARCH_WANT_COMPAT_SYS_PREADV64
# define __ARCH_WANT_COMPAT_SYS_PWRITEV64
# define __ARCH_WANT_COMPAT_SYS_PREADV64V2
diff --git a/fs/utimes.c b/fs/utimes.c
index 2f6f08061a26..bdcf2daf39c1 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -218,13 +218,14 @@ SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
}
#endif

-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_32BIT_TIME
/*
* Not all architectures have sys_utime, so implement this in terms
* of sys_utimes.
*/
+#ifdef __ARCH_WANT_SYS_UTIME32
COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
- struct compat_utimbuf __user *, t)
+ struct old_utimbuf32 __user *, t)
{
struct timespec64 tv[2];

@@ -237,6 +238,7 @@ COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
}
return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
}
+#endif

COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
{
@@ -253,6 +255,7 @@ COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filena
return do_utimes(dfd, filename, t ? tv : NULL, flags);
}

+#ifdef __ARCH_WANT_SYS_UTIME32
static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
struct old_timeval32 __user *t)
{
@@ -285,3 +288,4 @@ COMPAT_SYSCALL_DEFINE2(utimes, const char __user *, filename, struct old_timeval
return do_compat_futimesat(AT_FDCWD, filename, t);
}
#endif
+#endif
diff --git a/include/linux/compat.h b/include/linux/compat.h
index d376fa8be00d..6fb5abdb87be 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -113,11 +113,6 @@ typedef __compat_gid32_t compat_gid_t;
struct compat_sel_arg_struct;
struct rusage;

-struct compat_utimbuf {
- old_time32_t actime;
- old_time32_t modtime;
-};
-
struct compat_itimerval {
struct old_timeval32 it_interval;
struct old_timeval32 it_value;
@@ -942,7 +937,7 @@ asmlinkage long compat_sys_newlstat(const char __user *filename,
/* __ARCH_WANT_SYSCALL_DEPRECATED */
asmlinkage long compat_sys_time(old_time32_t __user *tloc);
asmlinkage long compat_sys_utime(const char __user *filename,
- struct compat_utimbuf __user *t);
+ struct old_utimbuf32 __user *t);
asmlinkage long compat_sys_futimesat(unsigned int dfd,
const char __user *filename,
struct old_timeval32 __user *t);
diff --git a/include/linux/time32.h b/include/linux/time32.h
index 0e0d7304d1a8..61904a6c098f 100644
--- a/include/linux/time32.h
+++ b/include/linux/time32.h
@@ -30,6 +30,11 @@ struct old_itimerspec32 {
struct old_timespec32 it_value;
};

+struct old_utimbuf32 {
+ old_time32_t actime;
+ old_time32_t modtime;
+};
+
extern int get_old_timespec32(struct timespec64 *, const void __user *);
extern int put_old_timespec32(const struct timespec64 *, void __user *);
extern int get_old_itimerspec32(struct itimerspec64 *its,
--
2.18.0