Using this helper allows us to avoid the in-kernel calls to the
compat_sys_{f,}statfs64() sycalls, as are necessary for parameter
mangling in arm64's compat handling.Following the example of ksys_* functions, kcompat_sys_* functions are intended to be a drop-in replacement for their compat_sys_* counterparts, with the same calling convention. This is necessary to enable conversion of arm64's syscall handling to use pt_regs wrappers. Signed-off-by: Mark Rutland <[email protected]> Cc: Al Viro <[email protected]> Cc: Dominik Brodowski <[email protected]> Cc: [email protected] --- fs/statfs.c | 14 ++++++++++++-- include/linux/syscalls.h | 8 ++++++++ 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/fs/statfs.c b/fs/statfs.c index 5b2a24f0f263..f0216629621d 100644 --- a/fs/statfs.c +++ b/fs/statfs.c @@ -335,7 +335,7 @@ static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstat return 0; } -COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf) +int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, struct compat_statfs64 __user * buf) { struct kstatfs tmp; int error; @@ -349,7 +349,12 @@ COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, s return error; } -COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf) +COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf) +{ + return kcompat_sys_statfs64(pathname, sz, buf); +} + +int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user * buf) { struct kstatfs tmp; int error; @@ -363,6 +368,11 @@ COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct co return error; } +COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf) +{ + return kcompat_sys_fstatfs64(fd, sz, buf); +} + /* * This is a copy of sys_ustat, just dealing with a structure layout. * Given how simple this syscall is that apporach is more maintainable diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 6723ea51ec99..e0bf3e4bb897 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -59,6 +59,7 @@ struct tms; struct utimbuf; struct mq_attr; struct compat_stat; +struct compat_statfs64; struct compat_timeval; struct robust_list_head; struct getcpu_cache; @@ -1150,6 +1151,13 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, ssize_t ksys_readahead(int fd, loff_t offset, size_t count); unsigned int ksys_personality(unsigned int personality); +#ifdef CONFIG_COMPAT +int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, + struct compat_statfs64 __user * buf); +int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, + struct compat_statfs64 __user * buf); +#endif + /* * The following kernel syscall equivalents are just wrappers to fs-internal * functions. Therefore, provide stubs to be inlined at the callsites. -- 2.11.0
