| Message ID | 20180514094640.27569-14-mark.rutland@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, May 14, 2018 at 10:46:35AM +0100, Mark Rutland wrote: > 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. > 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 I've moved these to <linux/compat.h>, so that they live with the rest of the compat syscall stuff. That should avoid build failures the kbuild test robot picked up where compat_size_t wasn't dfined. Thanks, Mark.
On Mon, May 14, 2018 at 06:14:28PM +0100, Mark Rutland wrote: > On Mon, May 14, 2018 at 10:46:35AM +0100, Mark Rutland wrote: > > 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. > > > 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 > > I've moved these to <linux/compat.h>, so that they live with the rest of > the compat syscall stuff. That should avoid build failures the kbuild > test robot picked up where compat_size_t wasn't dfined. Please add a comment there, similar to what is in syscalls.h: /* * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly. * Instead, use one of the functions which work equivalently, such as * the ksys_xyzyyz() functions prototyped below. */ Once you have done so, feel free to add my Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> tag to this patch. Thanks, Dominik
On Mon, May 14, 2018 at 10:34:14PM +0200, Dominik Brodowski wrote: > On Mon, May 14, 2018 at 06:14:28PM +0100, Mark Rutland wrote: > > On Mon, May 14, 2018 at 10:46:35AM +0100, Mark Rutland wrote: > > > +#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 > > > > I've moved these to <linux/compat.h>, so that they live with the rest of > > the compat syscall stuff. That should avoid build failures the kbuild > > test robot picked up where compat_size_t wasn't dfined. > > Please add a comment there, similar to what is in syscalls.h: > > /* > * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly. > * Instead, use one of the functions which work equivalently, such as > * the ksys_xyzyyz() functions prototyped below. > */ To make the kcompat_sys_* naming scheme clearer, I've added compat references to the above, i.e. /* * Kernel code should not call compat syscalls (i.e., compat_sys_xyzyyz()) * directly. Instead, use one of the functions which work equivalently, such * as the kcompat_sys_xyzyyz() functions prototyped below. */ > Once you have done so, feel free to add my > > Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> I hope that this still stands with the changes above? Thanks, Mark.
On Tue, May 15, 2018 at 10:53:51AM +0100, Mark Rutland wrote: > On Mon, May 14, 2018 at 10:34:14PM +0200, Dominik Brodowski wrote: > > On Mon, May 14, 2018 at 06:14:28PM +0100, Mark Rutland wrote: > > > On Mon, May 14, 2018 at 10:46:35AM +0100, Mark Rutland wrote: > > > > +#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 > > > > > > I've moved these to <linux/compat.h>, so that they live with the rest of > > > the compat syscall stuff. That should avoid build failures the kbuild > > > test robot picked up where compat_size_t wasn't dfined. > > > > Please add a comment there, similar to what is in syscalls.h: > > > > /* > > * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly. > > * Instead, use one of the functions which work equivalently, such as > > * the ksys_xyzyyz() functions prototyped below. > > */ > > To make the kcompat_sys_* naming scheme clearer, I've added compat references to > the above, i.e. > > /* > * Kernel code should not call compat syscalls (i.e., compat_sys_xyzyyz()) > * directly. Instead, use one of the functions which work equivalently, such > * as the kcompat_sys_xyzyyz() functions prototyped below. > */ That's what I meant ;) > > Once you have done so, feel free to add my > > > > Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> > > I hope that this still stands with the changes above? It does. Thanks! Dominik
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.
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 <mark.rutland@arm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: linux-fsdevel@vger.kernel.org --- fs/statfs.c | 14 ++++++++++++-- include/linux/syscalls.h | 8 ++++++++ 2 files changed, 20 insertions(+), 2 deletions(-)