On Wed Aug 24, 2022 at 12:05 PM AEST, Rohan McLure wrote:
> Arch-specific implementations of syscall handlers are currently used
> over generic implementations for the following reasons:
>
> 1. Semantics unique to powerpc
> 2. Compatibility syscalls require 'argument padding' to comply with
> 64-bit argument convention in ELF32 abi.
> 3. Parameter types or order is different in other architectures.
>
> These syscall handlers have been defined prior to this patch series
> without invoking the SYSCALL_DEFINE or COMPAT_SYSCALL_DEFINE macros with
> custom input and output types. We remove every such direct definition in
> favour of the aforementioned macros.
And what about sys_fallocate, where did that go?
>
> Also update syscalls.tbl in order to refer to the symbol names generated
> by each of these macros. Since ppc64_personality can be called by both
> 64 bit and 32 bit binaries through compatibility, we must generate both
> both compat_sys_ and sys_ symbols for this handler.
Actually I don't have a concern about this patch, I thoughtthere was
something odd going on with ppc64_personality but I misread, it all
looks pretty good.
>
> A number of architectures including arm and powerpc agree on an
> alternative argument order and numbering for most of these arch-specific
> handlers. A future patch series may allow for asm/unistd.h to signal
> through its defines that a generic implementation of these syscall
> handlers with the correct calling convention be omitted, through the
> __ARCH_WANT_COMPAT_SYS_... convention.
I'm on the fence about including this in changelog. arm developers
might not see it, for example. Putting it in include/linux/compat.h
as a comment might be better.
If you keep it in the changelog, maybe preface with something like
aside, side note, in future or something so that's clear it's not part
of the current patch.
Thanks,
Nick
>
> Signed-off-by: Rohan McLure <rmcl...@linux.ibm.com>
> ---
> V1 -> V2: All syscall handlers wrapped by this macro.
> V2 -> V3: Move creation of do_ppc64_personality helper to prior patch.
> V3 -> V4: Fix parenthesis alignment. Don't emit sys_*** symbols.
> ---
> arch/powerpc/include/asm/syscalls.h | 10 ++--
> arch/powerpc/kernel/sys_ppc32.c | 45 ++++++++++--------
> arch/powerpc/kernel/syscalls.c | 17 +++++--
> arch/powerpc/kernel/syscalls/syscall.tbl | 22 ++++-----
> .../arch/powerpc/entry/syscalls/syscall.tbl | 22 ++++-----
> 5 files changed, 64 insertions(+), 52 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/syscalls.h
> b/arch/powerpc/include/asm/syscalls.h
> index 739498c358a1..3e3aff0835a6 100644
> --- a/arch/powerpc/include/asm/syscalls.h
> +++ b/arch/powerpc/include/asm/syscalls.h
> @@ -16,10 +16,10 @@ long sys_mmap(unsigned long addr, size_t len,
> long sys_mmap2(unsigned long addr, size_t len,
> unsigned long prot, unsigned long flags,
> unsigned long fd, unsigned long pgoff);
> -long ppc64_personality(unsigned long personality);
> +long sys_ppc64_personality(unsigned long personality);
> long sys_rtas(struct rtas_args __user *uargs);
> -long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> - u32 len_high, u32 len_low);
> +long sys_ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32
> offset_low,
> + u32 len_high, u32 len_low);
>
> #ifdef CONFIG_COMPAT
> unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> @@ -40,8 +40,8 @@ int compat_sys_truncate64(const char __user *path, u32 reg4,
> int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
> unsigned long len2);
>
> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> - size_t len, int advice);
> +long compat_sys_ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> + size_t len, int advice);
>
> long compat_sys_sync_file_range2(int fd, unsigned int flags,
> unsigned int offset1, unsigned int offset2,
> diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
> index bc6491ed6454..dd9039671227 100644
> --- a/arch/powerpc/kernel/sys_ppc32.c
> +++ b/arch/powerpc/kernel/sys_ppc32.c
> @@ -59,52 +59,55 @@
> #define merge_64(high, low) ((u64)high << 32) | low
> #endif
>
> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf,
> compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +COMPAT_SYSCALL_DEFINE6(ppc_pread64,
> + unsigned int, fd,
> + char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
> }
>
> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf,
> compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +COMPAT_SYSCALL_DEFINE6(ppc_pwrite64,
> + unsigned int, fd,
> + const char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pwrite64(fd, ubuf, count, merge_64(pos1, pos2));
> }
>
> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32
> offset2, u32 count)
> +COMPAT_SYSCALL_DEFINE5(ppc_readahead,
> + int, fd, u32, r4,
> + u32, offset1, u32, offset2, u32, count)
> {
> return ksys_readahead(fd, merge_64(offset1, offset2), count);
> }
>
> -int compat_sys_truncate64(const char __user * path, u32 reg4,
> - unsigned long len1, unsigned long len2)
> +COMPAT_SYSCALL_DEFINE4(ppc_truncate64,
> + const char __user *, path, u32, reg4,
> + unsigned long, len1, unsigned long, len2)
> {
> return ksys_truncate(path, merge_64(len1, len2));
> }
>
> -long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2,
> - u32 len1, u32 len2)
> -{
> - return ksys_fallocate(fd, mode, ((loff_t)offset1 << 32) | offset2,
> - merge_64(len1, len2));
> -}
> -
> -int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
> - unsigned long len2)
> +COMPAT_SYSCALL_DEFINE4(ppc_ftruncate64,
> + unsigned int, fd, u32, reg4,
> + unsigned long, len1, unsigned long, len2)
> {
> return ksys_ftruncate(fd, merge_64(len1, len2));
> }
>
> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> - size_t len, int advice)
> +COMPAT_SYSCALL_DEFINE6(ppc32_fadvise64,
> + int, fd, u32, unused, u32, offset1, u32, offset2,
> + size_t, len, int, advice)
> {
> return ksys_fadvise64_64(fd, merge_64(offset1, offset2), len,
> advice);
> }
>
> -long compat_sys_sync_file_range2(int fd, unsigned int flags,
> - unsigned offset1, unsigned offset2,
> - unsigned nbytes1, unsigned nbytes2)
> +COMPAT_SYSCALL_DEFINE6(ppc_sync_file_range2,
> + int, fd, unsigned int, flags,
> + unsigned int, offset1, unsigned int, offset2,
> + unsigned int, nbytes1, unsigned int, nbytes2)
> {
> loff_t offset = merge_64(offset1, offset2);
> loff_t nbytes = merge_64(nbytes1, nbytes2);
> diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
> index 32fadf3c2cd3..2d4c62e5bac7 100644
> --- a/arch/powerpc/kernel/syscalls.c
> +++ b/arch/powerpc/kernel/syscalls.c
> @@ -87,14 +87,23 @@ static inline long do_ppc64_personality(unsigned long
> personality)
> ret = (ret & ~PER_MASK) | PER_LINUX;
> return ret;
> }
> -long ppc64_personality(unsigned long personality)
> +
> +SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
> {
> return do_ppc64_personality(personality);
> }
> -#endif
>
> -long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> - u32 len_high, u32 len_low)
> +#ifdef CONFIG_COMPAT
> +COMPAT_SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
> +{
> + return do_ppc64_personality(personality);
> +}
> +#endif /* CONFIG_COMPAT */
> +#endif /* CONFIG_PPC64 */
> +
> +SYSCALL_DEFINE6(ppc_fadvise64_64,
> + int, fd, int, advice, u32, offset_high, u32, offset_low,
> + u32, len_high, u32, len_low)
> {
> return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
> (u64)len_high << 32 | len_low, advice);
> diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl
> b/arch/powerpc/kernel/syscalls/syscall.tbl
> index 4cbbb810ae10..b4c970c9c6b1 100644
> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
> @@ -178,9 +178,9 @@
> 133 common fchdir sys_fchdir
> 134 common bdflush sys_ni_syscall
> 135 common sysfs sys_sysfs
> -136 32 personality sys_personality
> ppc64_personality
> -136 64 personality ppc64_personality
> -136 spu personality ppc64_personality
> +136 32 personality sys_personality
> compat_sys_ppc64_personality
> +136 64 personality sys_ppc64_personality
> +136 spu personality sys_ppc64_personality
> 137 common afs_syscall sys_ni_syscall
> 138 common setfsuid sys_setfsuid
> 139 common setfsgid sys_setfsgid
> @@ -228,8 +228,8 @@
> 176 64 rt_sigtimedwait sys_rt_sigtimedwait
> 177 nospu rt_sigqueueinfo sys_rt_sigqueueinfo
> compat_sys_rt_sigqueueinfo
> 178 nospu rt_sigsuspend sys_rt_sigsuspend
> compat_sys_rt_sigsuspend
> -179 common pread64 sys_pread64
> compat_sys_pread64
> -180 common pwrite64 sys_pwrite64
> compat_sys_pwrite64
> +179 common pread64 sys_pread64
> compat_sys_ppc_pread64
> +180 common pwrite64 sys_pwrite64
> compat_sys_ppc_pwrite64
> 181 common chown sys_chown
> 182 common getcwd sys_getcwd
> 183 common capget sys_capget
> @@ -242,10 +242,10 @@
> 188 common putpmsg sys_ni_syscall
> 189 nospu vfork sys_vfork
> 190 common ugetrlimit sys_getrlimit
> compat_sys_getrlimit
> -191 common readahead sys_readahead
> compat_sys_readahead
> +191 common readahead sys_readahead
> compat_sys_ppc_readahead
> 192 32 mmap2 sys_mmap2
> compat_sys_mmap2
> -193 32 truncate64 sys_truncate64
> compat_sys_truncate64
> -194 32 ftruncate64 sys_ftruncate64
> compat_sys_ftruncate64
> +193 32 truncate64 sys_truncate64
> compat_sys_ppc_truncate64
> +194 32 ftruncate64 sys_ftruncate64
> compat_sys_ppc_ftruncate64
> 195 32 stat64 sys_stat64
> 196 32 lstat64 sys_lstat64
> 197 32 fstat64 sys_fstat64
> @@ -288,7 +288,7 @@
> 230 common io_submit sys_io_submit
> compat_sys_io_submit
> 231 common io_cancel sys_io_cancel
> 232 nospu set_tid_address sys_set_tid_address
> -233 common fadvise64 sys_fadvise64
> ppc32_fadvise64
> +233 common fadvise64 sys_fadvise64
> compat_sys_ppc32_fadvise64
> 234 nospu exit_group sys_exit_group
> 235 nospu lookup_dcookie sys_lookup_dcookie
> compat_sys_lookup_dcookie
> 236 common epoll_create sys_epoll_create
> @@ -323,7 +323,7 @@
> 251 spu utimes sys_utimes
> 252 common statfs64 sys_statfs64
> compat_sys_statfs64
> 253 common fstatfs64 sys_fstatfs64
> compat_sys_fstatfs64
> -254 32 fadvise64_64 ppc_fadvise64_64
> +254 32 fadvise64_64 sys_ppc_fadvise64_64
> 254 spu fadvise64_64 sys_ni_syscall
> 255 common rtas sys_rtas
> 256 32 sys_debug_setcontext sys_debug_setcontext
> sys_ni_syscall
> @@ -390,7 +390,7 @@
> 305 common signalfd sys_signalfd
> compat_sys_signalfd
> 306 common timerfd_create sys_timerfd_create
> 307 common eventfd sys_eventfd
> -308 common sync_file_range2 sys_sync_file_range2
> compat_sys_sync_file_range2
> +308 common sync_file_range2 sys_sync_file_range2
> compat_sys_ppc_sync_file_range2
> 309 nospu fallocate sys_fallocate
> compat_sys_fallocate
> 310 nospu subpage_prot sys_subpage_prot
> 311 32 timerfd_settime sys_timerfd_settime32
> diff --git a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> index 4cbbb810ae10..b4c970c9c6b1 100644
> --- a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> +++ b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> @@ -178,9 +178,9 @@
> 133 common fchdir sys_fchdir
> 134 common bdflush sys_ni_syscall
> 135 common sysfs sys_sysfs
> -136 32 personality sys_personality
> ppc64_personality
> -136 64 personality ppc64_personality
> -136 spu personality ppc64_personality
> +136 32 personality sys_personality
> compat_sys_ppc64_personality
> +136 64 personality sys_ppc64_personality
> +136 spu personality sys_ppc64_personality
> 137 common afs_syscall sys_ni_syscall
> 138 common setfsuid sys_setfsuid
> 139 common setfsgid sys_setfsgid
> @@ -228,8 +228,8 @@
> 176 64 rt_sigtimedwait sys_rt_sigtimedwait
> 177 nospu rt_sigqueueinfo sys_rt_sigqueueinfo
> compat_sys_rt_sigqueueinfo
> 178 nospu rt_sigsuspend sys_rt_sigsuspend
> compat_sys_rt_sigsuspend
> -179 common pread64 sys_pread64
> compat_sys_pread64
> -180 common pwrite64 sys_pwrite64
> compat_sys_pwrite64
> +179 common pread64 sys_pread64
> compat_sys_ppc_pread64
> +180 common pwrite64 sys_pwrite64
> compat_sys_ppc_pwrite64
> 181 common chown sys_chown
> 182 common getcwd sys_getcwd
> 183 common capget sys_capget
> @@ -242,10 +242,10 @@
> 188 common putpmsg sys_ni_syscall
> 189 nospu vfork sys_vfork
> 190 common ugetrlimit sys_getrlimit
> compat_sys_getrlimit
> -191 common readahead sys_readahead
> compat_sys_readahead
> +191 common readahead sys_readahead
> compat_sys_ppc_readahead
> 192 32 mmap2 sys_mmap2
> compat_sys_mmap2
> -193 32 truncate64 sys_truncate64
> compat_sys_truncate64
> -194 32 ftruncate64 sys_ftruncate64
> compat_sys_ftruncate64
> +193 32 truncate64 sys_truncate64
> compat_sys_ppc_truncate64
> +194 32 ftruncate64 sys_ftruncate64
> compat_sys_ppc_ftruncate64
> 195 32 stat64 sys_stat64
> 196 32 lstat64 sys_lstat64
> 197 32 fstat64 sys_fstat64
> @@ -288,7 +288,7 @@
> 230 common io_submit sys_io_submit
> compat_sys_io_submit
> 231 common io_cancel sys_io_cancel
> 232 nospu set_tid_address sys_set_tid_address
> -233 common fadvise64 sys_fadvise64
> ppc32_fadvise64
> +233 common fadvise64 sys_fadvise64
> compat_sys_ppc32_fadvise64
> 234 nospu exit_group sys_exit_group
> 235 nospu lookup_dcookie sys_lookup_dcookie
> compat_sys_lookup_dcookie
> 236 common epoll_create sys_epoll_create
> @@ -323,7 +323,7 @@
> 251 spu utimes sys_utimes
> 252 common statfs64 sys_statfs64
> compat_sys_statfs64
> 253 common fstatfs64 sys_fstatfs64
> compat_sys_fstatfs64
> -254 32 fadvise64_64 ppc_fadvise64_64
> +254 32 fadvise64_64 sys_ppc_fadvise64_64
> 254 spu fadvise64_64 sys_ni_syscall
> 255 common rtas sys_rtas
> 256 32 sys_debug_setcontext sys_debug_setcontext
> sys_ni_syscall
> @@ -390,7 +390,7 @@
> 305 common signalfd sys_signalfd
> compat_sys_signalfd
> 306 common timerfd_create sys_timerfd_create
> 307 common eventfd sys_eventfd
> -308 common sync_file_range2 sys_sync_file_range2
> compat_sys_sync_file_range2
> +308 common sync_file_range2 sys_sync_file_range2
> compat_sys_ppc_sync_file_range2
> 309 nospu fallocate sys_fallocate
> compat_sys_fallocate
> 310 nospu subpage_prot sys_subpage_prot
> 311 32 timerfd_settime sys_timerfd_settime32
> --
> 2.34.1
