[PATCH 3/4] mm: remove compat_sys_move_pages
From: Arnd Bergmann
Date: Fri Sep 18 2020 - 09:25:52 EST
The compat move_pages() implementation uses compat_alloc_user_space()
for converting the pointer array. Moving the compat handling into
the function itself is a bit simpler and lets us avoid the
compat_alloc_user_space() call.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/arm64/include/asm/unistd32.h | 2 +-
arch/mips/kernel/syscalls/syscall_n32.tbl | 2 +-
arch/mips/kernel/syscalls/syscall_o32.tbl | 2 +-
arch/parisc/kernel/syscalls/syscall.tbl | 2 +-
arch/powerpc/kernel/syscalls/syscall.tbl | 2 +-
arch/s390/kernel/syscalls/syscall.tbl | 2 +-
arch/sparc/kernel/syscalls/syscall.tbl | 2 +-
arch/x86/entry/syscalls/syscall_32.tbl | 2 +-
arch/x86/entry/syscalls/syscall_64.tbl | 2 +-
include/linux/compat.h | 5 ---
include/uapi/asm-generic/unistd.h | 2 +-
kernel/sys_ni.c | 1 -
mm/migrate.c | 45 +++++++++++------------
13 files changed, 32 insertions(+), 39 deletions(-)
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index b6517df74037..af793775ba98 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -699,7 +699,7 @@ __SYSCALL(__NR_tee, sys_tee)
#define __NR_vmsplice 343
__SYSCALL(__NR_vmsplice, compat_sys_vmsplice)
#define __NR_move_pages 344
-__SYSCALL(__NR_move_pages, compat_sys_move_pages)
+__SYSCALL(__NR_move_pages, sys_move_pages)
#define __NR_getcpu 345
__SYSCALL(__NR_getcpu, sys_getcpu)
#define __NR_epoll_pwait 346
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index ad157aab4c09..7fa1ca45e44c 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -279,7 +279,7 @@
268 n32 sync_file_range sys_sync_file_range
269 n32 tee sys_tee
270 n32 vmsplice compat_sys_vmsplice
-271 n32 move_pages compat_sys_move_pages
+271 n32 move_pages sys_move_pages
272 n32 set_robust_list compat_sys_set_robust_list
273 n32 get_robust_list compat_sys_get_robust_list
274 n32 kexec_load sys_kexec_load
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 57baf6c8008f..194c7fbeedf7 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -319,7 +319,7 @@
305 o32 sync_file_range sys_sync_file_range sys32_sync_file_range
306 o32 tee sys_tee
307 o32 vmsplice sys_vmsplice compat_sys_vmsplice
-308 o32 move_pages sys_move_pages compat_sys_move_pages
+308 o32 move_pages sys_move_pages
309 o32 set_robust_list sys_set_robust_list compat_sys_set_robust_list
310 o32 get_robust_list sys_get_robust_list compat_sys_get_robust_list
311 o32 kexec_load sys_kexec_load
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 778bf166d7bd..5c17edaffe70 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -331,7 +331,7 @@
292 64 sync_file_range sys_sync_file_range
293 common tee sys_tee
294 common vmsplice sys_vmsplice compat_sys_vmsplice
-295 common move_pages sys_move_pages compat_sys_move_pages
+295 common move_pages sys_move_pages
296 common getcpu sys_getcpu
297 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait
298 common statfs64 sys_statfs64 compat_sys_statfs64
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index f128ba8b9a71..04fb42d7b377 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -389,7 +389,7 @@
298 common faccessat sys_faccessat
299 common get_robust_list sys_get_robust_list compat_sys_get_robust_list
300 common set_robust_list sys_set_robust_list compat_sys_set_robust_list
-301 common move_pages sys_move_pages compat_sys_move_pages
+301 common move_pages sys_move_pages
302 common getcpu sys_getcpu
303 nospu epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait
304 32 utimensat sys_utimensat_time32
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index d45952058be2..3197965d45e9 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -317,7 +317,7 @@
307 common sync_file_range sys_sync_file_range compat_sys_s390_sync_file_range
308 common tee sys_tee sys_tee
309 common vmsplice sys_vmsplice compat_sys_vmsplice
-310 common move_pages sys_move_pages compat_sys_move_pages
+310 common move_pages sys_move_pages
311 common getcpu sys_getcpu sys_getcpu
312 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait
313 common utimes sys_utimes sys_utimes_time32
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index a46edcdd950d..e36ac364e61a 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -370,7 +370,7 @@
304 common get_mempolicy sys_get_mempolicy compat_sys_get_mempolicy
305 common set_mempolicy sys_set_mempolicy compat_sys_set_mempolicy
306 common kexec_load sys_kexec_load sys_kexec_load
-307 common move_pages sys_move_pages compat_sys_move_pages
+307 common move_pages sys_move_pages
308 common getcpu sys_getcpu
309 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait
310 32 utimensat sys_utimensat_time32
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 7e4140b78aad..b3263b8b2eae 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -328,7 +328,7 @@
314 i386 sync_file_range sys_ia32_sync_file_range
315 i386 tee sys_tee
316 i386 vmsplice sys_vmsplice compat_sys_vmsplice
-317 i386 move_pages sys_move_pages compat_sys_move_pages
+317 i386 move_pages sys_move_pages
318 i386 getcpu sys_getcpu
319 i386 epoll_pwait sys_epoll_pwait
320 i386 utimensat sys_utimensat_time32
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 9986f5f08278..4a997a0cbf47 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -389,7 +389,7 @@
530 x32 set_robust_list compat_sys_set_robust_list
531 x32 get_robust_list compat_sys_get_robust_list
532 x32 vmsplice compat_sys_vmsplice
-533 x32 move_pages compat_sys_move_pages
+533 x32 move_pages sys_move_pages
534 x32 preadv compat_sys_preadv64
535 x32 pwritev compat_sys_pwritev64
536 x32 rt_tgsigqueueinfo compat_sys_rt_tgsigqueueinfo
diff --git a/include/linux/compat.h b/include/linux/compat.h
index a7a5a0ff59ef..db1d7ac2c9e0 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -763,11 +763,6 @@ asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
asmlinkage long compat_sys_migrate_pages(compat_pid_t pid,
compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,
const compat_ulong_t __user *new_nodes);
-asmlinkage long compat_sys_move_pages(pid_t pid, compat_ulong_t nr_pages,
- __u32 __user *pages,
- const int __user *nodes,
- int __user *status,
- int flags);
asmlinkage long compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid,
compat_pid_t pid, int sig,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 83f1fc7fd3d7..4da51702fb21 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -681,7 +681,7 @@ __SC_COMP(__NR_set_mempolicy, sys_set_mempolicy, compat_sys_set_mempolicy)
#define __NR_migrate_pages 238
__SC_COMP(__NR_migrate_pages, sys_migrate_pages, compat_sys_migrate_pages)
#define __NR_move_pages 239
-__SC_COMP(__NR_move_pages, sys_move_pages, compat_sys_move_pages)
+__SYSCALL(__NR_move_pages, sys_move_pages)
#endif
#define __NR_rt_tgsigqueueinfo 240
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index c925d1e1777e..783a24ceee88 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -290,7 +290,6 @@ COND_SYSCALL_COMPAT(set_mempolicy);
COND_SYSCALL(migrate_pages);
COND_SYSCALL_COMPAT(migrate_pages);
COND_SYSCALL(move_pages);
-COND_SYSCALL_COMPAT(move_pages);
COND_SYSCALL(perf_event_open);
COND_SYSCALL(accept4);
diff --git a/mm/migrate.c b/mm/migrate.c
index 34a842a8eb6a..e9dfbde5f12c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1835,6 +1835,27 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
mmap_read_unlock(mm);
}
+static int put_pages_array(const void __user *chunk_pages[],
+ const void __user * __user *pages,
+ unsigned long chunk_nr)
+{
+ compat_uptr_t __user *pages32 = (compat_uptr_t __user *)pages;
+ compat_uptr_t p;
+ int i;
+
+ if (!in_compat_syscall())
+ return copy_from_user(chunk_pages, pages,
+ chunk_nr * sizeof(*chunk_pages));
+
+ for (i = 0; i < chunk_nr; i++) {
+ if (get_user(p, pages32 + i))
+ return -EFAULT;
+ chunk_pages[i] = compat_ptr(p);
+ }
+
+ return 0;
+}
+
/*
* Determine the nodes of a user array of pages and store it in
* a user array of status.
@@ -1854,7 +1875,7 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
if (chunk_nr > DO_PAGES_STAT_CHUNK_NR)
chunk_nr = DO_PAGES_STAT_CHUNK_NR;
- if (copy_from_user(chunk_pages, pages, chunk_nr * sizeof(*chunk_pages)))
+ if (put_pages_array(chunk_pages, pages, chunk_nr))
break;
do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status);
@@ -1943,28 +1964,6 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags);
}
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
- compat_uptr_t __user *, pages32,
- const int __user *, nodes,
- int __user *, status,
- int, flags)
-{
- const void __user * __user *pages;
- int i;
-
- pages = compat_alloc_user_space(nr_pages * sizeof(void *));
- for (i = 0; i < nr_pages; i++) {
- compat_uptr_t p;
-
- if (get_user(p, pages32 + i) ||
- put_user(compat_ptr(p), pages + i))
- return -EFAULT;
- }
- return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags);
-}
-#endif /* CONFIG_COMPAT */
-
#ifdef CONFIG_NUMA_BALANCING
/*
* Returns true if this is a safe migration target node for misplaced NUMA
--
2.27.0