[PATCH 3/3] quota: simplify the quotactl compat handling
From: Christoph Hellwig
Date: Thu Sep 17 2020 - 03:51:28 EST
Fold the misaligned u64 workarounds into the main quotactl flow instead
of implementing a separate compat syscall handler.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Jan Kara <jack@xxxxxxx>
---
arch/x86/entry/syscalls/syscall_32.tbl | 2 +-
fs/quota/Kconfig | 5 --
fs/quota/Makefile | 1 -
fs/quota/compat.c | 120 -------------------------
fs/quota/compat.h | 34 +++++++
fs/quota/quota.c | 73 ++++++++++++---
include/linux/quotaops.h | 3 -
kernel/sys_ni.c | 1 -
8 files changed, 94 insertions(+), 145 deletions(-)
delete mode 100644 fs/quota/compat.c
create mode 100644 fs/quota/compat.h
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 9d11028736661b..3db3d8823dc899 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -142,7 +142,7 @@
128 i386 init_module sys_init_module
129 i386 delete_module sys_delete_module
130 i386 get_kernel_syms
-131 i386 quotactl sys_quotactl compat_sys_quotactl32
+131 i386 quotactl sys_quotactl
132 i386 getpgid sys_getpgid
133 i386 fchdir sys_fchdir
134 i386 bdflush sys_bdflush
diff --git a/fs/quota/Kconfig b/fs/quota/Kconfig
index d1ceb76adb71e7..b59cd172b5f97c 100644
--- a/fs/quota/Kconfig
+++ b/fs/quota/Kconfig
@@ -70,8 +70,3 @@ config QFMT_V2
config QUOTACTL
bool
default n
-
-config QUOTACTL_COMPAT
- bool
- depends on QUOTACTL && COMPAT_FOR_U64_ALIGNMENT
- default y
diff --git a/fs/quota/Makefile b/fs/quota/Makefile
index f2b49d0f0287c9..9160639daffa75 100644
--- a/fs/quota/Makefile
+++ b/fs/quota/Makefile
@@ -4,5 +4,4 @@ obj-$(CONFIG_QFMT_V1) += quota_v1.o
obj-$(CONFIG_QFMT_V2) += quota_v2.o
obj-$(CONFIG_QUOTA_TREE) += quota_tree.o
obj-$(CONFIG_QUOTACTL) += quota.o kqid.o
-obj-$(CONFIG_QUOTACTL_COMPAT) += compat.o
obj-$(CONFIG_QUOTA_NETLINK_INTERFACE) += netlink.o
diff --git a/fs/quota/compat.c b/fs/quota/compat.c
deleted file mode 100644
index c305728576193d..00000000000000
--- a/fs/quota/compat.c
+++ /dev/null
@@ -1,120 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-#include <linux/syscalls.h>
-#include <linux/compat.h>
-#include <linux/quotaops.h>
-
-/*
- * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
- * and is necessary due to alignment problems.
- */
-struct compat_if_dqblk {
- compat_u64 dqb_bhardlimit;
- compat_u64 dqb_bsoftlimit;
- compat_u64 dqb_curspace;
- compat_u64 dqb_ihardlimit;
- compat_u64 dqb_isoftlimit;
- compat_u64 dqb_curinodes;
- compat_u64 dqb_btime;
- compat_u64 dqb_itime;
- compat_uint_t dqb_valid;
-};
-
-/* XFS structures */
-struct compat_fs_qfilestat {
- compat_u64 dqb_bhardlimit;
- compat_u64 qfs_nblks;
- compat_uint_t qfs_nextents;
-};
-
-struct compat_fs_quota_stat {
- __s8 qs_version;
- __u16 qs_flags;
- __s8 qs_pad;
- struct compat_fs_qfilestat qs_uquota;
- struct compat_fs_qfilestat qs_gquota;
- compat_uint_t qs_incoredqs;
- compat_int_t qs_btimelimit;
- compat_int_t qs_itimelimit;
- compat_int_t qs_rtbtimelimit;
- __u16 qs_bwarnlimit;
- __u16 qs_iwarnlimit;
-};
-
-COMPAT_SYSCALL_DEFINE4(quotactl32, unsigned int, cmd,
- const char __user *, special, qid_t, id,
- void __user *, addr)
-{
- unsigned int cmds;
- struct if_dqblk __user *dqblk;
- struct compat_if_dqblk __user *compat_dqblk;
- struct fs_quota_stat __user *fsqstat;
- struct compat_fs_quota_stat __user *compat_fsqstat;
- compat_uint_t data;
- u16 xdata;
- long ret;
-
- cmds = cmd >> SUBCMDSHIFT;
-
- switch (cmds) {
- case Q_GETQUOTA:
- dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
- compat_dqblk = addr;
- ret = kernel_quotactl(cmd, special, id, dqblk);
- if (ret)
- break;
- if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
- get_user(data, &dqblk->dqb_valid) ||
- put_user(data, &compat_dqblk->dqb_valid))
- ret = -EFAULT;
- break;
- case Q_SETQUOTA:
- dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
- compat_dqblk = addr;
- ret = -EFAULT;
- if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
- get_user(data, &compat_dqblk->dqb_valid) ||
- put_user(data, &dqblk->dqb_valid))
- break;
- ret = kernel_quotactl(cmd, special, id, dqblk);
- break;
- case Q_XGETQSTAT:
- fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
- compat_fsqstat = addr;
- ret = kernel_quotactl(cmd, special, id, fsqstat);
- if (ret)
- break;
- ret = -EFAULT;
- /* Copying qs_version, qs_flags, qs_pad */
- if (copy_in_user(compat_fsqstat, fsqstat,
- offsetof(struct compat_fs_quota_stat, qs_uquota)))
- break;
- /* Copying qs_uquota */
- if (copy_in_user(&compat_fsqstat->qs_uquota,
- &fsqstat->qs_uquota,
- sizeof(compat_fsqstat->qs_uquota)) ||
- get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
- put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
- break;
- /* Copying qs_gquota */
- if (copy_in_user(&compat_fsqstat->qs_gquota,
- &fsqstat->qs_gquota,
- sizeof(compat_fsqstat->qs_gquota)) ||
- get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
- put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
- break;
- /* Copying the rest */
- if (copy_in_user(&compat_fsqstat->qs_incoredqs,
- &fsqstat->qs_incoredqs,
- sizeof(struct compat_fs_quota_stat) -
- offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
- get_user(xdata, &fsqstat->qs_iwarnlimit) ||
- put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
- break;
- ret = 0;
- break;
- default:
- ret = kernel_quotactl(cmd, special, id, addr);
- }
- return ret;
-}
diff --git a/fs/quota/compat.h b/fs/quota/compat.h
new file mode 100644
index 00000000000000..ef7d1e12d650b3
--- /dev/null
+++ b/fs/quota/compat.h
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/compat.h>
+
+struct compat_if_dqblk {
+ compat_u64 dqb_bhardlimit;
+ compat_u64 dqb_bsoftlimit;
+ compat_u64 dqb_curspace;
+ compat_u64 dqb_ihardlimit;
+ compat_u64 dqb_isoftlimit;
+ compat_u64 dqb_curinodes;
+ compat_u64 dqb_btime;
+ compat_u64 dqb_itime;
+ compat_uint_t dqb_valid;
+};
+
+struct compat_fs_qfilestat {
+ compat_u64 dqb_bhardlimit;
+ compat_u64 qfs_nblks;
+ compat_uint_t qfs_nextents;
+};
+
+struct compat_fs_quota_stat {
+ __s8 qs_version;
+ __u16 qs_flags;
+ __s8 qs_pad;
+ struct compat_fs_qfilestat qs_uquota;
+ struct compat_fs_qfilestat qs_gquota;
+ compat_uint_t qs_incoredqs;
+ compat_int_t qs_btimelimit;
+ compat_int_t qs_itimelimit;
+ compat_int_t qs_rtbtimelimit;
+ __u16 qs_bwarnlimit;
+ __u16 qs_iwarnlimit;
+};
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 47f9e151988b3e..6b37d58f1067d4 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -19,6 +19,7 @@
#include <linux/types.h>
#include <linux/writeback.h>
#include <linux/nospec.h>
+#include "compat.h"
static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
qid_t id)
@@ -211,8 +212,18 @@ static int quota_getquota(struct super_block *sb, int type, qid_t id,
if (ret)
return ret;
copy_to_if_dqblk(&idq, &fdq);
- if (copy_to_user(addr, &idq, sizeof(idq)))
- return -EFAULT;
+
+ if (compat_need_64bit_alignment_fixup()) {
+ struct compat_if_dqblk __user *compat_dqblk = addr;
+
+ if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
+ return -EFAULT;
+ if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(addr, &idq, sizeof(idq)))
+ return -EFAULT;
+ }
return 0;
}
@@ -277,8 +288,16 @@ static int quota_setquota(struct super_block *sb, int type, qid_t id,
struct if_dqblk idq;
struct kqid qid;
- if (copy_from_user(&idq, addr, sizeof(idq)))
- return -EFAULT;
+ if (compat_need_64bit_alignment_fixup()) {
+ struct compat_if_dqblk __user *compat_dqblk = addr;
+
+ if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
+ get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
+ return -EFAULT;
+ } else {
+ if (copy_from_user(&idq, addr, sizeof(idq)))
+ return -EFAULT;
+ }
if (!sb->s_qcop->set_dqblk)
return -ENOSYS;
qid = make_kqid(current_user_ns(), type, id);
@@ -382,6 +401,33 @@ static int quota_getstate(struct super_block *sb, int type,
return 0;
}
+static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
+ struct fs_qfilestat *from)
+{
+ if (copy_to_user(to, from, sizeof(*to)) ||
+ put_user(from->qfs_nextents, &to->qfs_nextents))
+ return -EFAULT;
+ return 0;
+}
+
+static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
+ struct fs_quota_stat *from)
+{
+ if (put_user(from->qs_version, &to->qs_version) ||
+ put_user(from->qs_flags, &to->qs_flags) ||
+ put_user(from->qs_pad, &to->qs_pad) ||
+ compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
+ compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
+ put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
+ put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
+ put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
+ put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
+ put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
+ put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
+ return -EFAULT;
+ return 0;
+}
+
static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
{
struct fs_quota_stat fqs;
@@ -390,9 +436,14 @@ static int quota_getxstate(struct super_block *sb, int type, void __user *addr)
if (!sb->s_qcop->get_state)
return -ENOSYS;
ret = quota_getstate(sb, type, &fqs);
- if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
+ if (ret)
+ return ret;
+
+ if (compat_need_64bit_alignment_fixup())
+ return compat_copy_fs_quota_stat(addr, &fqs);
+ if (copy_to_user(addr, &fqs, sizeof(fqs)))
return -EFAULT;
- return ret;
+ return 0;
}
static int quota_getstatev(struct super_block *sb, int type,
@@ -816,8 +867,8 @@ static struct super_block *quotactl_block(const char __user *special, int cmd)
* calls. Maybe we need to add the process quotas etc. in the future,
* but we probably should use rlimits for that.
*/
-int kernel_quotactl(unsigned int cmd, const char __user *special,
- qid_t id, void __user *addr)
+SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
+ qid_t, id, void __user *, addr)
{
uint cmds, type;
struct super_block *sb = NULL;
@@ -871,9 +922,3 @@ int kernel_quotactl(unsigned int cmd, const char __user *special,
path_put(pathp);
return ret;
}
-
-SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
- qid_t, id, void __user *, addr)
-{
- return kernel_quotactl(cmd, special, id, addr);
-}
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index 9cf0cd3dc88c68..a0f6668924d3ef 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -27,9 +27,6 @@ static inline bool is_quota_modification(struct inode *inode, struct iattr *ia)
(ia->ia_valid & ATTR_GID && !gid_eq(ia->ia_gid, inode->i_gid));
}
-int kernel_quotactl(unsigned int cmd, const char __user *special,
- qid_t id, void __user *addr);
-
#if defined(CONFIG_QUOTA)
#define quota_error(sb, fmt, args...) \
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 4d59775ea79c1e..c925d1e1777efc 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -369,7 +369,6 @@ COND_SYSCALL_COMPAT(fanotify_mark);
/* x86 */
COND_SYSCALL(vm86old);
COND_SYSCALL(modify_ldt);
-COND_SYSCALL_COMPAT(quotactl32);
COND_SYSCALL(vm86);
COND_SYSCALL(kexec_file_load);
--
2.28.0