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quota: simplify the quotactl compat handling 

Fold the misaligned u64 workarounds into the main quotactl flow instead
of implementing a separate compat syscall handler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2020-09-17 09:41:59 +02:00 committed by Al Viro
parent 527c412519
commit 80bdad3d7e
8 changed files with 94 additions and 145 deletions
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2
arch/x86/entry/syscalls/syscall_32.tbl
View File

@ -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

5
fs/quota/Kconfig
View File

@ -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

1
fs/quota/Makefile
View File

@ -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

120
fs/quota/compat.c
View File

@ -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;
}

34
fs/quota/compat.h Normal file
View File

@ -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;
};

73
fs/quota/quota.c
View File

@ -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 @@ out:
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);
}

3
include/linux/quotaops.h
View File

@ -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...) \

1
kernel/sys_ni.c
View File

@ -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);