From: Vasily Tarasov <[email protected]>
This patch should be applied after Arnd Bergmann's patch,
that intoduces new compat types:
http://lkml.org/lkml/2007/6/15/98
OpenVZ Linux kernel team has discovered the problem
with 32bit quota tools working on 64bit architectures.
In 2.6.10 kernel sys32_quotactl() function was replaced by sys_quotactl() with
the comment "sys_quotactl seems to be 32/64bit clean, enable it for 32bit"
However this isn't right. Look at if_dqblk structure:
struct if_dqblk {
__u64 dqb_bhardlimit;
__u64 dqb_bsoftlimit;
__u64 dqb_curspace;
__u64 dqb_ihardlimit;
__u64 dqb_isoftlimit;
__u64 dqb_curinodes;
__u64 dqb_btime;
__u64 dqb_itime;
__u32 dqb_valid;
};
For 32 bit quota tools sizeof(if_dqblk) == 0x44.
But for 64 bit kernel its size is 0x48, 'cause of alignment!
Thus we got a problem. Attached patch reintroduce sys32_quotactl() function,
that handles this and related situations.
Signed-off-by: Vasily Tarasov <[email protected]>
---
In OpenVZ technology 32 bit Virtual Environments over
64 bit OS are common, hence we have customers, that complains on this bad quota
behaviour:
# /usr/bin/quota
quota: error while getting quota from /dev/sda1 for 0: Success
The reason is caused above.
--- linux-2.6.22-rc4-fixed/arch/x86_64/ia32/ia32entry.S.orig 2007-06-14 15:55:24.000000000 +0400
+++ linux-2.6.22-rc4-fixed/arch/x86_64/ia32/ia32entry.S 2007-06-14 16:22:52.000000000 +0400
@@ -526,7 +526,7 @@ ia32_sys_call_table:
.quad sys_init_module
.quad sys_delete_module
.quad quiet_ni_syscall /* 130 get_kernel_syms */
- .quad sys_quotactl
+ .quad sys32_quotactl
.quad sys_getpgid
.quad sys_fchdir
.quad quiet_ni_syscall /* bdflush */
--- linux-2.6.22-rc4-fixed/arch/ia64/ia32/ia32_entry.S.orig 2007-06-14 15:55:24.000000000 +0400
+++ linux-2.6.22-rc4-fixed/arch/ia64/ia32/ia32_entry.S 2007-06-14 16:22:52.000000000 +0400
@@ -304,7 +304,7 @@ ia32_syscall_table:
data8 sys_ni_syscall /* init_module */
data8 sys_ni_syscall /* delete_module */
data8 sys_ni_syscall /* get_kernel_syms */ /* 130 */
- data8 sys_quotactl
+ data8 sys32_quotactl
data8 sys_getpgid
data8 sys_fchdir
data8 sys_ni_syscall /* sys_bdflush */
--- linux-2.6.22-rc4-fixed/fs/quota.c.orig 2007-06-14 15:55:26.000000000 +0400
+++ linux-2.6.22-rc4-fixed/fs/quota.c 2007-06-18 12:00:56.000000000 +0400
@@ -10,12 +10,14 @@
#include <linux/slab.h>
#include <asm/current.h>
#include <asm/uaccess.h>
+#include <asm/compat.h>
#include <linux/kernel.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
+#include <linux/types.h>
/* Check validity of generic quotactl commands */
static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
@@ -384,3 +386,119 @@ asmlinkage long sys_quotactl(unsigned in
return ret;
}
+
+#if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
+/*
+ * 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;
+};
+
+asmlinkage long sys32_quotactl(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 = sys_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 = sys_quotactl(cmd, special, id, dqblk);
+ break;
+ case Q_XGETQSTAT:
+ fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
+ compat_fsqstat = addr;
+ ret = sys_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 = sys_quotactl(cmd, special, id, addr);
+ }
+ return ret;
+}
+#endif
On Mon, 18 Jun 2007 12:21:47 +0400
Vasily Tarasov <[email protected]> wrote:
> From: Vasily Tarasov <[email protected]>
>
> This patch should be applied after Arnd Bergmann's patch,
> that intoduces new compat types:
> http://lkml.org/lkml/2007/6/15/98
>
> OpenVZ Linux kernel team has discovered the problem
> with 32bit quota tools working on 64bit architectures.
> In 2.6.10 kernel sys32_quotactl() function was replaced by sys_quotactl() with
> the comment "sys_quotactl seems to be 32/64bit clean, enable it for 32bit"
> However this isn't right. Look at if_dqblk structure:
>
> struct if_dqblk {
> __u64 dqb_bhardlimit;
> __u64 dqb_bsoftlimit;
> __u64 dqb_curspace;
> __u64 dqb_ihardlimit;
> __u64 dqb_isoftlimit;
> __u64 dqb_curinodes;
> __u64 dqb_btime;
> __u64 dqb_itime;
> __u32 dqb_valid;
> };
>
> For 32 bit quota tools sizeof(if_dqblk) == 0x44.
> But for 64 bit kernel its size is 0x48, 'cause of alignment!
> Thus we got a problem. Attached patch reintroduce sys32_quotactl() function,
> that handles this and related situations.
>
> Signed-off-by: Vasily Tarasov <[email protected]>
>
> ---
>
> In OpenVZ technology 32 bit Virtual Environments over
> 64 bit OS are common, hence we have customers, that complains on this bad quota
> behaviour:
>
> # /usr/bin/quota
> quota: error while getting quota from /dev/sda1 for 0: Success
>
> The reason is caused above.
Only x86_64 and ia64 are fixed. Would it be correct to assume that the
other CONFIG_COMPAT architectures also need to be fixed?
> --- linux-2.6.22-rc4-fixed/arch/x86_64/ia32/ia32entry.S.orig 2007-06-14 15:55:24.000000000 +0400
> +++ linux-2.6.22-rc4-fixed/arch/x86_64/ia32/ia32entry.S 2007-06-14 16:22:52.000000000 +0400
> @@ -526,7 +526,7 @@ ia32_sys_call_table:
> .quad sys_init_module
> .quad sys_delete_module
> .quad quiet_ni_syscall /* 130 get_kernel_syms */
> - .quad sys_quotactl
> + .quad sys32_quotactl
> .quad sys_getpgid
> .quad sys_fchdir
> .quad quiet_ni_syscall /* bdflush */
> --- linux-2.6.22-rc4-fixed/arch/ia64/ia32/ia32_entry.S.orig 2007-06-14 15:55:24.000000000 +0400
> +++ linux-2.6.22-rc4-fixed/arch/ia64/ia32/ia32_entry.S 2007-06-14 16:22:52.000000000 +0400
> @@ -304,7 +304,7 @@ ia32_syscall_table:
> data8 sys_ni_syscall /* init_module */
> data8 sys_ni_syscall /* delete_module */
> data8 sys_ni_syscall /* get_kernel_syms */ /* 130 */
> - data8 sys_quotactl
> + data8 sys32_quotactl
> data8 sys_getpgid
> data8 sys_fchdir
> data8 sys_ni_syscall /* sys_bdflush */
> --- linux-2.6.22-rc4-fixed/fs/quota.c.orig 2007-06-14 15:55:26.000000000 +0400
> +++ linux-2.6.22-rc4-fixed/fs/quota.c 2007-06-18 12:00:56.000000000 +0400
> @@ -10,12 +10,14 @@
> #include <linux/slab.h>
> #include <asm/current.h>
> #include <asm/uaccess.h>
> +#include <asm/compat.h>
> #include <linux/kernel.h>
> #include <linux/security.h>
> #include <linux/syscalls.h>
> #include <linux/buffer_head.h>
> #include <linux/capability.h>
> #include <linux/quotaops.h>
> +#include <linux/types.h>
>
> /* Check validity of generic quotactl commands */
> static int generic_quotactl_valid(struct super_block *sb, int type, int cmd, qid_t id)
> @@ -384,3 +386,119 @@ asmlinkage long sys_quotactl(unsigned in
>
> return ret;
> }
> +
> +#if defined(CONFIG_X86_64) || defined(CONFIG_IA64)
> +/*
> + * 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;
> +};
> +
> +asmlinkage long sys32_quotactl(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 = sys_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 = sys_quotactl(cmd, special, id, dqblk);
> + break;
> + case Q_XGETQSTAT:
> + fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
> + compat_fsqstat = addr;
> + ret = sys_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 = sys_quotactl(cmd, special, id, addr);
> + }
> + return ret;
> +}
> +#endif
Andrew Morton writes:
> On Mon, 18 Jun 2007 12:21:47 +0400
> Vasily Tarasov <[email protected]> wrote:
>
> > From: Vasily Tarasov <[email protected]>
> >
> > This patch should be applied after Arnd Bergmann's patch,
> > that intoduces new compat types:
> > http://lkml.org/lkml/2007/6/15/98
> >
> > OpenVZ Linux kernel team has discovered the problem
> > with 32bit quota tools working on 64bit architectures.
> > In 2.6.10 kernel sys32_quotactl() function was replaced by sys_quotactl() with
> > the comment "sys_quotactl seems to be 32/64bit clean, enable it for 32bit"
> > However this isn't right. Look at if_dqblk structure:
> >
> > struct if_dqblk {
> > __u64 dqb_bhardlimit;
> > __u64 dqb_bsoftlimit;
> > __u64 dqb_curspace;
> > __u64 dqb_ihardlimit;
> > __u64 dqb_isoftlimit;
> > __u64 dqb_curinodes;
> > __u64 dqb_btime;
> > __u64 dqb_itime;
> > __u32 dqb_valid;
> > };
> >
> > For 32 bit quota tools sizeof(if_dqblk) == 0x44.
> > But for 64 bit kernel its size is 0x48, 'cause of alignment!
> > Thus we got a problem. Attached patch reintroduce sys32_quotactl() function,
> > that handles this and related situations.
> >
> > Signed-off-by: Vasily Tarasov <[email protected]>
> >
> > ---
> >
> > In OpenVZ technology 32 bit Virtual Environments over
> > 64 bit OS are common, hence we have customers, that complains on this bad quota
> > behaviour:
> >
> > # /usr/bin/quota
> > quota: error while getting quota from /dev/sda1 for 0: Success
> >
> > The reason is caused above.
>
> Only x86_64 and ia64 are fixed. Would it be correct to assume that the
> other CONFIG_COMPAT architectures also need to be fixed?
I complained about this very issue when a previous version of
this patch was submitted last week, and Arnd explained that
non-x86 doesn't have a problem here because alignof(u64) is the
same in 32- and 64-bit modes.
However, the fact that the patch description talks about 32-
and 64-bit machines _in_general_, while the patch clearly only
handles x86-32 on x86-64 and ia64, is itself a bug. A more
precise patch description and a better comment in the code
is in order, I think.
/Mikael
From: Andrew Morton <[email protected]>
Date: Tue, 19 Jun 2007 12:33:16 -0700
> Only x86_64 and ia64 are fixed. Would it be correct to assume that the
> other CONFIG_COMPAT architectures also need to be fixed?
Only platforms which compat to "i386" have the issue wrt.
the alignment of "u64" types, which is "4" on i386 and
"8" on the platforms that compat to them.
This has been mentioned at least 3 times in this thread.