From: "David S. Miller" <davem@redhat.com>
The issue is that proc_dointvec_jiffies does not normalize
to/from USER_HZ, and there are a bunch of networking bits that
need this.
Begin forwarded message:
Date: Thu, 18 Dec 2003 15:42:27 +0900 (JST)
From: YOSHIFUJI Hideaki / _$B5HF#1QL@ <yoshfuji@linux-ipv6.org>
To: davem@redhat.com
Cc: netdev@oss.sgi.com, yoshfuji@linux-ipv6.org
Subject: Re: [PATCH] NET: Normalize jiffies reported to userspace, in neighbor management code
Hello.
In article <20031111160200.72cee93a.davem@redhat.com> (at Tue, 11 Nov 2003 16:02:00 -0800), "David S. Miller" <davem@redhat.com> says:
> On Tue, 11 Nov 2003 16:31:28 -0600 (CST)
> YOSHIFUJI Hideaki / _$B5HF#1QL@ <yoshfuji@linux-ipv6.org> wrote:
>
> > In article <20031110230233.254061da.davem@redhat.com> (at Mon, 10 Nov 2003 23:02:33 -0800), "David S. Miller" <davem@redhat.com> says:
> >
> > > Another idea is to change do_proc_dointvec() to take a conversion function
> > > pointer instead of this "conv" thing. Maybe even proc_dointvec_minmax()
> > > could be implemented in terms of do_proc_dointvec() with such a scheme.
> >
> > This is essentially identical to what I thought.
> > Okay, how about this?
>
> This looks very nice, thank you Yoshfuji.
>
> I'm asking Linus what we should do here. It's a big change to
> make to fix this bug, and if he thinks so too we'll just use
> your original patch which is a safer version of the fix for 2.6.0
> purposes. If that happens, we'll integrate this nicer version
> for 2.6.1 or something like this.
2.6.0 is out finally; it would be the good time for resending the patch.
Thanks you in advance.
===== include/linux/sysctl.h 1.53 vs edited =====
include/linux/sysctl.h | 2
kernel/sysctl.c | 327 ++++++++++++++++++++++++++++++-------------------
net/core/neighbour.c | 9 -
3 files changed, 212 insertions(+), 126 deletions(-)
diff -puN include/linux/sysctl.h~net-jiffy-normalisation-fix include/linux/sysctl.h
--- 25/include/linux/sysctl.h~net-jiffy-normalisation-fix 2003-12-30 16:44:27.000000000 -0800
+++ 25-akpm/include/linux/sysctl.h 2003-12-30 16:44:27.000000000 -0800
@@ -734,6 +734,8 @@ extern int proc_dointvec_minmax(ctl_tabl
void __user *, size_t *);
extern int proc_dointvec_jiffies(ctl_table *, int, struct file *,
void __user *, size_t *);
+extern int proc_dointvec_userhz_jiffies(ctl_table *, int, struct file *,
+ void __user *, size_t *);
extern int proc_doulongvec_minmax(ctl_table *, int, struct file *,
void __user *, size_t *);
extern int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int,
diff -puN kernel/sysctl.c~net-jiffy-normalisation-fix kernel/sysctl.c
--- 25/kernel/sysctl.c~net-jiffy-normalisation-fix 2003-12-30 16:44:27.000000000 -0800
+++ 25-akpm/kernel/sysctl.c 2003-12-30 16:44:27.000000000 -0800
@@ -37,6 +37,7 @@
#include <linux/hugetlb.h>
#include <linux/security.h>
#include <linux/initrd.h>
+#include <linux/times.h>
#include <asm/uaccess.h>
#ifdef CONFIG_ROOT_NFS
@@ -1050,8 +1051,8 @@ int do_sysctl_strategy (ctl_table *table
* cover common cases -
*
* proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
- * proc_dointvec_minmax(), proc_doulongvec_ms_jiffies_minmax(),
- * proc_doulongvec_minmax()
+ * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
+ * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
*
* It is the handler's job to read the input buffer from user memory
* and process it. The handler should return 0 on success.
@@ -1322,19 +1323,36 @@ static int proc_doutsstring(ctl_table *t
return r;
}
-#define OP_SET 0
-#define OP_AND 1
-#define OP_OR 2
-#define OP_MAX 3
-#define OP_MIN 4
+static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
+ int *valp,
+ int write, void *data)
+{
+ if (write) {
+ *valp = *negp ? -*lvalp : *lvalp;
+ } else {
+ int val = *valp;
+ if (val < 0) {
+ *negp = -1;
+ *lvalp = (unsigned long)-val;
+ } else {
+ *negp = 0;
+ *lvalp = (unsigned long)val;
+ }
+ }
+ return 0;
+}
static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp, int conv, int op)
+ void __user *buffer, size_t *lenp,
+ int (*conv)(int *negp, unsigned long *lvalp, int *valp,
+ int write, void *data),
+ void *data)
{
+#define TMPBUFLEN 20
int *i, vleft, first=1, neg, val;
+ unsigned long lval;
size_t left, len;
- #define TMPBUFLEN 20
char buf[TMPBUFLEN], *p;
if (!table->data || !table->maxlen || !*lenp ||
@@ -1344,9 +1362,12 @@ static int do_proc_dointvec(ctl_table *t
}
i = (int *) table->data;
- vleft = table->maxlen / sizeof(int);
+ vleft = table->maxlen / sizeof(*i);
left = *lenp;
-
+
+ if (!conv)
+ conv = do_proc_dointvec_conv;
+
for (; left && vleft--; i++, first=0) {
if (write) {
while (left) {
@@ -1362,8 +1383,8 @@ static int do_proc_dointvec(ctl_table *t
break;
neg = 0;
len = left;
- if (len > TMPBUFLEN-1)
- len = TMPBUFLEN-1;
+ if (len > sizeof(buf) - 1)
+ len = sizeof(buf) - 1;
if(copy_from_user(buf, buffer, len))
return -EFAULT;
buf[len] = 0;
@@ -1374,7 +1395,9 @@ static int do_proc_dointvec(ctl_table *t
}
if (*p < '0' || *p > '9')
break;
- val = simple_strtoul(p, &p, 0) * conv;
+
+ lval = simple_strtoul(p, &p, 0);
+
len = p-buf;
if ((len < left) && *p && !isspace(*p))
break;
@@ -1382,22 +1405,18 @@ static int do_proc_dointvec(ctl_table *t
val = -val;
buffer += len;
left -= len;
- switch(op) {
- case OP_SET: *i = val; break;
- case OP_AND: *i &= val; break;
- case OP_OR: *i |= val; break;
- case OP_MAX: if(*i < val)
- *i = val;
- break;
- case OP_MIN: if(*i > val)
- *i = val;
- break;
- }
+
+ if (conv(&neg, &lval, i, 1, data))
+ break;
} else {
p = buf;
if (!first)
*p++ = '\t';
- sprintf(p, "%d", (*i) / conv);
+
+ if (conv(&neg, &lval, i, 0, data))
+ break;
+
+ sprintf(p, "%s%lu", neg ? "-" : "", lval);
len = strlen(buf);
if (len > left)
len = left;
@@ -1429,6 +1448,7 @@ static int do_proc_dointvec(ctl_table *t
*lenp -= left;
filp->f_pos += *lenp;
return 0;
+#undef TMPBUFLEN
}
/**
@@ -1447,7 +1467,45 @@ static int do_proc_dointvec(ctl_table *t
int proc_dointvec(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp)
{
- return do_proc_dointvec(table,write,filp,buffer,lenp,1,OP_SET);
+ return do_proc_dointvec(table,write,filp,buffer,lenp,
+ NULL,NULL);
+}
+
+#define OP_SET 0
+#define OP_AND 1
+#define OP_OR 2
+#define OP_MAX 3
+#define OP_MIN 4
+
+static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
+ int *valp,
+ int write, void *data)
+{
+ int op = *(int *)data;
+ if (write) {
+ int val = *negp ? -*lvalp : *lvalp;
+ switch(op) {
+ case OP_SET: *valp = val; break;
+ case OP_AND: *valp &= val; break;
+ case OP_OR: *valp |= val; break;
+ case OP_MAX: if(*valp < val)
+ *valp = val;
+ break;
+ case OP_MIN: if(*valp > val)
+ *valp = val;
+ break;
+ }
+ } else {
+ int val = *valp;
+ if (val < 0) {
+ *negp = -1;
+ *lvalp = (unsigned long)-val;
+ } else {
+ *negp = 0;
+ *lvalp = (unsigned long)val;
+ }
+ }
+ return 0;
}
/*
@@ -1457,11 +1515,44 @@ int proc_dointvec(ctl_table *table, int
int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp)
{
+ int op;
+
if (!capable(CAP_SYS_MODULE)) {
return -EPERM;
}
- return do_proc_dointvec(table,write,filp,buffer,lenp,1,
- (current->pid == 1) ? OP_SET : OP_AND);
+
+ op = (current->pid == 1) ? OP_SET : OP_AND;
+ return do_proc_dointvec(table,write,filp,buffer,lenp,
+ do_proc_dointvec_bset_conv,&op);
+}
+
+struct do_proc_dointvec_minmax_conv_param {
+ int *min;
+ int *max;
+};
+
+static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
+ int *valp,
+ int write, void *data)
+{
+ struct do_proc_dointvec_minmax_conv_param *param = data;
+ if (write) {
+ int val = *negp ? -*lvalp : *lvalp;
+ if ((param->min && *param->min > val) ||
+ (param->max && *param->max < val))
+ return -EINVAL;
+ *valp = val;
+ } else {
+ int val = *valp;
+ if (val < 0) {
+ *negp = -1;
+ *lvalp = (unsigned long)-val;
+ } else {
+ *negp = 0;
+ *lvalp = (unsigned long)val;
+ }
+ }
+ return 0;
}
/**
@@ -1483,98 +1574,12 @@ int proc_dointvec_bset(ctl_table *table,
int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp)
{
- int *i, *min, *max, vleft, first=1, neg, val;
- size_t len, left;
- #define TMPBUFLEN 20
- char buf[TMPBUFLEN], *p;
-
- if (!table->data || !table->maxlen || !*lenp ||
- (filp->f_pos && !write)) {
- *lenp = 0;
- return 0;
- }
-
- i = (int *) table->data;
- min = (int *) table->extra1;
- max = (int *) table->extra2;
- vleft = table->maxlen / sizeof(int);
- left = *lenp;
-
- for (; left && vleft--; i++, min++, max++, first=0) {
- if (write) {
- while (left) {
- char c;
- if(get_user(c, (char *) buffer))
- return -EFAULT;
- if (!isspace(c))
- break;
- left--;
- buffer++;
- }
- if (!left)
- break;
- neg = 0;
- len = left;
- if (len > TMPBUFLEN-1)
- len = TMPBUFLEN-1;
- if(copy_from_user(buf, buffer, len))
- return -EFAULT;
- buf[len] = 0;
- p = buf;
- if (*p == '-' && left > 1) {
- neg = 1;
- left--, p++;
- }
- if (*p < '0' || *p > '9')
- break;
- val = simple_strtoul(p, &p, 0);
- len = p-buf;
- if ((len < left) && *p && !isspace(*p))
- break;
- if (neg)
- val = -val;
- buffer += len;
- left -= len;
-
- if ((min && val < *min) || (max && val > *max))
- continue;
- *i = val;
- } else {
- p = buf;
- if (!first)
- *p++ = '\t';
- sprintf(p, "%d", *i);
- len = strlen(buf);
- if (len > left)
- len = left;
- if(copy_to_user(buffer, buf, len))
- return -EFAULT;
- left -= len;
- buffer += len;
- }
- }
-
- if (!write && !first && left) {
- if(put_user('\n', (char *) buffer))
- return -EFAULT;
- left--, buffer++;
- }
- if (write) {
- p = (char *) buffer;
- while (left) {
- char c;
- if(get_user(c, p++))
- return -EFAULT;
- if (!isspace(c))
- break;
- left--;
- }
- }
- if (write && first)
- return -EINVAL;
- *lenp -= left;
- filp->f_pos += *lenp;
- return 0;
+ struct do_proc_dointvec_minmax_conv_param param = {
+ .min = (int *) table->extra1,
+ .max = (int *) table->extra2,
+ };
+ return do_proc_dointvec(table, write, filp, buffer, lenp,
+ do_proc_dointvec_minmax_conv, ¶m);
}
static int do_proc_doulongvec_minmax(ctl_table *table, int write,
@@ -1729,6 +1734,48 @@ int proc_doulongvec_ms_jiffies_minmax(ct
}
+static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
+ int *valp,
+ int write, void *data)
+{
+ if (write) {
+ *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
+ } else {
+ int val = *valp;
+ unsigned long lval;
+ if (val < 0) {
+ *negp = -1;
+ lval = (unsigned long)-val;
+ } else {
+ *negp = 0;
+ lval = (unsigned long)val;
+ }
+ *lvalp = lval / HZ;
+ }
+ return 0;
+}
+
+static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
+ int *valp,
+ int write, void *data)
+{
+ if (write) {
+ *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
+ } else {
+ int val = *valp;
+ unsigned long lval;
+ if (val < 0) {
+ *negp = -1;
+ lval = (unsigned long)-val;
+ } else {
+ *negp = 0;
+ lval = (unsigned long)val;
+ }
+ *lvalp = jiffies_to_clock_t(lval);
+ }
+ return 0;
+}
+
/**
* proc_dointvec_jiffies - read a vector of integers as seconds
* @table: the sysctl table
@@ -1747,7 +1794,30 @@ int proc_doulongvec_ms_jiffies_minmax(ct
int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp)
{
- return do_proc_dointvec(table,write,filp,buffer,lenp,HZ,OP_SET);
+ return do_proc_dointvec(table,write,filp,buffer,lenp,
+ do_proc_dointvec_jiffies_conv,NULL);
+}
+
+/**
+ * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @filp: the file structure
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
+ * values from/to the user buffer, treated as an ASCII string.
+ * The values read are assumed to be in 1/USER_HZ seconds, and
+ * are converted into jiffies.
+ *
+ * Returns 0 on success.
+ */
+int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
+ void __user *buffer, size_t *lenp)
+{
+ return do_proc_dointvec(table,write,filp,buffer,lenp,
+ do_proc_dointvec_userhz_jiffies_conv,NULL);
}
#else /* CONFIG_PROC_FS */
@@ -1788,6 +1858,12 @@ int proc_dointvec_jiffies(ctl_table *tab
return -ENOSYS;
}
+int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
+ void *buffer, size_t *lenp)
+{
+ return -ENOSYS;
+}
+
int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
@@ -1975,6 +2051,12 @@ int proc_dointvec_jiffies(ctl_table *tab
return -ENOSYS;
}
+int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
+ void *buffer, size_t *lenp)
+{
+ return -ENOSYS;
+}
+
int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp)
{
@@ -2007,6 +2089,7 @@ void unregister_sysctl_table(struct ctl_
EXPORT_SYMBOL(proc_dointvec);
EXPORT_SYMBOL(proc_dointvec_jiffies);
EXPORT_SYMBOL(proc_dointvec_minmax);
+EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
EXPORT_SYMBOL(proc_dostring);
EXPORT_SYMBOL(proc_doulongvec_minmax);
EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
diff -puN net/core/neighbour.c~net-jiffy-normalisation-fix net/core/neighbour.c
--- 25/net/core/neighbour.c~net-jiffy-normalisation-fix 2003-12-30 16:44:27.000000000 -0800
+++ 25-akpm/net/core/neighbour.c 2003-12-30 16:44:27.000000000 -0800
@@ -24,6 +24,7 @@
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
+#include <linux/times.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/sock.h>
@@ -1510,7 +1511,7 @@ struct neigh_sysctl_table {
.procname = "retrans_time",
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_dointvec_userhz_jiffies,
},
{
.ctl_name = NET_NEIGH_REACHABLE_TIME,
@@ -1555,21 +1556,21 @@ struct neigh_sysctl_table {
.procname = "anycast_delay",
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_dointvec_userhz_jiffies,
},
{
.ctl_name = NET_NEIGH_PROXY_DELAY,
.procname = "proxy_delay",
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_dointvec_userhz_jiffies,
},
{
.ctl_name = NET_NEIGH_LOCKTIME,
.procname = "locktime",
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_dointvec_userhz_jiffies,
},
{
.ctl_name = NET_NEIGH_GC_INTERVAL,
_