sysctl: enable strict writes

[firefly-linux-kernel-4.4.55.git] / kernel / sysctl.c

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index dc6858d6639ed022d65129bdbb869ff7bcc05789..464a7864e4c50b95903f024dd6a009b02aee0e09 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -65,6 +65,7 @@
 #include <linux/sched/sysctl.h>
 #include <linux/kexec.h>
 #include <linux/bpf.h>
+#include <linux/mount.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -173,7 +174,7 @@ extern int no_unaligned_warning;
 #define SYSCTL_WRITES_WARN      0
 #define SYSCTL_WRITES_STRICT    1
 
-static int sysctl_writes_strict = SYSCTL_WRITES_WARN;
+static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
 
 static int proc_do_cad_pid(struct ctl_table *table, int write,
                  void __user *buffer, size_t *lenp, loff_t *ppos);
@@ -1735,6 +1736,28 @@ static struct ctl_table fs_table[] = {
                .proc_handler   = &pipe_proc_fn,
                .extra1         = &pipe_min_size,
        },
+       {
+               .procname       = "pipe-user-pages-hard",
+               .data           = &pipe_user_pages_hard,
+               .maxlen         = sizeof(pipe_user_pages_hard),
+               .mode           = 0644,
+               .proc_handler   = proc_doulongvec_minmax,
+       },
+       {
+               .procname       = "pipe-user-pages-soft",
+               .data           = &pipe_user_pages_soft,
+               .maxlen         = sizeof(pipe_user_pages_soft),
+               .mode           = 0644,
+               .proc_handler   = proc_doulongvec_minmax,
+       },
+       {
+               .procname       = "mount-max",
+               .data           = &sysctl_mount_max,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &one,
+       },
        { }
 };
 
@@ -2037,6 +2060,21 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
        return 0;
 }
 
+static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
+                                int *valp,
+                                int write, void *data)
+{
+       if (write) {
+               if (*negp)
+                       return -EINVAL;
+               *valp = *lvalp;
+       } else {
+               unsigned int val = *valp;
+               *lvalp = (unsigned long)val;
+       }
+       return 0;
+}
+
 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
 
 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
@@ -2164,8 +2202,27 @@ static int do_proc_dointvec(struct ctl_table *table, int write,
 int proc_dointvec(struct ctl_table *table, int write,
                     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-    return do_proc_dointvec(table,write,buffer,lenp,ppos,
-                           NULL,NULL);
+       return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
+}
+
+/**
+ * proc_douintvec - read a vector of unsigned integers
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
+ * values from/to the user buffer, treated as an ASCII string.
+ *
+ * Returns 0 on success.
+ */
+int proc_douintvec(struct ctl_table *table, int write,
+                    void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       return do_proc_dointvec(table, write, buffer, lenp, ppos,
+                               do_proc_douintvec_conv, NULL);
 }
 
 /*
@@ -2366,6 +2423,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
                                break;
                        if (neg)
                                continue;
+                       val = convmul * val / convdiv;
                        if ((min && val < *min) || (max && val > *max))
                                continue;
                        *i = val;
@@ -2778,6 +2836,12 @@ int proc_dointvec(struct ctl_table *table, int write,
        return -ENOSYS;
 }
 
+int proc_douintvec(struct ctl_table *table, int write,
+                 void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       return -ENOSYS;
+}
+
 int proc_dointvec_minmax(struct ctl_table *table, int write,
                    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2823,6 +2887,7 @@ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
  * exception granted :-)
  */
 EXPORT_SYMBOL(proc_dointvec);
+EXPORT_SYMBOL(proc_douintvec);
 EXPORT_SYMBOL(proc_dointvec_jiffies);
 EXPORT_SYMBOL(proc_dointvec_minmax);
 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);