diff options
Diffstat (limited to 'include/linux/sysctl.h')
| -rw-r--r-- | include/linux/sysctl.h | 157 |
1 files changed, 134 insertions, 23 deletions
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 92e9146b1104..288fe0055cd5 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -59,6 +59,121 @@ extern const int sysctl_vals[]; #define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1]) #define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2]) +#define SYSCTL_CONV_IDENTITY(val) (val) +/** + * + * "dir" originates from read_iter (dir = 0) or write_iter (dir = 1) + * in the file_operations struct at proc/proc_sysctl.c. Its value means + * one of two things for sysctl: + * 1. SYSCTL_USER_TO_KERN(dir) Writing to an internal kernel variable from user + * space (dir > 0) + * 2. SYSCTL_KERN_TO_USER(dir) Writing to a user space buffer from a kernel + * variable (dir == 0). + */ +#define SYSCTL_USER_TO_KERN(dir) (!!(dir)) +#define SYSCTL_KERN_TO_USER(dir) (!dir) + +#define SYSCTL_USER_TO_KERN_INT_CONV(name, u_ptr_op) \ +int sysctl_user_to_kern_int_conv##name(const bool *negp, \ + const unsigned long *u_ptr,\ + int *k_ptr) \ +{ \ + unsigned long u = u_ptr_op(*u_ptr); \ + if (*negp) { \ + if (u > (unsigned long) INT_MAX + 1) \ + return -EINVAL; \ + WRITE_ONCE(*k_ptr, -u); \ + } else { \ + if (u > (unsigned long) INT_MAX) \ + return -EINVAL; \ + WRITE_ONCE(*k_ptr, u); \ + } \ + return 0; \ +} + +#define SYSCTL_KERN_TO_USER_INT_CONV(name, k_ptr_op) \ +int sysctl_kern_to_user_int_conv##name(bool *negp, \ + unsigned long *u_ptr, \ + const int *k_ptr) \ +{ \ + int val = READ_ONCE(*k_ptr); \ + if (val < 0) { \ + *negp = true; \ + *u_ptr = -k_ptr_op((unsigned long)val); \ + } else { \ + *negp = false; \ + *u_ptr = k_ptr_op((unsigned long)val); \ + } \ + return 0; \ +} + +/** + * To range check on a converted value, use a temp k_ptr + * When checking range, value should be within (tbl->extra1, tbl->extra2) + */ +#define SYSCTL_INT_CONV_CUSTOM(name, user_to_kern, kern_to_user, \ + k_ptr_range_check) \ +int do_proc_int_conv##name(bool *negp, unsigned long *u_ptr, int *k_ptr,\ + int dir, const struct ctl_table *tbl) \ +{ \ + if (SYSCTL_KERN_TO_USER(dir)) \ + return kern_to_user(negp, u_ptr, k_ptr); \ + \ + if (k_ptr_range_check) { \ + int tmp_k, ret; \ + if (!tbl) \ + return -EINVAL; \ + ret = user_to_kern(negp, u_ptr, &tmp_k); \ + if (ret) \ + return ret; \ + if ((tbl->extra1 && *(int *)tbl->extra1 > tmp_k) || \ + (tbl->extra2 && *(int *)tbl->extra2 < tmp_k)) \ + return -EINVAL; \ + WRITE_ONCE(*k_ptr, tmp_k); \ + } else \ + return user_to_kern(negp, u_ptr, k_ptr); \ + return 0; \ +} + +#define SYSCTL_USER_TO_KERN_UINT_CONV(name, u_ptr_op) \ +int sysctl_user_to_kern_uint_conv##name(const unsigned long *u_ptr,\ + unsigned int *k_ptr) \ +{ \ + unsigned long u = u_ptr_op(*u_ptr); \ + if (u > UINT_MAX) \ + return -EINVAL; \ + WRITE_ONCE(*k_ptr, u); \ + return 0; \ +} + +#define SYSCTL_UINT_CONV_CUSTOM(name, user_to_kern, kern_to_user, \ + k_ptr_range_check) \ +int do_proc_uint_conv##name(unsigned long *u_ptr, unsigned int *k_ptr, \ + int dir, const struct ctl_table *tbl) \ +{ \ + if (SYSCTL_KERN_TO_USER(dir)) \ + return kern_to_user(u_ptr, k_ptr); \ + \ + if (k_ptr_range_check) { \ + unsigned int tmp_k; \ + int ret; \ + if (!tbl) \ + return -EINVAL; \ + ret = user_to_kern(u_ptr, &tmp_k); \ + if (ret) \ + return ret; \ + if ((tbl->extra1 && \ + *(unsigned int *)tbl->extra1 > tmp_k) || \ + (tbl->extra2 && \ + *(unsigned int *)tbl->extra2 < tmp_k)) \ + return -ERANGE; \ + WRITE_ONCE(*k_ptr, tmp_k); \ + } else \ + return user_to_kern(u_ptr, k_ptr); \ + return 0; \ +} + + extern const unsigned long sysctl_long_vals[]; typedef int proc_handler(const struct ctl_table *ctl, int write, void *buffer, @@ -68,25 +183,30 @@ int proc_dostring(const struct ctl_table *, int, void *, size_t *, loff_t *); int proc_dobool(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); int proc_dointvec(const struct ctl_table *, int, void *, size_t *, loff_t *); +int proc_dointvec_minmax(const struct ctl_table *table, int dir, void *buffer, + size_t *lenp, loff_t *ppos); +int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer, + size_t *lenp, loff_t *ppos, + int (*conv)(bool *negp, unsigned long *u_ptr, int *k_ptr, + int dir, const struct ctl_table *table)); int proc_douintvec(const struct ctl_table *, int, void *, size_t *, loff_t *); -int proc_dointvec_minmax(const struct ctl_table *, int, void *, size_t *, loff_t *); int proc_douintvec_minmax(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); +int proc_douintvec_conv(const struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos, + int (*conv)(unsigned long *lvalp, unsigned int *valp, + int write, const struct ctl_table *table)); + int proc_dou8vec_minmax(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); -int proc_dointvec_jiffies(const struct ctl_table *, int, void *, size_t *, loff_t *); -int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos); -int proc_dointvec_userhz_jiffies(const struct ctl_table *, int, void *, size_t *, - loff_t *); -int proc_dointvec_ms_jiffies(const struct ctl_table *, int, void *, size_t *, - loff_t *); int proc_doulongvec_minmax(const struct ctl_table *, int, void *, size_t *, loff_t *); -int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int, void *, - size_t *, loff_t *); +int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir, + void *buffer, size_t *lenp, loff_t *ppos, + unsigned long convmul, unsigned long convdiv); int proc_do_large_bitmap(const struct ctl_table *, int, void *, size_t *, loff_t *); int proc_do_static_key(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos); +int sysctl_kern_to_user_uint_conv(unsigned long *u_ptr, const unsigned int *k_ptr); /* * Register a set of sysctl names by calling register_sysctl @@ -156,6 +276,10 @@ struct ctl_node { * @nreg: When nreg drops to 0 the ctl_table_header will be unregistered. * @rcu: Delays the freeing of the inode. Introduced with "unfuck proc_sysctl ->d_compare()" * + * @type: Enumeration to differentiate between ctl target types + * @type.SYSCTL_TABLE_TYPE_DEFAULT: ctl target with no special considerations + * @type.SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY: Identifies a permanently empty dir + * target to serve as a mount point */ struct ctl_table_header { union { @@ -175,13 +299,6 @@ struct ctl_table_header { struct ctl_dir *parent; struct ctl_node *node; struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */ - /** - * enum type - Enumeration to differentiate between ctl target types - * @SYSCTL_TABLE_TYPE_DEFAULT: ctl target with no special considerations - * @SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY: Used to identify a permanently - * empty directory target to serve - * as mount point. - */ enum { SYSCTL_TABLE_TYPE_DEFAULT, SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY, @@ -235,12 +352,6 @@ extern struct ctl_table_header *register_sysctl_mount_point(const char *path); void do_sysctl_args(void); bool sysctl_is_alias(char *param); -int do_proc_douintvec(const struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos, - int (*conv)(unsigned long *lvalp, - unsigned int *valp, - int write, void *data), - void *data); extern int unaligned_enabled; extern int no_unaligned_warning; |