diff options
| author | Joel Granados <joel.granados@kernel.org> | 2025-10-14 12:42:01 +0200 |
|---|---|---|
| committer | Joel Granados <joel.granados@kernel.org> | 2025-11-27 15:45:37 +0100 |
| commit | e2e5dac304fdf991fb974510db4565db04ef1335 (patch) | |
| tree | 8d511d100e4ed086c5507df53c6b0d9e74e1013d /include/linux/sysctl.h | |
| parent | c5b4c183f7aeb46cd27ddea9dab776655b8d7034 (diff) | |
sysctl: Move INT converter macros to sysctl header
Move direction macros (SYSCTL_{USER_TO_KERN,KERN_TO_USER}) and the
integer converter macros (SYSCTL_{USER_TO_KERN,KERN_TO_USER}_INT_CONV,
SYSCTL_INT_CONV_CUSTOM) into include/linux/sysctl.h. This is a
preparation commit to enable jiffies converter creation outside
kernel/sysctl.c.
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Diffstat (limited to 'include/linux/sysctl.h')
| -rw-r--r-- | include/linux/sysctl.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index a48273757c99..a0ca9496119a 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -59,6 +59,81 @@ extern const int sysctl_vals[]; #define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1]) #define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2]) +/** + * + * "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; \ +} + extern const unsigned long sysctl_long_vals[]; typedef int proc_handler(const struct ctl_table *ctl, int write, void *buffer, |