diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sysctl.h | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 1b24bd45e08..d98562f1df7 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -6,10 +6,17 @@ **************************************************************** **************************************************************** ** + ** WARNING: ** The values in this file are exported to user space via - ** the sysctl() binary interface. However this interface - ** is unstable and deprecated and will be removed in the future. - ** For a stable interface use /proc/sys. + ** the sysctl() binary interface. Do *NOT* change the + ** numbering of any existing values here, and do not change + ** any numbers within any one set of values. If you have to + ** have to redefine an existing interface, use a new number for it. + ** The kernel will then return -ENOTDIR to any application using + ** the old binary interface. + ** + ** For new interfaces unless you really need a binary number + ** please use CTL_UNNUMBERED. ** **************************************************************** **************************************************************** @@ -48,6 +55,7 @@ struct __sysctl_args { #ifdef __KERNEL__ #define CTL_ANY -1 /* Matches any name */ #define CTL_NONE 0 +#define CTL_UNNUMBERED CTL_NONE /* sysctl without a binary number */ #endif enum @@ -961,8 +969,8 @@ extern ctl_handler sysctl_ms_jiffies; /* * Register a set of sysctl names by calling register_sysctl_table * with an initialised array of ctl_table's. An entry with zero - * ctl_name terminates the table. table->de will be set up by the - * registration and need not be initialised in advance. + * ctl_name and NULL procname terminates the table. table->de will be + * set up by the registration and need not be initialised in advance. * * sysctl names can be mirrored automatically under /proc/sys. The * procname supplied controls /proc naming. @@ -973,7 +981,10 @@ extern ctl_handler sysctl_ms_jiffies; * Leaf nodes in the sysctl tree will be represented by a single file * under /proc; non-leaf nodes will be represented by directories. A * null procname disables /proc mirroring at this node. - * + * + * sysctl entries with a zero ctl_name will not be available through + * the binary sysctl interface. + * * sysctl(2) can automatically manage read and write requests through * the sysctl table. The data and maxlen fields of the ctl_table * struct enable minimal validation of the values being written to be |