From: Luis Chamberlain mcgrof@kernel.org
commit 1dc8689e4cc651e21566e10206a84c4006e81fb1 upstream.
Expand documentation to clarify:
o that paths don't need to exist for the new API callers o clarify that we *require* callers to keep the memory of the table around during the lifetime of the sysctls o annotate routines we are trying to deprecate and later remove
Cc: stable@vger.kernel.org # v5.17 Cc: Christian Brauner brauner@kernel.org Cc: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Luis Chamberlain mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/proc/proc_sysctl.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-)
--- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1281,7 +1281,10 @@ out: * __register_sysctl_table - register a leaf sysctl table * @set: Sysctl tree to register on * @path: The path to the directory the sysctl table is in. - * @table: the top-level table structure without any child + * @table: the top-level table structure without any child. This table + * should not be free'd after registration. So it should not be + * used on stack. It can either be a global or dynamically allocated + * by the caller and free'd later after sysctl unregistration. * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. @@ -1396,8 +1399,15 @@ fail:
/** * register_sysctl - register a sysctl table - * @path: The path to the directory the sysctl table is in. - * @table: the table structure + * @path: The path to the directory the sysctl table is in. If the path + * doesn't exist we will create it for you. + * @table: the table structure. The calller must ensure the life of the @table + * will be kept during the lifetime use of the syctl. It must not be freed + * until unregister_sysctl_table() is called with the given returned table + * with this registration. If your code is non modular then you don't need + * to call unregister_sysctl_table() and can instead use something like + * register_sysctl_init() which does not care for the result of the syctl + * registration. * * Register a sysctl table. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. @@ -1413,8 +1423,11 @@ EXPORT_SYMBOL(register_sysctl);
/** * __register_sysctl_init() - register sysctl table to path - * @path: path name for sysctl base - * @table: This is the sysctl table that needs to be registered to the path + * @path: path name for sysctl base. If that path doesn't exist we will create + * it for you. + * @table: This is the sysctl table that needs to be registered to the path. + * The caller must ensure the life of the @table will be kept during the + * lifetime use of the sysctl. * @table_name: The name of sysctl table, only used for log printing when * registration fails * @@ -1559,6 +1572,7 @@ out: * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. + * We are slowly deprecating this call so avoid its use. * * See __register_sysctl_table for more details. */ @@ -1630,6 +1644,7 @@ err_register_leaves: * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. + * We are slowly deprecating this caller so avoid future uses of it. * * See __register_sysctl_paths for more details. */