[PATCH] [0/2] SYSCTL: Warn once for all legacy syctls

[PATCH] [0/2] SYSCTL: Warn once for all legacy syctls

[Andi Kleen]

Even with my recent patch to not warn for CTL_KERN,KERN_VERSION there
is still the theoretical possibility that some program who uses another
binary sysctl regularly will get a flooded syslog.

This patchkit changes this to only warn once for every possible binary sysctl.

-Andi

[PATCH] [1/2] SYSCTL: Make bin_table not const

[Andi Kleen]

Turn all the bin_tables from const to non-const. This is needed for the next
patch. Unfortunately there were a lot of them, so the patch is rather 
large, but it is completely mechanic. 

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 kernel/sysctl_binary.c |  120 ++++++++++++++++++++++++-------------------------
 1 file changed, 60 insertions(+), 60 deletions(-)

Index: linux-2.6.33-rc1-ak/kernel/sysctl_binary.c
===================================================================
--- linux-2.6.33-rc1-ak.orig/kernel/sysctl_binary.c
+++ linux-2.6.33-rc1-ak/kernel/sysctl_binary.c
@@ -40,10 +40,10 @@ struct bin_table {
 	bin_convert_t		*convert;
 	int			ctl_name;
 	const char		*procname;
-	const struct bin_table	*child;
+	struct bin_table	*child;
 };
 
-static const struct bin_table bin_random_table[] = {
+static struct bin_table bin_random_table[] = {
 	{ CTL_INT,	RANDOM_POOLSIZE,	"poolsize" },
 	{ CTL_INT,	RANDOM_ENTROPY_COUNT,	"entropy_avail" },
 	{ CTL_INT,	RANDOM_READ_THRESH,	"read_wakeup_threshold" },
@@ -53,13 +53,13 @@ static const struct bin_table bin_random
 	{}
 };
 
-static const struct bin_table bin_pty_table[] = {
+static struct bin_table bin_pty_table[] = {
 	{ CTL_INT,	PTY_MAX,	"max" },
 	{ CTL_INT,	PTY_NR,		"nr" },
 	{}
 };
 
-static const struct bin_table bin_kern_table[] = {
+static struct bin_table bin_kern_table[] = {
 	{ CTL_STR,	KERN_OSTYPE,			"ostype" },
 	{ CTL_STR,	KERN_OSRELEASE,			"osrelease" },
 	/* KERN_OSREV not used */
@@ -139,7 +139,7 @@ static const struct bin_table bin_kern_t
 	{}
 };
 
-static const struct bin_table bin_vm_table[] = {
+static struct bin_table bin_vm_table[] = {
 	{ CTL_INT,	VM_OVERCOMMIT_MEMORY,		"overcommit_memory" },
 	{ CTL_INT,	VM_PAGE_CLUSTER,		"page-cluster" },
 	{ CTL_INT,	VM_DIRTY_BACKGROUND,		"dirty_background_ratio" },
@@ -171,7 +171,7 @@ static const struct bin_table bin_vm_tab
 	{}
 };
 
-static const struct bin_table bin_net_core_table[] = {
+static struct bin_table bin_net_core_table[] = {
 	{ CTL_INT,	NET_CORE_WMEM_MAX,	"wmem_max" },
 	{ CTL_INT,	NET_CORE_RMEM_MAX,	"rmem_max" },
 	{ CTL_INT,	NET_CORE_WMEM_DEFAULT,	"wmem_default" },
@@ -197,14 +197,14 @@ static const struct bin_table bin_net_co
 	{},
 };
 
-static const struct bin_table bin_net_unix_table[] = {
+static struct bin_table bin_net_unix_table[] = {
 	/* NET_UNIX_DESTROY_DELAY unused */
 	/* NET_UNIX_DELETE_DELAY unused */
 	{ CTL_INT,	NET_UNIX_MAX_DGRAM_QLEN,	"max_dgram_qlen" },
 	{}
 };
 
-static const struct bin_table bin_net_ipv4_route_table[] = {
+static struct bin_table bin_net_ipv4_route_table[] = {
 	{ CTL_INT,	NET_IPV4_ROUTE_FLUSH,			"flush" },
 	/* NET_IPV4_ROUTE_MIN_DELAY "min_delay" no longer used */
 	/* NET_IPV4_ROUTE_MAX_DELAY "max_delay" no longer used */
@@ -227,7 +227,7 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_ipv4_conf_vars_table[] = {
+static struct bin_table bin_net_ipv4_conf_vars_table[] = {
 	{ CTL_INT,	NET_IPV4_CONF_FORWARDING,		"forwarding" },
 	{ CTL_INT,	NET_IPV4_CONF_MC_FORWARDING,		"mc_forwarding" },
 
@@ -255,14 +255,14 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_ipv4_conf_table[] = {
+static struct bin_table bin_net_ipv4_conf_table[] = {
 	{ CTL_DIR,	NET_PROTO_CONF_ALL,	"all",		bin_net_ipv4_conf_vars_table },
 	{ CTL_DIR,	NET_PROTO_CONF_DEFAULT,	"default",	bin_net_ipv4_conf_vars_table },
 	{ CTL_DIR,	0, NULL, bin_net_ipv4_conf_vars_table },
 	{}
 };
 
-static const struct bin_table bin_net_neigh_vars_table[] = {
+static struct bin_table bin_net_neigh_vars_table[] = {
 	{ CTL_INT,	NET_NEIGH_MCAST_SOLICIT,	"mcast_solicit" },
 	{ CTL_INT,	NET_NEIGH_UCAST_SOLICIT,	"ucast_solicit" },
 	{ CTL_INT,	NET_NEIGH_APP_SOLICIT,		"app_solicit" },
@@ -284,13 +284,13 @@ static const struct bin_table bin_net_ne
 	{}
 };
 
-static const struct bin_table bin_net_neigh_table[] = {
+static struct bin_table bin_net_neigh_table[] = {
 	{ CTL_DIR,	NET_PROTO_CONF_DEFAULT, "default", bin_net_neigh_vars_table },
 	{ CTL_DIR,	0, NULL, bin_net_neigh_vars_table },
 	{}
 };
 
-static const struct bin_table bin_net_ipv4_netfilter_table[] = {
+static struct bin_table bin_net_ipv4_netfilter_table[] = {
 	{ CTL_INT,	NET_IPV4_NF_CONNTRACK_MAX,		"ip_conntrack_max" },
 
 	/* NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT "ip_conntrack_tcp_timeout_syn_sent" no longer used */
@@ -327,7 +327,7 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_ipv4_table[] = {
+static struct bin_table bin_net_ipv4_table[] = {
 	{CTL_INT,	NET_IPV4_FORWARD,			"ip_forward" },
 
 	{ CTL_DIR,	NET_IPV4_CONF,		"conf",		bin_net_ipv4_conf_table },
@@ -431,13 +431,13 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_ipx_table[] = {
+static struct bin_table bin_net_ipx_table[] = {
 	{ CTL_INT,	NET_IPX_PPROP_BROADCASTING,	"ipx_pprop_broadcasting" },
 	/* NET_IPX_FORWARDING unused */
 	{}
 };
 
-static const struct bin_table bin_net_atalk_table[] = {
+static struct bin_table bin_net_atalk_table[] = {
 	{ CTL_INT,	NET_ATALK_AARP_EXPIRY_TIME,		"aarp-expiry-time" },
 	{ CTL_INT,	NET_ATALK_AARP_TICK_TIME,		"aarp-tick-time" },
 	{ CTL_INT,	NET_ATALK_AARP_RETRANSMIT_LIMIT,	"aarp-retransmit-limit" },
@@ -445,7 +445,7 @@ static const struct bin_table bin_net_at
 	{},
 };
 
-static const struct bin_table bin_net_netrom_table[] = {
+static struct bin_table bin_net_netrom_table[] = {
 	{ CTL_INT,	NET_NETROM_DEFAULT_PATH_QUALITY,		"default_path_quality" },
 	{ CTL_INT,	NET_NETROM_OBSOLESCENCE_COUNT_INITIALISER,	"obsolescence_count_initialiser" },
 	{ CTL_INT,	NET_NETROM_NETWORK_TTL_INITIALISER,		"network_ttl_initialiser" },
@@ -461,7 +461,7 @@ static const struct bin_table bin_net_ne
 	{}
 };
 
-static const struct bin_table bin_net_ax25_param_table[] = {
+static struct bin_table bin_net_ax25_param_table[] = {
 	{ CTL_INT,	NET_AX25_IP_DEFAULT_MODE,	"ip_default_mode" },
 	{ CTL_INT,	NET_AX25_DEFAULT_MODE,		"ax25_default_mode" },
 	{ CTL_INT,	NET_AX25_BACKOFF_TYPE,		"backoff_type" },
@@ -479,12 +479,12 @@ static const struct bin_table bin_net_ax
 	{}
 };
 
-static const struct bin_table bin_net_ax25_table[] = {
+static struct bin_table bin_net_ax25_table[] = {
 	{ CTL_DIR,	0, NULL, bin_net_ax25_param_table },
 	{}
 };
 
-static const struct bin_table bin_net_rose_table[] = {
+static struct bin_table bin_net_rose_table[] = {
 	{ CTL_INT,	NET_ROSE_RESTART_REQUEST_TIMEOUT,	"restart_request_timeout" },
 	{ CTL_INT,	NET_ROSE_CALL_REQUEST_TIMEOUT,		"call_request_timeout" },
 	{ CTL_INT,	NET_ROSE_RESET_REQUEST_TIMEOUT,		"reset_request_timeout" },
@@ -498,7 +498,7 @@ static const struct bin_table bin_net_ro
 	{}
 };
 
-static const struct bin_table bin_net_ipv6_conf_var_table[] = {
+static struct bin_table bin_net_ipv6_conf_var_table[] = {
 	{ CTL_INT,	NET_IPV6_FORWARDING,			"forwarding" },
 	{ CTL_INT,	NET_IPV6_HOP_LIMIT,			"hop_limit" },
 	{ CTL_INT,	NET_IPV6_MTU,				"mtu" },
@@ -526,14 +526,14 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_ipv6_conf_table[] = {
+static struct bin_table bin_net_ipv6_conf_table[] = {
 	{ CTL_DIR,	NET_PROTO_CONF_ALL,		"all",	bin_net_ipv6_conf_var_table },
 	{ CTL_DIR,	NET_PROTO_CONF_DEFAULT, 	"default", bin_net_ipv6_conf_var_table },
 	{ CTL_DIR,	0, NULL, bin_net_ipv6_conf_var_table },
 	{}
 };
 
-static const struct bin_table bin_net_ipv6_route_table[] = {
+static struct bin_table bin_net_ipv6_route_table[] = {
 	/* NET_IPV6_ROUTE_FLUSH	"flush"  no longer used */
 	{ CTL_INT,	NET_IPV6_ROUTE_GC_THRESH,		"gc_thresh" },
 	{ CTL_INT,	NET_IPV6_ROUTE_MAX_SIZE,		"max_size" },
@@ -547,12 +547,12 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_ipv6_icmp_table[] = {
+static struct bin_table bin_net_ipv6_icmp_table[] = {
 	{ CTL_INT,	NET_IPV6_ICMP_RATELIMIT,	"ratelimit" },
 	{}
 };
 
-static const struct bin_table bin_net_ipv6_table[] = {
+static struct bin_table bin_net_ipv6_table[] = {
 	{ CTL_DIR,	NET_IPV6_CONF,		"conf",		bin_net_ipv6_conf_table },
 	{ CTL_DIR,	NET_IPV6_NEIGH,		"neigh",	bin_net_neigh_table },
 	{ CTL_DIR,	NET_IPV6_ROUTE,		"route",	bin_net_ipv6_route_table },
@@ -567,7 +567,7 @@ static const struct bin_table bin_net_ip
 	{}
 };
 
-static const struct bin_table bin_net_x25_table[] = {
+static struct bin_table bin_net_x25_table[] = {
 	{ CTL_INT,	NET_X25_RESTART_REQUEST_TIMEOUT,	"restart_request_timeout" },
 	{ CTL_INT,	NET_X25_CALL_REQUEST_TIMEOUT,		"call_request_timeout" },
 	{ CTL_INT,	NET_X25_RESET_REQUEST_TIMEOUT,	"reset_request_timeout" },
@@ -577,13 +577,13 @@ static const struct bin_table bin_net_x2
 	{}
 };
 
-static const struct bin_table bin_net_tr_table[] = {
+static struct bin_table bin_net_tr_table[] = {
 	{ CTL_INT,	NET_TR_RIF_TIMEOUT,	"rif_timeout" },
 	{}
 };
 
 
-static const struct bin_table bin_net_decnet_conf_vars[] = {
+static struct bin_table bin_net_decnet_conf_vars[] = {
 	{ CTL_INT,	NET_DECNET_CONF_DEV_FORWARDING,	"forwarding" },
 	{ CTL_INT,	NET_DECNET_CONF_DEV_PRIORITY,	"priority" },
 	{ CTL_INT,	NET_DECNET_CONF_DEV_T2,		"t2" },
@@ -591,7 +591,7 @@ static const struct bin_table bin_net_de
 	{}
 };
 
-static const struct bin_table bin_net_decnet_conf[] = {
+static struct bin_table bin_net_decnet_conf[] = {
 	{ CTL_DIR, NET_DECNET_CONF_ETHER,    "ethernet", bin_net_decnet_conf_vars },
 	{ CTL_DIR, NET_DECNET_CONF_GRE,	     "ipgre",    bin_net_decnet_conf_vars },
 	{ CTL_DIR, NET_DECNET_CONF_X25,	     "x25",      bin_net_decnet_conf_vars },
@@ -602,7 +602,7 @@ static const struct bin_table bin_net_de
 	{}
 };
 
-static const struct bin_table bin_net_decnet_table[] = {
+static struct bin_table bin_net_decnet_table[] = {
 	{ CTL_DIR,	NET_DECNET_CONF,		"conf",	bin_net_decnet_conf },
 	{ CTL_DNADR,	NET_DECNET_NODE_ADDRESS,	"node_address" },
 	{ CTL_STR,	NET_DECNET_NODE_NAME,		"node_name" },
@@ -620,7 +620,7 @@ static const struct bin_table bin_net_de
 	{}
 };
 
-static const struct bin_table bin_net_sctp_table[] = {
+static struct bin_table bin_net_sctp_table[] = {
 	{ CTL_INT,	NET_SCTP_RTO_INITIAL,		"rto_initial" },
 	{ CTL_INT,	NET_SCTP_RTO_MIN,		"rto_min" },
 	{ CTL_INT,	NET_SCTP_RTO_MAX,		"rto_max" },
@@ -641,7 +641,7 @@ static const struct bin_table bin_net_sc
 	{}
 };
 
-static const struct bin_table bin_net_llc_llc2_timeout_table[] = {
+static struct bin_table bin_net_llc_llc2_timeout_table[] = {
 	{ CTL_INT,	NET_LLC2_ACK_TIMEOUT,	"ack" },
 	{ CTL_INT,	NET_LLC2_P_TIMEOUT,	"p" },
 	{ CTL_INT,	NET_LLC2_REJ_TIMEOUT,	"rej" },
@@ -649,23 +649,23 @@ static const struct bin_table bin_net_ll
 	{}
 };
 
-static const struct bin_table bin_net_llc_station_table[] = {
+static struct bin_table bin_net_llc_station_table[] = {
 	{ CTL_INT,	NET_LLC_STATION_ACK_TIMEOUT,	"ack_timeout" },
 	{}
 };
 
-static const struct bin_table bin_net_llc_llc2_table[] = {
+static struct bin_table bin_net_llc_llc2_table[] = {
 	{ CTL_DIR,	NET_LLC2,		"timeout",	bin_net_llc_llc2_timeout_table },
 	{}
 };
 
-static const struct bin_table bin_net_llc_table[] = {
+static struct bin_table bin_net_llc_table[] = {
 	{ CTL_DIR,	NET_LLC2,		"llc2",		bin_net_llc_llc2_table },
 	{ CTL_DIR,	NET_LLC_STATION,	"station",	bin_net_llc_station_table },
 	{}
 };
 
-static const struct bin_table bin_net_netfilter_table[] = {
+static struct bin_table bin_net_netfilter_table[] = {
 	{ CTL_INT,	NET_NF_CONNTRACK_MAX,			"nf_conntrack_max" },
 	/* NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT "nf_conntrack_tcp_timeout_syn_sent" no longer used */
 	/* NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV "nf_conntrack_tcp_timeout_syn_recv" no longer used */
@@ -702,7 +702,7 @@ static const struct bin_table bin_net_ne
 	{}
 };
 
-static const struct bin_table bin_net_irda_table[] = {
+static struct bin_table bin_net_irda_table[] = {
 	{ CTL_INT,	NET_IRDA_DISCOVERY,		"discovery" },
 	{ CTL_STR,	NET_IRDA_DEVNAME,		"devname" },
 	{ CTL_INT,	NET_IRDA_DEBUG,			"debug" },
@@ -720,7 +720,7 @@ static const struct bin_table bin_net_ir
 	{}
 };
 
-static const struct bin_table bin_net_table[] = {
+static struct bin_table bin_net_table[] = {
 	{ CTL_DIR,	NET_CORE,		"core",		bin_net_core_table },
 	/* NET_ETHER not used */
 	/* NET_802 not used */
@@ -746,7 +746,7 @@ static const struct bin_table bin_net_ta
 	{}
 };
 
-static const struct bin_table bin_fs_quota_table[] = {
+static struct bin_table bin_fs_quota_table[] = {
 	{ CTL_INT,	FS_DQ_LOOKUPS,		"lookups" },
 	{ CTL_INT,	FS_DQ_DROPS,		"drops" },
 	{ CTL_INT,	FS_DQ_READS,		"reads" },
@@ -759,7 +759,7 @@ static const struct bin_table bin_fs_quo
 	{}
 };
 
-static const struct bin_table bin_fs_xfs_table[] = {
+static struct bin_table bin_fs_xfs_table[] = {
 	{ CTL_INT,	XFS_SGID_INHERIT,	"irix_sgid_inherit" },
 	{ CTL_INT,	XFS_SYMLINK_MODE,	"irix_symlink_mode" },
 	{ CTL_INT,	XFS_PANIC_MASK,		"panic_mask" },
@@ -779,24 +779,24 @@ static const struct bin_table bin_fs_xfs
 	{}
 };
 
-static const struct bin_table bin_fs_ocfs2_nm_table[] = {
+static struct bin_table bin_fs_ocfs2_nm_table[] = {
 	{ CTL_STR,	1, "hb_ctl_path" },
 	{}
 };
 
-static const struct bin_table bin_fs_ocfs2_table[] = {
+static struct bin_table bin_fs_ocfs2_table[] = {
 	{ CTL_DIR,	1,	"nm",	bin_fs_ocfs2_nm_table },
 	{}
 };
 
-static const struct bin_table bin_inotify_table[] = {
+static struct bin_table bin_inotify_table[] = {
 	{ CTL_INT,	INOTIFY_MAX_USER_INSTANCES,	"max_user_instances" },
 	{ CTL_INT,	INOTIFY_MAX_USER_WATCHES,	"max_user_watches" },
 	{ CTL_INT,	INOTIFY_MAX_QUEUED_EVENTS,	"max_queued_events" },
 	{}
 };
 
-static const struct bin_table bin_fs_table[] = {
+static struct bin_table bin_fs_table[] = {
 	{ CTL_INT,	FS_NRINODE,		"inode-nr" },
 	{ CTL_INT,	FS_STATINODE,		"inode-state" },
 	/* FS_MAXINODE unused */
@@ -822,12 +822,12 @@ static const struct bin_table bin_fs_tab
 	{}
 };
 
-static const struct bin_table bin_ipmi_table[] = {
+static struct bin_table bin_ipmi_table[] = {
 	{ CTL_INT,	DEV_IPMI_POWEROFF_POWERCYCLE,	"poweroff_powercycle" },
 	{}
 };
 
-static const struct bin_table bin_mac_hid_files[] = {
+static struct bin_table bin_mac_hid_files[] = {
 	/* DEV_MAC_HID_KEYBOARD_SENDS_LINUX_KEYCODES unused */
 	/* DEV_MAC_HID_KEYBOARD_LOCK_KEYCODES unused */
 	{ CTL_INT,	DEV_MAC_HID_MOUSE_BUTTON_EMULATION,	"mouse_button_emulation" },
@@ -837,18 +837,18 @@ static const struct bin_table bin_mac_hi
 	{}
 };
 
-static const struct bin_table bin_raid_table[] = {
+static struct bin_table bin_raid_table[] = {
 	{ CTL_INT,	DEV_RAID_SPEED_LIMIT_MIN,	"speed_limit_min" },
 	{ CTL_INT,	DEV_RAID_SPEED_LIMIT_MAX,	"speed_limit_max" },
 	{}
 };
 
-static const struct bin_table bin_scsi_table[] = {
+static struct bin_table bin_scsi_table[] = {
 	{ CTL_INT, DEV_SCSI_LOGGING_LEVEL, "logging_level" },
 	{}
 };
 
-static const struct bin_table bin_dev_table[] = {
+static struct bin_table bin_dev_table[] = {
 	/* DEV_CDROM	"cdrom" no longer used */
 	/* DEV_HWMON unused */
 	/* DEV_PARPORT	"parport" no longer used */
@@ -859,26 +859,26 @@ static const struct bin_table bin_dev_ta
 	{}
 };
 
-static const struct bin_table bin_bus_isa_table[] = {
+static struct bin_table bin_bus_isa_table[] = {
 	{ CTL_INT,	BUS_ISA_MEM_BASE,	"membase" },
 	{ CTL_INT,	BUS_ISA_PORT_BASE,	"portbase" },
 	{ CTL_INT,	BUS_ISA_PORT_SHIFT,	"portshift" },
 	{}
 };
 
-static const struct bin_table bin_bus_table[] = {
+static struct bin_table bin_bus_table[] = {
 	{ CTL_DIR,	CTL_BUS_ISA,	"isa",	bin_bus_isa_table },
 	{}
 };
 
 
-static const struct bin_table bin_s390dbf_table[] = {
+static struct bin_table bin_s390dbf_table[] = {
 	{ CTL_INT,	5678 /* CTL_S390DBF_STOPPABLE */, "debug_stoppable" },
 	{ CTL_INT,	5679 /* CTL_S390DBF_ACTIVE */,	  "debug_active" },
 	{}
 };
 
-static const struct bin_table bin_sunrpc_table[] = {
+static struct bin_table bin_sunrpc_table[] = {
 	/* CTL_RPCDEBUG	"rpc_debug"  no longer used */
 	/* CTL_NFSDEBUG "nfs_debug"  no longer used */
 	/* CTL_NFSDDEBUG "nfsd_debug" no longer used  */
@@ -891,7 +891,7 @@ static const struct bin_table bin_sunrpc
 	{}
 };
 
-static const struct bin_table bin_pm_table[] = {
+static struct bin_table bin_pm_table[] = {
 	/* frv specific */
 	/* 1 == CTL_PM_SUSPEND	"suspend"  no longer used" */
 	{ CTL_INT,	2 /* CTL_PM_CMODE */,		"cmode" },
@@ -900,7 +900,7 @@ static const struct bin_table bin_pm_tab
 	{}
 };
 
-static const struct bin_table bin_root_table[] = {
+static struct bin_table bin_root_table[] = {
 	{ CTL_DIR,	CTL_KERN,	"kernel",	bin_kern_table },
 	{ CTL_DIR,	CTL_VM,		"vm",		bin_vm_table },
 	{ CTL_DIR,	CTL_NET,	"net",		bin_net_table },
@@ -1248,9 +1248,9 @@ out:
 	return result;
 }
 
-static const struct bin_table *get_sysctl(const int *name, int nlen, char *path)
+static struct bin_table *get_sysctl(const int *name, int nlen, char *path)
 {
-	const struct bin_table *table = &bin_root_table[0];
+	struct bin_table *table = &bin_root_table[0];
 	int ctl_name;
 
 	/* The binary sysctl tables have a small maximum depth so
@@ -1303,14 +1303,14 @@ repeat:
 	return ERR_PTR(-ENOTDIR);
 }
 
-static char *sysctl_getname(const int *name, int nlen, const struct bin_table **tablep)
+static char *sysctl_getname(const int *name, int nlen, struct bin_table **tablep)
 {
 	char *tmp, *result;
 
 	result = ERR_PTR(-ENOMEM);
 	tmp = __getname();
 	if (tmp) {
-		const struct bin_table *table = get_sysctl(name, nlen, tmp);
+		struct bin_table *table = get_sysctl(name, nlen, tmp);
 		result = tmp;
 		*tablep = table;
 		if (IS_ERR(table)) {
@@ -1324,7 +1324,7 @@ static char *sysctl_getname(const int *n
 static ssize_t binary_sysctl(const int *name, int nlen,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	const struct bin_table *table = NULL;
+	struct bin_table *table = NULL;
 	struct nameidata nd;
 	struct vfsmount *mnt;
 	struct file *file;

Re: [PATCH] [1/2] SYSCTL: Make bin_table not const

[Linus Torvalds]

On Sat, 19 Dec 2009, Andi Kleen wrote:
> 
> Turn all the bin_tables from const to non-const. This is needed for the next
> patch. Unfortunately there were a lot of them, so the patch is rather 
> large, but it is completely mechanic. 

Ouch. I hate this.

I'd much rather have a constant sysctl bin_table.

If the _only_ thing you want to do is to do a "warn-on-once" logic, I 
would seriously suggest you use a small hash-table instead of turning 
bin_table non-const.

IOW, d something like this:

	#define WARN_ONCE_HASH_BITS (10)
	#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)

	static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);

	/*
	 * NOTE! We don't use the SMP-safe bit tests. We simply
	 * don't care enough. 
	 */
	static void warn_on_bintable(const int *name, int nlen)
	{
		unsigned int hash = full_name_hash(name, nlen);
		hash = hash_32(hash, WARN_ONCE_HASH_BITS);
		if (__test_and_set_bit(warn_once_bitmap, hash))
			return;
		deprecated_sysctl_warning(name, nlen);
	}

which should do the right thing in all practical circumstances.

(The above is obviously totally untested, I wrote it in the mail reader, 
but it's obvious enough what the intent is).

			Linus

Re: [PATCH] [1/2] SYSCTL: Make bin_table not const

[Andi Kleen]

On Sat, Dec 19, 2009 at 09:40:56AM -0800, Linus Torvalds wrote:
> 
> 
> On Sat, 19 Dec 2009, Andi Kleen wrote:
> > 
> > Turn all the bin_tables from const to non-const. This is needed for the next
> > patch. Unfortunately there were a lot of them, so the patch is rather 
> > large, but it is completely mechanic. 
> 
> Ouch. I hate this.
> 
> I'd much rather have a constant sysctl bin_table.

Understood. I'll poke at that and try to come up with a tested patch
tomorrow or so.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [PATCH] [1/2] SYSCTL: Make bin_table not const

[Eric W. Biederman]

Andi Kleen <andi@firstfloor.org> writes:

> On Sat, Dec 19, 2009 at 09:40:56AM -0800, Linus Torvalds wrote:
>> 
>> 
>> On Sat, 19 Dec 2009, Andi Kleen wrote:
>> > 
>> > Turn all the bin_tables from const to non-const. This is needed for the next
>> > patch. Unfortunately there were a lot of them, so the patch is rather 
>> > large, but it is completely mechanic. 
>> 
>> Ouch. I hate this.
>> 
>> I'd much rather have a constant sysctl bin_table.
>
> Understood. I'll poke at that and try to come up with a tested patch
> tomorrow or so.

Is printk_ratelimit truly ineffective at what it does?

Arguably we don't need to warn anywhere near that often, so even
if printk_ratelimit works we are good.

If printk_ratelimit let's too much through we really should also write
a patch to let fewer messages through that way.

Eric

Re: [PATCH] [1/2] SYSCTL: Make bin_table not const

[Andi Kleen]

> Is printk_ratelimit truly ineffective at what it does?
> 
> Arguably we don't need to warn anywhere near that often, so even
> if printk_ratelimit works we are good.
> 
> If printk_ratelimit let's too much through we really should also write
> a patch to let fewer messages through that way.

Any time based rate is too much for compatibility. Assume even if you only 
printed one per hour and the user keeps running a program that 
uses sysctl it would still be >5000 messages each month.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.

[PATCH] SYSCTL: Print binary sysctl warnings (nearly) only once

[Andi Kleen]

On Sat, Dec 19, 2009 at 09:40:56AM -0800, Linus Torvalds wrote:
> 
> 
> On Sat, 19 Dec 2009, Andi Kleen wrote:
> > 
> > Turn all the bin_tables from const to non-const. This is needed for the next
> > patch. Unfortunately there were a lot of them, so the patch is rather 
> > large, but it is completely mechanic. 
> 
> Ouch. I hate this.
> 
> I'd much rather have a constant sysctl bin_table.
> 
> If the _only_ thing you want to do is to do a "warn-on-once" logic, I 
> would seriously suggest you use a small hash-table instead of turning 
> bin_table non-const.

I played around with this. The standard name hash couldn't be used
because this is a string of ints, not chars. I ended up using
FNV32 hash which seemed to do bests when hashing all the possible
binary sysctls.

Tested patch appended.

-Andi

---

SYSCTL: Print binary sysctl warnings (nearly) only once

When printing legacy sysctls print the warning message
for each of them only once.  This way there is a guarantee
the syslog won't be flooded for any sane program.

The original attempt at this made the tables non const and stored
the flag inline.

Linus suggested using a separate hash table for this, this is based on a 
code snippet from him.

The hash implies this is not exact and can sometimes not print a 
new sysctl due to a hash collision, but in practice this should not 
be a problem

I used a FNV32 hash over the binary string with a 32byte bitmap. This
gives relatively little collisions when all the predefined binary sysctls
are hashed:

size 256
bucket
length      number
0:          [25] 
1:          [67] 
2:          [88] 
ak@linux.intel.com -- Speaking for myself only.
3:          [47] 
4:          [22] 
5:          [6] 
6:          [1] 

The worst case is a single collision of 6 hash values.


Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 kernel/sysctl_binary.c |   31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

Index: linux-2.6.33-rc1-ak/kernel/sysctl_binary.c
===================================================================
--- linux-2.6.33-rc1-ak.orig/kernel/sysctl_binary.c
+++ linux-2.6.33-rc1-ak/kernel/sysctl_binary.c
@@ -1417,6 +1417,35 @@ static void deprecated_sysctl_warning(co
 	return;
 }
 
+#define WARN_ONCE_HASH_BITS 8
+#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)
+
+static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);
+
+#define FNV32_OFFSET 2166136261U
+#define FNV32_PRIME 0x01000193
+
+/*
+ * Print each legacy sysctl (approximately) only once.
+ * To avoid making the tables non-const use a external
+ * hash-table instead.
+ * Worst case hash collision: 6, but very rarely.
+ * NOTE! We don't use the SMP-safe bit tests. We simply
+ * don't care enough.
+ */
+static void warn_on_bintable(const int *name, int nlen)
+{
+	int i;
+	u32 hash = FNV32_OFFSET;
+
+	for (i = 0; i < nlen; i++)
+		hash = (hash ^ name[i]) * FNV32_PRIME;
+	hash %= WARN_ONCE_HASH_SIZE;
+	if (__test_and_set_bit(hash, warn_once_bitmap))
+		return;
+	deprecated_sysctl_warning(name, nlen);
+}
+
 static ssize_t do_sysctl(int __user *args_name, int nlen,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
@@ -1431,7 +1460,7 @@ static ssize_t do_sysctl(int __user *arg
 		if (get_user(name[i], args_name + i))
 			return -EFAULT;
 
-	deprecated_sysctl_warning(name, nlen);
+	warn_on_bintable(name, nlen);
 
 	return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
 }

[PATCH] [2/2] SYSCTL: Warn once for every binary sysctl

[Andi Kleen]

Even with my recent patch to not warn for CTL_KERN,KERN_VERSION there
is still the theoretical possibility that some program who uses another
binary sysctl regularly will get a flooded syslog.

Only warn once for every possible binary sysctl.

To avoid bloating the tables i used a high bit in `ctl_name' as a flag
bit.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 kernel/sysctl_binary.c |   27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

Index: linux-2.6.33-rc1-ak/kernel/sysctl_binary.c
===================================================================
--- linux-2.6.33-rc1-ak.orig/kernel/sysctl_binary.c
+++ linux-2.6.33-rc1-ak/kernel/sysctl_binary.c
@@ -17,6 +17,8 @@
 #ifdef CONFIG_SYSCTL_SYSCALL
 
 struct bin_table;
+static void deprecated_sysctl_warning(struct bin_table *table,
+				      const int *name, int nlen);
 typedef ssize_t bin_convert_t(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen);
 
@@ -36,9 +38,12 @@ static bin_convert_t bin_dn_node_address
 
 #define BUFSZ 256
 
+#define CTL_MASK 0xffffff /* upper 8 bits for flags */
+#define CTL_WARNED (1U << 30)
+
 struct bin_table {
 	bin_convert_t		*convert;
-	int			ctl_name;
+	int			ctl_name;	/* Some upper bits for flags */
 	const char		*procname;
 	struct bin_table	*child;
 };
@@ -1268,12 +1273,13 @@ repeat:
 	nlen--;
 	for ( ; table->convert; table++) {
 		int len = 0;
+		int cn = table->ctl_name & CTL_MASK;
 
 		/*
 		 * For a wild card entry map from ifindex to network
 		 * device name.
 		 */
-		if (!table->ctl_name) {
+		if (!cn) {
 #ifdef CONFIG_NET
 			struct net *net = current->nsproxy->net_ns;
 			struct net_device *dev;
@@ -1285,7 +1291,7 @@ repeat:
 			}
 #endif
 		/* Use the well known sysctl number to proc name mapping */
-		} else if (ctl_name == table->ctl_name) {
+		} else if (ctl_name == cn) {
 			len = strlen(table->procname);
 			memcpy(path, table->procname, len);
 		}
@@ -1338,6 +1344,8 @@ static ssize_t binary_sysctl(const int *
 	if (IS_ERR(pathname))
 		goto out;
 
+	deprecated_sysctl_warning(table, name, nlen);
+
 	/* How should the sysctl be accessed? */
 	if (oldval && oldlen && newval && newlen) {
 		flags = O_RDWR;
@@ -1394,8 +1402,8 @@ static ssize_t binary_sysctl(const int *
 
 #endif /* CONFIG_SYSCTL_SYSCALL */
 
-
-static void deprecated_sysctl_warning(const int *name, int nlen)
+static void deprecated_sysctl_warning(struct bin_table *table,
+				      const int *name, int nlen)
 {
 	int i;
 
@@ -1406,6 +1414,14 @@ static void deprecated_sysctl_warning(co
 	if (name[0] == CTL_KERN && name[1] == KERN_VERSION)
 		return;
 
+	/*
+	 * Warn only once for every sysctl
+	 */
+	if (table->ctl_name & CTL_WARNED)
+		return;
+	/* Not atomic, but races are harmless */
+	table->ctl_name |= CTL_WARNED;
+
 	if (printk_ratelimit()) {
 		printk(KERN_INFO
 			"warning: process `%s' used the deprecated sysctl "
@@ -1431,7 +1447,6 @@ static ssize_t do_sysctl(int __user *arg
 		if (get_user(name[i], args_name + i))
 			return -EFAULT;
 
-	deprecated_sysctl_warning(name, nlen);
 
 	return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
 }