[PATCH] video: constify geode ops structures

[PATCH] video: constify geode ops structures

[Julia Lawall]

These geode ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/video/fbdev/geode/display_gx1.c  |    2 +-
 drivers/video/fbdev/geode/display_gx1.h  |    2 +-
 drivers/video/fbdev/geode/geodefb.h      |    4 ++--
 drivers/video/fbdev/geode/video_cs5530.c |    2 +-
 drivers/video/fbdev/geode/video_cs5530.h |    2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/video/fbdev/geode/display_gx1.c b/drivers/video/fbdev/geode/display_gx1.c
index 926d53e..b383eb9 100644
--- a/drivers/video/fbdev/geode/display_gx1.c
+++ b/drivers/video/fbdev/geode/display_gx1.c
@@ -208,7 +208,7 @@ static void gx1_set_hw_palette_reg(struct fb_info *info, unsigned regno,
 	writel(val, par->dc_regs + DC_PAL_DATA);
 }
 
-struct geode_dc_ops gx1_dc_ops = {
+const struct geode_dc_ops gx1_dc_ops = {
 	.set_mode	 = gx1_set_mode,
 	.set_palette_reg = gx1_set_hw_palette_reg,
 };
diff --git a/drivers/video/fbdev/geode/display_gx1.h b/drivers/video/fbdev/geode/display_gx1.h
index 671c055..e1cc41b 100644
--- a/drivers/video/fbdev/geode/display_gx1.h
+++ b/drivers/video/fbdev/geode/display_gx1.h
@@ -18,7 +18,7 @@
 unsigned gx1_gx_base(void);
 int gx1_frame_buffer_size(void);
 
-extern struct geode_dc_ops gx1_dc_ops;
+extern const struct geode_dc_ops gx1_dc_ops;
 
 /* GX1 configuration I/O registers */
 
diff --git a/drivers/video/fbdev/geode/geodefb.h b/drivers/video/fbdev/geode/geodefb.h
index ae04820..e2e0793 100644
--- a/drivers/video/fbdev/geode/geodefb.h
+++ b/drivers/video/fbdev/geode/geodefb.h
@@ -31,8 +31,8 @@ struct geodefb_par {
 	int panel_y;
 	void __iomem *dc_regs;
 	void __iomem *vid_regs;
-	struct geode_dc_ops  *dc_ops;
-	struct geode_vid_ops *vid_ops;
+	const struct geode_dc_ops  *dc_ops;
+	const struct geode_vid_ops *vid_ops;
 };
 
 #endif /* !__GEODEFB_H__ */
diff --git a/drivers/video/fbdev/geode/video_cs5530.c b/drivers/video/fbdev/geode/video_cs5530.c
index 649c394..8806132 100644
--- a/drivers/video/fbdev/geode/video_cs5530.c
+++ b/drivers/video/fbdev/geode/video_cs5530.c
@@ -186,7 +186,7 @@ static int cs5530_blank_display(struct fb_info *info, int blank_mode)
 	return 0;
 }
 
-struct geode_vid_ops cs5530_vid_ops = {
+const struct geode_vid_ops cs5530_vid_ops = {
 	.set_dclk          = cs5530_set_dclk_frequency,
 	.configure_display = cs5530_configure_display,
 	.blank_display     = cs5530_blank_display,
diff --git a/drivers/video/fbdev/geode/video_cs5530.h b/drivers/video/fbdev/geode/video_cs5530.h
index 56cecca..c843348 100644
--- a/drivers/video/fbdev/geode/video_cs5530.h
+++ b/drivers/video/fbdev/geode/video_cs5530.h
@@ -15,7 +15,7 @@
 #ifndef __VIDEO_CS5530_H__
 #define __VIDEO_CS5530_H__
 
-extern struct geode_vid_ops cs5530_vid_ops;
+extern const struct geode_vid_ops cs5530_vid_ops;
 
 /* CS5530 Video device registers */
 

Re: [PATCH] video: constify geode ops structures

[Dan Carpenter]

Cool.  So, in grsec they use a GCC plugin to make these const
automatically since they only contain function pointers.  There about
100 struct types marked as __no_const.  Kees would like to adopt the
grsec pluggin approach I expect.  Do you have an idea how many structs
only contain function pointers or how many consts we would have to add
to get the same effect without the plugin?

regards,
dan carpenter

Re: [PATCH] video: constify geode ops structures

[Julia Lawall]

On Mon, 9 Nov 2015, Dan Carpenter wrote:

> Cool.  So, in grsec they use a GCC plugin to make these const
> automatically since they only contain function pointers.  There about
> 100 struct types marked as __no_const.  Kees would like to adopt the
> grsec pluggin approach I expect.  Do you have an idea how many structs
> only contain function pointers or how many consts we would have to add
> to get the same effect without the plugin?

My list has 373 type names.  In the list there are counts for good
(already const) and bad (not const).  The sum of the bad values is 2467.
The list is below.

julia

cpuidle_ops: 	good: 0, bad: 1
xen_pci_frontend_ops: 	good: 0, bad: 1
pch_dev_ops: 	good: 0, bad: 1
s3c_ide_platdata: 	good: 0, bad: 1
bfin_cpu_pm_fns: 	good: 0, bad: 1
meta_type_ops: 	good: 0, bad: 1
bnx2x_func_sp_drv_ops: 	good: 0, bad: 1
hfi1_filter_array: 	good: 0, bad: 1
ttusbdecfe_config: 	good: 0, bad: 1
au1k_irda_platform_data: 	good: 0, bad: 1
dao_rsc_ops: 	good: 0, bad: 1
mic_hw_intr_ops: 	good: 0, bad: 1
mic_smpt_ops: 	good: 0, bad: 1
scpi_ops: 	good: 0, bad: 1
fmc_operations: 	good: 0, bad: 1
geode_dc_ops: 	good: 0, bad: 1
superhyway_ops: 	good: 0, bad: 1
vsock_transport: 	good: 0, bad: 1
ti_clk_ll_ops: 	good: 0, bad: 1
enclosure_component_callbacks: 	good: 0, bad: 1
dai_rsc_ops: 	good: 0, bad: 1
cfs_psdev_ops: 	good: 0, bad: 1
x86_msi_ops: 	good: 0, bad: 1
intel_sst_ops: 	good: 0, bad: 1
nf_ct_event_notifier: 	good: 0, bad: 1
geode_vid_ops: 	good: 0, bad: 1
menelaus_platform_data: 	good: 0, bad: 1
mipi_dsim_master_ops: 	good: 0, bad: 1
in_cache_ops: 	good: 0, bad: 1
ste_modem_dev_cb: 	good: 0, bad: 1
kernfs_syscall_ops: 	good: 0, bad: 1
amixer_rsc_ops: 	good: 0, bad: 1
nes_cm_ops: 	good: 0, bad: 1
radio_tea5777_ops: 	good: 0, bad: 1
x86_cpuinit_ops: 	good: 0, bad: 1
hpc_ops: 	good: 0, bad: 1
vexpress_config_bridge_ops: 	good: 0, bad: 1
x86_platform_ops: 	good: 0, bad: 1
powercap_zone_ops: 	good: 0, bad: 1
as102_priv_ops_t: 	good: 0, bad: 1
lpc32xx_slc_platform_data: 	good: 0, bad: 1
src_rsc_ops: 	good: 0, bad: 1
pxafb_layer_ops: 	good: 0, bad: 1
ds278x_battery_ops: 	good: 0, bad: 1
hnae_buf_ops: 	good: 0, bad: 1
mcp_ops: 	good: 0, bad: 1
nfnl_ct_hook: 	good: 0, bad: 1
xpc_interface: 	good: 0, bad: 1
vpbe_device_ops: 	good: 0, bad: 1
stmp3xxx_wdt_pdata: 	good: 0, bad: 1
cosm_hw_ops: 	good: 0, bad: 1
fm10k_iov_ops: 	good: 0, bad: 1
s3fwrn5_phy_ops: 	good: 0, bad: 1
tc6387xb_platform_data: 	good: 0, bad: 1
visorchipset_busdev_responders: 	good: 0, bad: 1
csio_hw_chip_ops: 	good: 0, bad: 1
visorchipset_busdev_notifiers: 	good: 0, bad: 1
concap_device_ops: 	good: 0, bad: 1
stv6110x_devctl: 	good: 0, bad: 1
powercap_zone_constraint_ops: 	good: 0, bad: 1
eg_cache_ops: 	good: 0, bad: 1
trace_lock_handler: 	good: 0, bad: 1
gnttab_ops: 	good: 0, bad: 1
ldlm_valblock_ops: 	good: 0, bad: 1
rtl_btc_ops: 	good: 0, bad: 1
max197_platform_data: 	good: 0, bad: 1
qla_tgt_func_tmpl: 	good: 0, bad: 1
arm_pmu_platdata: 	good: 0, bad: 1
amd_sched_backend_ops: 	good: 0, bad: 1
da903x_chip_ops: 	good: 0, bad: 1
hnae_ae_ops: 	good: 0, bad: 1
ds2404_chip_ops: 	good: 0, bad: 1
cardbus_type: 	good: 0, bad: 1
sh_mobile_lcdc_sys_bus_ops: 	good: 0, bad: 1
ieee802154_llsec_ops: 	good: 0, bad: 1
kvm_mips_callbacks: 	good: 0, bad: 1
nf_exp_event_notifier: 	good: 0, bad: 1
usb_mon_operations: 	good: 0, bad: 1
nlmsvc_binding: 	good: 0, bad: 1
cleancache_ops: 	good: 0, bad: 1
bfa_fcs_mod_s: 	good: 0, bad: 1
dac_ops: 	good: 0, bad: 1
sst_block_ops: 	good: 0, bad: 1
lane2_ops: 	good: 0, bad: 1
llog_operations: 	good: 0, bad: 1
concap_proto_ops: 	good: 0, bad: 1
x86_io_apic_ops: 	good: 0, bad: 1
od_ops: 	good: 0, bad: 1
omap_mcbsp_ops: 	good: 0, bad: 1
cpuidle_exynos_data: 	good: 0, bad: 1
pci_platform_pm_ops: 	good: 0, bad: 1
lpc32xx_mlc_platform_data: 	good: 0, bad: 1
dw_spi_dma_ops: 	good: 0, bad: 1
mmp_overlay_ops: 	good: 0, bad: 1
iommu_table_group_ops: 	good: 0, bad: 1
md_cluster_operations: 	good: 0, bad: 1
cpu_pm_ops: 	good: 0, bad: 1
mxl111sf_demod_config: 	good: 0, bad: 1
srcimp_rsc_ops: 	good: 0, bad: 1
dca_ops: 	good: 0, bad: 1
mcfqspi_cs_control: 	good: 0, bad: 1
skl_dsp_fw_ops: 	good: 0, bad: 1
iser_reg_ops: 	good: 0, bad: 2
saa7146_use_ops: 	good: 0, bad: 2
qlcnic_dcb_ops: 	good: 0, bad: 2
fm10k_mac_ops: 	good: 0, bad: 2
v3020_chip_ops: 	good: 0, bad: 2
intel_mid_ops: 	good: 0, bad: 2
wlcore_ops: 	good: 0, bad: 2
au1200fb_platdata: 	good: 0, bad: 2
mxr_layer_ops: 	good: 0, bad: 2
ocfs2_stack_operations: 	good: 0, bad: 2
kvm_pmu_ops: 	good: 0, bad: 2
hdmi_phy_ops: 	good: 0, bad: 2
rtl_intf_ops: 	good: 0, bad: 2
mxc_extra_irq: 	good: 0, bad: 2
hwicap_driver_config: 	good: 0, bad: 2
dev_power_governor: 	good: 0, bad: 2
ptlrpc_ctx_ops: 	good: 0, bad: 2
olpc_ec_driver: 	good: 0, bad: 2
xpc_arch_operations: 	good: 0, bad: 2
cal_chipset_ops: 	good: 0, bad: 2
mal_commac_ops: 	good: 0, bad: 2
mmc_pwrseq_ops: 	good: 0, bad: 2
mem_access: 	good: 0, bad: 2
fd_dma_ops: 	good: 0, bad: 2
mvumi_instance_template: 	good: 0, bad: 2
imx_pwm_data: 	good: 0, bad: 2
nfc_llc_ops: 	good: 0, bad: 2
amba_pl010_data: 	good: 0, bad: 2
emitter: 	good: 0, bad: 2
fc_rport_operations: 	good: 0, bad: 2
adfs_dir_ops: 	good: 0, bad: 2
mpt_pci_driver: 	good: 0, bad: 2
gpio_methods: 	good: 0, bad: 2
s5p_mfc_hw_cmds: 	good: 0, bad: 2
bfin_sport_transfer_ops: 	good: 0, bad: 2
ct_timer_ops: 	good: 0, bad: 2
cmac_ops: 	good: 0, bad: 2
vio_driver_ops: 	good: 0, bad: 2
dummy_timer_ops: 	good: 0, bad: 2
mdesc_mem_ops: 	good: 0, bad: 2
uprobe_xol_ops: 	good: 0, bad: 2
dcon_platform_data: 	good: 0, bad: 2
vmci_transport_notify_ops: 	good: 0, bad: 2
w100_tg_info: 	good: 0, bad: 2
knav_range_ops: 	good: 0, bad: 2
drm_dp_mst_topology_cbs: 	good: 0, bad: 2
snd_rawmidi_global_ops: 	good: 0, bad: 2
s5p_mfc_codec_ops: 	good: 0, bad: 2
hwbus_ops: 	good: 0, bad: 2
ufs_qcom_phy_specific_ops: 	good: 0, bad: 2
nfc_digital_ops: 	good: 0, bad: 2
alpha_agp_ops: 	good: 0, bad: 2
ath_ps_ops: 	good: 0, bad: 2
hmcdrv_ftp_ops: 	good: 0, bad: 2
spu_context_ops: 	good: 0, bad: 2
snd_i2c_ops: 	good: 0, bad: 2
md_ops: 	good: 0, bad: 2
sunhv_ops: 	good: 0, bad: 2
uartlite_reg_ops: 	good: 0, bad: 2
ptlrpc_sec_sops: 	good: 0, bad: 2
pci_bios_ops: 	good: 0, bad: 2
microcode_ops: 	good: 0, bad: 2
s5p_mfc_hw_ops: 	good: 0, bad: 2
of_pdt_ops: 	good: 0, bad: 2
wl1271_if_operations: 	good: 0, bad: 2
otg_fsm_ops: 	good: 0, bad: 2
nfsd4_callback_ops: 	good: 0, bad: 2
abx500_ops: 	good: 0, bad: 2
m48t86_ops: 	good: 0, bad: 2
ptlrpc_sec_cops: 	good: 0, bad: 2
mbus_hw_ops: 	good: 0, bad: 2
fcoe_sysfs_function_template: 	good: 0, bad: 2
smp_ops: 	good: 1, bad: 1
pv_time_ops: 	good: 1, bad: 1
wl1251_if_operations: 	good: 1, bad: 1
pv_init_ops: 	good: 1, bad: 1
xfs_nameops: 	good: 1, bad: 1
ixgbe_mbx_operations: 	good: 1, bad: 1
dm_space_map: 	good: 0, bad: 3
at91_pinctrl_mux_ops: 	good: 0, bad: 3
ipmi_user_hndl: 	good: 0, bad: 3
brcmf_bus_ops: 	good: 0, bad: 3
ixgbe_eeprom_operations: 	good: 0, bad: 3
fsi_stream_handler: 	good: 0, bad: 3
xgene_mac_ops: 	good: 0, bad: 3
sbc_ops: 	good: 0, bad: 3
snd_vx_ops: 	good: 0, bad: 3
go7007_hpi_ops: 	good: 0, bad: 3
ixgbe_phy_operations: 	good: 0, bad: 3
sh_irda_xir_func: 	good: 0, bad: 3
matrox_switch: 	good: 0, bad: 3
qlcnic_hardware_ops: 	good: 0, bad: 3
btrfs_free_space_op: 	good: 0, bad: 3
snd_compr_ops: 	good: 0, bad: 3
xgene_port_ops: 	good: 0, bad: 3
nfsd4_client_tracking_ops: 	good: 0, bad: 3
samsung_gpio_pm: 	good: 0, bad: 3
drbg_state_ops: 	good: 0, bad: 3
nilfs_sc_operations: 	good: 0, bad: 3
snd_i2c_bit_ops: 	good: 0, bad: 3
snd_midi_op: 	good: 0, bad: 3
fatent_operations: 	good: 0, bad: 3
mwifiex_if_ops: 	good: 0, bad: 3
pci_port_ops: 	good: 0, bad: 3
portals_handle_ops: 	good: 0, bad: 3
logfs_block_ops: 	good: 0, bad: 3
nfc_hci_ops: 	good: 0, bad: 3
ace_reg_ops: 	good: 0, bad: 3
cx2341x_handler_ops: 	good: 0, bad: 3
conf_printer: 	good: 0, bad: 3
ui_progress_ops: 	good: 0, bad: 3
trace_sched_handler: 	good: 0, bad: 3
perf_error_ops: 	good: 0, bad: 3
perf_guest_info_callbacks: 	good: 0, bad: 3
aes_ops: 	good: 0, bad: 3
xfrm_replay: 	good: 0, bad: 3
pccard_resource_ops: 	good: 0, bad: 3
qtree_fmt_operations: 	good: 0, bad: 3
ui_helpline: 	good: 0, bad: 3
machine_ops: 	good: 1, bad: 2
bpf_verifier_ops: 	good: 2, bad: 1
sn_pcibus_provider: 	good: 0, bad: 4
sas_function_template: 	good: 0, bad: 4
cfs_hash_hlist_ops: 	good: 0, bad: 4
io_pgtable_init_fns: 	good: 0, bad: 4
rproc_ops: 	good: 0, bad: 4
fb_tile_ops: 	good: 0, bad: 4
sst_ops: 	good: 0, bad: 4
usb_phy_io_ops: 	good: 0, bad: 4
raw3270_fn: 	good: 0, bad: 4
radeon_audio_basic_funcs: 	good: 0, bad: 4
qlcnic_nic_template: 	good: 0, bad: 4
board_ops: 	good: 0, bad: 4
irda_platform_data: 	good: 0, bad: 4
drm_encoder_slave_funcs: 	good: 0, bad: 4
rchan_callbacks: 	good: 0, bad: 4
hppa_dma_ops: 	good: 0, bad: 4
nfcmrvl_if_ops: 	good: 0, bad: 4
iommu_gather_ops: 	good: 0, bad: 4
cm_ll_data: 	good: 0, bad: 4
plat_sci_port_ops: 	good: 0, bad: 4
sas_domain_function_template: 	good: 0, bad: 4
ib_dma_mapping_ops: 	good: 0, bad: 4
psc_ops: 	good: 0, bad: 4
z8530_irqhandler: 	good: 0, bad: 4
prm_ll_data: 	good: 0, bad: 4
ixgbe_mac_operations: 	good: 1, bad: 3
v4l2_subdev_sensor_ops: 	good: 1, bad: 3
of_bus: 	good: 1, bad: 3
e1000_mac_operations: 	good: 3, bad: 1
mipi_dsi_host_ops: 	good: 3, bad: 1
rpc_xprt_ops: 	good: 0, bad: 5
ep93xx_spi_chip_ops: 	good: 0, bad: 5
item_operations: 	good: 0, bad: 5
page_ext_operations: 	good: 0, bad: 5
bcache_ops: 	good: 0, bad: 5
ocfs2_extent_tree_operations: 	good: 0, bad: 5
ion_heap_ops: 	good: 0, bad: 5
svc_xprt_ops: 	good: 0, bad: 5
clkdm_ops: 	good: 0, bad: 5
nfc_ops: 	good: 0, bad: 5
pwrdm_ops: 	good: 0, bad: 5
megasas_instance_template: 	good: 0, bad: 5
esp_driver_ops: 	good: 4, bad: 1
exynos_drm_crtc_ops: 	good: 4, bad: 1
lu_device_operations: 	good: 4, bad: 1
e1000_nvm_operations: 	good: 4, bad: 1
cl_device_operations: 	good: 4, bad: 1
ins_ops: 	good: 0, bad: 6
exynos_drm_ipp_ops: 	good: 0, bad: 6
snd_tea575x_ops: 	good: 0, bad: 6
intel_dvo_dev_ops: 	good: 0, bad: 6
cfs_hash_lock_ops: 	good: 0, bad: 6
hid_ll_driver: 	good: 0, bad: 6
ftdi_sio_quirk: 	good: 0, bad: 6
e1000_phy_operations: 	good: 5, bad: 1
mbox_chan_ops: 	good: 5, bad: 1
kset_uevent_ops: 	good: 5, bad: 1
crypt_iv_operations: 	good: 0, bad: 7
sa1100_port_fns: 	good: 0, bad: 7
radeon_audio_funcs: 	good: 0, bad: 7
rsc_ops: 	good: 0, bad: 7
dma_ops: 	good: 0, bad: 7
nfc_phy_ops: 	good: 0, bad: 7
fsnotify_ops: 	good: 6, bad: 1
cl_lock_operations: 	good: 6, bad: 1
pcie_host_ops: 	good: 0, bad: 8
action_ops: 	good: 0, bad: 8
cpu_user_fns: 	good: 0, bad: 8
snd_info_entry_ops: 	good: 0, bad: 8
cfs_hash_ops: 	good: 0, bad: 8
sparc32_cachetlb_ops: 	good: 5, bad: 3
virtio_config_ops: 	good: 6, bad: 2
xfs_item_ops: 	good: 7, bad: 1
msi_domain_ops: 	good: 0, bad: 9
plat_lcd_data: 	good: 0, bad: 9
rtl_hal_ops: 	good: 0, bad: 9
ttm_bo_driver: 	good: 0, bad: 10
usbhs_pkt_handle: 	good: 0, bad: 10
usb_protocol_ops: 	good: 0, bad: 10
clkops: 	good: 6, bad: 4
drm_bridge_funcs: 	good: 7, bad: 3
fence_ops: 	good: 9, bad: 1
omap_dss_driver: 	good: 0, bad: 11
dma_buf_ops: 	good: 5, bad: 6
thermal_zone_of_device_ops: 	good: 7, bad: 4
mmu_notifier_ops: 	good: 8, bad: 3
kvm_io_device_ops: 	good: 10, bad: 1
ttm_backend_func: 	good: 0, bad: 12
access_method: 	good: 0, bad: 12
event_trigger_ops: 	good: 0, bad: 12
stacktrace_ops: 	good: 10, bad: 2
isp_operations: 	good: 0, bad: 13
hv_ops: 	good: 11, bad: 2
ftrace_probe_ops: 	good: 0, bad: 14
v4l2_m2m_ops: 	good: 2, bad: 12
thermal_cooling_device_ops: 	good: 7, bad: 7
plat_smp_ops: 	good: 0, bad: 15
clk_hw_omap_ops: 	good: 14, bad: 1
videobuf_queue_ops: 	good: 1, bad: 15
drm_plane_helper_funcs: 	good: 15, bad: 1
pccard_operations: 	good: 0, bad: 17
mii_phy_ops: 	good: 0, bad: 18
radeon_asic_ring: 	good: 0, bad: 19
drm_fb_helper_funcs: 	good: 18, bad: 1
reset_control_ops: 	good: 0, bad: 20
ide_dma_ops: 	good: 18, bad: 2
thermal_zone_device_ops: 	good: 0, bad: 21
drm_framebuffer_funcs: 	good: 15, bad: 6
drm_plane_funcs: 	good: 18, bad: 4
lcd_ops: 	good: 0, bad: 24
intel_uncore_ops: 	good: 0, bad: 24
export_operations: 	good: 24, bad: 2
drm_mode_config_funcs: 	good: 25, bad: 2
header_ops: 	good: 26, bad: 3
iio_buffer_setup_ops: 	good: 29, bad: 1
usb_gadget_ops: 	good: 31, bad: 2
mmc_host_ops: 	good: 21, bad: 13
drm_crtc_funcs: 	good: 28, bad: 6
rfkill_ops: 	good: 29, bad: 5
drm_crtc_helper_funcs: 	good: 30, bad: 4
usb_ep_ops: 	good: 18, bad: 18
tty_port_operations: 	good: 33, bad: 4
configfs_group_operations: 	good: 0, bad: 38
v4l2_subdev_internal_ops: 	good: 37, bad: 1
configfs_item_operations: 	good: 0, bad: 44
platform_suspend_ops: 	good: 41, bad: 4
snd_ac97_bus_ops: 	good: 0, bad: 49
pinctrl_ops: 	good: 40, bad: 9
dentry_operations: 	good: 52, bad: 1
pci_error_handlers: 	good: 46, bad: 9
snd_rawmidi_ops: 	good: 0, bad: 68
drm_connector_helper_funcs: 	good: 50, bad: 18
drm_encoder_funcs: 	good: 61, bad: 14
drm_connector_funcs: 	good: 56, bad: 20
drm_encoder_helper_funcs: 	good: 65, bad: 12
vb2_ops: 	good: 20, bad: 59
snd_soc_ops: 	good: 2, bad: 85
snd_device_ops: 	good: 0, bad: 93
v4l2_subdev_video_ops: 	good: 81, bad: 32
pci_ops: 	good: 0, bad: 121
rtc_class_ops: 	good: 117, bad: 31
v4l2_ctrl_ops: 	good: 198, bad: 6
inode_operations: 	good: 209, bad: 5
snd_soc_dai_ops: 	good: 226, bad: 18
ethtool_ops: 	good: 239, bad: 11
regulator_ops: 	good: 15, bad: 237
snd_pcm_ops: 	good: 7, bad: 278
clk_ops: 	good: 257, bad: 71
seq_operations: 	good: 328, bad: 1
dev_pm_ops: 	good: 337, bad: 19

Re: [PATCH] video: constify geode ops structures

[Kees Cook]

On Sun, Nov 8, 2015 at 2:16 PM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> Cool.  So, in grsec they use a GCC plugin to make these const
> automatically since they only contain function pointers.  There about
> 100 struct types marked as __no_const.  Kees would like to adopt the
> grsec pluggin approach I expect.  Do you have an idea how many structs
> only contain function pointers or how many consts we would have to add
> to get the same effect without the plugin?

Just to remind everyone: while we certainly want to clean these up in
the code where possible, we still want to make the constification
plugin part of the regular builds. We want to provide a
secure-by-default build, even when vendors are adding their own
out-of-tree code when producing Linux-based products. So, we'll always
want to have the plugin as a back-stop for out-of-tree code, or places
where const was accidentally missed upstream.

-Kees

>
> regards,
> dan carpenter
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/



-- 
Kees Cook
Chrome OS Security

Re: [PATCH] video: constify geode ops structures

[Christoph Hellwig]

On Mon, Nov 09, 2015 at 01:20:12PM -0800, Kees Cook wrote:
> Just to remind everyone: while we certainly want to clean these up in
> the code where possible, we still want to make the constification
> plugin part of the regular builds. We want to provide a
> secure-by-default build, even when vendors are adding their own
> out-of-tree code when producing Linux-based products. So, we'll always
> want to have the plugin as a back-stop for out-of-tree code, or places
> where const was accidentally missed upstream.

Who is 'we'?  While a plugin like this that warns would be very ueful
I strongly disagree with bloating the kernel tree with any infrastructure
primarily aimed at out of tree code.

Re: [PATCH] video: constify geode ops structures

[Kees Cook]

On Mon, Nov 9, 2015 at 10:38 PM, Christoph Hellwig <hch@infradead.org> wrote:
> On Mon, Nov 09, 2015 at 01:20:12PM -0800, Kees Cook wrote:
>> Just to remind everyone: while we certainly want to clean these up in
>> the code where possible, we still want to make the constification
>> plugin part of the regular builds. We want to provide a
>> secure-by-default build, even when vendors are adding their own
>> out-of-tree code when producing Linux-based products. So, we'll always
>> want to have the plugin as a back-stop for out-of-tree code, or places
>> where const was accidentally missed upstream.
>
> Who is 'we'?  While a plugin like this that warns would be very ueful

I understand "we" here to mean people interested in the proactive
defense of the Linux kernel, and by extension the Linux kernel
community as a whole. :)

> I strongly disagree with bloating the kernel tree with any infrastructure
> primarily aimed at out of tree code.

It's not "primarily aimed at out of tree code", that is simply an
additional side-effect (though the need must be recognized: a billion
android devices, and none of them are running a stock kernel). What it
gets us is _coverage_. We can't make everything work just by static
analyzers and checkpatch.pl runs (meaning the "backstop" comment
above).

Additionally, having the plugin infrastructure gets us the ability to
do things that aren't presently possible (see the thread on the
initify plugin, which can't be done in source alone).

-Kees

-- 
Kees Cook
Chrome OS Security

Re: [PATCH] video: constify geode ops structures

[Joe Perches]

On Tue, 2015-11-10 at 12:34 -0800, Kees Cook wrote:
> We can't make everything work just by static
> analyzers and checkpatch.pl runs (meaning the "backstop" comment
> above).
> 
> Additionally, having the plugin infrastructure gets us the ability to
> do things that aren't presently possible (see the thread on the
> initify plugin, which can't be done in source alone).

#define __do_const __attribute__((do_const))
...
#ifndef __do_const
#define __do_const
#endif

I think it's always better for the reader to know that a
const struct declaration is used over a non-const struct
when the compiler, via plug-in extension, could convert
the declaration to const.

Is there a warning/info message produced by gcc and the
plug-in when a non-const declaration is converted to
const because of this attribute?

Re: [PATCH] video: constify geode ops structures

[Dan Carpenter]

On Tue, Nov 10, 2015 at 12:49:29PM -0800, Joe Perches wrote:
> Is there a warning/info message produced by gcc and the
> plug-in when a non-const declaration is converted to
> const because of this attribute?

I'm not sure I understand the question.  What would the warning say?

We'll hopefully automatically make over 3000 structs const.  I
understand warning that people should make structs const when possible
but I don't understand why we would want to remove auto consting?

Putting __do_const in the .h file is basically the same as marking
every struct of that type as const in the .c file.  The errors are
caught at compile time.

regards,
dan carpenter

Re: [PATCH] video: constify geode ops structures

[Joe Perches]

On Wed, 2015-11-11 at 01:02 +0300, Dan Carpenter wrote:
> On Tue, Nov 10, 2015 at 12:49:29PM -0800, Joe Perches wrote:
> > Is there a warning/info message produced by gcc and the
> > plug-in when a non-const declaration is converted to
> > const because of this attribute?
> 
> I'm not sure I understand the question.  What would the warning say?

Perhaps something like:

declaration of struct <foo> converted to const by __attribute__((do_const))

> We'll hopefully automatically make over 3000 structs const.  I
> understand warning that people should make structs const when possible
> but I don't understand why we would want to remove auto consting?

I'm not suggesting removing the attribute.
It seems sensible enough.

I just think the plug-in should at least optionally
note the instances when non-const declarations are
converted to const.

> Putting __do_const in the .h file is basically the same as marking
> every struct of that type as const in the .c file.

Not for a reader of the code that doesn't first
inspect the header files.

Re: [PATCH] video: constify geode ops structures

[Dan Carpenter]

On Tue, Nov 10, 2015 at 02:17:12PM -0800, Joe Perches wrote:
> On Wed, 2015-11-11 at 01:02 +0300, Dan Carpenter wrote:
> > On Tue, Nov 10, 2015 at 12:49:29PM -0800, Joe Perches wrote:
> > > Is there a warning/info message produced by gcc and the
> > > plug-in when a non-const declaration is converted to
> > > const because of this attribute?
> > 
> > I'm not sure I understand the question.  What would the warning say?
> 
> Perhaps something like:
> 
> declaration of struct <foo> converted to const by __attribute__((do_const))

No one will ever think to turn on that output.  By the time they think
of turning it on, it means they have already figured out the issue.

regards,
dan carpenter

Re: [PATCH] video: constify geode ops structures

[Joe Perches]

On Wed, 2015-11-11 at 01:34 +0300, Dan Carpenter wrote:
> On Tue, Nov 10, 2015 at 02:17:12PM -0800, Joe Perches wrote:
> > On Wed, 2015-11-11 at 01:02 +0300, Dan Carpenter wrote:
> > > On Tue, Nov 10, 2015 at 12:49:29PM -0800, Joe Perches wrote:
> > > > Is there a warning/info message produced by gcc and the
> > > > plug-in when a non-const declaration is converted to
> > > > const because of this attribute?
> > > 
> > > I'm not sure I understand the question.  What would the warning
> > > say?
> > 
> > Perhaps something like:
> > 
> > declaration of struct <foo> converted to const by
> > __attribute__((do_const))
> 
> No one will ever think to turn on that output.  By the time they think
> of turning it on, it means they have already figured out the issue.

Dubious assertion.

Re: [PATCH] video: constify geode ops structures

[Tomi Valkeinen]

[-- Attachment #1: Type: text/plain, Size: 598 bytes --]



On 08/11/15 23:34, Julia Lawall wrote:
> These geode ops structures are never modified, so declare them as const.
> 
> Done with the help of Coccinelle.
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> 
> ---
>  drivers/video/fbdev/geode/display_gx1.c  |    2 +-
>  drivers/video/fbdev/geode/display_gx1.h  |    2 +-
>  drivers/video/fbdev/geode/geodefb.h      |    4 ++--
>  drivers/video/fbdev/geode/video_cs5530.c |    2 +-
>  drivers/video/fbdev/geode/video_cs5530.h |    2 +-
>  5 files changed, 6 insertions(+), 6 deletions(-)

Thanks, queued for 4.5.

 Tomi


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]