mirror of
https://github.com/coolsnowwolf/lede.git
synced 2025-04-16 14:23:38 +00:00
145 lines
5.7 KiB
Diff
145 lines
5.7 KiB
Diff
From b2549465cdeac3847487ce88b15ca47c37b60b88 Mon Sep 17 00:00:00 2001
|
|
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
|
|
Date: Tue, 28 Sep 2021 12:05:44 +0300
|
|
Subject: [PATCH] ath11k: Replace one-element array with flexible-array member
|
|
|
|
There is a regular need in the kernel to provide a way to declare having a
|
|
dynamically sized set of trailing elements in a structure. Kernel code
|
|
should always use "flexible array members"[1] for these cases. The older
|
|
style of one-element or zero-length arrays should no longer be used[2].
|
|
|
|
Refactor the code a bit according to the use of a flexible-array member in
|
|
struct scan_chan_list_params instead of a one-element array, and use the
|
|
struct_size() helper.
|
|
|
|
Also, save 25 (too many) bytes that were being allocated:
|
|
|
|
$ pahole -C channel_param drivers/net/wireless/ath/ath11k/reg.o
|
|
struct channel_param {
|
|
u8 chan_id; /* 0 1 */
|
|
u8 pwr; /* 1 1 */
|
|
u32 mhz; /* 2 4 */
|
|
|
|
/* Bitfield combined with next fields */
|
|
|
|
u32 half_rate:1; /* 4:16 4 */
|
|
u32 quarter_rate:1; /* 4:17 4 */
|
|
u32 dfs_set:1; /* 4:18 4 */
|
|
u32 dfs_set_cfreq2:1; /* 4:19 4 */
|
|
u32 is_chan_passive:1; /* 4:20 4 */
|
|
u32 allow_ht:1; /* 4:21 4 */
|
|
u32 allow_vht:1; /* 4:22 4 */
|
|
u32 allow_he:1; /* 4:23 4 */
|
|
u32 set_agile:1; /* 4:24 4 */
|
|
u32 psc_channel:1; /* 4:25 4 */
|
|
|
|
/* XXX 6 bits hole, try to pack */
|
|
|
|
u32 phy_mode; /* 8 4 */
|
|
u32 cfreq1; /* 12 4 */
|
|
u32 cfreq2; /* 16 4 */
|
|
char maxpower; /* 20 1 */
|
|
char minpower; /* 21 1 */
|
|
char maxregpower; /* 22 1 */
|
|
u8 antennamax; /* 23 1 */
|
|
u8 reg_class_id; /* 24 1 */
|
|
|
|
/* size: 25, cachelines: 1, members: 21 */
|
|
/* sum members: 23 */
|
|
/* sum bitfield members: 10 bits, bit holes: 1, sum bit holes: 6 bits */
|
|
/* last cacheline: 25 bytes */
|
|
} __attribute__((__packed__));
|
|
|
|
as previously, sizeof(struct scan_chan_list_params) was 32 bytes:
|
|
|
|
$ pahole -C scan_chan_list_params drivers/net/wireless/ath/ath11k/reg.o
|
|
struct scan_chan_list_params {
|
|
u32 pdev_id; /* 0 4 */
|
|
u16 nallchans; /* 4 2 */
|
|
struct channel_param ch_param[1]; /* 6 25 */
|
|
|
|
/* size: 32, cachelines: 1, members: 3 */
|
|
/* padding: 1 */
|
|
/* last cacheline: 32 bytes */
|
|
};
|
|
|
|
and now with the flexible array transformation it is just 8 bytes:
|
|
|
|
$ pahole -C scan_chan_list_params drivers/net/wireless/ath/ath11k/reg.o
|
|
struct scan_chan_list_params {
|
|
u32 pdev_id; /* 0 4 */
|
|
u16 nallchans; /* 4 2 */
|
|
struct channel_param ch_param[]; /* 6 0 */
|
|
|
|
/* size: 8, cachelines: 1, members: 3 */
|
|
/* padding: 2 */
|
|
/* last cacheline: 8 bytes */
|
|
};
|
|
|
|
This helps with the ongoing efforts to globally enable -Warray-bounds and
|
|
get us closer to being able to tighten the FORTIFY_SOURCE routines on
|
|
memcpy().
|
|
|
|
This issue was found with the help of Coccinelle and audited and fixed,
|
|
manually.
|
|
|
|
[1] https://en.wikipedia.org/wiki/Flexible_array_member
|
|
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
|
|
|
|
Link: https://github.com/KSPP/linux/issues/79
|
|
Link: https://github.com/KSPP/linux/issues/109
|
|
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
|
|
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
|
|
Link: https://lore.kernel.org/r/20210823172159.GA25800@embeddedor
|
|
---
|
|
drivers/net/wireless/ath/ath11k/reg.c | 7 ++-----
|
|
drivers/net/wireless/ath/ath11k/wmi.c | 2 +-
|
|
drivers/net/wireless/ath/ath11k/wmi.h | 2 +-
|
|
3 files changed, 4 insertions(+), 7 deletions(-)
|
|
|
|
--- a/drivers/net/wireless/ath/ath11k/reg.c
|
|
+++ b/drivers/net/wireless/ath/ath11k/reg.c
|
|
@@ -97,7 +97,6 @@ int ath11k_reg_update_chan_list(struct a
|
|
struct channel_param *ch;
|
|
enum nl80211_band band;
|
|
int num_channels = 0;
|
|
- int params_len;
|
|
int i, ret;
|
|
|
|
bands = hw->wiphy->bands;
|
|
@@ -117,10 +116,8 @@ int ath11k_reg_update_chan_list(struct a
|
|
if (WARN_ON(!num_channels))
|
|
return -EINVAL;
|
|
|
|
- params_len = sizeof(struct scan_chan_list_params) +
|
|
- num_channels * sizeof(struct channel_param);
|
|
- params = kzalloc(params_len, GFP_KERNEL);
|
|
-
|
|
+ params = kzalloc(struct_size(params, ch_param, num_channels),
|
|
+ GFP_KERNEL);
|
|
if (!params)
|
|
return -ENOMEM;
|
|
|
|
--- a/drivers/net/wireless/ath/ath11k/wmi.c
|
|
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
|
|
@@ -2303,7 +2303,7 @@ int ath11k_wmi_send_scan_chan_list_cmd(s
|
|
u16 num_send_chans, num_sends = 0, max_chan_limit = 0;
|
|
u32 *reg1, *reg2;
|
|
|
|
- tchan_info = &chan_list->ch_param[0];
|
|
+ tchan_info = chan_list->ch_param;
|
|
while (chan_list->nallchans) {
|
|
len = sizeof(*cmd) + TLV_HDR_SIZE;
|
|
max_chan_limit = (wmi->wmi_ab->max_msg_len[ar->pdev_idx] - len) /
|
|
--- a/drivers/net/wireless/ath/ath11k/wmi.h
|
|
+++ b/drivers/net/wireless/ath/ath11k/wmi.h
|
|
@@ -3659,7 +3659,7 @@ struct wmi_stop_scan_cmd {
|
|
struct scan_chan_list_params {
|
|
u32 pdev_id;
|
|
u16 nallchans;
|
|
- struct channel_param ch_param[1];
|
|
+ struct channel_param ch_param[];
|
|
};
|
|
|
|
struct wmi_scan_chan_list_cmd {
|