Using the ARRAY_SIZE macro improves the readability of the code. Also,
it is not always useful to use a variable to store this constant
calculated at compile time.
Found with Coccinelle with the following semantic patch:
@r depends on (org || report)@
type T;
T[] E;
position p;
@@
(
(sizeof(E)@p /sizeof(*E))
|
(sizeof(E)@p /sizeof(E[...]))
|
(sizeof(E)@p /sizeof(T))
)
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
In the previous commit I left the indentation alone to help reviewing
the patch, this one now runs the three new functions through 'indent -kr -8'
with some manual fixups to avoid silliness.
No changes other than whitespace are intended here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The stack consumption in this driver is still relatively high, with one
remaining warning if the warning level is lowered to 1536 bytes:
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:17135:1: error: the frame size of 1880 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
The affected function is actually a collection of three separate implementations,
and each of them is fairly large by itself. Splitting them up is done easily
and improves readability at the same time.
I'm leaving the original indentation to make the review easier.
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
With KASAN and a couple of other patches applied, this driver is one
of the few remaining ones that actually use more than 2048 bytes of
kernel stack:
broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function 'wlc_phy_workarounds_nphy_gainctrl':
broadcom/brcm80211/brcmsmac/phy/phy_n.c:16065:1: warning: the frame size of 3264 bytes is larger than 2048 bytes [-Wframe-larger-than=]
broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function 'wlc_phy_workarounds_nphy':
broadcom/brcm80211/brcmsmac/phy/phy_n.c:17138:1: warning: the frame size of 2864 bytes is larger than 2048 bytes [-Wframe-larger-than=]
Here, I'm reducing the stack size by marking as many local variables as
'static const' as I can without changing the actual code.
This is the first of three patches to improve the stack usage in this
driver. It would be good to have this backported to stabl kernels
to get all drivers in 'allmodconfig' below the 2048 byte limit so
we can turn on the frame warning again globally, but I realize that
the patch is larger than the normal limit for stable backports.
The other two patches do not need to be backported.
Cc: <stable@vger.kernel.org>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Don't populate const array ucode_ofdm_rates on the stack, instead make it
static. Makes the object code smaller by 100 bytes:
Before:
text data bss dec hex filename
39482 564 0 40046 9c6e phy_cmn.o
After
text data bss dec hex filename
39326 620 0 39946 9c0a phy_cmn.o
(gcc 6.3.0, x86-64)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
I get the following UBSAN warning during boot on my laptop:
================================================================================
UBSAN: Undefined behaviour in drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_qmath.c:280:21
index 32 is out of range for type 's16 [32]'
CPU: 0 PID: 879 Comm: NetworkManager Not tainted 4.9.0-rc4 #28
Hardware name: LENOVO Lenovo IdeaPad N581/INVALID, BIOS 5ECN96WW(V9.01) 03/14/2013
ffff8800b74a6478 ffffffff828e59d2 0000000041b58ab3 ffffffff8398330c
ffffffff828e5920 ffff8800b74a64a0 ffff8800b74a6450 0000000000000020
1ffffffff845848c ffffed0016e94bf1 ffffffffc22c2460 000000006b9c0514
Call Trace:
[<ffffffff828e59d2>] dump_stack+0xb2/0x110
[<ffffffff828e5920>] ? _atomic_dec_and_lock+0x150/0x150
[<ffffffff82968c9d>] ubsan_epilogue+0xd/0x4e
[<ffffffff82969875>] __ubsan_handle_out_of_bounds+0xfa/0x13e
[<ffffffff8296977b>] ? __ubsan_handle_shift_out_of_bounds+0x241/0x241
[<ffffffffc0d48379>] ? bcma_host_pci_read16+0x59/0xa0 [bcma]
[<ffffffffc0d48388>] ? bcma_host_pci_read16+0x68/0xa0 [bcma]
[<ffffffffc212ad78>] ? read_phy_reg+0xe8/0x180 [brcmsmac]
[<ffffffffc2184714>] qm_log10+0x2e4/0x350 [brcmsmac]
[<ffffffffc2142eb8>] wlc_phy_init_lcnphy+0x538/0x1f20 [brcmsmac]
[<ffffffffc2142980>] ? wlc_lcnphy_periodic_cal+0x5c0/0x5c0 [brcmsmac]
[<ffffffffc1ba0c93>] ? ieee80211_open+0xb3/0x110 [mac80211]
[<ffffffff82f73a02>] ? sk_busy_loop+0x1e2/0x840
[<ffffffff82f7a6ce>] ? __dev_change_flags+0xae/0x220
...
The report is valid: doing the math in this function, with an input value
N=63 the variable s16tableIndex gets a value of 31. This value is used as
an index in the array log_table with 32 entries. But the next line is:
s16errorApproximation = (s16) qm_mulu16(u16offset,
(u16) (log_table[s16tableIndex + 1] -
log_table[s16tableIndex]));
With s16tableIndex + 1 we are trying an out-of-bounds access to the array.
The log_table array provides log2 values in q.15 format and the above
statement tries an error approximation with the next value. To fix this
issue add the next value to the array and update the comment accordingly.
Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Part of reorganising wireless drivers directory and Kconfig. Note that I had to
edit Makefiles from subdirectories to use the new location.
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
