Re: [PATCH -next] iwlwifi: dbg: work around clang bug by marking debug strings static

From: Nick Desaulniers <ndesaulniers@google.com>
To: Kalle Valo <kvalo@codeaurora.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Johannes Berg <johannes.berg@intel.com>,
	Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
	Luca Coelho <luciano.coelho@intel.com>,
	Intel Linux Wireless <linuxwifi@intel.com>,
	"David S. Miller" <davem@davemloft.net>,
	Shahar S Matityahu <shahar.s.matityahu@intel.com>,
	Sara Sharon <sara.sharon@intel.com>,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH -next] iwlwifi: dbg: work around clang bug by marking debug strings static
Date: Thu, 11 Jul 2019 17:18:54 -0700	[thread overview]
Message-ID: <CAKwvOd=C_fTxT20mv5LrNmrSWezNgtBy5nzFJb2gpuo_Lx-f0Q@mail.gmail.com> (raw)
In-Reply-To: <20190712001708.170259-1-ndesaulniers@google.com>

On Thu, Jul 11, 2019 at 5:17 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> Commit r353569 in prerelease Clang-9 is producing a linkage failure:
>
> ld: drivers/net/wireless/intel/iwlwifi/fw/dbg.o:
> in function `_iwl_fw_dbg_apply_point':
> dbg.c:(.text+0x827a): undefined reference to `__compiletime_assert_2387'
>
> when the following configs are enabled:
> - CONFIG_IWLWIFI
> - CONFIG_IWLMVM
> - CONFIG_KASAN
>
> Work around the issue for now by marking the debug strings as `static`,
> which they probably should be any ways.
>
> Link: https://bugs.llvm.org/show_bug.cgi?id=42580
> Link: https://github.com/ClangBuiltLinux/linux/issues/580
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Reported-by: Nathan Chancellor <natechancellor@gmail.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Sorry, I forgot a very important:
Suggested-by: Eli Friedman <efriedma@quicinc.com>

> ---
>  drivers/net/wireless/intel/iwlwifi/fw/dbg.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
> index e411ac98290d..f8c90ea4e9b4 100644
> --- a/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
> +++ b/drivers/net/wireless/intel/iwlwifi/fw/dbg.c
> @@ -2438,7 +2438,7 @@ static void iwl_fw_dbg_info_apply(struct iwl_fw_runtime *fwrt,
>  {
>         u32 img_name_len = le32_to_cpu(dbg_info->img_name_len);
>         u32 dbg_cfg_name_len = le32_to_cpu(dbg_info->dbg_cfg_name_len);
> -       const char err_str[] =
> +       static const char err_str[] =
>                 "WRT: ext=%d. Invalid %s name length %d, expected %d\n";
>
>         if (img_name_len != IWL_FW_INI_MAX_IMG_NAME_LEN) {
> @@ -2775,7 +2775,7 @@ static void _iwl_fw_dbg_apply_point(struct iwl_fw_runtime *fwrt,
>                 struct iwl_ucode_tlv *tlv = iter;
>                 void *ini_tlv = (void *)tlv->data;
>                 u32 type = le32_to_cpu(tlv->type);
> -               const char invalid_ap_str[] =
> +               static const char invalid_ap_str[] =
>                         "WRT: ext=%d. Invalid apply point %d for %s\n";
>
>                 switch (type) {
> --
> 2.22.0.410.gd8fdbe21b5-goog
>


-- 
Thanks,
~Nick Desaulniers