From: Avri Altman <Avri.Altman@wdc.com>
To: Bean Huo <huobean@gmail.com>,
"ulf.hansson@linaro.org" <ulf.hansson@linaro.org>,
"adrian.hunter@intel.com" <adrian.hunter@intel.com>,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "beanhuo@micron.com" <beanhuo@micron.com>
Subject: RE: [PATCH v1 1/2] mmc-utils: Use memcpy instead of strncpy
Date: Mon, 15 Nov 2021 08:38:33 +0000 [thread overview]
Message-ID: <DM6PR04MB65753B3AB67AB262FC3383EFFC989@DM6PR04MB6575.namprd04.prod.outlook.com> (raw)
In-Reply-To: <20211114204331.39555-2-huobean@gmail.com>
Hi Bean,
>
> The -Wstringop-truncation warning added in GCC 8.0:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82944
>
> If you use the GCC > v8.0, you probably will get this compilation error:
>
> error: ‘__builtin_strncpy’ output may be truncated copying 8 bytes from a
> string of length 511 [-Werror=stringop-truncation]
>
> Use memcpy instead of strncpy to avoid this compilation error.
>
> Signed-off-by: Bean Huo <beanhuo@micron.com>
Looking into the link above, it say that this warning:
"... is specifically intended to highlight likely unintended uses of the strncpy function that truncate the terminating NUL charcter from the source string."
As this is not the case here, I wouldn't worry about this warning.
Thanks,
Avri
> ---
> mmc_cmds.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index 205e6e5b89f9..ecbde3937c81 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1835,7 +1835,8 @@ int do_read_extcsd(int nargs, char **argv)
>
> if (ext_csd_rev >= 7) {
> memset(lbuf, 0, sizeof(lbuf));
> - strncpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], 8);
> + memcpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], 8);
> + lbuf[8] = '\0';
> printf("eMMC Firmware Version: %s\n", lbuf);
> printf("eMMC Life Time Estimation A
> [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]: 0x%02x\n",
> ext_csd[EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]);
> --
> 2.25.1
next prev parent reply other threads:[~2021-11-15 8:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-14 20:43 [PATCH v1 0/2] Two change for mmc-utils Bean Huo
2021-11-14 20:43 ` [PATCH v1 1/2] mmc-utils: Use memcpy instead of strncpy Bean Huo
2021-11-15 7:09 ` Ajay Garg
2021-11-15 10:49 ` Bean Huo
2021-11-15 11:37 ` Ajay Garg
2021-11-15 8:38 ` Avri Altman [this message]
2021-11-14 20:43 ` [PATCH v1 2/2] mmc-utils: Add note for CMDQ_MODE_EN runtime value Bean Huo
2021-11-15 9:07 ` Avri Altman
2021-11-15 15:08 ` Ulf Hansson
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