[PATCH] Fix strncpy() usage

[PATCH] Fix strncpy() usage

[Oleh Kravchenko]

Manpage of strncpy() says:
If there is no null byte among the first n bytes of src,
the string placed in dest will not be null-terminated.

Put \0 to the end of the buffer to ensure that
the destination string is NULL-terminated.

This patch also fixes a compile error with a newer version of GCC.

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
---
 mmc_cmds.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 73bd32a..016fe70 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1834,8 +1834,8 @@ 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);
+		strncpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], sizeof(lbuf) - 1);
+		lbuf[sizeof(lbuf) - 1] = 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]);
-- 
2.32.0

Re: [PATCH] Fix strncpy() usage

[Ulf Hansson]

+ Avri, Bean


On Tue, 16 Nov 2021 at 11:51, Oleh Kravchenko <oleg@kaa.org.ua> wrote:
>
> Manpage of strncpy() says:
> If there is no null byte among the first n bytes of src,
> the string placed in dest will not be null-terminated.
>
> Put \0 to the end of the buffer to ensure that
> the destination string is NULL-terminated.
>
> This patch also fixes a compile error with a newer version of GCC.
>
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
> ---
>  mmc_cmds.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index 73bd32a..016fe70 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1834,8 +1834,8 @@ 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);
> +               strncpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], sizeof(lbuf) - 1);

This may look better, but is actually making it worse. lbuf is 10
bytes long, while the ext_csd is 8 bytes.

> +               lbuf[sizeof(lbuf) - 1] = 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]);
> --
> 2.32.0
>

Kind regards
Uffe

[PATCH v2] Replace strncpy() usage by printf()

[Oleh Kravchenko]

Manpage of strncpy() says:
If there is no null byte among the first n bytes of src,
the string placed in dest will not be null-terminated.

Put \0 to the end of the buffer to ensure that
the destination string is NULL-terminated.

This patch also fixes a compile error with a newer version of GCC.

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
---
 mmc_cmds.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 73bd32a..753fcd9 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
 	__u32 regl;
 	int fd, ret;
 	char *device;
-	char lbuf[10];
 	const char *str;
 
 	if (nargs != 2) {
@@ -1834,9 +1833,7 @@ 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);
-		printf("eMMC Firmware Version: %s\n", lbuf);
+		printf("eMMC Firmware Version: %.*s\n", 8, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
 		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]);
 		printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
-- 
2.32.0

Re: [PATCH v2] Replace strncpy() usage by printf()

[Ulf Hansson]

+ Avri

On Fri, 26 Nov 2021 at 15:48, Oleh Kravchenko <oleg@kaa.org.ua> wrote:
>
> Manpage of strncpy() says:
> If there is no null byte among the first n bytes of src,
> the string placed in dest will not be null-terminated.
>
> Put \0 to the end of the buffer to ensure that
> the destination string is NULL-terminated.

Please update the commit message to reflect what the patch really
does, as the above is no longer correct.

>
> This patch also fixes a compile error with a newer version of GCC.
>
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>

At next submission, please also add Avri Altman <avri.altman@wdc.com>,
who co-maintains the mmc-utils.

> ---
>  mmc_cmds.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index 73bd32a..753fcd9 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
>         __u32 regl;
>         int fd, ret;
>         char *device;
> -       char lbuf[10];
>         const char *str;
>
>         if (nargs != 2) {
> @@ -1834,9 +1833,7 @@ 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);
> -               printf("eMMC Firmware Version: %s\n", lbuf);
> +               printf("eMMC Firmware Version: %.*s\n", 8, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);

This looks good to me. However, I suggest you skip the dynamic length
format. Just use %.8s.


>                 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]);
>                 printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
> --
> 2.32.0
>

Kind regards
Uffe

[PATCH v3] Use printf() to extract and print fw version

[Oleh Kravchenko]

This patch also fixes a compile error with a newer version of GCC:
error: '__builtin_strncpy' output may be truncated copying 8 bytes from
a string of length 511 [-Werror=stringop-truncation]

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
---
 mmc_cmds.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 73bd32a..e07ec94 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
 	__u32 regl;
 	int fd, ret;
 	char *device;
-	char lbuf[10];
 	const char *str;
 
 	if (nargs != 2) {
@@ -1834,9 +1833,7 @@ 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);
-		printf("eMMC Firmware Version: %s\n", lbuf);
+		printf("eMMC Firmware Version: %.8s\n", (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
 		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]);
 		printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
-- 
2.32.0

RE: [EXT] [PATCH v3] Use printf() to extract and print fw version

[Bean Huo (beanhuo)]

Micron Confidential

> Cc: Oleh Kravchenko <oleg@kaa.org.ua>
> Subject: [EXT] [PATCH v3] Use printf() to extract and print fw version
> 
> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless you
> recognize the sender and were expecting this message.
> 
> 
> This patch also fixes a compile error with a newer version of GCC:
> error: '__builtin_strncpy' output may be truncated copying 8 bytes from a string
> of length 511 [-Werror=stringop-truncation]
> 
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>

Hi Oleh,

It is better to add the prefix "mmc-utils:" in the Commit subject to distinguish it from Linux kernel changes


Reviewed-by: Bean Huo <beanhuo@micron.com>



Micron Confidential

Re: [EXT] [PATCH v3] Use printf() to extract and print fw version

[Oleh Kravchenko]

29.11.21 17:05, Bean Huo (beanhuo) пише:
> Micron Confidential
>
>> Cc: Oleh Kravchenko <oleg@kaa.org.ua>
>> Subject: [EXT] [PATCH v3] Use printf() to extract and print fw version
>>
>> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless you
>> recognize the sender and were expecting this message.
>>
>>
>> This patch also fixes a compile error with a newer version of GCC:
>> error: '__builtin_strncpy' output may be truncated copying 8 bytes from a string
>> of length 511 [-Werror=stringop-truncation]
>>
>> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
> Hi Oleh,
>
> It is better to add the prefix "mmc-utils:" in the Commit subject to distinguish it from Linux kernel changes

Will do it.

> Reviewed-by: Bean Huo <beanhuo@micron.com>

Thanks!

[PATCH v3] mmc-utils: Use printf() to extract and print fw version

[Oleh Kravchenko]

This patch also fixes a compile error with a newer version of GCC:
error: '__builtin_strncpy' output may be truncated copying 8 bytes from
a string of length 511 [-Werror=stringop-truncation]

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: Bean Huo <beanhuo@micron.com>
---
 mmc_cmds.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

Update commit message.

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 73bd32a..e07ec94 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
 	__u32 regl;
 	int fd, ret;
 	char *device;
-	char lbuf[10];
 	const char *str;
 
 	if (nargs != 2) {
@@ -1834,9 +1833,7 @@ 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);
-		printf("eMMC Firmware Version: %s\n", lbuf);
+		printf("eMMC Firmware Version: %.8s\n", (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
 		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]);
 		printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
-- 
2.32.0

[PATCH v4] mmc-utils: Use printf() to extract and print fw version

[Oleh Kravchenko]

This patch also fixes a compile error with a newer version of GCC:
error: '__builtin_strncpy' output may be truncated copying 8 bytes from
a string of length 511 [-Werror=stringop-truncation]

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: Bean Huo <beanhuo@micron.com>
---
 mmc_cmds.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

PATCH v4
Update commit message.

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 73bd32a..e07ec94 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
 	__u32 regl;
 	int fd, ret;
 	char *device;
-	char lbuf[10];
 	const char *str;
 
 	if (nargs != 2) {
@@ -1834,9 +1833,7 @@ 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);
-		printf("eMMC Firmware Version: %s\n", lbuf);
+		printf("eMMC Firmware Version: %.8s\n", (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
 		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]);
 		printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
-- 
2.32.0

RE: [PATCH v4] mmc-utils: Use printf() to extract and print fw version

[Avri Altman]

Hi,
> 
> This patch also fixes a compile error with a newer version of GCC:
> error: '__builtin_strncpy' output may be truncated copying 8 bytes from a
> string of length 511 [-Werror=stringop-truncation]
You are reverting commit 0eea71e4f2 (mmc-utils: Fix for Firmware Version string printing).
Please use git revert and add an explanation in your commit log.

You might also would like to take a look at the correspondence concerning a different approach to the same issue here - https://lore.kernel.org/lkml/20211114204331.39555-2-huobean@gmail.com/

Thanks,
Avri

> 
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
> Reviewed-by: Bean Huo <beanhuo@micron.com>
> ---
>  mmc_cmds.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> PATCH v4
> Update commit message.
> 
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index 73bd32a..e07ec94 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
>         __u32 regl;
>         int fd, ret;
>         char *device;
> -       char lbuf[10];
>         const char *str;
> 
>         if (nargs != 2) {
> @@ -1834,9 +1833,7 @@ 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);
> -               printf("eMMC Firmware Version: %s\n", lbuf);
> +               printf("eMMC Firmware Version: %.8s\n",
> + (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
>                 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]);
>                 printf("eMMC Life Time Estimation B
> [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
> --
> 2.32.0

Re: [PATCH v4] mmc-utils: Use printf() to extract and print fw version

[Oleh Kravchenko]

Hello Avri!

30.11.21 09:42, Avri Altman пише:
> Hi,
>> This patch also fixes a compile error with a newer version of GCC:
>> error: '__builtin_strncpy' output may be truncated copying 8 bytes from a
>> string of length 511 [-Werror=stringop-truncation]
> You are reverting commit 0eea71e4f2 (mmc-utils: Fix for Firmware Version string printing).
> Please use git revert and add an explanation in your commit log.

I'm not reverting this commit.
It's similar but not.

>
> You might also would like to take a look at the correspondence concerning a different approach to the same issue here - https://lore.kernel.org/lkml/20211114204331.39555-2-huobean@gmail.com/

Thank you.
I didn't know that.

>
> Thanks,
> Avri
>
>> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
>> Reviewed-by: Bean Huo <beanhuo@micron.com>
>> ---
>>   mmc_cmds.c | 5 +----
>>   1 file changed, 1 insertion(+), 4 deletions(-)
>>
>> PATCH v4
>> Update commit message.
>>
>> diff --git a/mmc_cmds.c b/mmc_cmds.c
>> index 73bd32a..e07ec94 100644
>> --- a/mmc_cmds.c
>> +++ b/mmc_cmds.c
>> @@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
>>          __u32 regl;
>>          int fd, ret;
>>          char *device;
>> -       char lbuf[10];
>>          const char *str;
>>
>>          if (nargs != 2) {
>> @@ -1834,9 +1833,7 @@ 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);
>> -               printf("eMMC Firmware Version: %s\n", lbuf);
>> +               printf("eMMC Firmware Version: %.8s\n",
>> + (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
>>                  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]);
>>                  printf("eMMC Life Time Estimation B
>> [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
>> --
>> 2.32.0

Re: [PATCH v4] mmc-utils: Use printf() to extract and print fw version

[Ulf Hansson]

On Tue, 30 Nov 2021 at 13:07, Oleh Kravchenko <oleg@kaa.org.ua> wrote:
>
> Hello Avri!
>
> 30.11.21 09:42, Avri Altman пише:
> > Hi,
> >> This patch also fixes a compile error with a newer version of GCC:
> >> error: '__builtin_strncpy' output may be truncated copying 8 bytes from a
> >> string of length 511 [-Werror=stringop-truncation]
> > You are reverting commit 0eea71e4f2 (mmc-utils: Fix for Firmware Version string printing).
> > Please use git revert and add an explanation in your commit log.
>
> I'm not reverting this commit.
> It's similar but not.

Right, this time we limit the print to 8 chars, which avoids garbage
from a non-NULL terminated string.

Perhaps we should add (similar to what we do for kernel commits):
Fixes: 0eea71e4f22a ("mmc-utils: Fix for Firmware Version string printing")

[...]

Kind regards
Uffe

Re: [PATCH v4] mmc-utils: Use printf() to extract and print fw version

[Oleh Kravchenko]

Hello Ulf,

30.11.21 14:14, Ulf Hansson пише:
> On Tue, 30 Nov 2021 at 13:07, Oleh Kravchenko <oleg@kaa.org.ua> wrote:
>> Hello Avri!
>>
>> 30.11.21 09:42, Avri Altman пише:
>>> Hi,
>>>> This patch also fixes a compile error with a newer version of GCC:
>>>> error: '__builtin_strncpy' output may be truncated copying 8 bytes from a
>>>> string of length 511 [-Werror=stringop-truncation]
>>> You are reverting commit 0eea71e4f2 (mmc-utils: Fix for Firmware Version string printing).
>>> Please use git revert and add an explanation in your commit log.
>> I'm not reverting this commit.
>> It's similar but not.
> Right, this time we limit the print to 8 chars, which avoids garbage
> from a non-NULL terminated string.
>
> Perhaps we should add (similar to what we do for kernel commits):
> Fixes: 0eea71e4f22a ("mmc-utils: Fix for Firmware Version string printing")

Good point!

>
> [...]
>
> Kind regards
> Uffe

[PATCH v5] mmc-utils: Use printf() to extract and print fw version

[Oleh Kravchenko]

This patch also fixes a compile error with a newer version of GCC:
error: '__builtin_strncpy' output may be truncated copying 8 bytes from
a string of length 511 [-Werror=stringop-truncation]

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Fixes: 0eea71e4f22a (mmc-utils: Fix for Firmware Version string printing)
---
 mmc_cmds.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

PATCH v5
Updating commit message.
Adding Fixes: 0eea71e4f22a

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 73bd32a..e07ec94 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
 	__u32 regl;
 	int fd, ret;
 	char *device;
-	char lbuf[10];
 	const char *str;
 
 	if (nargs != 2) {
@@ -1834,9 +1833,7 @@ 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);
-		printf("eMMC Firmware Version: %s\n", lbuf);
+		printf("eMMC Firmware Version: %.8s\n", (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
 		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]);
 		printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
-- 
2.32.0

Re: [PATCH v5] mmc-utils: Use printf() to extract and print fw version

[Ulf Hansson]

On Tue, 30 Nov 2021 at 15:27, Oleh Kravchenko <oleg@kaa.org.ua> wrote:
>
> This patch also fixes a compile error with a newer version of GCC:
> error: '__builtin_strncpy' output may be truncated copying 8 bytes from
> a string of length 511 [-Werror=stringop-truncation]
>
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
> Reviewed-by: Bean Huo <beanhuo@micron.com>
> Fixes: 0eea71e4f22a (mmc-utils: Fix for Firmware Version string printing)

Applied to git.kernel.org/pub/scm/utils/mmc/mmc-utils.git master, thanks!

Kind regards
Uffe

> ---
>  mmc_cmds.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> PATCH v5
> Updating commit message.
> Adding Fixes: 0eea71e4f22a
>
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index 73bd32a..e07ec94 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1392,7 +1392,6 @@ int do_read_extcsd(int nargs, char **argv)
>         __u32 regl;
>         int fd, ret;
>         char *device;
> -       char lbuf[10];
>         const char *str;
>
>         if (nargs != 2) {
> @@ -1834,9 +1833,7 @@ 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);
> -               printf("eMMC Firmware Version: %s\n", lbuf);
> +               printf("eMMC Firmware Version: %.8s\n", (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION]);
>                 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]);
>                 printf("eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x%02x\n",
> --
> 2.32.0
>