hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
Also added 'static' for the array 'desc[]'.
Fixes: 82b0945ce2c2 ("tools: hv: Add new fcopy application based on uio driver") Cc: stable@vger.kernel.org # 6.10+ Signed-off-by: Dexuan Cui decui@microsoft.com --- tools/hv/hv_fcopy_uio_daemon.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c index 3ce316cc9f97..f7741af08a79 100644 --- a/tools/hv/hv_fcopy_uio_daemon.c +++ b/tools/hv/hv_fcopy_uio_daemon.c @@ -35,8 +35,6 @@ #define WIN8_SRV_MINOR 1 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
-#define MAX_FOLDER_NAME 15 -#define MAX_PATH_LEN 15 #define FCOPY_UIO "/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/uio"
#define FCOPY_VER_COUNT 1 @@ -51,7 +49,7 @@ static const int fw_versions[] = {
#define HV_RING_SIZE 0x4000 /* 16KB ring buffer size */
-unsigned char desc[HV_RING_SIZE]; +static unsigned char desc[HV_RING_SIZE];
static int target_fd; static char target_fname[PATH_MAX]; @@ -402,8 +400,8 @@ int main(int argc, char *argv[]) struct vmbus_br txbr, rxbr; void *ring; uint32_t len = HV_RING_SIZE; - char uio_name[MAX_FOLDER_NAME] = {0}; - char uio_dev_path[MAX_PATH_LEN] = {0}; + char uio_name[NAME_MAX] = {0}; + char uio_dev_path[PATH_MAX] = {0};
static struct option long_options[] = { {"help", no_argument, 0, 'h' },
On Tue, Sep 10, 2024 at 12:44:32AM +0000, Dexuan Cui wrote:
hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
Makefile today doesn't have -Wformat-truncation flag enabled, I tried to add -Wformat-truncation=2 but I don't see any error in this file.
Do you mind sharing more details how you get this error ?
- Saurabh
From: Saurabh Singh Sengar ssengar@linux.microsoft.com Sent: Friday, September 13, 2024 12:31 AM To: Dexuan Cui decui@microsoft.com Cc: KY Srinivasan kys@microsoft.com; Haiyang Zhang haiyangz@microsoft.com; Wei Liu wei.liu@kernel.org; Long Li longli@microsoft.com; Greg Kroah-Hartman gregkh@linuxfoundation.org; open list:Hyper-V/Azure CORE AND DRIVERS linux-hyperv@vger.kernel.org; open list linux-kernel@vger.kernel.org; stable@vger.kernel.org Subject: Re: [PATCH] tools: hv: Fix a complier warning in the fcopy uio daemon
On Tue, Sep 10, 2024 at 12:44:32AM +0000, Dexuan Cui wrote:
hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be
truncated
writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s",
uio_name);
Makefile today doesn't have -Wformat-truncation flag enabled, I tried to add -Wformat-truncation=2 but I don't see any error in this file.
Do you mind sharing more details how you get this error ?
- Saurabh
This repros in a Ubuntu 20.04 VM:
root@decui-u2004-2024-0920:~/linux/tools/hv# cat /etc/os-release NAME="Ubuntu" VERSION="20.04.6 LTS (Focal Fossa)" ...
root@decui-u2004-2024-0920:~/linux/tools/hv# gcc --version gcc (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0 Copyright (C) 2019 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
root@decui-u2004-2024-0920:~/linux/tools/hv# make clean; make ... make -f /root/linux/tools/build/Makefile.build dir=. obj=hv_fcopy_uio_daemon make[1]: Entering directory '/root/linux/tools/hv' CC hv_fcopy_uio_daemon.o hv_fcopy_uio_daemon.c: In function 'main': hv_fcopy_uio_daemon.c:443:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 443 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name); | ^~ ~~~~~~~~ In file included from /usr/include/stdio.h:867, from hv_fcopy_uio_daemon.c:20: /usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output between 6 and 20 bytes into a destination of size 15 67 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 68 | __bos (__s), __fmt, __va_arg_pack ()); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ CC vmbus_bufring.o LD hv_fcopy_uio_daemon-in.o make[1]: Leaving directory '/root/linux/tools/hv' LINK hv_fcopy_uio_daemon
On Sat, Sep 21, 2024 at 01:23:09AM +0000, Dexuan Cui wrote:
From: Saurabh Singh Sengar ssengar@linux.microsoft.com Sent: Friday, September 13, 2024 12:31 AM To: Dexuan Cui decui@microsoft.com Cc: KY Srinivasan kys@microsoft.com; Haiyang Zhang haiyangz@microsoft.com; Wei Liu wei.liu@kernel.org; Long Li longli@microsoft.com; Greg Kroah-Hartman gregkh@linuxfoundation.org; open list:Hyper-V/Azure CORE AND DRIVERS linux-hyperv@vger.kernel.org; open list linux-kernel@vger.kernel.org; stable@vger.kernel.org Subject: Re: [PATCH] tools: hv: Fix a complier warning in the fcopy uio daemon
On Tue, Sep 10, 2024 at 12:44:32AM +0000, Dexuan Cui wrote:
hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be
truncated
writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s",
uio_name);
Makefile today doesn't have -Wformat-truncation flag enabled, I tried to add -Wformat-truncation=2 but I don't see any error in this file.
Do you mind sharing more details how you get this error ?
- Saurabh
This repros in a Ubuntu 20.04 VM:
root@decui-u2004-2024-0920:~/linux/tools/hv# cat /etc/os-release NAME="Ubuntu" VERSION="20.04.6 LTS (Focal Fossa)" ...
root@decui-u2004-2024-0920:~/linux/tools/hv# gcc --version gcc (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0 Copyright (C) 2019 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
root@decui-u2004-2024-0920:~/linux/tools/hv# make clean; make ... make -f /root/linux/tools/build/Makefile.build dir=. obj=hv_fcopy_uio_daemon make[1]: Entering directory '/root/linux/tools/hv' CC hv_fcopy_uio_daemon.o hv_fcopy_uio_daemon.c: In function 'main': hv_fcopy_uio_daemon.c:443:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 443 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name); | ^~ ~~~~~~~~ In file included from /usr/include/stdio.h:867, from hv_fcopy_uio_daemon.c:20: /usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output between 6 and 20 bytes into a destination of size 15 67 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 68 | __bos (__s), __fmt, __va_arg_pack ()); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ CC vmbus_bufring.o LD hv_fcopy_uio_daemon-in.o make[1]: Leaving directory '/root/linux/tools/hv' LINK hv_fcopy_uio_daemon
Thanks for the details. Looks this is the behaviour of old gcc versions. How about fixing it like this :
--- a/tools/hv/hv_fcopy_uio_daemon.c +++ b/tools/hv/hv_fcopy_uio_daemon.c @@ -35,7 +35,7 @@ #define WIN8_SRV_MINOR 1 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
-#define MAX_FOLDER_NAME 15 +#define MAX_FOLDER_NAME 10 #define MAX_PATH_LEN 15
- Saurabh
On Tue, Sep 24, 2024 at 11:22:50AM -0700, Saurabh Singh Sengar wrote:
On Sat, Sep 21, 2024 at 01:23:09AM +0000, Dexuan Cui wrote:
From: Saurabh Singh Sengar ssengar@linux.microsoft.com Sent: Friday, September 13, 2024 12:31 AM To: Dexuan Cui decui@microsoft.com Cc: KY Srinivasan kys@microsoft.com; Haiyang Zhang haiyangz@microsoft.com; Wei Liu wei.liu@kernel.org; Long Li longli@microsoft.com; Greg Kroah-Hartman gregkh@linuxfoundation.org; open list:Hyper-V/Azure CORE AND DRIVERS linux-hyperv@vger.kernel.org; open list linux-kernel@vger.kernel.org; stable@vger.kernel.org Subject: Re: [PATCH] tools: hv: Fix a complier warning in the fcopy uio daemon
On Tue, Sep 10, 2024 at 12:44:32AM +0000, Dexuan Cui wrote:
hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be
truncated
writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s",
uio_name);
Makefile today doesn't have -Wformat-truncation flag enabled, I tried to add -Wformat-truncation=2 but I don't see any error in this file.
Do you mind sharing more details how you get this error ?
- Saurabh
This repros in a Ubuntu 20.04 VM:
root@decui-u2004-2024-0920:~/linux/tools/hv# cat /etc/os-release NAME="Ubuntu" VERSION="20.04.6 LTS (Focal Fossa)" ...
root@decui-u2004-2024-0920:~/linux/tools/hv# gcc --version gcc (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0 Copyright (C) 2019 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
root@decui-u2004-2024-0920:~/linux/tools/hv# make clean; make ... make -f /root/linux/tools/build/Makefile.build dir=. obj=hv_fcopy_uio_daemon make[1]: Entering directory '/root/linux/tools/hv' CC hv_fcopy_uio_daemon.o hv_fcopy_uio_daemon.c: In function 'main': hv_fcopy_uio_daemon.c:443:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 443 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name); | ^~ ~~~~~~~~ In file included from /usr/include/stdio.h:867, from hv_fcopy_uio_daemon.c:20: /usr/include/x86_64-linux-gnu/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output between 6 and 20 bytes into a destination of size 15 67 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 68 | __bos (__s), __fmt, __va_arg_pack ()); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ CC vmbus_bufring.o LD hv_fcopy_uio_daemon-in.o make[1]: Leaving directory '/root/linux/tools/hv' LINK hv_fcopy_uio_daemon
Thanks for the details. Looks this is the behaviour of old gcc versions. How about fixing it like this :
--- a/tools/hv/hv_fcopy_uio_daemon.c +++ b/tools/hv/hv_fcopy_uio_daemon.c @@ -35,7 +35,7 @@ #define WIN8_SRV_MINOR 1 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
-#define MAX_FOLDER_NAME 15 +#define MAX_FOLDER_NAME 10 #define MAX_PATH_LEN 15
Had a offline discussion with Dexuan. The above suggested approach saves few bytes of userspace memory, using standard macros for path and folder length would be preferable for better code readability
Please add, Reviewed-by: Saurabh Sengar ssengar@linux.microsoft.com
- Saurabh
On Tue, Sep 10, 2024 at 12:44:32AM +0000, Dexuan Cui wrote:
hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
Also added 'static' for the array 'desc[]'.
Fixes: 82b0945ce2c2 ("tools: hv: Add new fcopy application based on uio driver") Cc: stable@vger.kernel.org # 6.10+ Signed-off-by: Dexuan Cui decui@microsoft.com
Applied to hyperv-fixes. Thanks.
linux-stable-mirror@lists.linaro.org
-
Dexuan Cui -
Saurabh Singh Sengar -
Wei Liu