| Message ID | 3de58159c6fde0cdfa4d0f292fa55fdb931cb3aa.1601913536.git.bertrand.marquis@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tools: solve gcc 10 compilation issues | expand |
On Mon, Oct 05, 2020 at 05:02:48PM +0100, Bertrand Marquis wrote: > Use memcpy in getBridge to prevent gcc warnings about truncated > strings. We know that we might truncate it, so the gcc warning > here is wrong. > Revert previous change changing buffer sizes as bigger buffers > are not needed. > > Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com> Juergen, are you happy with this change? I have not followed closely the discussion on #xendevel. > --- > tools/libs/stat/xenstat_linux.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c > index d2ee6fda64..1db35c604c 100644 > --- a/tools/libs/stat/xenstat_linux.c > +++ b/tools/libs/stat/xenstat_linux.c > @@ -78,7 +78,12 @@ static void getBridge(char *excludeName, char *result, size_t resultLen) > sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name); > > if (access(tmp, F_OK) == 0) { > - strncpy(result, de->d_name, resultLen); > + /* > + * Do not use strncpy to prevent compiler warning with > + * gcc >= 10.0 > + * If de->d_name is longer then resultLen we truncate it > + */ > + memcpy(result, de->d_name, resultLen - 1); > result[resultLen - 1] = 0; > } > } > @@ -264,7 +269,7 @@ int xenstat_collect_networks(xenstat_node * node) > { > /* Helper variables for parseNetDevLine() function defined above */ > int i; > - char line[512] = { 0 }, iface[16] = { 0 }, devBridge[256] = { 0 }, devNoBridge[257] = { 0 }; > + char line[512] = { 0 }, iface[16] = { 0 }, devBridge[16] = { 0 }, devNoBridge[17] = { 0 }; > unsigned long long rxBytes, rxPackets, rxErrs, rxDrops, txBytes, txPackets, txErrs, txDrops; > > struct priv_data *priv = get_priv_data(node->handle); > -- > 2.17.1 >
On 05.10.20 18:02, Bertrand Marquis wrote: > Use memcpy in getBridge to prevent gcc warnings about truncated > strings. We know that we might truncate it, so the gcc warning > here is wrong. > Revert previous change changing buffer sizes as bigger buffers > are not needed. > > Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com> > --- > tools/libs/stat/xenstat_linux.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c > index d2ee6fda64..1db35c604c 100644 > --- a/tools/libs/stat/xenstat_linux.c > +++ b/tools/libs/stat/xenstat_linux.c > @@ -78,7 +78,12 @@ static void getBridge(char *excludeName, char *result, size_t resultLen) > sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name); > > if (access(tmp, F_OK) == 0) { > - strncpy(result, de->d_name, resultLen); > + /* > + * Do not use strncpy to prevent compiler warning with > + * gcc >= 10.0 > + * If de->d_name is longer then resultLen we truncate it > + */ > + memcpy(result, de->d_name, resultLen - 1); I think you want min(NAME_MAX, resultLen - 1) for the length. Juergen
> On 6 Oct 2020, at 05:34, Jürgen Groß <jgross@suse.com> wrote: > > On 05.10.20 18:02, Bertrand Marquis wrote: >> Use memcpy in getBridge to prevent gcc warnings about truncated >> strings. We know that we might truncate it, so the gcc warning >> here is wrong. >> Revert previous change changing buffer sizes as bigger buffers >> are not needed. >> Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com> >> --- >> tools/libs/stat/xenstat_linux.c | 9 +++++++-- >> 1 file changed, 7 insertions(+), 2 deletions(-) >> diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c >> index d2ee6fda64..1db35c604c 100644 >> --- a/tools/libs/stat/xenstat_linux.c >> +++ b/tools/libs/stat/xenstat_linux.c >> @@ -78,7 +78,12 @@ static void getBridge(char *excludeName, char *result, size_t resultLen) >> sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name); >> if (access(tmp, F_OK) == 0) { >> - strncpy(result, de->d_name, resultLen); >> + /* >> + * Do not use strncpy to prevent compiler warning with >> + * gcc >= 10.0 >> + * If de->d_name is longer then resultLen we truncate it >> + */ >> + memcpy(result, de->d_name, resultLen - 1); > > I think you want min(NAME_MAX, resultLen - 1) for the length. true, I will fix that and send a v2. Cheers Bertrand
On 06.10.20 09:51, Bertrand Marquis wrote: > > >> On 6 Oct 2020, at 05:34, Jürgen Groß <jgross@suse.com> wrote: >> >> On 05.10.20 18:02, Bertrand Marquis wrote: >>> Use memcpy in getBridge to prevent gcc warnings about truncated >>> strings. We know that we might truncate it, so the gcc warning >>> here is wrong. >>> Revert previous change changing buffer sizes as bigger buffers >>> are not needed. >>> Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com> >>> --- >>> tools/libs/stat/xenstat_linux.c | 9 +++++++-- >>> 1 file changed, 7 insertions(+), 2 deletions(-) >>> diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c >>> index d2ee6fda64..1db35c604c 100644 >>> --- a/tools/libs/stat/xenstat_linux.c >>> +++ b/tools/libs/stat/xenstat_linux.c >>> @@ -78,7 +78,12 @@ static void getBridge(char *excludeName, char *result, size_t resultLen) >>> sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name); >>> if (access(tmp, F_OK) == 0) { >>> - strncpy(result, de->d_name, resultLen); >>> + /* >>> + * Do not use strncpy to prevent compiler warning with >>> + * gcc >= 10.0 >>> + * If de->d_name is longer then resultLen we truncate it >>> + */ >>> + memcpy(result, de->d_name, resultLen - 1); >> >> I think you want min(NAME_MAX, resultLen - 1) for the length. > > true, I will fix that and send a v2. Hmm, maybe you should use min(strnlen(de->d_name, NAME_MAX), resultLen - 1) for the case that de->d_name is near the end of a page, as otherwise you could try to copy unallocated space. Juergen
Hi Jurgen, > On 6 Oct 2020, at 09:19, Jürgen Groß <jgross@suse.com> wrote: > > On 06.10.20 09:51, Bertrand Marquis wrote: >>> On 6 Oct 2020, at 05:34, Jürgen Groß <jgross@suse.com> wrote: >>> >>> On 05.10.20 18:02, Bertrand Marquis wrote: >>>> Use memcpy in getBridge to prevent gcc warnings about truncated >>>> strings. We know that we might truncate it, so the gcc warning >>>> here is wrong. >>>> Revert previous change changing buffer sizes as bigger buffers >>>> are not needed. >>>> Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com> >>>> --- >>>> tools/libs/stat/xenstat_linux.c | 9 +++++++-- >>>> 1 file changed, 7 insertions(+), 2 deletions(-) >>>> diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c >>>> index d2ee6fda64..1db35c604c 100644 >>>> --- a/tools/libs/stat/xenstat_linux.c >>>> +++ b/tools/libs/stat/xenstat_linux.c >>>> @@ -78,7 +78,12 @@ static void getBridge(char *excludeName, char *result, size_t resultLen) >>>> sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name); >>>> if (access(tmp, F_OK) == 0) { >>>> - strncpy(result, de->d_name, resultLen); >>>> + /* >>>> + * Do not use strncpy to prevent compiler warning with >>>> + * gcc >= 10.0 >>>> + * If de->d_name is longer then resultLen we truncate it >>>> + */ >>>> + memcpy(result, de->d_name, resultLen - 1); >>> >>> I think you want min(NAME_MAX, resultLen - 1) for the length. >> true, I will fix that and send a v2. > > Hmm, maybe you should use > > min(strnlen(de->d_name, NAME_MAX), resultLen - 1) > > for the case that de->d_name is near the end of a page, as otherwise > you could try to copy unallocated space. > Agree, I will do that. Cheers Bertrand
diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c index d2ee6fda64..1db35c604c 100644 --- a/tools/libs/stat/xenstat_linux.c +++ b/tools/libs/stat/xenstat_linux.c @@ -78,7 +78,12 @@ static void getBridge(char *excludeName, char *result, size_t resultLen) sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name); if (access(tmp, F_OK) == 0) { - strncpy(result, de->d_name, resultLen); + /* + * Do not use strncpy to prevent compiler warning with + * gcc >= 10.0 + * If de->d_name is longer then resultLen we truncate it + */ + memcpy(result, de->d_name, resultLen - 1); result[resultLen - 1] = 0; } } @@ -264,7 +269,7 @@ int xenstat_collect_networks(xenstat_node * node) { /* Helper variables for parseNetDevLine() function defined above */ int i; - char line[512] = { 0 }, iface[16] = { 0 }, devBridge[256] = { 0 }, devNoBridge[257] = { 0 }; + char line[512] = { 0 }, iface[16] = { 0 }, devBridge[16] = { 0 }, devNoBridge[17] = { 0 }; unsigned long long rxBytes, rxPackets, rxErrs, rxDrops, txBytes, txPackets, txErrs, txDrops; struct priv_data *priv = get_priv_data(node->handle);
Use memcpy in getBridge to prevent gcc warnings about truncated strings. We know that we might truncate it, so the gcc warning here is wrong. Revert previous change changing buffer sizes as bigger buffers are not needed. Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com> --- tools/libs/stat/xenstat_linux.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)