Message ID | 1432897445.7456.76.camel@edumazet-glaptop2.roam.corp.google.com |
---|---|
State | Accepted, archived |
Delegated to: | stephen hemminger |
Headers | show |
On 05/29/2015 01:04 PM, Eric Dumazet wrote: ... > I doubt TCP_CA_NAME_MAX will ever change in the kernel : 16 bytes. > > Its typically "cubic" and less than 8 bytes. > > Using 8 bytes to point to a malloc(8) is a waste. > > Please remove the memory allocation, or store the pointer, since > tcp_show_info() does the malloc()/free() before return. +1, much better -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, May 29, 2015 at 04:04:05AM -0700, Eric Dumazet wrote: > On Fri, 2015-05-29 at 13:30 +0300, Vadim Kochan wrote: > > From: Vadim Kochan <vadim4j@gmail.com> > > > > Use strdup instead of malloc, and get rid of bad strcpy. > > > > Signed-off-by: Vadim Kochan <vadim4j@gmail.com> > > --- > > misc/ss.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/misc/ss.c b/misc/ss.c > > index 347e3a1..a719466 100644 > > --- a/misc/ss.c > > +++ b/misc/ss.c > > @@ -1908,8 +1908,7 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r, > > > > if (tb[INET_DIAG_CONG]) { > > const char *cong_attr = rta_getattr_str(tb[INET_DIAG_CONG]); > > - s.cong_alg = malloc(strlen(cong_attr + 1)); > > - strcpy(s.cong_alg, cong_attr); > > + s.cong_alg = strdup(cong_attr); > > } > > > > if (TCPI_HAS_OPT(info, TCPI_OPT_WSCALE)) { > > I doubt TCP_CA_NAME_MAX will ever change in the kernel : 16 bytes. > > Its typically "cubic" and less than 8 bytes. > > Using 8 bytes to point to a malloc(8) is a waste. > > Please remove the memory allocation, or store the pointer, since > tcp_show_info() does the malloc()/free() before return. > > diff --git a/misc/ss.c b/misc/ss.c > index 347e3a1..9fe229f 100644 > --- a/misc/ss.c > +++ b/misc/ss.c > @@ -755,7 +755,7 @@ struct tcpstat > int timer; > int timeout; > int probes; > - char *cong_alg; > + char cong_alg[16]; > double rto, ato, rtt, rttvar; > int qack, cwnd, ssthresh, backoff; > double send_bps; > @@ -1664,7 +1664,7 @@ static void tcp_stats_print(struct tcpstat *s) > printf(" ecnseen"); > if (s->has_fastopen_opt) > printf(" fastopen"); > - if (s->cong_alg) > + if (s->cong_alg[0]) > printf(" %s", s->cong_alg); > if (s->has_wscale_opt) > printf(" wscale:%d,%d", s->snd_wscale, s->rcv_wscale); > @@ -1906,11 +1906,10 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r, > s.has_fastopen_opt = TCPI_HAS_OPT(info, TCPI_OPT_SYN_DATA); > } > > - if (tb[INET_DIAG_CONG]) { > - const char *cong_attr = rta_getattr_str(tb[INET_DIAG_CONG]); > - s.cong_alg = malloc(strlen(cong_attr + 1)); > - strcpy(s.cong_alg, cong_attr); > - } > + if (tb[INET_DIAG_CONG]) > + strncpy(s.cong_alg, > + rta_getattr_str(tb[INET_DIAG_CONG]), > + sizeof(s.cong_alg) - 1); > > if (TCPI_HAS_OPT(info, TCPI_OPT_WSCALE)) { > s.has_wscale_opt = true; > @@ -1984,8 +1983,6 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r, > tcp_stats_print(&s); > if (s.dctcp) > free(s.dctcp); > - if (s.cong_alg) > - free(s.cong_alg); > } > } > > > Thanks! Should I put you in "From" tag or in "Signed-off-by" ? Or your diff might be used from this email thread ? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2015-05-29 at 15:53 +0300, Vadim Kochan wrote: > Thanks! > > Should I put you in "From" tag or in "Signed-off-by" ? > Or your diff might be used from this email thread ? Don't worry, just submit the patch officially on your own ;) Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/misc/ss.c b/misc/ss.c index 347e3a1..9fe229f 100644 --- a/misc/ss.c +++ b/misc/ss.c @@ -755,7 +755,7 @@ struct tcpstat int timer; int timeout; int probes; - char *cong_alg; + char cong_alg[16]; double rto, ato, rtt, rttvar; int qack, cwnd, ssthresh, backoff; double send_bps; @@ -1664,7 +1664,7 @@ static void tcp_stats_print(struct tcpstat *s) printf(" ecnseen"); if (s->has_fastopen_opt) printf(" fastopen"); - if (s->cong_alg) + if (s->cong_alg[0]) printf(" %s", s->cong_alg); if (s->has_wscale_opt) printf(" wscale:%d,%d", s->snd_wscale, s->rcv_wscale); @@ -1906,11 +1906,10 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r, s.has_fastopen_opt = TCPI_HAS_OPT(info, TCPI_OPT_SYN_DATA); } - if (tb[INET_DIAG_CONG]) { - const char *cong_attr = rta_getattr_str(tb[INET_DIAG_CONG]); - s.cong_alg = malloc(strlen(cong_attr + 1)); - strcpy(s.cong_alg, cong_attr); - } + if (tb[INET_DIAG_CONG]) + strncpy(s.cong_alg, + rta_getattr_str(tb[INET_DIAG_CONG]), + sizeof(s.cong_alg) - 1); if (TCPI_HAS_OPT(info, TCPI_OPT_WSCALE)) { s.has_wscale_opt = true; @@ -1984,8 +1983,6 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r, tcp_stats_print(&s); if (s.dctcp) free(s.dctcp); - if (s.cong_alg) - free(s.cong_alg); } }