Hello,
This patchset fixes trivial things that I found
when testing 'samples/bpf/' sample code.
I'd appreciate it, if you review this.
Thanks,
Taeung
Taeung Song (4):
samples/bpf: add missing <linux/if_vlan.h>
samples/bpf: Check the result of system()
samples/bpf: Check the error of write() and read()
samples/bpf: add .gitignore file
samples/bpf/.gitignore | 49 ++++++++++++++++++++++++++++++++++++++++
samples/bpf/parse_varlen.c | 6 +----
samples/bpf/test_overhead_user.c | 20 ++++++++++++----
samples/bpf/trace_event_user.c | 27 +++++++++++++++++++---
4 files changed, 89 insertions(+), 13 deletions(-)
create mode 100644 samples/bpf/.gitignore
--
2.7.4
This fixes build error regarding redefinition:
CLANG-bpf samples/bpf/parse_varlen.o
samples/bpf/parse_varlen.c:111:8: error: redefinition of 'vlan_hdr'
struct vlan_hdr {
^
./include/linux/if_vlan.h:38:8: note: previous definition is here
So remove duplicate 'struct vlan_hdr' in sample code and include if_vlan.h
Signed-off-by: Taeung Song <[email protected]>
---
samples/bpf/parse_varlen.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/samples/bpf/parse_varlen.c b/samples/bpf/parse_varlen.c
index 95c1632..0b6f22f 100644
--- a/samples/bpf/parse_varlen.c
+++ b/samples/bpf/parse_varlen.c
@@ -6,6 +6,7 @@
*/
#define KBUILD_MODNAME "foo"
#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/in.h>
@@ -108,11 +109,6 @@ static int parse_ipv6(void *data, uint64_t nh_off, void *data_end)
return 0;
}
-struct vlan_hdr {
- uint16_t h_vlan_TCI;
- uint16_t h_vlan_encapsulated_proto;
-};
-
SEC("varlen")
int handle_ingress(struct __sk_buff *skb)
{
--
2.7.4
To avoid the below build warning message,
use new generate_load() checking the return value.
ignoring return value of ‘system’, declared with attribute warn_unused_result
And it also refactors the duplicate code of both
test_perf_event_all_cpu() and test_perf_event_task()
Cc: Teng Qin <[email protected]>
Signed-off-by: Taeung Song <[email protected]>
---
samples/bpf/trace_event_user.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
index 1fa1bec..d08046ab8 100644
--- a/samples/bpf/trace_event_user.c
+++ b/samples/bpf/trace_event_user.c
@@ -122,6 +122,16 @@ static void print_stacks(void)
}
}
+static inline int generate_load(void)
+{
+ if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
+ printf("failed to generate some load with dd: %s\n", strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
static void test_perf_event_all_cpu(struct perf_event_attr *attr)
{
int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
@@ -142,7 +152,11 @@ static void test_perf_event_all_cpu(struct perf_event_attr *attr)
assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0);
}
- system("dd if=/dev/zero of=/dev/null count=5000k status=none");
+
+ if (generate_load() < 0) {
+ error = 1;
+ goto all_cpu_err;
+ }
print_stacks();
all_cpu_err:
for (i--; i >= 0; i--) {
@@ -156,7 +170,7 @@ static void test_perf_event_all_cpu(struct perf_event_attr *attr)
static void test_perf_event_task(struct perf_event_attr *attr)
{
- int pmu_fd;
+ int pmu_fd, error = 0;
/* per task perf event, enable inherit so the "dd ..." command can be traced properly.
* Enabling inherit will cause bpf_perf_prog_read_time helper failure.
@@ -171,10 +185,17 @@ static void test_perf_event_task(struct perf_event_attr *attr)
}
assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0);
- system("dd if=/dev/zero of=/dev/null count=5000k status=none");
+
+ if (generate_load() < 0) {
+ error = 1;
+ goto err;
+ }
print_stacks();
+err:
ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close(pmu_fd);
+ if (error)
+ int_exit(0);
}
static void test_bpf_perf_event(void)
--
2.7.4
test_task_rename() and test_urandom_read()
can be failed during write() and read(),
So check the result of them.
Signed-off-by: Taeung Song <[email protected]>
---
samples/bpf/test_overhead_user.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c
index 6caf47a..8a88d9c 100644
--- a/samples/bpf/test_overhead_user.c
+++ b/samples/bpf/test_overhead_user.c
@@ -6,6 +6,7 @@
*/
#define _GNU_SOURCE
#include <sched.h>
+#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <asm/unistd.h>
@@ -44,8 +45,12 @@ static void test_task_rename(int cpu)
exit(1);
}
start_time = time_get_ns();
- for (i = 0; i < MAX_CNT; i++)
- write(fd, buf, sizeof(buf));
+ for (i = 0; i < MAX_CNT; i++) {
+ if (write(fd, buf, sizeof(buf)) < 0) {
+ printf("task rename failed: %s\n", strerror(errno));
+ break;
+ }
+ }
printf("task_rename:%d: %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
close(fd);
@@ -55,7 +60,7 @@ static void test_urandom_read(int cpu)
{
__u64 start_time;
char buf[4];
- int i, fd;
+ int i, fd, err = 0;
fd = open("/dev/urandom", O_RDONLY);
if (fd < 0) {
@@ -63,8 +68,13 @@ static void test_urandom_read(int cpu)
exit(1);
}
start_time = time_get_ns();
- for (i = 0; i < MAX_CNT; i++)
- read(fd, buf, sizeof(buf));
+ for (i = 0; i < MAX_CNT; i++) {
+ err = read(fd, buf, sizeof(buf));
+ if (err < 0 || err >= sizeof(buf)) {
+ printf("failed to read from /dev/urandom: %s\n", strerror(errno));
+ break;
+ }
+ }
printf("urandom_read:%d: %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
close(fd);
--
2.7.4
From: Taeung Song
> Sent: 02 July 2018 10:15
> test_task_rename() and test_urandom_read()
> can be failed during write() and read(),
> So check the result of them.
>
> Signed-off-by: Taeung Song <[email protected]>
> ---
> samples/bpf/test_overhead_user.c | 20 +++++++++++++++-----
> 1 file changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c
> index 6caf47a..8a88d9c 100644
> --- a/samples/bpf/test_overhead_user.c
> +++ b/samples/bpf/test_overhead_user.c
> @@ -6,6 +6,7 @@
> */
> #define _GNU_SOURCE
> #include <sched.h>
> +#include <errno.h>
> #include <stdio.h>
> #include <sys/types.h>
> #include <asm/unistd.h>
> @@ -44,8 +45,12 @@ static void test_task_rename(int cpu)
> exit(1);
> }
> start_time = time_get_ns();
> - for (i = 0; i < MAX_CNT; i++)
> - write(fd, buf, sizeof(buf));
> + for (i = 0; i < MAX_CNT; i++) {
> + if (write(fd, buf, sizeof(buf)) < 0) {
> + printf("task rename failed: %s\n", strerror(errno));
> + break;
I'm not sure 'break' generates sensible output.
> + }
> + }
What about partial writes??
> printf("task_rename:%d: %lld events per sec\n",
> cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
> close(fd);
> @@ -55,7 +60,7 @@ static void test_urandom_read(int cpu)
> {
> __u64 start_time;
> char buf[4];
> - int i, fd;
> + int i, fd, err = 0;
>
> fd = open("/dev/urandom", O_RDONLY);
> if (fd < 0) {
> @@ -63,8 +68,13 @@ static void test_urandom_read(int cpu)
> exit(1);
> }
> start_time = time_get_ns();
> - for (i = 0; i < MAX_CNT; i++)
> - read(fd, buf, sizeof(buf));
> + for (i = 0; i < MAX_CNT; i++) {
> + err = read(fd, buf, sizeof(buf));
> + if (err < 0 || err >= sizeof(buf)) {
Overlong reads indicate that something is seriously awry.
Short reads are valid - but maybe not expected.
> + printf("failed to read from /dev/urandom: %s\n", strerror(errno));
strerror() won't give anything sensible unless err == -1;
You probably want to include the loop count.
> + break;
The summary print will be gibberish after break.
> + }
> + }
> printf("urandom_read:%d: %lld events per sec\n",
> cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
> close(fd);
> --
> 2.7.4
Hi David Laight,
On 07/02/2018 06:25 PM, David Laight wrote:
> From: Taeung Song
>> Sent: 02 July 2018 10:15
>> test_task_rename() and test_urandom_read()
>> can be failed during write() and read(),
>> So check the result of them.
>>
>> Signed-off-by: Taeung Song <[email protected]>
>> ---
>> samples/bpf/test_overhead_user.c | 20 +++++++++++++++-----
>> 1 file changed, 15 insertions(+), 5 deletions(-)
>>
>> diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c
>> index 6caf47a..8a88d9c 100644
>> --- a/samples/bpf/test_overhead_user.c
>> +++ b/samples/bpf/test_overhead_user.c
>> @@ -6,6 +6,7 @@
>> */
>> #define _GNU_SOURCE
>> #include <sched.h>
>> +#include <errno.h>
>> #include <stdio.h>
>> #include <sys/types.h>
>> #include <asm/unistd.h>
>> @@ -44,8 +45,12 @@ static void test_task_rename(int cpu)
>> exit(1);
>> }
>> start_time = time_get_ns();
>> - for (i = 0; i < MAX_CNT; i++)
>> - write(fd, buf, sizeof(buf));
>> + for (i = 0; i < MAX_CNT; i++) {
>> + if (write(fd, buf, sizeof(buf)) < 0) {
>> + printf("task rename failed: %s\n", strerror(errno));
>> + break;
>
> I'm not sure 'break' generates sensible output.
>
OK,
it seems to be better to off on the above error case instead of break;
>> + }
>> + }
>
> What about partial writes??
>
Hum..
do you mean just skipping several errors of the above write() ?
>> printf("task_rename:%d: %lld events per sec\n",
>> cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
>> close(fd);
>> @@ -55,7 +60,7 @@ static void test_urandom_read(int cpu)
>> {
>> __u64 start_time;
>> char buf[4];
>> - int i, fd;
>> + int i, fd, err = 0;
>>
>> fd = open("/dev/urandom", O_RDONLY);
>> if (fd < 0) {
>> @@ -63,8 +68,13 @@ static void test_urandom_read(int cpu)
>> exit(1);
>> }
>> start_time = time_get_ns();
>> - for (i = 0; i < MAX_CNT; i++)
>> - read(fd, buf, sizeof(buf));
>> + for (i = 0; i < MAX_CNT; i++) {
>> + err = read(fd, buf, sizeof(buf));
>> + if (err < 0 || err >= sizeof(buf)) {
>
> Overlong reads indicate that something is seriously awry.
> Short reads are valid - but maybe not expected.
>> + printf("failed to read from /dev/urandom: %s\n", strerror(errno));
>
>
> strerror() won't give anything sensible unless err == -1;
> You probably want to include the loop count.
>
>> + break;
>
> The summary print will be gibberish after break.
>
Ditto, will change the code to do exit(1);
on the err == -1 case.
What do you think about it ?
Thanks,
Taeung
>> + }
>> + }
>> printf("urandom_read:%d: %lld events per sec\n",
>> cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
>> close(fd);
>> --
>> 2.7.4
>
For untracked executables of samples/bpf, add this.
Untracked files:
(use "git add <file>..." to include in what will be committed)
samples/bpf/cpustat
samples/bpf/fds_example
samples/bpf/lathist
samples/bpf/load_sock_ops
...
Signed-off-by: Taeung Song <[email protected]>
---
samples/bpf/.gitignore | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
create mode 100644 samples/bpf/.gitignore
diff --git a/samples/bpf/.gitignore b/samples/bpf/.gitignore
new file mode 100644
index 0000000..8ae4940
--- /dev/null
+++ b/samples/bpf/.gitignore
@@ -0,0 +1,49 @@
+cpustat
+fds_example
+lathist
+load_sock_ops
+lwt_len_hist
+map_perf_test
+offwaketime
+per_socket_stats_example
+sampleip
+sock_example
+sockex1
+sockex2
+sockex3
+spintest
+syscall_nrs.h
+syscall_tp
+task_fd_query
+tc_l2_redirect
+test_cgrp2_array_pin
+test_cgrp2_attach
+test_cgrp2_attach2
+test_cgrp2_sock
+test_cgrp2_sock2
+test_current_task_under_cgroup
+test_lru_dist
+test_map_in_map
+test_overhead
+test_probe_write_user
+trace_event
+trace_output
+tracex1
+tracex2
+tracex3
+tracex4
+tracex5
+tracex6
+tracex7
+xdp1
+xdp2
+xdp_adjust_tail
+xdp_fwd
+xdp_monitor
+xdp_redirect
+xdp_redirect_cpu
+xdp_redirect_map
+xdp_router_ipv4
+xdp_rxq_info
+xdp_tx_iptunnel
+xdpsock
--
2.7.4