[PATCH bpf-next 4/5] samples/bpf: Refine printing symbol for sampleip

From: Leo Yan
Date: Wed Apr 18 2018 - 21:34:44 EST


The code defines macro 'PAGE_OFFSET' and uses it to decide if the
address is in kernel space or not. But different architecture has
different 'PAGE_OFFSET' so this program cannot be used for all
platforms.

This commit changes to check returned pointer from ksym_search() to
judge if the address falls into kernel space or not, and removes
macro 'PAGE_OFFSET' as it isn't used anymore. As result, this program
has no architecture dependency.

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
samples/bpf/sampleip_user.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c
index 4ed690b..0eea1b3 100644
--- a/samples/bpf/sampleip_user.c
+++ b/samples/bpf/sampleip_user.c
@@ -26,7 +26,6 @@
#define DEFAULT_FREQ 99
#define DEFAULT_SECS 5
#define MAX_IPS 8192
-#define PAGE_OFFSET 0xffff880000000000

static int nr_cpus;

@@ -107,14 +106,13 @@ static void print_ip_map(int fd)
/* sort and print */
qsort(counts, max, sizeof(struct ipcount), count_cmp);
for (i = 0; i < max; i++) {
- if (counts[i].ip > PAGE_OFFSET) {
- sym = ksym_search(counts[i].ip);
+ sym = ksym_search(counts[i].ip);
+ if (sym)
printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name,
counts[i].count);
- } else {
+ else
printf("0x%-17llx %-32s %u\n", counts[i].ip, "(user)",
counts[i].count);
- }
}

if (max == MAX_IPS) {
--
1.9.1