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

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Date:   Thu, 19 Apr 2018 09:34:05 +0800
From:   Leo Yan <leo.yan@...aro.org>
To:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     Leo Yan <leo.yan@...aro.org>
Subject: [PATCH bpf-next 4/5] samples/bpf: Refine printing symbol for sampleip

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@...aro.org>
---
 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