lkml.org 
[lkml]   [2018]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH bpf-next 4/5] samples/bpf: Refine printing symbol for sampleip
    On Thu, Apr 19, 2018 at 09:34:05AM +0800, Leo Yan wrote:
    > 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@linaro.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);

    yes. it is x64 specific, since it's a sample code,
    but simply removing it is not a fix.
    It makes this sampleip code behaving incorrectly.
    To do such 'cleanup of ksym' please refactor it in the true generic way,
    so these ksym* helpers can work on all archs and put this new
    functionality into selftests.
    If you can convert these examples into proper self-checking tests
    that run out of selftests that would be awesome.
    Thanks!

    \
     
     \ /
      Last update: 2018-04-19 06:48    [W:3.823 / U:0.204 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site