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SubjectRe: [PATCH] perf callchain: Compare dsos (as well) for CCKEY_FUNCTION
Hi,

On Thu, Oct 05, 2017 at 09:20:21AM +0530, Ravi Bangoria wrote:
> Two functions from different binaries can have same start
> address. Thus, comparing only start address in match_chain()
> leads to inconsistent callchains. Fix this by adding a check
> for dsos as well.
>
> Ex, https://www.spinics.net/lists/linux-perf-users/msg04067.html
>
> Reported-by: Alexander Pozdneev <pozdneyev@gmail.com>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
> ---
> tools/perf/util/callchain.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
> index be09d77..6d7f645 100644
> --- a/tools/perf/util/callchain.c
> +++ b/tools/perf/util/callchain.c
> @@ -685,6 +685,9 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
> {
> struct symbol *sym = node->sym;
> u64 left, right;
> + struct dso *left_dso = NULL;
> + struct dso *right_dso = NULL;
> +
>
> if (callchain_param.key == CCKEY_SRCLINE) {
> enum match_result match = match_chain_srcline(node, cnode);
> @@ -696,12 +699,16 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
> if (cnode->ms.sym && sym && callchain_param.key == CCKEY_FUNCTION) {
> left = cnode->ms.sym->start;
> right = sym->start;
> + if (cnode->ms.map)
> + left_dso = cnode->ms.map->dso;
> + if (node->map)
> + right_dso = node->map->dso;

AFAIK having a symbol guarantees having a map too. So it could simply
be:

left_dso = cnode->ms.map->dso;
right_dso = node->map->dso;

Thanks,
Namhyung


> } else {
> left = cnode->ip;
> right = node->ip;
> }
>
> - if (left == right) {
> + if (left == right && left_dso == right_dso) {
> if (node->branch) {
> cnode->branch_count++;
>
> --
> 1.8.3.1
>
> --
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