Re: [PATCH] perf tests: Fix false TEST_OK result for 'perf test hist'

From: Jiri Olsa
Date: Tue Dec 15 2015 - 03:01:14 EST


On Tue, Dec 15, 2015 at 04:18:44AM +0000, Wang Nan wrote:
> Commit 71d6de64feddd4b455555326fba2111b3006d9e0 ('perf test: Fix hist
> testcases when kptr_restrict is on') solves a double free problem when
> 'perf test hist' calling setup_fake_machine(). However, the result is
> still incorrect. For example:
>
> $ ./perf test -v 'filtering hist entries'
> 25: Test filtering hist entries :
> --- start ---
> test child forked, pid 4186
> Cannot create kernel maps
> test child finished with 0
> ---- end ----
> Test filtering hist entries: Ok
>
> In this case the body of this test is not get executed at all, but the
> result is 'Ok'. I think 'Skip' should be better.
>
> The reason is that *ALL* hists test cases forget to reset err after
> using it to hold an error code.
>
> This patch ensure err is reset.
>
> In case when kptr_restrict prevent normal user get kernel address, this
> test should be skipped, not fail. This patch uses linux/err.h to store
> error code in return value of setup_fake_machine(), and let 'EACCES' to
> indicate this problem.
>
> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka
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