| Message ID | 1383845166.3401.77.camel@linaro1.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11/07/13 12:26, Jon Medhurst (Tixy) wrote: > On Tue, 2013-10-15 at 17:04 -0400, David Long wrote: >> From: "David A. Long" <dave.long@linaro.org> >> >> jprobe kernel selftests are not supported for thumb kernels. Conditionally >> disable them in the kernel kprobes-test module. > > I don't think it's fair to say they aren't supported, it's just that the > implementation of jprobes and/or symbol lookup has bugs on Thumb kernels > which the test code is finding, see > http://lists.infradead.org/pipermail/linux-arm-kernel/2011-August/063026.html > > Note, the current code works OK if the function being probed is in a > loadable module (which is why I didn't spot the problem when doing the > original Thumb kprobes work). > > Now I admit that having the tests always bombing out because of this > hinders testing of kprobes, but simply disabling the test is just > burying this long standing problem even more. So what do people think > about something like the change below, to let other tests get run but > make the overall test still fail...? > > --- a/arch/arm/kernel/kprobes-test.c > +++ b/arch/arm/kernel/kprobes-test.c > @@ -221,6 +221,7 @@ static int pre_handler_called; > static int post_handler_called; > static int jprobe_func_called; > static int kretprobe_handler_called; > +static int tests_failed; > > #define FUNC_ARG1 0x12345678 > #define FUNC_ARG2 0xabcdef > @@ -457,6 +458,13 @@ static int run_api_tests(long (*func)(long, long)) > > pr_info(" jprobe\n"); > ret = test_jprobe(func); > +#if defined(CONFIG_THUMB2_KERNEL) && !defined(MODULE) > + if (ret == -EINVAL) { > + pr_err("FAIL: Known longtime bug with jprobe on Thumb kernels"); > + tests_failed = ret; > + ret = 0; > + } > +#endif > if (ret < 0) > return ret; > > @@ -1667,6 +1675,8 @@ static int __init run_all_tests(void) > > out: > if (ret == 0) > + ret = tests_failed; > + if (ret == 0) > pr_info("Finished kprobe tests OK\n"); > else > pr_err("kprobe tests failed\n"); > > > > Thanks for clarifying the problem Tixy. I agree we should try and allow the tests to run for these more typical use cases where they do actually work. I have tested your patch and I will use it in place of mine unless there are strong objections. -dl
--- a/arch/arm/kernel/kprobes-test.c +++ b/arch/arm/kernel/kprobes-test.c @@ -221,6 +221,7 @@ static int pre_handler_called; static int post_handler_called; static int jprobe_func_called; static int kretprobe_handler_called; +static int tests_failed; #define FUNC_ARG1 0x12345678 #define FUNC_ARG2 0xabcdef @@ -457,6 +458,13 @@ static int run_api_tests(long (*func)(long, long)) pr_info(" jprobe\n"); ret = test_jprobe(func); +#if defined(CONFIG_THUMB2_KERNEL) && !defined(MODULE) + if (ret == -EINVAL) { + pr_err("FAIL: Known longtime bug with jprobe on Thumb kernels"); + tests_failed = ret; + ret = 0; + } +#endif if (ret < 0) return ret; @@ -1667,6 +1675,8 @@ static int __init run_all_tests(void) out: if (ret == 0) + ret = tests_failed; + if (ret == 0) pr_info("Finished kprobe tests OK\n"); else pr_err("kprobe tests failed\n");