Hi Steven and Fengguang, (2012/08/25 10:00), Steven Rostedt wrote: > On Fri, 2012-08-24 at 09:41 -0400, Steven Rostedt wrote: > >> On Fri, 2012-08-24 at 15:15 +0800, Fengguang Wu wrote: >>> Hi Steven, >>> >>> The following test fails are mostly due to this commit, or one of the >>> last 4 commits in >>> >>> tree: >>> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git >>> tip/perf/core >>> head: d57c5d51a30152f3175d2344cb6395f08bf8ee0c >>> commit: d57c5d51a30152f3175d2344cb6395f08bf8ee0c [100/100] ftrace/x86: Add >>> support for -mfentry to x86_64 >>> >>> [ 9.084881] Kprobe smoke test failed: register_jprobe returned -22 >>> [ 9.086786] Kprobe smoke test failed: register_jprobes returned -22 > > Masami, > > Seems that when we use fentry, we break jprobes. I thought the patches > that we added would just move the call to the next op, not fail totally?
Ah! yes, it would be kprobe-side problem. Since ftrace_regs_call allows handlers to set regs->ip, it is not necessarily to move jprobe onto the next instruction (even it will be the simplest one). Instead, I think we can allow it on ftrace entries. Of course, ftrace side change is also needed, e.g. sorting handlers for moving such ip-modifying handler to the last. Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
