Hello All, this is core implementation of the uretprobes. This enables a breakpoint on function's return for the tools such as perf.
Introduce additional handler* for uprobe consumer that makes possible the distinguish uprobe from uretprobe. Note, behind every uretprobe a regular uprobe with return probe handler(rp_handler). Once hit the uprobe that has rp_handler, we hijack the return address of the probed function and replacing it with the address of trampoline. Trampoline is the preallocated page in probed task's xol area that filled with breakpoint opcode. In turn, when the return breakpoint is hit, invoke the rp_handler. The patchset shouldn't be difficult to read and hopefully the comments to commits will help. Please, review. patchset in git: http://github.com/arapov/linux-aa/commits/uretprobes_v0 RFC reviews: v4: https://lkml.org/lkml/2013/3/4/246 v3: https://lkml.org/lkml/2013/2/28/148 v2: https://lkml.org/lkml/2013/1/9/157 v1: https://lkml.org/lkml/2012/12/21/133 thanks, Anton. Anton Arapov (7): uretprobes: preparation patch uretprobes: extract fill_page() and trampoline implementation uretprobes/x86: hijack return address uretprobes: return probe entry, prepare_uretprobe() uretprobes: return probe exit, invoke handlers uretprobes: limit the depth of return probe nestedness uretprobes: remove -ENOSYS as return probes implemented arch/x86/include/asm/uprobes.h | 1 + arch/x86/kernel/uprobes.c | 29 ++++++ include/linux/uprobes.h | 5 + kernel/events/uprobes.c | 205 ++++++++++++++++++++++++++++++++++++++--- 4 files changed, 229 insertions(+), 11 deletions(-) -- 1.8.1.4 -- 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/
