Hello All! Uretprobes' core implementation. Enables a function's return probes in uprobe- based event tracing.
Patchset introduce additional handler (ret_handler) in uprobe consumer that defines uretprobe. There is a regular uprobe with return probe handler behind every uretprobe. Once hit the uprobe that has ret_handler set, we hijack the return address of the probed function and replace it with the address of trampoline. Trampoline is a preallocated page in probed task's xol area that filled with breakpoint opcode. In turn, when the return breakpoint is hit, we invoke the ret_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_v1 previous versions: v0: https://lkml.org/lkml/2013/3/22/218 RFC reviews: RFCv4: https://lkml.org/lkml/2013/3/4/246 RFCv3: https://lkml.org/lkml/2013/2/28/148 RFCv2: https://lkml.org/lkml/2013/1/9/157 RFCv1: https://lkml.org/lkml/2012/12/21/133 thanks, Anton. Anton Arapov (9): uretprobes: Introduce uprobe_consumer->ret_handler() uretprobes: Reserve the first slot in xol_vma for trampoline uretprobes/x86: Hijack return address uretprobes/ppc: 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 uretprobes: Documentation update Documentation/trace/uprobetracer.txt | 126 +++++++++++++--------- arch/powerpc/include/asm/uprobes.h | 1 + arch/powerpc/kernel/uprobes.c | 13 +++ arch/x86/include/asm/uprobes.h | 1 + arch/x86/kernel/uprobes.c | 29 +++++ include/linux/uprobes.h | 7 ++ kernel/events/uprobes.c | 202 +++++++++++++++++++++++++++++++++-- 7 files changed, 320 insertions(+), 59 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/