Currrently the are 2 problems with pre-filtering: 1. It is not possible to add/remove a task (mm) after uprobe_register() 2. A forked child inherits all breakpoints and uprobe_consumer can not control this. This patch does the first step to improve the filtering. handler_chain() removes the breakpoints installed by this uprobe from current->mm if all handlers return UPROBE_HANDLER_REMOVE. Note that handler_chain() relies on ->register_rwsem to avoid the race with uprobe_register/unregister which can add/del a consumer, or even remove and then insert the new uprobe at the same address. Perhaps we will add uprobe_apply_mm(uprobe, mm, is_register) and teach copy_mm() to do filter(UPROBE_FILTER_FORK), but I think this change makes sense anyway. Note: instead of checking the retcode from uc->handler, we could add uc->filter(UPROBE_FILTER_BPHIT). But I think this is not optimal to call 2 hooks in a row. This buys nothing, and if handler/filter do something nontrivial they will probably do the same work twice. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> |
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acpi | ||
asm-generic | ||
clocksource | ||
crypto | ||
drm | ||
keys | ||
linux | ||
math-emu | ||
media | ||
memory | ||
misc | ||
net | ||
pcmcia | ||
ras | ||
rdma | ||
rxrpc | ||
scsi | ||
sound | ||
target | ||
trace | ||
uapi | ||
video | ||
xen | ||
Kbuild |