The following is a patch provided by Ananth Mavinakayanahalli that implements the new PPC64 specific parts of the new function return probe design. NOTE: Since getting Ananth's patch, I changed trampoline_probe_handler() to consume each of the outstanding return probem instances (feedback on my original RFC after Ananth cut a patch), and also added the arch_init() function (adding arch specific initialization.) I have cross compiled but have not testing this on a PPC64 machine. Changes include: * Addition of kretprobe_trampoline to act as a dummy function for instrumented functions to return to, and for the return probe infrastructure to place a kprobe on on, gaining control so that the return probe handler can be called, and so that the instruction pointer can be moved back to the original return address. * Addition of arch_init(), allowing a kprobe to be registered on kretprobe_trampoline * Addition of trampoline_probe_handler() which is used as the pre_handler for the kprobe inserted on kretprobe_implementation. This is the function that handles the details for calling the return probe handler function and returning control back at the original return address * Addition of arch_prepare_kretprobe() which is setup as the pre_handler for a kprobe registered at the beginning of the target function by kernel/kprobes.c so that a return probe instance can be setup when a caller enters the target function. (A return probe instance contains all the needed information for trampoline_probe_handler to do it's job.) * Hooks added to the exit path of a task so that we can cleanup any left-over return probe instances (i.e. if a task dies while inside a targeted function then the return probe instance was reserved at the beginning of the function but the function never returns so we need to mark the instance as unused.) Signed-off-by: Rusty Lynch <rusty.lynch@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> |
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boot | ||
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kernel | ||
lib | ||
mm | ||
oprofile | ||
xmon | ||
Kconfig | ||
Kconfig.debug | ||
Makefile | ||
defconfig |