From 97f7943d70ff0e1e92ea627c44cfacfdae65dbc4 Mon Sep 17 00:00:00 2001 From: Rusty Lynch Date: Mon, 27 Jun 2005 15:17:15 -0700 Subject: [PATCH] Return probe redesign: ppc64 specific implementation 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ppc64/kernel/process.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/ppc64/kernel/process.c') diff --git a/arch/ppc64/kernel/process.c b/arch/ppc64/kernel/process.c index aba89554d89..f7cae05e40f 100644 --- a/arch/ppc64/kernel/process.c +++ b/arch/ppc64/kernel/process.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -307,6 +308,8 @@ void show_regs(struct pt_regs * regs) void exit_thread(void) { + kprobe_flush_task(current); + #ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = NULL; @@ -321,6 +324,7 @@ void flush_thread(void) { struct thread_info *t = current_thread_info(); + kprobe_flush_task(current); if (t->flags & _TIF_ABI_PENDING) t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); -- cgit v1.2.3