[PATCH] Kprobes/IA64: architecture specific JProbes support (b2761dc2) · Commits · e / devices / android_kernel_xiaomi_markw

arch/ia64/kernel/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -20,7 +20,7 @@ obj-$(CONFIG_SMP) += smp.o smpboot.o domain.o
		obj-$(CONFIG_PERFMON) += perfmon_default_smpl.o
		obj-$(CONFIG_IA64_CYCLONE) += cyclone.o
		obj-$(CONFIG_IA64_MCA_RECOVERY) += mca_recovery.o
		obj-$(CONFIG_KPROBES) += kprobes.o
		obj-$(CONFIG_KPROBES) += kprobes.o jprobes.o
		obj-$(CONFIG_IA64_UNCACHED_ALLOCATOR) += uncached.o
		mca_recovery-y += mca_drv.o mca_drv_asm.o

arch/ia64/kernel/jprobes.S

0 → 100644

+61 −0

Original line number	Diff line number	Diff line
		/*
		* Jprobe specific operations
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
		*
		* Copyright (C) Intel Corporation, 2005
		*
		* 2005-May Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
		* <anil.s.keshavamurthy@intel.com> initial implementation
		*
		* Jprobes (a.k.a. "jump probes" which is built on-top of kprobes) allow a
		* probe to be inserted into the beginning of a function call. The fundamental
		* difference between a jprobe and a kprobe is the jprobe handler is executed
		* in the same context as the target function, while the kprobe handlers
		* are executed in interrupt context.
		*
		* For jprobes we initially gain control by placing a break point in the
		* first instruction of the targeted function. When we catch that specific
		* break, we:
		* * set the return address to our jprobe_inst_return() function
		* * jump to the jprobe handler function
		*
		* Since we fixed up the return address, the jprobe handler will return to our
		* jprobe_inst_return() function, giving us control again. At this point we
		* are back in the parents frame marker, so we do yet another call to our
		* jprobe_break() function to fix up the frame marker as it would normally
		* exist in the target function.
		*
		* Our jprobe_return function then transfers control back to kprobes.c by
		* executing a break instruction using one of our reserved numbers. When we
		* catch that break in kprobes.c, we continue like we do for a normal kprobe
		* by single stepping the emulated instruction, and then returning execution
		* to the correct location.
		*/
		#include <asm/asmmacro.h>

		/*
		* void jprobe_break(void)
		*/
		ENTRY(jprobe_break)
		break.m 0x80300
		END(jprobe_break)

		/*
		* void jprobe_inst_return(void)
		*/
		GLOBAL_ENTRY(jprobe_inst_return)
		br.call.sptk.many b0=jprobe_break
		END(jprobe_inst_return)

arch/ia64/kernel/kprobes.c

+22 −6

Original line number	Diff line number	Diff line
		@@ -35,12 +35,15 @@
		#include <asm/pgtable.h>
		#include <asm/kdebug.h>

		extern void jprobe_inst_return(void);

		/* kprobe_status settings */
		#define KPROBE_HIT_ACTIVE 0x00000001
		#define KPROBE_HIT_SS 0x00000002

		static struct kprobe *current_kprobe;
		static unsigned long kprobe_status;
		static struct pt_regs jprobe_saved_regs;

		enum instruction_type {A, I, M, F, B, L, X, u};
		static enum instruction_type bundle_encoding[32][3] = {
		@@ -318,15 +321,28 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,

		int setjmp_pre_handler(struct kprobe p, struct pt_regs regs)
		{
		printk(KERN_WARNING "Jprobes is not supported\n");
		return 0;
		}
		struct jprobe *jp = container_of(p, struct jprobe, kp);
		unsigned long addr = ((struct fnptr *)(jp->entry))->ip;

		void jprobe_return(void)
		{
		/* save architectural state */
		jprobe_saved_regs = *regs;

		/* after rfi, execute the jprobe instrumented function */
		regs->cr_iip = addr & ~0xFULL;
		ia64_psr(regs)->ri = addr & 0xf;
		regs->r1 = ((struct fnptr *)(jp->entry))->gp;

		/*
		* fix the return address to our jprobe_inst_return() function
		* in the jprobes.S file
		*/
		regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip;

		return 1;
		}

		int longjmp_break_handler(struct kprobe p, struct pt_regs regs)
		{
		return 0;
		*regs = jprobe_saved_regs;
		return 1;
		}

include/asm-ia64/kprobes.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -59,6 +59,11 @@ struct arch_specific_insn {
		kprobe_opcode_t insn;
		};

		/* ia64 does not need this */
		static inline void jprobe_return(void)
		{
		}

		#ifdef CONFIG_KPROBES
		extern int kprobe_exceptions_notify(struct notifier_block *self,
		unsigned long val, void *data);