Commit 24ba613c authored by Abhishek Sagar's avatar Abhishek Sagar Committed by Russell King

ARM kprobes: core code

This is a full implementation of Kprobes including Jprobes and
Kretprobes support.

This ARM implementation does not follow the usual kprobes double-
exception model. The traditional model is where the initial kprobes
breakpoint calls kprobe_handler(), which returns from exception to
execute the instruction in its original context, then immediately
re-enters after a second breakpoint (or single-stepping exception)
into post_kprobe_handler(), each time the probe is hit..  The ARM
implementation only executes one kprobes exception per hit, so no
post_kprobe_handler() phase. All side-effects from the kprobe'd
instruction are resolved before returning from the initial exception.
As a result, all instructions are _always_ effectively boosted
regardless of the type of instruction, and even regardless of whether
or not there is a post-handler for the probe.
Signed-off-by: default avatarAbhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: default avatarQuentin Barnes <qbarnes@gmail.com>
Signed-off-by: default avatarNicolas Pitre <nico@marvell.com>
parent 35aa1df4
...@@ -19,7 +19,7 @@ obj-$(CONFIG_ISA_DMA) += dma-isa.o ...@@ -19,7 +19,7 @@ obj-$(CONFIG_ISA_DMA) += dma-isa.o
obj-$(CONFIG_PCI) += bios32.o isa.o obj-$(CONFIG_PCI) += bios32.o isa.o
obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
obj-$(CONFIG_KPROBES) += kprobes-decode.o obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o
obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o
obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o
......
This diff is collapsed.
...@@ -18,6 +18,16 @@ ...@@ -18,6 +18,16 @@
#include <linux/types.h> #include <linux/types.h>
#include <linux/ptrace.h> #include <linux/ptrace.h>
#include <linux/percpu.h>
#define ARCH_SUPPORTS_KRETPROBES
#define __ARCH_WANT_KPROBES_INSN_SLOT
#define MAX_INSN_SIZE 2
#define MAX_STACK_SIZE 64 /* 32 would probably be OK */
#define regs_return_value(regs) ((regs)->ARM_r0)
#define flush_insn_slot(p) do { } while (0)
#define kretprobe_blacklist_size 0
typedef u32 kprobe_opcode_t; typedef u32 kprobe_opcode_t;
...@@ -30,6 +40,25 @@ struct arch_specific_insn { ...@@ -30,6 +40,25 @@ struct arch_specific_insn {
kprobe_insn_handler_t *insn_handler; kprobe_insn_handler_t *insn_handler;
}; };
struct prev_kprobe {
struct kprobe *kp;
unsigned int status;
};
/* per-cpu kprobe control block */
struct kprobe_ctlblk {
unsigned int kprobe_status;
struct prev_kprobe prev_kprobe;
struct pt_regs jprobe_saved_regs;
char jprobes_stack[MAX_STACK_SIZE];
};
void arch_remove_kprobe(struct kprobe *);
int kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr);
int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
enum kprobe_insn { enum kprobe_insn {
INSN_REJECTED, INSN_REJECTED,
INSN_GOOD, INSN_GOOD,
......
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