sh: Add kprobes support.

Initial support for kprobes/kretprobes for 32-bit SH platforms.

[ General cleanup and some rework for the kretprobe hash lock. -- PFM ]

Signed-off-by: Chris Smith <chris.smith@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/arch/sh/include/asm/kprobes.h b/arch/sh/include/asm/kprobes.h
new file mode 100644
index 000000000000..70fc629df904
--- /dev/null
+++ b/arch/sh/include/asm/kprobes.h
@@ -0,0 +1,59 @@
+#ifndef __ASM_SH_KPROBES_H
+#define __ASM_SH_KPROBES_H
+
+#ifdef CONFIG_KPROBES
+
+#include <linux/types.h>
+#include <linux/ptrace.h>
+
+struct pt_regs;
+
+typedef u16 kprobe_opcode_t;
+#define BREAKPOINT_INSTRUCTION  0xc3ff
+
+#define MAX_INSN_SIZE 16
+#define MAX_STACK_SIZE 64
+#define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
+        (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
+        ? (MAX_STACK_SIZE) \
+        : (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
+
+#define regs_return_value(regs)         ((regs)->regs[0])
+#define flush_insn_slot(p)              do { } while (0)
+#define kretprobe_blacklist_size        0
+
+struct kprobe;
+
+void arch_remove_kprobe(struct kprobe *);
+void kretprobe_trampoline(void);
+void jprobe_return_end(void);
+
+/* Architecture specific copy of original instruction*/
+struct arch_specific_insn {
+        /* copy of the original instruction */
+        kprobe_opcode_t insn[MAX_INSN_SIZE];
+};
+
+struct prev_kprobe {
+        struct kprobe *kp;
+        unsigned long status;
+};
+
+/* per-cpu kprobe control block */
+struct kprobe_ctlblk {
+        unsigned long kprobe_status;
+        unsigned long jprobe_saved_r15;
+        struct pt_regs jprobe_saved_regs;
+        kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
+        struct prev_kprobe prev_kprobe;
+};
+
+extern int kprobe_exceptions_notify(struct notifier_block *self,
+                                    unsigned long val, void *data);
+extern int kprobe_handle_illslot(unsigned long pc);
+#else
+
+#define kprobe_handle_illslot(pc)       (-1)
+
+#endif /* CONFIG_KPROBES */
+#endif /* __ASM_SH_KPROBES_H */