parisc/ftrace: Add KPROBES_ON_FTRACE

Allow KPROBES to use the ftrace infrastructure on PA-RISC.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

3 files changed, 156 insertions, 3 deletions

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 6d732e451071..ee59171edffe 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -61,6 +61,8 @@ config PARISC
         select HAVE_KRETPROBES
         select HAVE_DYNAMIC_FTRACE if $(cc-option,-fpatchable-function-entry=1,1)
         select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
+        select HAVE_KPROBES_ON_FTRACE
+        select HAVE_DYNAMIC_FTRACE_WITH_REGS
 
         help
           The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index d9d3387f7c47..1d1d748c227f 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1996,6 +1996,7 @@ _mcount:
          * calling mcount(), and 2 instructions for ftrace_stub().  That way we
          * have all on one L1 cacheline.
          */
+        ldi     0, %arg3
         b       ftrace_function_trampoline
         copy    %r3, %arg2      /* caller original %sp */
 ftrace_stub:
@@ -2048,6 +2049,7 @@ ftrace_caller:
         LDREG   0(%r3), %r25
         copy    %rp, %r26
         ldo     -8(%r25), %r25
+        ldi     0, %r23         /* no pt_regs */
         b,l     ftrace_function_trampoline, %rp
         copy    %r3, %r24
 
@@ -2075,6 +2077,103 @@ ftrace_caller:
 
 ENDPROC_CFI(ftrace_caller)
 
+#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS
+ENTRY_CFI(ftrace_regs_caller,caller,frame=FTRACE_FRAME_SIZE+PT_SZ_ALGN,
+        CALLS,SAVE_RP,SAVE_SP)
+ftrace_regs_caller:
+        .global ftrace_regs_caller
+
+        ldo     -FTRACE_FRAME_SIZE(%sp), %r1
+        STREG   %rp, -RP_OFFSET(%r1)
+
+        copy    %sp, %r1
+        ldo     PT_SZ_ALGN(%sp), %sp
+
+        STREG   %rp, PT_GR2(%r1)
+        STREG   %r3, PT_GR3(%r1)
+        STREG   %r4, PT_GR4(%r1)
+        STREG   %r5, PT_GR5(%r1)
+        STREG   %r6, PT_GR6(%r1)
+        STREG   %r7, PT_GR7(%r1)
+        STREG   %r8, PT_GR8(%r1)
+        STREG   %r9, PT_GR9(%r1)
+        STREG   %r10, PT_GR10(%r1)
+        STREG   %r11, PT_GR11(%r1)
+        STREG   %r12, PT_GR12(%r1)
+        STREG   %r13, PT_GR13(%r1)
+        STREG   %r14, PT_GR14(%r1)
+        STREG   %r15, PT_GR15(%r1)
+        STREG   %r16, PT_GR16(%r1)
+        STREG   %r17, PT_GR17(%r1)
+        STREG   %r18, PT_GR18(%r1)
+        STREG   %r19, PT_GR19(%r1)
+        STREG   %r20, PT_GR20(%r1)
+        STREG   %r21, PT_GR21(%r1)
+        STREG   %r22, PT_GR22(%r1)
+        STREG   %r23, PT_GR23(%r1)
+        STREG   %r24, PT_GR24(%r1)
+        STREG   %r25, PT_GR25(%r1)
+        STREG   %r26, PT_GR26(%r1)
+        STREG   %r27, PT_GR27(%r1)
+        STREG   %r28, PT_GR28(%r1)
+        STREG   %r29, PT_GR29(%r1)
+        STREG   %r30, PT_GR30(%r1)
+        STREG   %r31, PT_GR31(%r1)
+        mfctl   %cr11, %r26
+        STREG   %r26, PT_SAR(%r1)
+
+        copy    %rp, %r26
+        LDREG   -FTRACE_FRAME_SIZE-PT_SZ_ALGN(%sp), %r25
+        ldo     -8(%r25), %r25
+        copy    %r3, %arg2
+        b,l     ftrace_function_trampoline, %rp
+        copy    %r1, %arg3 /* struct pt_regs */
+
+        ldo     -PT_SZ_ALGN(%sp), %r1
+
+        LDREG   PT_SAR(%r1), %rp
+        mtctl   %rp, %cr11
+
+        LDREG   PT_GR2(%r1), %rp
+        LDREG   PT_GR3(%r1), %r3
+        LDREG   PT_GR4(%r1), %r4
+        LDREG   PT_GR5(%r1), %r5
+        LDREG   PT_GR6(%r1), %r6
+        LDREG   PT_GR7(%r1), %r7
+        LDREG   PT_GR8(%r1), %r8
+        LDREG   PT_GR9(%r1), %r9
+        LDREG   PT_GR10(%r1),%r10
+        LDREG   PT_GR11(%r1),%r11
+        LDREG   PT_GR12(%r1),%r12
+        LDREG   PT_GR13(%r1),%r13
+        LDREG   PT_GR14(%r1),%r14
+        LDREG   PT_GR15(%r1),%r15
+        LDREG   PT_GR16(%r1),%r16
+        LDREG   PT_GR17(%r1),%r17
+        LDREG   PT_GR18(%r1),%r18
+        LDREG   PT_GR19(%r1),%r19
+        LDREG   PT_GR20(%r1),%r20
+        LDREG   PT_GR21(%r1),%r21
+        LDREG   PT_GR22(%r1),%r22
+        LDREG   PT_GR23(%r1),%r23
+        LDREG   PT_GR24(%r1),%r24
+        LDREG   PT_GR25(%r1),%r25
+        LDREG   PT_GR26(%r1),%r26
+        LDREG   PT_GR27(%r1),%r27
+        LDREG   PT_GR28(%r1),%r28
+        LDREG   PT_GR29(%r1),%r29
+        LDREG   PT_GR30(%r1),%r30
+        LDREG   PT_GR31(%r1),%r31
+
+        ldo     -PT_SZ_ALGN(%sp), %sp
+        LDREGM  -FTRACE_FRAME_SIZE(%sp), %r1
+        /* Adjust return point to jump back to beginning of traced function */
+        ldo     -4(%r1), %r1
+        bv,n    (%r1)
+
+ENDPROC_CFI(ftrace_regs_caller)
+
+#endif
 #endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
index 23ce416787ac..b836fc61a24f 100644
--- a/arch/parisc/kernel/ftrace.c
+++ b/arch/parisc/kernel/ftrace.c
@@ -13,6 +13,8 @@
 #include <linux/init.h>
 #include <linux/ftrace.h>
 #include <linux/uaccess.h>
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
 
 #include <asm/assembly.h>
 #include <asm/sections.h>
@@ -48,7 +50,8 @@ static void __hot prepare_ftrace_return(unsigned long *parent,
 
 void notrace __hot ftrace_function_trampoline(unsigned long parent,
                                 unsigned long self_addr,
-                                unsigned long org_sp_gr3)
+                                unsigned long org_sp_gr3,
+                                struct pt_regs *regs)
 {
 #ifndef CONFIG_DYNAMIC_FTRACE
         extern ftrace_func_t ftrace_trace_function;
@@ -58,11 +61,11 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent,
         if (function_trace_op->flags & FTRACE_OPS_FL_ENABLED &&
             ftrace_trace_function != ftrace_stub)
                 ftrace_trace_function(self_addr, parent,
-                                function_trace_op, NULL);
+                                function_trace_op, regs);
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
-                ftrace_graph_entry != ftrace_graph_entry_stub) {
+            ftrace_graph_entry != ftrace_graph_entry_stub) {
                 unsigned long *parent_rp;
 
                 /* calculate pointer to %rp in stack */
@@ -100,6 +103,12 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
         return 0;
 }
 
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+                        unsigned long addr)
+{
+        return 0;
+}
+
 unsigned long ftrace_call_adjust(unsigned long addr)
 {
         return addr+(FTRACE_PATCHABLE_FUNCTION_SIZE-1)*4;
@@ -191,3 +200,46 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
         return 0;
 }
 #endif
+
+#ifdef CONFIG_KPROBES_ON_FTRACE
+void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
+                           struct ftrace_ops *ops, struct pt_regs *regs)
+{
+        struct kprobe_ctlblk *kcb;
+        struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
+
+        if (unlikely(!p) || kprobe_disabled(p))
+                return;
+
+        if (kprobe_running()) {
+                kprobes_inc_nmissed_count(p);
+                return;
+        }
+
+        __this_cpu_write(current_kprobe, p);
+
+        kcb = get_kprobe_ctlblk();
+        kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+        regs->iaoq[0] = ip;
+        regs->iaoq[1] = ip + 4;
+
+        if (!p->pre_handler || !p->pre_handler(p, regs)) {
+                regs->iaoq[0] = ip + 4;
+                regs->iaoq[1] = ip + 8;
+
+                if (unlikely(p->post_handler)) {
+                        kcb->kprobe_status = KPROBE_HIT_SSDONE;
+                        p->post_handler(p, regs, 0);
+                }
+        }
+        __this_cpu_write(current_kprobe, NULL);
+}
+NOKPROBE_SYMBOL(kprobe_ftrace_handler);
+
+int arch_prepare_kprobe_ftrace(struct kprobe *p)
+{
+        p->ainsn.insn = NULL;
+        return 0;
+}
+#endif