ARM: Remove use of struct kprobe from generic probes code

Change the generic ARM probes code to pass in the opcode and architecture-specific
structure separately instead of using struct kprobe, so we do not pollute
code being used only for uprobes or other non-kprobes instruction
interpretation.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>

arch/arm/include/asm/probes.h

@@ -21,9 +21,14 @@
 
 struct kprobe;
 
-typedef void (kprobe_insn_handler_t)(struct kprobe *, struct pt_regs *);
+struct arch_specific_insn;
+typedef void (kprobe_insn_handler_t)(kprobe_opcode_t,
+				     struct arch_specific_insn *,
+				     struct pt_regs *);
 typedef unsigned long (kprobe_check_cc)(unsigned long);
-typedef void (kprobe_insn_singlestep_t)(struct kprobe *, struct pt_regs *);
+typedef void (kprobe_insn_singlestep_t)(kprobe_opcode_t,
+					struct arch_specific_insn *,
+					struct pt_regs *);
 typedef void (kprobe_insn_fn_t)(void);
 
 /* Architecture specific copy of original instruction. */

arch/arm/kernel/kprobes-arm.c

@@ -72,12 +72,11 @@
 			"mov	pc, "reg"	\n\t"
 #endif
 
-
 static void __kprobes
-emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
+emulate_ldrdstrd(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
-	unsigned long pc = (unsigned long)p->addr + 8;
+	unsigned long pc = regs->ARM_pc + 4;
 	int rt = (insn >> 12) & 0xf;
 	int rn = (insn >> 16) & 0xf;
 	int rm = insn & 0xf;
@@ -92,7 +91,7 @@ emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
 		BLX("%[fn]")
 		: "=r" (rtv), "=r" (rt2v), "=r" (rnv)
 		: "0" (rtv), "1" (rt2v), "2" (rnv), "r" (rmv),
-		  [fn] "r" (p->ainsn.insn_fn)
+		  [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -103,10 +102,10 @@ emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_ldr(struct kprobe *p, struct pt_regs *regs)
+emulate_ldr(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
-	unsigned long pc = (unsigned long)p->addr + 8;
+	unsigned long pc = regs->ARM_pc + 4;
 	int rt = (insn >> 12) & 0xf;
 	int rn = (insn >> 16) & 0xf;
 	int rm = insn & 0xf;
@@ -119,7 +118,7 @@ emulate_ldr(struct kprobe *p, struct pt_regs *regs)
 	__asm__ __volatile__ (
 		BLX("%[fn]")
 		: "=r" (rtv), "=r" (rnv)
-		: "1" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)
+		: "1" (rnv), "r" (rmv), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -133,11 +132,11 @@ emulate_ldr(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_str(struct kprobe *p, struct pt_regs *regs)
+emulate_str(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
-	unsigned long rtpc = (unsigned long)p->addr + str_pc_offset;
-	unsigned long rnpc = (unsigned long)p->addr + 8;
+	unsigned long rtpc = regs->ARM_pc - 4 + str_pc_offset;
+	unsigned long rnpc = regs->ARM_pc + 4;
 	int rt = (insn >> 12) & 0xf;
 	int rn = (insn >> 16) & 0xf;
 	int rm = insn & 0xf;
@@ -151,7 +150,7 @@ emulate_str(struct kprobe *p, struct pt_regs *regs)
 	__asm__ __volatile__ (
 		BLX("%[fn]")
 		: "=r" (rnv)
-		: "r" (rtv), "0" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)
+		: "r" (rtv), "0" (rnv), "r" (rmv), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -160,10 +159,10 @@ emulate_str(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)
+emulate_rd12rn16rm0rs8_rwflags(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
-	unsigned long pc = (unsigned long)p->addr + 8;
+	unsigned long pc = regs->ARM_pc + 4;
 	int rd = (insn >> 12) & 0xf;
 	int rn = (insn >> 16) & 0xf;
 	int rm = insn & 0xf;
@@ -183,7 +182,7 @@ emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)
 		"mrs	%[cpsr], cpsr		\n\t"
 		: "=r" (rdv), [cpsr] "=r" (cpsr)
 		: "0" (rdv), "r" (rnv), "r" (rmv), "r" (rsv),
-		  "1" (cpsr), [fn] "r" (p->ainsn.insn_fn)
+		  "1" (cpsr), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -195,9 +194,9 @@ emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
+emulate_rd12rn16rm0_rwflags_nopc(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rd = (insn >> 12) & 0xf;
 	int rn = (insn >> 16) & 0xf;
 	int rm = insn & 0xf;
@@ -213,7 +212,7 @@ emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 		"mrs	%[cpsr], cpsr		\n\t"
 		: "=r" (rdv), [cpsr] "=r" (cpsr)
 		: "0" (rdv), "r" (rnv), "r" (rmv),
-		  "1" (cpsr), [fn] "r" (p->ainsn.insn_fn)
+		  "1" (cpsr), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -222,9 +221,10 @@ emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
+emulate_rd16rn12rm0rs8_rwflags_nopc(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi,
+	struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rd = (insn >> 16) & 0xf;
 	int rn = (insn >> 12) & 0xf;
 	int rm = insn & 0xf;
@@ -242,7 +242,7 @@ emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 		"mrs	%[cpsr], cpsr		\n\t"
 		: "=r" (rdv), [cpsr] "=r" (cpsr)
 		: "0" (rdv), "r" (rnv), "r" (rmv), "r" (rsv),
-		  "1" (cpsr), [fn] "r" (p->ainsn.insn_fn)
+		  "1" (cpsr), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -251,9 +251,9 @@ emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_rd12rm0_noflags_nopc(struct kprobe *p, struct pt_regs *regs)
+emulate_rd12rm0_noflags_nopc(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rd = (insn >> 12) & 0xf;
 	int rm = insn & 0xf;
 
@@ -263,7 +263,7 @@ emulate_rd12rm0_noflags_nopc(struct kprobe *p, struct pt_regs *regs)
 	__asm__ __volatile__ (
 		BLX("%[fn]")
 		: "=r" (rdv)
-		: "0" (rdv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)
+		: "0" (rdv), "r" (rmv), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 
@@ -271,9 +271,10 @@ emulate_rd12rm0_noflags_nopc(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
+emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi,
+	struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rdlo = (insn >> 12) & 0xf;
 	int rdhi = (insn >> 16) & 0xf;
 	int rn = insn & 0xf;
@@ -291,7 +292,7 @@ emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
 		"mrs	%[cpsr], cpsr		\n\t"
 		: "=r" (rdlov), "=r" (rdhiv), [cpsr] "=r" (cpsr)
 		: "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv),
-		  "2" (cpsr), [fn] "r" (p->ainsn.insn_fn)
+		  "2" (cpsr), [fn] "r" (asi->insn_fn)
 		: "lr", "memory", "cc"
 	);
 

arch/arm/kernel/kprobes-common.c

@@ -17,9 +17,10 @@
 #include "kprobes.h"
 
 
-static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes simulate_ldm1stm1(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi,
+		struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rn = (insn >> 16) & 0xf;
 	int lbit = insn & (1 << 20);
 	int wbit = insn & (1 << 21);
@@ -58,24 +59,31 @@ static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs)
 	}
 }
 
-static void __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes simulate_stm1_pc(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi,
+	struct pt_regs *regs)
 {
-	regs->ARM_pc = (long)p->addr + str_pc_offset;
-	simulate_ldm1stm1(p, regs);
-	regs->ARM_pc = (long)p->addr + 4;
+	unsigned long addr = regs->ARM_pc - 4;
+
+	regs->ARM_pc = (long)addr + str_pc_offset;
+	simulate_ldm1stm1(insn, asi, regs);
+	regs->ARM_pc = (long)addr + 4;
 }
 
-static void __kprobes simulate_ldm1_pc(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes simulate_ldm1_pc(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi,
+	struct pt_regs *regs)
 {
-	simulate_ldm1stm1(p, regs);
+	simulate_ldm1stm1(insn, asi, regs);
 	load_write_pc(regs->ARM_pc, regs);
 }
 
 static void __kprobes
-emulate_generic_r0_12_noflags(struct kprobe *p, struct pt_regs *regs)
+emulate_generic_r0_12_noflags(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
 	register void *rregs asm("r1") = regs;
-	register void *rfn asm("lr") = p->ainsn.insn_fn;
+	register void *rfn asm("lr") = asi->insn_fn;
 
 	__asm__ __volatile__ (
 		"stmdb	sp!, {%[regs], r11}	\n\t"
@@ -99,15 +107,19 @@ emulate_generic_r0_12_noflags(struct kprobe *p, struct pt_regs *regs)
 }
 
 static void __kprobes
-emulate_generic_r2_14_noflags(struct kprobe *p, struct pt_regs *regs)
+emulate_generic_r2_14_noflags(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	emulate_generic_r0_12_noflags(p, (struct pt_regs *)(regs->uregs+2));
+	emulate_generic_r0_12_noflags(insn, asi,
+		(struct pt_regs *)(regs->uregs+2));
 }
 
 static void __kprobes
-emulate_ldm_r3_15(struct kprobe *p, struct pt_regs *regs)
+emulate_ldm_r3_15(kprobe_opcode_t insn,
+	struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	emulate_generic_r0_12_noflags(p, (struct pt_regs *)(regs->uregs+3));
+	emulate_generic_r0_12_noflags(insn, asi,
+		(struct pt_regs *)(regs->uregs+3));
 	load_write_pc(regs->ARM_pc, regs);
 }
 

arch/arm/kernel/kprobes.c

@@ -204,7 +204,7 @@ singlestep_skip(struct kprobe *p, struct pt_regs *regs)
 static inline void __kprobes
 singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb)
 {
-	p->ainsn.insn_singlestep(p, regs);
+	p->ainsn.insn_singlestep(p->opcode, &p->ainsn, regs);
 }
 
 /*

arch/arm/kernel/probes-arm.c

@@ -19,9 +19,8 @@
 #include <linux/module.h>
 #include <linux/stddef.h>
 #include <linux/ptrace.h>
-#include <linux/kprobes.h>
 
-#include "kprobes.h"
+#include "probes.h"
 #include "probes-arm.h"
 
 #define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
@@ -58,10 +57,10 @@
  * read and write of flags.
  */
 
-void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs)
+void __kprobes simulate_bbl(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
-	long iaddr = (long)p->addr;
+	long iaddr = (long) regs->ARM_pc - 4;
 	int disp  = branch_displacement(insn);
 
 	if (insn & (1 << 24))
@@ -70,10 +69,10 @@ void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_pc = iaddr + 8 + disp;
 }
 
-void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs)
+void __kprobes simulate_blx1(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
-	long iaddr = (long)p->addr;
+	long iaddr = (long) regs->ARM_pc - 4;
 	int disp = branch_displacement(insn);
 
 	regs->ARM_lr = iaddr + 4;
@@ -81,14 +80,14 @@ void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs)
 	regs->ARM_cpsr |= PSR_T_BIT;
 }
 
-void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs)
+void __kprobes simulate_blx2bx(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rm = insn & 0xf;
 	long rmv = regs->uregs[rm];
 
 	if (insn & (1 << 5))
-		regs->ARM_lr = (long)p->addr + 4;
+		regs->ARM_lr = (long) regs->ARM_pc;
 
 	regs->ARM_pc = rmv & ~0x1;
 	regs->ARM_cpsr &= ~PSR_T_BIT;
@@ -96,15 +95,16 @@ void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs)
 		regs->ARM_cpsr |= PSR_T_BIT;
 }
 
-void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs)
+void __kprobes simulate_mrs(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi, struct pt_regs *regs)
 {
-	kprobe_opcode_t insn = p->opcode;
 	int rd = (insn >> 12) & 0xf;
 	unsigned long mask = 0xf8ff03df; /* Mask out execution state */
 	regs->uregs[rd] = regs->ARM_cpsr & mask;
 }
 
-void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs)
+void __kprobes simulate_mov_ipsp(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi, struct pt_regs *regs)
 {
 	regs->uregs[12] = regs->uregs[13];
 }
@@ -704,10 +704,11 @@ const union decode_item kprobe_decode_arm_table[] = {
 EXPORT_SYMBOL_GPL(kprobe_decode_arm_table);
 #endif
 
-static void __kprobes arm_singlestep(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes arm_singlestep(kprobe_opcode_t insn,
+		struct arch_specific_insn *asi, struct pt_regs *regs)
 {
 	regs->ARM_pc += 4;
-	p->ainsn.insn_handler(p, regs);
+	asi->insn_handler(insn, asi, regs);
 }
 
 /* Return:

arch/arm/kernel/probes-arm.h

@@ -53,10 +53,15 @@ enum probes_arm_action {
 	NUM_PROBES_ARM_ACTIONS
 };
 
-void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs);
-void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs);
-void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs);
-void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs);
-void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs);
+void __kprobes simulate_bbl(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi, struct pt_regs *regs);
+void __kprobes simulate_blx1(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi, struct pt_regs *regs);
+void __kprobes simulate_blx2bx(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi, struct pt_regs *regs);
+void __kprobes simulate_mrs(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi, struct pt_regs *regs);
+void __kprobes simulate_mov_ipsp(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi, struct pt_regs *regs);
 
 #endif

arch/arm/kernel/probes-thumb.c

@@ -10,10 +10,9 @@
 
 #include <linux/stddef.h>
 #include <linux/kernel.h>
-#include <linux/kprobes.h>
 #include <linux/module.h>
 
-#include "kprobes.h"
+#include "probes.h"
 #include "probes-thumb.h"
 
 
@@ -844,17 +843,21 @@ static unsigned long __kprobes thumb_check_cc(unsigned long cpsr)
 	return true;
 }
 
-static void __kprobes thumb16_singlestep(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes thumb16_singlestep(kprobe_opcode_t opcode,
+		struct arch_specific_insn *asi,
+		struct pt_regs *regs)
 {
 	regs->ARM_pc += 2;
-	p->ainsn.insn_handler(p, regs);
+	asi->insn_handler(opcode, asi, regs);
 	regs->ARM_cpsr = it_advance(regs->ARM_cpsr);
 }
 
-static void __kprobes thumb32_singlestep(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes thumb32_singlestep(kprobe_opcode_t opcode,
+		struct arch_specific_insn *asi,
+		struct pt_regs *regs)
 {
 	regs->ARM_pc += 4;
-	p->ainsn.insn_handler(p, regs);
+	asi->insn_handler(opcode, asi, regs);
 	regs->ARM_cpsr = it_advance(regs->ARM_cpsr);
 }
 

arch/arm/kernel/probes.c

@@ -13,12 +13,11 @@
 
 #include <linux/kernel.h>
 #include <linux/types.h>
-#include <linux/kprobes.h>
 #include <asm/system_info.h>
 #include <asm/ptrace.h>
 #include <linux/bug.h>
 
-#include "kprobes.h"
+#include "probes.h"
 
 
 #ifndef find_str_pc_offset
@@ -176,13 +175,17 @@ kprobe_check_cc * const kprobe_condition_checks[16] = {
 };
 
 
-void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs)
+void __kprobes kprobe_simulate_nop(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi,
+	struct pt_regs *regs)
 {
 }
 
-void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs)
+void __kprobes kprobe_emulate_none(kprobe_opcode_t opcode,
+	struct arch_specific_insn *asi,
+	struct pt_regs *regs)
 {
-	p->ainsn.insn_fn();
+	asi->insn_fn();
 }
 
 /*

arch/arm/kernel/probes.h

@@ -22,6 +22,7 @@
 #include <linux/types.h>
 #include <linux/stddef.h>
 #include <linux/kprobes.h>
+#include "kprobes.h"
 
 #if __LINUX_ARM_ARCH__ >= 7
 
@@ -37,6 +38,7 @@ void __init find_str_pc_offset(void);
 
 #endif
 
+struct decode_header;
 
 /*
  * Update ITSTATE after normal execution of an IT block instruction.
@@ -129,8 +131,10 @@ static inline void __kprobes alu_write_pc(long pcv, struct pt_regs *regs)
 }
 
 
-void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs);
-void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs);
+void __kprobes kprobe_simulate_nop(kprobe_opcode_t, struct arch_specific_insn *,
+		struct pt_regs *regs);
+void __kprobes kprobe_emulate_none(kprobe_opcode_t, struct arch_specific_insn *,
+		struct pt_regs *regs);
 
 enum kprobe_insn __kprobes
 kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi,