arm64: kprobe: protect/rename few definitions to be reused by uprobe

decode-insn code has to be reused by arm64 uprobe implementation as well.
Therefore, this patch protects some portion of kprobe code and renames few
other, so that decode-insn functionality can be reused by uprobe even when
CONFIG_KPROBES is not defined.

kprobe_opcode_t and struct arch_specific_insn are also defined by
linux/kprobes.h, when CONFIG_KPROBES is not defined. So, protect these
definitions in asm/probes.h.

linux/kprobes.h already includes asm/kprobes.h. Therefore, remove inclusion
of asm/kprobes.h from decode-insn.c.

There are some definitions like kprobe_insn and kprobes_handler_t etc can
be re-used by uprobe. So, it would be better to remove 'k' from their
names.

struct arch_specific_insn is specific to kprobe. Therefore, introduce a new
struct arch_probe_insn which will be common for both kprobe and uprobe, so
that decode-insn code can be shared. Modify kprobe code accordingly.

Function arm_probe_decode_insn() will be needed by uprobe as well. So make
it global.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 17 insertions, 15 deletions

diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c
index d1731bf977ef..8a29d2982eec 100644
--- a/arch/arm64/kernel/probes/decode-insn.c
+++ b/arch/arm64/kernel/probes/decode-insn.c
@@ -78,8 +78,8 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn)
  *   INSN_GOOD         If instruction is supported and uses instruction slot,
  *   INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
  */
-static enum kprobe_insn __kprobes
-arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+enum probe_insn __kprobes
+arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *api)
 {
 	/*
 	 * Instructions reading or modifying the PC won't work from the XOL
@@ -89,26 +89,26 @@ arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 		return INSN_GOOD;
 
 	if (aarch64_insn_is_bcond(insn)) {
-		asi->handler = simulate_b_cond;
+		api->handler = simulate_b_cond;
 	} else if (aarch64_insn_is_cbz(insn) ||
 	    aarch64_insn_is_cbnz(insn)) {
-		asi->handler = simulate_cbz_cbnz;
+		api->handler = simulate_cbz_cbnz;
 	} else if (aarch64_insn_is_tbz(insn) ||
 	    aarch64_insn_is_tbnz(insn)) {
-		asi->handler = simulate_tbz_tbnz;
+		api->handler = simulate_tbz_tbnz;
 	} else if (aarch64_insn_is_adr_adrp(insn)) {
-		asi->handler = simulate_adr_adrp;
+		api->handler = simulate_adr_adrp;
 	} else if (aarch64_insn_is_b(insn) ||
 	    aarch64_insn_is_bl(insn)) {
-		asi->handler = simulate_b_bl;
+		api->handler = simulate_b_bl;
 	} else if (aarch64_insn_is_br(insn) ||
 	    aarch64_insn_is_blr(insn) ||
 	    aarch64_insn_is_ret(insn)) {
-		asi->handler = simulate_br_blr_ret;
+		api->handler = simulate_br_blr_ret;
 	} else if (aarch64_insn_is_ldr_lit(insn)) {
-		asi->handler = simulate_ldr_literal;
+		api->handler = simulate_ldr_literal;
 	} else if (aarch64_insn_is_ldrsw_lit(insn)) {
-		asi->handler = simulate_ldrsw_literal;
+		api->handler = simulate_ldrsw_literal;
 	} else {
 		/*
 		 * Instruction cannot be stepped out-of-line and we don't
@@ -120,6 +120,7 @@ arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
 	return INSN_GOOD_NO_SLOT;
 }
 
+#ifdef CONFIG_KPROBES
 static bool __kprobes
 is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end)
 {
@@ -138,12 +139,12 @@ is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end)
 	return false;
 }
 
-enum kprobe_insn __kprobes
+enum probe_insn __kprobes
 arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
 {
-	enum kprobe_insn decoded;
-	kprobe_opcode_t insn = le32_to_cpu(*addr);
-	kprobe_opcode_t *scan_end = NULL;
+	enum probe_insn decoded;
+	probe_opcode_t insn = le32_to_cpu(*addr);
+	probe_opcode_t *scan_end = NULL;
 	unsigned long size = 0, offset = 0;
 
 	/*
@@ -162,7 +163,7 @@ arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
 		else
 			scan_end = addr - MAX_ATOMIC_CONTEXT_SIZE;
 	}
-	decoded = arm_probe_decode_insn(insn, asi);
+	decoded = arm_probe_decode_insn(insn, &asi->api);
 
 	if (decoded != INSN_REJECTED && scan_end)
 		if (is_probed_address_atomic(addr - 1, scan_end))
@@ -170,3 +171,4 @@ arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
 
 	return decoded;
 }
+#endif