powerpc/bpf: Add support for bpf constant blinding

[cascardo/linux.git] / arch / powerpc / net / bpf_jit64.h

diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h
index 5046d6f..62fa758 100644 (file)
--- a/arch/powerpc/net/bpf_jit64.h
+++ b/arch/powerpc/net/bpf_jit64.h
@@ -16,30 +16,33 @@
 
 /*
  * Stack layout:
+ * Ensure the top half (upto local_tmp_var) stays consistent
+ * with our redzone usage.
  *
  *             [       prev sp         ] <-------------
  *             [   nv gpr save area    ] 8*8           |
+ *             [    tail_call_cnt      ] 8             |
+ *             [    local_tmp_var      ] 8             |
  * fp (r31) -->        [   ebpf stack space    ] 512           |
- *             [  local/tmp var space  ] 16            |
  *             [     frame header      ] 32/112        |
  * sp (r1) --->        [    stack pointer      ] --------------
  */
 
-/* for bpf JIT code internal usage */
-#define BPF_PPC_STACK_LOCALS   16
 /* for gpr non volatile registers BPG_REG_6 to 10, plus skb cache registers */
 #define BPF_PPC_STACK_SAVE     (8*8)
+/* for bpf JIT code internal usage */
+#define BPF_PPC_STACK_LOCALS   16
 /* Ensure this is quadword aligned */
-#define BPF_PPC_STACKFRAME     (STACK_FRAME_MIN_SIZE + BPF_PPC_STACK_LOCALS + \
-                                MAX_BPF_STACK + BPF_PPC_STACK_SAVE)
+#define BPF_PPC_STACKFRAME     (STACK_FRAME_MIN_SIZE + MAX_BPF_STACK + \
+                                BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
 
 #ifndef __ASSEMBLY__
 
 /* BPF register usage */
-#define SKB_HLEN_REG   (MAX_BPF_REG + 0)
-#define SKB_DATA_REG   (MAX_BPF_REG + 1)
-#define TMP_REG_1      (MAX_BPF_REG + 2)
-#define TMP_REG_2      (MAX_BPF_REG + 3)
+#define SKB_HLEN_REG   (MAX_BPF_JIT_REG + 0)
+#define SKB_DATA_REG   (MAX_BPF_JIT_REG + 1)
+#define TMP_REG_1      (MAX_BPF_JIT_REG + 2)
+#define TMP_REG_2      (MAX_BPF_JIT_REG + 3)
 
 /* BPF to ppc register mappings */
 static const int b2p[] = {
@@ -59,12 +62,16 @@ static const int b2p[] = {
        /* frame pointer aka BPF_REG_10 */
        [BPF_REG_FP] = 31,
        /* eBPF jit internal registers */
+       [BPF_REG_AX] = 2,
        [SKB_HLEN_REG] = 25,
        [SKB_DATA_REG] = 26,
        [TMP_REG_1] = 9,
        [TMP_REG_2] = 10
 };
 
+/* PPC NVR range -- update this if we ever use NVRs below r24 */
+#define BPF_PPC_NVR_MIN                24
+
 /* Assembly helpers */
 #define DECLARE_LOAD_FUNC(func)        u64 func(u64 r3, u64 r4);                       \
                                u64 func##_negative_offset(u64 r3, u64 r4);     \
@@ -82,6 +89,7 @@ DECLARE_LOAD_FUNC(sk_load_byte);
 #define SEEN_FUNC      0x1000 /* might call external helpers */
 #define SEEN_STACK     0x2000 /* uses BPF stack */
 #define SEEN_SKB       0x4000 /* uses sk_buff */
+#define SEEN_TAILCALL  0x8000 /* uses tail calls */
 
 struct codegen_context {
        /*