net: filter: Fix redefinition warnings on x86-64.

Do not collide with the x86-64 PTRACE user API namespace.

net/core/filter.c:57:0: warning: "R8" redefined [enabled by default]
arch/x86/include/uapi/asm/ptrace-abi.h:38:0: note: this is the location of the previous definition

Fix by adding a BPF_ prefix to the register macros.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/filter.c b/net/core/filter.c
index 9aaa05ad8fe3b1194c41f560db824cbe83c40e84..c442a0d7d0f7e5afb8174956ebf270f8f30f2ce4 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -46,17 +46,17 @@
 #include <linux/if_vlan.h>
 
 /* Registers */
-#define R0     regs[BPF_REG_0]
-#define R1     regs[BPF_REG_1]
-#define R2     regs[BPF_REG_2]
-#define R3     regs[BPF_REG_3]
-#define R4     regs[BPF_REG_4]
-#define R5     regs[BPF_REG_5]
-#define R6     regs[BPF_REG_6]
-#define R7     regs[BPF_REG_7]
-#define R8     regs[BPF_REG_8]
-#define R9     regs[BPF_REG_9]
-#define R10    regs[BPF_REG_10]
+#define BPF_R0 regs[BPF_REG_0]
+#define BPF_R1 regs[BPF_REG_1]
+#define BPF_R2 regs[BPF_REG_2]
+#define BPF_R3 regs[BPF_REG_3]
+#define BPF_R4 regs[BPF_REG_4]
+#define BPF_R5 regs[BPF_REG_5]
+#define BPF_R6 regs[BPF_REG_6]
+#define BPF_R7 regs[BPF_REG_7]
+#define BPF_R8 regs[BPF_REG_8]
+#define BPF_R9 regs[BPF_REG_9]
+#define BPF_R10        regs[BPF_REG_10]
 
 /* Named registers */
 #define A      regs[insn->a_reg]
@@ -383,10 +383,12 @@ select_insn:
 
        /* CALL */
        JMP_CALL_0:
-               /* Function call scratches R1-R5 registers, preserves R6-R9,
-                * and stores return value into R0.
+               /* Function call scratches BPF_R1-BPF_R5 registers,
+                * preserves BPF_R6-BPF_R9, and stores return value
+                * into BPF_R0.
                 */
-               R0 = (__bpf_call_base + insn->imm)(R1, R2, R3, R4, R5);
+               BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
+                                                      BPF_R4, BPF_R5);
                CONT;
 
        /* JMP */
@@ -478,7 +480,7 @@ select_insn:
                }
                CONT;
        JMP_EXIT_0:
-               return R0;
+               return BPF_R0;
 
        /* STX and ST and LDX*/
 #define LDST(SIZEOP, SIZE)                                     \
@@ -505,18 +507,19 @@ select_insn:
                atomic64_add((u64) X, (atomic64_t *)(unsigned long)
                             (A + insn->off));
                CONT;
-       LD_ABS_W: /* R0 = ntohl(*(u32 *) (skb->data + K)) */
+       LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + K)) */
                off = K;
 load_word:
-               /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only
-                * appearing in the programs where ctx == skb. All programs
-                * keep 'ctx' in regs[BPF_REG_CTX] == R6, sk_convert_filter()
-                * saves it in R6, internal BPF verifier will check that
-                * R6 == ctx.
+               /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are
+                * only appearing in the programs where ctx ==
+                * skb. All programs keep 'ctx' in regs[BPF_REG_CTX]
+                * == BPF_R6, sk_convert_filter() saves it in BPF_R6,
+                * internal BPF verifier will check that BPF_R6 ==
+                * ctx.
                 *
-                * BPF_ABS and BPF_IND are wrappers of function calls, so
-                * they scratch R1-R5 registers, preserve R6-R9, and store
-                * return value into R0.
+                * BPF_ABS and BPF_IND are wrappers of function calls,
+                * so they scratch BPF_R1-BPF_R5 registers, preserve
+                * BPF_R6-BPF_R9, and store return value into BPF_R0.
                 *
                 * Implicit input:
                 *   ctx
@@ -526,39 +529,39 @@ load_word:
                 *   K == 32-bit immediate
                 *
                 * Output:
-                *   R0 - 8/16/32-bit skb data converted to cpu endianness
+                *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
                 */
                ptr = load_pointer((struct sk_buff *) ctx, off, 4, &tmp);
                if (likely(ptr != NULL)) {
-                       R0 = get_unaligned_be32(ptr);
+                       BPF_R0 = get_unaligned_be32(ptr);
                        CONT;
                }
                return 0;
-       LD_ABS_H: /* R0 = ntohs(*(u16 *) (skb->data + K)) */
+       LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + K)) */
                off = K;
 load_half:
                ptr = load_pointer((struct sk_buff *) ctx, off, 2, &tmp);
                if (likely(ptr != NULL)) {
-                       R0 = get_unaligned_be16(ptr);
+                       BPF_R0 = get_unaligned_be16(ptr);
                        CONT;
                }
                return 0;
-       LD_ABS_B: /* R0 = *(u8 *) (ctx + K) */
+       LD_ABS_B: /* BPF_R0 = *(u8 *) (ctx + K) */
                off = K;
 load_byte:
                ptr = load_pointer((struct sk_buff *) ctx, off, 1, &tmp);
                if (likely(ptr != NULL)) {
-                       R0 = *(u8 *)ptr;
+                       BPF_R0 = *(u8 *)ptr;
                        CONT;
                }
                return 0;
-       LD_IND_W: /* R0 = ntohl(*(u32 *) (skb->data + X + K)) */
+       LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + X + K)) */
                off = K + X;
                goto load_word;
-       LD_IND_H: /* R0 = ntohs(*(u16 *) (skb->data + X + K)) */
+       LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + X + K)) */
                off = K + X;
                goto load_half;
-       LD_IND_B: /* R0 = *(u8 *) (skb->data + X + K) */
+       LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + X + K) */
                off = K + X;
                goto load_byte;
 
@@ -1001,7 +1004,7 @@ do_pass:
                        *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_TMP, BPF_REG_A);
                        insn++;
 
-                       /* A = R0 = *(u8 *) (skb->data + K) */
+                       /* A = BPF_R0 = *(u8 *) (skb->data + K) */
                        *insn = BPF_LD_ABS(BPF_B, fp->k);
                        insn++;