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authorDavid S. Miller <davem@davemloft.net>2020-09-23 02:45:34 +0300
committerDavid S. Miller <davem@davemloft.net>2020-09-23 02:45:34 +0300
commit3ab0a7a0c349a1d7beb2bb371a62669d1528269d (patch)
treed2ae17c3bfc829ce0c747ad97021cd4bc8fb11dc /arch/arm64/net/bpf_jit_comp.c
parent92ec804f3dbf0d986f8e10850bfff14f316d7aaf (diff)
parent805c6d3c19210c90c109107d189744e960eae025 (diff)
downloadlinux-3ab0a7a0c349a1d7beb2bb371a62669d1528269d.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/arm64/net/bpf_jit_comp.c')
-rw-r--r--arch/arm64/net/bpf_jit_comp.c43
1 files changed, 31 insertions, 12 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index f8912e45be7a..ef9f1d5e989d 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -143,14 +143,17 @@ static inline void emit_addr_mov_i64(const int reg, const u64 val,
}
}
-static inline int bpf2a64_offset(int bpf_to, int bpf_from,
+static inline int bpf2a64_offset(int bpf_insn, int off,
const struct jit_ctx *ctx)
{
- int to = ctx->offset[bpf_to];
- /* -1 to account for the Branch instruction */
- int from = ctx->offset[bpf_from] - 1;
-
- return to - from;
+ /* BPF JMP offset is relative to the next instruction */
+ bpf_insn++;
+ /*
+ * Whereas arm64 branch instructions encode the offset
+ * from the branch itself, so we must subtract 1 from the
+ * instruction offset.
+ */
+ return ctx->offset[bpf_insn + off] - (ctx->offset[bpf_insn] - 1);
}
static void jit_fill_hole(void *area, unsigned int size)
@@ -642,7 +645,7 @@ emit_bswap_uxt:
/* JUMP off */
case BPF_JMP | BPF_JA:
- jmp_offset = bpf2a64_offset(i + off, i, ctx);
+ jmp_offset = bpf2a64_offset(i, off, ctx);
check_imm26(jmp_offset);
emit(A64_B(jmp_offset), ctx);
break;
@@ -669,7 +672,7 @@ emit_bswap_uxt:
case BPF_JMP32 | BPF_JSLE | BPF_X:
emit(A64_CMP(is64, dst, src), ctx);
emit_cond_jmp:
- jmp_offset = bpf2a64_offset(i + off, i, ctx);
+ jmp_offset = bpf2a64_offset(i, off, ctx);
check_imm19(jmp_offset);
switch (BPF_OP(code)) {
case BPF_JEQ:
@@ -908,10 +911,21 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass)
const struct bpf_prog *prog = ctx->prog;
int i;
+ /*
+ * - offset[0] offset of the end of prologue,
+ * start of the 1st instruction.
+ * - offset[1] - offset of the end of 1st instruction,
+ * start of the 2nd instruction
+ * [....]
+ * - offset[3] - offset of the end of 3rd instruction,
+ * start of 4th instruction
+ */
for (i = 0; i < prog->len; i++) {
const struct bpf_insn *insn = &prog->insnsi[i];
int ret;
+ if (ctx->image == NULL)
+ ctx->offset[i] = ctx->idx;
ret = build_insn(insn, ctx, extra_pass);
if (ret > 0) {
i++;
@@ -919,11 +933,16 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass)
ctx->offset[i] = ctx->idx;
continue;
}
- if (ctx->image == NULL)
- ctx->offset[i] = ctx->idx;
if (ret)
return ret;
}
+ /*
+ * offset is allocated with prog->len + 1 so fill in
+ * the last element with the offset after the last
+ * instruction (end of program)
+ */
+ if (ctx->image == NULL)
+ ctx->offset[i] = ctx->idx;
return 0;
}
@@ -1002,7 +1021,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
memset(&ctx, 0, sizeof(ctx));
ctx.prog = prog;
- ctx.offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL);
+ ctx.offset = kcalloc(prog->len + 1, sizeof(int), GFP_KERNEL);
if (ctx.offset == NULL) {
prog = orig_prog;
goto out_off;
@@ -1089,7 +1108,7 @@ skip_init_ctx:
prog->jited_len = prog_size;
if (!prog->is_func || extra_pass) {
- bpf_prog_fill_jited_linfo(prog, ctx.offset);
+ bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);
out_off:
kfree(ctx.offset);
kfree(jit_data);