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authorDavid S. Miller <davem@davemloft.net>2018-01-18 09:17:04 -0500
committerDavid S. Miller <davem@davemloft.net>2018-01-18 09:17:04 -0500
commit7155f8f391576f133ed26c8d6bb8c7f03ceb404a (patch)
treec1c219defbaaf8ac3569b4e2ebccd76bda627a31 /arch
parentad9294dbc227cbc8e173b3b963e7dd9af5314f77 (diff)
parent6f16101e6a8b4324c36e58a29d9e0dbb287cdedb (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says: ==================== pull-request: bpf 2018-01-18 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix a divide by zero due to wrong if (src_reg == 0) check in 64-bit mode. Properly handle this in interpreter and mask it also generically in verifier to guard against similar checks in JITs, from Eric and Alexei. 2) Fix a bug in arm64 JIT when tail calls are involved and progs have different stack sizes, from Daniel. 3) Reject stores into BPF context that are not expected BPF_STX | BPF_MEM variant, from Daniel. 4) Mark dst reg as unknown on {s,u}bounds adjustments when the src reg has derived bounds from dead branches, from Daniel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/net/bpf_jit_comp.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index ba38d403abb2..bb32f7f6dd0f 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -148,7 +148,8 @@ static inline int epilogue_offset(const struct jit_ctx *ctx)
/* Stack must be multiples of 16B */
#define STACK_ALIGN(sz) (((sz) + 15) & ~15)
-#define PROLOGUE_OFFSET 8
+/* Tail call offset to jump into */
+#define PROLOGUE_OFFSET 7
static int build_prologue(struct jit_ctx *ctx)
{
@@ -200,19 +201,19 @@ static int build_prologue(struct jit_ctx *ctx)
/* Initialize tail_call_cnt */
emit(A64_MOVZ(1, tcc, 0, 0), ctx);
- /* 4 byte extra for skb_copy_bits buffer */
- ctx->stack_size = prog->aux->stack_depth + 4;
- ctx->stack_size = STACK_ALIGN(ctx->stack_size);
-
- /* Set up function call stack */
- emit(A64_SUB_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
-
cur_offset = ctx->idx - idx0;
if (cur_offset != PROLOGUE_OFFSET) {
pr_err_once("PROLOGUE_OFFSET = %d, expected %d!\n",
cur_offset, PROLOGUE_OFFSET);
return -1;
}
+
+ /* 4 byte extra for skb_copy_bits buffer */
+ ctx->stack_size = prog->aux->stack_depth + 4;
+ ctx->stack_size = STACK_ALIGN(ctx->stack_size);
+
+ /* Set up function call stack */
+ emit(A64_SUB_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
return 0;
}
@@ -260,11 +261,12 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx)
emit(A64_LDR64(prg, tmp, prg), ctx);
emit(A64_CBZ(1, prg, jmp_offset), ctx);
- /* goto *(prog->bpf_func + prologue_size); */
+ /* goto *(prog->bpf_func + prologue_offset); */
off = offsetof(struct bpf_prog, bpf_func);
emit_a64_mov_i64(tmp, off, ctx);
emit(A64_LDR64(tmp, prg, tmp), ctx);
emit(A64_ADD_I(1, tmp, tmp, sizeof(u32) * PROLOGUE_OFFSET), ctx);
+ emit(A64_ADD_I(1, A64_SP, A64_SP, ctx->stack_size), ctx);
emit(A64_BR(tmp), ctx);
/* out: */