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author | David S. Miller <davem@davemloft.net> | 2021-09-28 13:52:46 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2021-09-28 13:52:46 +0100 |
commit | 4ccb9f03fee7b20484187ba7e25a7b9b79fe63d5 (patch) | |
tree | 3e6fd2e4a67b6e2be99331518f3c7c541367ad3d /arch | |
parent | c894b51e2a23c8c00acb3cea5045c5b70691e790 (diff) | |
parent | ced185824c89b60e65b5a2606954c098320cdfb8 (diff) | |
download | linux-stable-4ccb9f03fee7b20484187ba7e25a7b9b79fe63d5.tar.gz linux-stable-4ccb9f03fee7b20484187ba7e25a7b9b79fe63d5.tar.bz2 linux-stable-4ccb9f03fee7b20484187ba7e25a7b9b79fe63d5.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:
====================
pull-request: bpf 2021-09-28
The following pull-request contains BPF updates for your *net* tree.
We've added 10 non-merge commits during the last 14 day(s) which contain
a total of 11 files changed, 139 insertions(+), 53 deletions(-).
The main changes are:
1) Fix MIPS JIT jump code emission for too large offsets, from Piotr Krysiuk.
2) Fix x86 JIT atomic/fetch emission when dst reg maps to rax, from Johan Almbladh.
3) Fix cgroup_sk_alloc corner case when called from interrupt, from Daniel Borkmann.
4) Fix segfault in libbpf's linker for objects without BTF, from Kumar Kartikeya Dwivedi.
5) Fix bpf_jit_charge_modmem for applications with CAP_BPF, from Lorenz Bauer.
6) Fix return value handling for struct_ops BPF programs, from Hou Tao.
7) Various fixes to BPF selftests, from Jiri Benc.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
,
Diffstat (limited to 'arch')
-rw-r--r-- | arch/mips/net/bpf_jit.c | 57 | ||||
-rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 66 |
2 files changed, 91 insertions, 32 deletions
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c index 0af88622c619..cb6d22439f71 100644 --- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -662,6 +662,11 @@ static void build_epilogue(struct jit_ctx *ctx) ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative : func) : \ func##_positive) +static bool is_bad_offset(int b_off) +{ + return b_off > 0x1ffff || b_off < -0x20000; +} + static int build_body(struct jit_ctx *ctx) { const struct bpf_prog *prog = ctx->skf; @@ -728,7 +733,10 @@ load_common: /* Load return register on DS for failures */ emit_reg_move(r_ret, r_zero, ctx); /* Return with error */ - emit_b(b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_b(b_off, ctx); emit_nop(ctx); break; case BPF_LD | BPF_W | BPF_IND: @@ -775,8 +783,10 @@ load_ind: emit_jalr(MIPS_R_RA, r_s0, ctx); emit_reg_move(MIPS_R_A0, r_skb, ctx); /* delay slot */ /* Check the error value */ - emit_bcond(MIPS_COND_NE, r_ret, 0, - b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_bcond(MIPS_COND_NE, r_ret, 0, b_off, ctx); emit_reg_move(r_ret, r_zero, ctx); /* We are good */ /* X <- P[1:K] & 0xf */ @@ -855,8 +865,10 @@ load_ind: /* A /= X */ ctx->flags |= SEEN_X | SEEN_A; /* Check if r_X is zero */ - emit_bcond(MIPS_COND_EQ, r_X, r_zero, - b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_bcond(MIPS_COND_EQ, r_X, r_zero, b_off, ctx); emit_load_imm(r_ret, 0, ctx); /* delay slot */ emit_div(r_A, r_X, ctx); break; @@ -864,8 +876,10 @@ load_ind: /* A %= X */ ctx->flags |= SEEN_X | SEEN_A; /* Check if r_X is zero */ - emit_bcond(MIPS_COND_EQ, r_X, r_zero, - b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_bcond(MIPS_COND_EQ, r_X, r_zero, b_off, ctx); emit_load_imm(r_ret, 0, ctx); /* delay slot */ emit_mod(r_A, r_X, ctx); break; @@ -926,7 +940,10 @@ load_ind: break; case BPF_JMP | BPF_JA: /* pc += K */ - emit_b(b_imm(i + k + 1, ctx), ctx); + b_off = b_imm(i + k + 1, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_b(b_off, ctx); emit_nop(ctx); break; case BPF_JMP | BPF_JEQ | BPF_K: @@ -1056,12 +1073,16 @@ jmp_cmp: break; case BPF_RET | BPF_A: ctx->flags |= SEEN_A; - if (i != prog->len - 1) + if (i != prog->len - 1) { /* * If this is not the last instruction * then jump to the epilogue */ - emit_b(b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_b(b_off, ctx); + } emit_reg_move(r_ret, r_A, ctx); /* delay slot */ break; case BPF_RET | BPF_K: @@ -1075,7 +1096,10 @@ jmp_cmp: * If this is not the last instruction * then jump to the epilogue */ - emit_b(b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_b(b_off, ctx); emit_nop(ctx); } break; @@ -1133,8 +1157,10 @@ jmp_cmp: /* Load *dev pointer */ emit_load_ptr(r_s0, r_skb, off, ctx); /* error (0) in the delay slot */ - emit_bcond(MIPS_COND_EQ, r_s0, r_zero, - b_imm(prog->len, ctx), ctx); + b_off = b_imm(prog->len, ctx); + if (is_bad_offset(b_off)) + return -E2BIG; + emit_bcond(MIPS_COND_EQ, r_s0, r_zero, b_off, ctx); emit_reg_move(r_ret, r_zero, ctx); if (code == (BPF_ANC | SKF_AD_IFINDEX)) { BUILD_BUG_ON(sizeof_field(struct net_device, ifindex) != 4); @@ -1244,7 +1270,10 @@ void bpf_jit_compile(struct bpf_prog *fp) /* Generate the actual JIT code */ build_prologue(&ctx); - build_body(&ctx); + if (build_body(&ctx)) { + module_memfree(ctx.target); + goto out; + } build_epilogue(&ctx); /* Update the icache */ diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 0fe6aacef3db..9ea57389c554 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1341,9 +1341,10 @@ st: if (is_imm8(insn->off)) if (insn->imm == (BPF_AND | BPF_FETCH) || insn->imm == (BPF_OR | BPF_FETCH) || insn->imm == (BPF_XOR | BPF_FETCH)) { - u8 *branch_target; bool is64 = BPF_SIZE(insn->code) == BPF_DW; u32 real_src_reg = src_reg; + u32 real_dst_reg = dst_reg; + u8 *branch_target; /* * Can't be implemented with a single x86 insn. @@ -1354,11 +1355,13 @@ st: if (is_imm8(insn->off)) emit_mov_reg(&prog, true, BPF_REG_AX, BPF_REG_0); if (src_reg == BPF_REG_0) real_src_reg = BPF_REG_AX; + if (dst_reg == BPF_REG_0) + real_dst_reg = BPF_REG_AX; branch_target = prog; /* Load old value */ emit_ldx(&prog, BPF_SIZE(insn->code), - BPF_REG_0, dst_reg, insn->off); + BPF_REG_0, real_dst_reg, insn->off); /* * Perform the (commutative) operation locally, * put the result in the AUX_REG. @@ -1369,7 +1372,8 @@ st: if (is_imm8(insn->off)) add_2reg(0xC0, AUX_REG, real_src_reg)); /* Attempt to swap in new value */ err = emit_atomic(&prog, BPF_CMPXCHG, - dst_reg, AUX_REG, insn->off, + real_dst_reg, AUX_REG, + insn->off, BPF_SIZE(insn->code)); if (WARN_ON(err)) return err; @@ -1383,11 +1387,10 @@ st: if (is_imm8(insn->off)) /* Restore R0 after clobbering RAX */ emit_mov_reg(&prog, true, BPF_REG_0, BPF_REG_AX); break; - } err = emit_atomic(&prog, insn->imm, dst_reg, src_reg, - insn->off, BPF_SIZE(insn->code)); + insn->off, BPF_SIZE(insn->code)); if (err) return err; break; @@ -1744,7 +1747,7 @@ static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_args, } static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, - struct bpf_prog *p, int stack_size, bool mod_ret) + struct bpf_prog *p, int stack_size, bool save_ret) { u8 *prog = *pprog; u8 *jmp_insn; @@ -1777,11 +1780,15 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, if (emit_call(&prog, p->bpf_func, prog)) return -EINVAL; - /* BPF_TRAMP_MODIFY_RETURN trampolines can modify the return + /* + * BPF_TRAMP_MODIFY_RETURN trampolines can modify the return * of the previous call which is then passed on the stack to * the next BPF program. + * + * BPF_TRAMP_FENTRY trampoline may need to return the return + * value of BPF_PROG_TYPE_STRUCT_OPS prog. */ - if (mod_ret) + if (save_ret) emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); /* replace 2 nops with JE insn, since jmp target is known */ @@ -1828,13 +1835,15 @@ static int emit_cond_near_jump(u8 **pprog, void *func, void *ip, u8 jmp_cond) } static int invoke_bpf(const struct btf_func_model *m, u8 **pprog, - struct bpf_tramp_progs *tp, int stack_size) + struct bpf_tramp_progs *tp, int stack_size, + bool save_ret) { int i; u8 *prog = *pprog; for (i = 0; i < tp->nr_progs; i++) { - if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, false)) + if (invoke_bpf_prog(m, &prog, tp->progs[i], stack_size, + save_ret)) return -EINVAL; } *pprog = prog; @@ -1877,6 +1886,23 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, return 0; } +static bool is_valid_bpf_tramp_flags(unsigned int flags) +{ + if ((flags & BPF_TRAMP_F_RESTORE_REGS) && + (flags & BPF_TRAMP_F_SKIP_FRAME)) + return false; + + /* + * BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops, + * and it must be used alone. + */ + if ((flags & BPF_TRAMP_F_RET_FENTRY_RET) && + (flags & ~BPF_TRAMP_F_RET_FENTRY_RET)) + return false; + + return true; +} + /* Example: * __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); * its 'struct btf_func_model' will be nr_args=2 @@ -1949,17 +1975,19 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i struct bpf_tramp_progs *fmod_ret = &tprogs[BPF_TRAMP_MODIFY_RETURN]; u8 **branches = NULL; u8 *prog; + bool save_ret; /* x86-64 supports up to 6 arguments. 7+ can be added in the future */ if (nr_args > 6) return -ENOTSUPP; - if ((flags & BPF_TRAMP_F_RESTORE_REGS) && - (flags & BPF_TRAMP_F_SKIP_FRAME)) + if (!is_valid_bpf_tramp_flags(flags)) return -EINVAL; - if (flags & BPF_TRAMP_F_CALL_ORIG) - stack_size += 8; /* room for return value of orig_call */ + /* room for return value of orig_call or fentry prog */ + save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET); + if (save_ret) + stack_size += 8; if (flags & BPF_TRAMP_F_IP_ARG) stack_size += 8; /* room for IP address argument */ @@ -2005,7 +2033,8 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i } if (fentry->nr_progs) - if (invoke_bpf(m, &prog, fentry, stack_size)) + if (invoke_bpf(m, &prog, fentry, stack_size, + flags & BPF_TRAMP_F_RET_FENTRY_RET)) return -EINVAL; if (fmod_ret->nr_progs) { @@ -2052,7 +2081,7 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i } if (fexit->nr_progs) - if (invoke_bpf(m, &prog, fexit, stack_size)) { + if (invoke_bpf(m, &prog, fexit, stack_size, false)) { ret = -EINVAL; goto cleanup; } @@ -2072,9 +2101,10 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i ret = -EINVAL; goto cleanup; } - /* restore original return value back into RAX */ - emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8); } + /* restore return value of orig_call or fentry prog back into RAX */ + if (save_ret) + emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8); EMIT1(0x5B); /* pop rbx */ EMIT1(0xC9); /* leave */ |