diff options
Diffstat (limited to 'arch/s390/net')
-rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 60 |
1 files changed, 31 insertions, 29 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index b418333bb086..4be8f5cadd02 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -516,11 +516,12 @@ static void bpf_skip(struct bpf_jit *jit, int size) * PLT for hotpatchable calls. The calling convention is the same as for the * ftrace hotpatch trampolines: %r0 is return address, %r1 is clobbered. */ -extern const char bpf_plt[]; -extern const char bpf_plt_ret[]; -extern const char bpf_plt_target[]; -extern const char bpf_plt_end[]; -#define BPF_PLT_SIZE 32 +struct bpf_plt { + char code[16]; + void *ret; + void *target; +} __packed; +extern const struct bpf_plt bpf_plt; asm( ".pushsection .rodata\n" " .balign 8\n" @@ -531,15 +532,14 @@ asm( " .balign 8\n" "bpf_plt_ret: .quad 0\n" "bpf_plt_target: .quad 0\n" - "bpf_plt_end:\n" " .popsection\n" ); -static void bpf_jit_plt(void *plt, void *ret, void *target) +static void bpf_jit_plt(struct bpf_plt *plt, void *ret, void *target) { - memcpy(plt, bpf_plt, BPF_PLT_SIZE); - *(void **)((char *)plt + (bpf_plt_ret - bpf_plt)) = ret; - *(void **)((char *)plt + (bpf_plt_target - bpf_plt)) = target ?: ret; + memcpy(plt, &bpf_plt, sizeof(*plt)); + plt->ret = ret; + plt->target = target; } /* @@ -662,9 +662,9 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) jit->prg = ALIGN(jit->prg, 8); jit->prologue_plt = jit->prg; if (jit->prg_buf) - bpf_jit_plt(jit->prg_buf + jit->prg, + bpf_jit_plt((struct bpf_plt *)(jit->prg_buf + jit->prg), jit->prg_buf + jit->prologue_plt_ret, NULL); - jit->prg += BPF_PLT_SIZE; + jit->prg += sizeof(struct bpf_plt); } static int get_probe_mem_regno(const u8 *insn) @@ -1427,8 +1427,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, EMIT6_DISP_LH(0xeb000000, is32 ? (op32) : (op64), \ (insn->imm & BPF_FETCH) ? src_reg : REG_W0, \ src_reg, dst_reg, off); \ - if (is32 && (insn->imm & BPF_FETCH)) \ - EMIT_ZERO(src_reg); \ + if (insn->imm & BPF_FETCH) { \ + /* bcr 14,0 - see atomic_fetch_{add,and,or,xor}() */ \ + _EMIT2(0x07e0); \ + if (is32) \ + EMIT_ZERO(src_reg); \ + } \ } while (0) case BPF_ADD: case BPF_ADD | BPF_FETCH: @@ -2040,9 +2044,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) struct bpf_jit jit; int pass; - if (WARN_ON_ONCE(bpf_plt_end - bpf_plt != BPF_PLT_SIZE)) - return orig_fp; - if (!fp->jit_requested) return orig_fp; @@ -2111,7 +2112,11 @@ skip_init_ctx: print_fn_code(jit.prg_buf, jit.size_prg); } if (!fp->is_func || extra_pass) { - bpf_jit_binary_lock_ro(header); + if (bpf_jit_binary_lock_ro(header)) { + bpf_jit_binary_free(header); + fp = orig_fp; + goto free_addrs; + } } else { jit_data->header = header; jit_data->ctx = jit; @@ -2148,14 +2153,11 @@ bool bpf_jit_supports_far_kfunc_call(void) int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, void *old_addr, void *new_addr) { + struct bpf_plt expected_plt, current_plt, new_plt, *plt; struct { u16 opc; s32 disp; } __packed insn; - char expected_plt[BPF_PLT_SIZE]; - char current_plt[BPF_PLT_SIZE]; - char new_plt[BPF_PLT_SIZE]; - char *plt; char *ret; int err; @@ -2174,18 +2176,18 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, */ } else { /* Verify the PLT. */ - plt = (char *)ip + (insn.disp << 1); - err = copy_from_kernel_nofault(current_plt, plt, BPF_PLT_SIZE); + plt = ip + (insn.disp << 1); + err = copy_from_kernel_nofault(¤t_plt, plt, + sizeof(current_plt)); if (err < 0) return err; ret = (char *)ip + 6; - bpf_jit_plt(expected_plt, ret, old_addr); - if (memcmp(current_plt, expected_plt, BPF_PLT_SIZE)) + bpf_jit_plt(&expected_plt, ret, old_addr); + if (memcmp(¤t_plt, &expected_plt, sizeof(current_plt))) return -EINVAL; /* Adjust the call address. */ - bpf_jit_plt(new_plt, ret, new_addr); - s390_kernel_write(plt + (bpf_plt_target - bpf_plt), - new_plt + (bpf_plt_target - bpf_plt), + bpf_jit_plt(&new_plt, ret, new_addr); + s390_kernel_write(&plt->target, &new_plt.target, sizeof(void *)); } |