From 90d862f370b6e9de1b5d607843c5a2f9823990f3 Mon Sep 17 00:00:00 2001 From: Hari Bathini Date: Fri, 20 Oct 2023 19:43:58 +0530 Subject: powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free] Use bpf_jit_binary_pack_alloc in powerpc jit. The jit engine first writes the program to the rw buffer. When the jit is done, the program is copied to the final location with bpf_jit_binary_pack_finalize. With multiple jit_subprogs, bpf_jit_free is called on some subprograms that haven't got bpf_jit_binary_pack_finalize() yet. Implement custom bpf_jit_free() like in commit 1d5f82d9dd47 ("bpf, x86: fix freeing of not-finalized bpf_prog_pack") to call bpf_jit_binary_pack_finalize(), if necessary. As bpf_flush_icache() is not needed anymore, remove it. Signed-off-by: Hari Bathini Acked-by: Song Liu Signed-off-by: Michael Ellerman Link: https://msgid.link/20231020141358.643575-6-hbathini@linux.ibm.com --- arch/powerpc/net/bpf_jit.h | 18 ++----- arch/powerpc/net/bpf_jit_comp.c | 106 ++++++++++++++++++++++++++++---------- arch/powerpc/net/bpf_jit_comp32.c | 13 ++--- arch/powerpc/net/bpf_jit_comp64.c | 10 ++-- 4 files changed, 96 insertions(+), 51 deletions(-) diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 72b7bb34fade..cdea5dccaefe 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -36,9 +36,6 @@ EMIT(PPC_RAW_BRANCH(offset)); \ } while (0) -/* bl (unconditional 'branch' with link) */ -#define PPC_BL(dest) EMIT(PPC_RAW_BL((dest) - (unsigned long)(image + ctx->idx))) - /* "cond" here covers BO:BI fields. */ #define PPC_BCC_SHORT(cond, dest) \ do { \ @@ -147,12 +144,6 @@ struct codegen_context { #define BPF_FIXUP_LEN 2 /* Two instructions => 8 bytes */ #endif -static inline void bpf_flush_icache(void *start, void *end) -{ - smp_wmb(); /* smp write barrier */ - flush_icache_range((unsigned long)start, (unsigned long)end); -} - static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i) { return ctx->seen & (1 << (31 - i)); @@ -169,16 +160,17 @@ static inline void bpf_clear_seen_register(struct codegen_context *ctx, int i) } void bpf_jit_init_reg_mapping(struct codegen_context *ctx); -int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func); -int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func); +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, u32 *addrs, int pass, bool extra_pass); void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx); void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx); void bpf_jit_realloc_regs(struct codegen_context *ctx); int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr); -int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx, - int insn_idx, int jmp_off, int dst_reg); +int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, u32 *fimage, int pass, + struct codegen_context *ctx, int insn_idx, + int jmp_off, int dst_reg); #endif diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index 7a01bbc2513a..0f9a21783329 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -44,9 +44,12 @@ int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, } struct powerpc_jit_data { - struct bpf_binary_header *header; + /* address of rw header */ + struct bpf_binary_header *hdr; + /* address of ro final header */ + struct bpf_binary_header *fhdr; u32 *addrs; - u8 *image; + u8 *fimage; u32 proglen; struct codegen_context ctx; }; @@ -67,11 +70,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) struct codegen_context cgctx; int pass; int flen; - struct bpf_binary_header *bpf_hdr; + struct bpf_binary_header *fhdr = NULL; + struct bpf_binary_header *hdr = NULL; struct bpf_prog *org_fp = fp; struct bpf_prog *tmp_fp; bool bpf_blinded = false; bool extra_pass = false; + u8 *fimage = NULL; + u32 *fcode_base; u32 extable_len; u32 fixup_len; @@ -101,9 +107,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) addrs = jit_data->addrs; if (addrs) { cgctx = jit_data->ctx; - image = jit_data->image; - bpf_hdr = jit_data->header; + /* + * JIT compiled to a writable location (image/code_base) first. + * It is then moved to the readonly final location (fimage/fcode_base) + * using instruction patching. + */ + fimage = jit_data->fimage; + fhdr = jit_data->fhdr; proglen = jit_data->proglen; + hdr = jit_data->hdr; + image = (void *)hdr + ((void *)fimage - (void *)fhdr); extra_pass = true; /* During extra pass, ensure index is reset before repopulating extable entries */ cgctx.exentry_idx = 0; @@ -123,7 +136,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) cgctx.stack_size = round_up(fp->aux->stack_depth, 16); /* Scouting faux-generate pass 0 */ - if (bpf_jit_build_body(fp, 0, &cgctx, addrs, 0, false)) { + if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) { /* We hit something illegal or unsupported. */ fp = org_fp; goto out_addrs; @@ -138,7 +151,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) */ if (cgctx.seen & SEEN_TAILCALL || !is_offset_in_branch_range((long)cgctx.idx * 4)) { cgctx.idx = 0; - if (bpf_jit_build_body(fp, 0, &cgctx, addrs, 0, false)) { + if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) { fp = org_fp; goto out_addrs; } @@ -160,17 +173,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) proglen = cgctx.idx * 4; alloclen = proglen + FUNCTION_DESCR_SIZE + fixup_len + extable_len; - bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, bpf_jit_fill_ill_insns); - if (!bpf_hdr) { + fhdr = bpf_jit_binary_pack_alloc(alloclen, &fimage, 4, &hdr, &image, + bpf_jit_fill_ill_insns); + if (!fhdr) { fp = org_fp; goto out_addrs; } if (extable_len) - fp->aux->extable = (void *)image + FUNCTION_DESCR_SIZE + proglen + fixup_len; + fp->aux->extable = (void *)fimage + FUNCTION_DESCR_SIZE + proglen + fixup_len; skip_init_ctx: code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); + fcode_base = (u32 *)(fimage + FUNCTION_DESCR_SIZE); /* Code generation passes 1-2 */ for (pass = 1; pass < 3; pass++) { @@ -178,8 +193,10 @@ skip_init_ctx: cgctx.idx = 0; cgctx.alt_exit_addr = 0; bpf_jit_build_prologue(code_base, &cgctx); - if (bpf_jit_build_body(fp, code_base, &cgctx, addrs, pass, extra_pass)) { - bpf_jit_binary_free(bpf_hdr); + if (bpf_jit_build_body(fp, code_base, fcode_base, &cgctx, addrs, pass, + extra_pass)) { + bpf_arch_text_copy(&fhdr->size, &hdr->size, sizeof(hdr->size)); + bpf_jit_binary_pack_free(fhdr, hdr); fp = org_fp; goto out_addrs; } @@ -199,17 +216,19 @@ skip_init_ctx: #ifdef CONFIG_PPC64_ELF_ABI_V1 /* Function descriptor nastiness: Address + TOC */ - ((u64 *)image)[0] = (u64)code_base; + ((u64 *)image)[0] = (u64)fcode_base; ((u64 *)image)[1] = local_paca->kernel_toc; #endif - fp->bpf_func = (void *)image; + fp->bpf_func = (void *)fimage; fp->jited = 1; fp->jited_len = proglen + FUNCTION_DESCR_SIZE; - bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + bpf_hdr->size); if (!fp->is_func || extra_pass) { - bpf_jit_binary_lock_ro(bpf_hdr); + if (bpf_jit_binary_pack_finalize(fp, fhdr, hdr)) { + fp = org_fp; + goto out_addrs; + } bpf_prog_fill_jited_linfo(fp, addrs); out_addrs: kfree(addrs); @@ -219,8 +238,9 @@ out_addrs: jit_data->addrs = addrs; jit_data->ctx = cgctx; jit_data->proglen = proglen; - jit_data->image = image; - jit_data->header = bpf_hdr; + jit_data->fimage = fimage; + jit_data->fhdr = fhdr; + jit_data->hdr = hdr; } out: @@ -234,12 +254,13 @@ out: * The caller should check for (BPF_MODE(code) == BPF_PROBE_MEM) before calling * this function, as this only applies to BPF_PROBE_MEM, for now. */ -int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx, - int insn_idx, int jmp_off, int dst_reg) +int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, u32 *fimage, int pass, + struct codegen_context *ctx, int insn_idx, int jmp_off, + int dst_reg) { off_t offset; unsigned long pc; - struct exception_table_entry *ex; + struct exception_table_entry *ex, *ex_entry; u32 *fixup; /* Populate extable entries only in the last pass */ @@ -250,9 +271,16 @@ int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct code WARN_ON_ONCE(ctx->exentry_idx >= fp->aux->num_exentries)) return -EINVAL; + /* + * Program is first written to image before copying to the + * final location (fimage). Accordingly, update in the image first. + * As all offsets used are relative, copying as is to the + * final location should be alright. + */ pc = (unsigned long)&image[insn_idx]; + ex = (void *)fp->aux->extable - (void *)fimage + (void *)image; - fixup = (void *)fp->aux->extable - + fixup = (void *)ex - (fp->aux->num_exentries * BPF_FIXUP_LEN * 4) + (ctx->exentry_idx * BPF_FIXUP_LEN * 4); @@ -263,17 +291,17 @@ int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct code fixup[BPF_FIXUP_LEN - 1] = PPC_RAW_BRANCH((long)(pc + jmp_off) - (long)&fixup[BPF_FIXUP_LEN - 1]); - ex = &fp->aux->extable[ctx->exentry_idx]; + ex_entry = &ex[ctx->exentry_idx]; - offset = pc - (long)&ex->insn; + offset = pc - (long)&ex_entry->insn; if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) return -ERANGE; - ex->insn = offset; + ex_entry->insn = offset; - offset = (long)fixup - (long)&ex->fixup; + offset = (long)fixup - (long)&ex_entry->fixup; if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) return -ERANGE; - ex->fixup = offset; + ex_entry->fixup = offset; ctx->exentry_idx++; return 0; @@ -307,3 +335,27 @@ int bpf_arch_text_invalidate(void *dst, size_t len) return ret; } + +void bpf_jit_free(struct bpf_prog *fp) +{ + if (fp->jited) { + struct powerpc_jit_data *jit_data = fp->aux->jit_data; + struct bpf_binary_header *hdr; + + /* + * If we fail the final pass of JIT (from jit_subprogs), + * the program may not be finalized yet. Call finalize here + * before freeing it. + */ + if (jit_data) { + bpf_jit_binary_pack_finalize(fp, jit_data->fhdr, jit_data->hdr); + kvfree(jit_data->addrs); + kfree(jit_data); + } + hdr = bpf_jit_binary_pack_hdr(fp); + bpf_jit_binary_pack_free(hdr, NULL); + WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); + } + + bpf_prog_unlock_free(fp); +} diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index bc7f92ec7f2d..2f39c50ca729 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -200,12 +200,13 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) EMIT(PPC_RAW_BLR()); } -int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func) +/* Relative offset needs to be calculated based on final image location */ +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func) { - s32 rel = (s32)func - (s32)(image + ctx->idx); + s32 rel = (s32)func - (s32)(fimage + ctx->idx); if (image && rel < 0x2000000 && rel >= -0x2000000) { - PPC_BL(func); + EMIT(PPC_RAW_BL(rel)); } else { /* Load function address into r0 */ EMIT(PPC_RAW_LIS(_R0, IMM_H(func))); @@ -278,7 +279,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o } /* Assemble the body code between the prologue & epilogue */ -int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, u32 *addrs, int pass, bool extra_pass) { const struct bpf_insn *insn = fp->insnsi; @@ -997,7 +998,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * jmp_off += 4; } - ret = bpf_add_extable_entry(fp, image, pass, ctx, insn_idx, + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, insn_idx, jmp_off, dst_reg); if (ret) return ret; @@ -1053,7 +1054,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_STW(bpf_to_ppc(BPF_REG_5), _R1, 12)); } - ret = bpf_jit_emit_func_call_rel(image, ctx, func_addr); + ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); if (ret) return ret; diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 0f8048f6dad6..79f23974a320 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -240,7 +240,7 @@ static int bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, u return 0; } -int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func) +int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func) { unsigned int i, ctx_idx = ctx->idx; @@ -361,7 +361,7 @@ asm ( ); /* Assemble the body code between the prologue & epilogue */ -int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, u32 *addrs, int pass, bool extra_pass) { enum stf_barrier_type stf_barrier = stf_barrier_type_get(); @@ -940,8 +940,8 @@ emit_clear: addrs[++i] = ctx->idx * 4; if (BPF_MODE(code) == BPF_PROBE_MEM) { - ret = bpf_add_extable_entry(fp, image, pass, ctx, ctx->idx - 1, - 4, dst_reg); + ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx, + ctx->idx - 1, 4, dst_reg); if (ret) return ret; } @@ -995,7 +995,7 @@ emit_clear: if (func_addr_fixed) ret = bpf_jit_emit_func_call_hlp(image, ctx, func_addr); else - ret = bpf_jit_emit_func_call_rel(image, ctx, func_addr); + ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr); if (ret) return ret; -- cgit