diff options
author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-03-22 16:37:49 +0000 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-03 21:22:20 +1100 |
commit | 4ea76e90a97d22f86adbb10044d29d919e620f2e (patch) | |
tree | 68d7f6e77adee278a947f002bfd3a1c64268a4b4 | |
parent | f1b1583d5faa86cb3dcb7b740594868debad7c30 (diff) | |
download | linux-4ea76e90a97d22f86adbb10044d29d919e620f2e.tar.bz2 |
powerpc/bpf: Move common functions into bpf_jit_comp.c
Move into bpf_jit_comp.c the functions that will remain common to
PPC64 and PPC32 when we add support of EBPF for PPC32.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2c339d77fb168ef12b213ccddfee3cb6c8ce8ae1.1616430991.git.christophe.leroy@csgroup.eu
-rw-r--r-- | arch/powerpc/net/Makefile | 2 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit.h | 6 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_comp.c | 269 | ||||
-rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 263 |
4 files changed, 281 insertions, 259 deletions
diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile index 52c939cef5b2..969cde177880 100644 --- a/arch/powerpc/net/Makefile +++ b/arch/powerpc/net/Makefile @@ -2,4 +2,4 @@ # # Arch-specific network modules # -obj-$(CONFIG_BPF_JIT) += bpf_jit_comp64.o +obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o bpf_jit_comp64.o diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index b8fa6908fc5e..b34abfce15a6 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -143,6 +143,12 @@ static inline void bpf_set_seen_register(struct codegen_context *ctx, int i) ctx->seen |= 1 << (31 - i); } +void 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, + u32 *addrs, 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); + #endif #endif diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c new file mode 100644 index 000000000000..efac89964873 --- /dev/null +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -0,0 +1,269 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * eBPF JIT compiler + * + * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> + * IBM Corporation + * + * Based on the powerpc classic BPF JIT compiler by Matt Evans + */ +#include <linux/moduleloader.h> +#include <asm/cacheflush.h> +#include <asm/asm-compat.h> +#include <linux/netdevice.h> +#include <linux/filter.h> +#include <linux/if_vlan.h> +#include <asm/kprobes.h> +#include <linux/bpf.h> + +#include "bpf_jit.h" + +static void bpf_jit_fill_ill_insns(void *area, unsigned int size) +{ + memset32(area, BREAKPOINT_INSTRUCTION, size / 4); +} + +/* Fix the branch target addresses for subprog calls */ +static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image, + struct codegen_context *ctx, u32 *addrs) +{ + const struct bpf_insn *insn = fp->insnsi; + bool func_addr_fixed; + u64 func_addr; + u32 tmp_idx; + int i, ret; + + for (i = 0; i < fp->len; i++) { + /* + * During the extra pass, only the branch target addresses for + * the subprog calls need to be fixed. All other instructions + * can left untouched. + * + * The JITed image length does not change because we already + * ensure that the JITed instruction sequence for these calls + * are of fixed length by padding them with NOPs. + */ + if (insn[i].code == (BPF_JMP | BPF_CALL) && + insn[i].src_reg == BPF_PSEUDO_CALL) { + ret = bpf_jit_get_func_addr(fp, &insn[i], true, + &func_addr, + &func_addr_fixed); + if (ret < 0) + return ret; + + /* + * Save ctx->idx as this would currently point to the + * end of the JITed image and set it to the offset of + * the instruction sequence corresponding to the + * subprog call temporarily. + */ + tmp_idx = ctx->idx; + ctx->idx = addrs[i] / 4; + bpf_jit_emit_func_call_rel(image, ctx, func_addr); + + /* + * Restore ctx->idx here. This is safe as the length + * of the JITed sequence remains unchanged. + */ + ctx->idx = tmp_idx; + } + } + + return 0; +} + +struct powerpc64_jit_data { + struct bpf_binary_header *header; + u32 *addrs; + u8 *image; + u32 proglen; + struct codegen_context ctx; +}; + +bool bpf_jit_needs_zext(void) +{ + return true; +} + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) +{ + u32 proglen; + u32 alloclen; + u8 *image = NULL; + u32 *code_base; + u32 *addrs; + struct powerpc64_jit_data *jit_data; + struct codegen_context cgctx; + int pass; + int flen; + struct bpf_binary_header *bpf_hdr; + struct bpf_prog *org_fp = fp; + struct bpf_prog *tmp_fp; + bool bpf_blinded = false; + bool extra_pass = false; + + if (!fp->jit_requested) + return org_fp; + + tmp_fp = bpf_jit_blind_constants(org_fp); + if (IS_ERR(tmp_fp)) + return org_fp; + + if (tmp_fp != org_fp) { + bpf_blinded = true; + fp = tmp_fp; + } + + jit_data = fp->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + fp = org_fp; + goto out; + } + fp->aux->jit_data = jit_data; + } + + flen = fp->len; + addrs = jit_data->addrs; + if (addrs) { + cgctx = jit_data->ctx; + image = jit_data->image; + bpf_hdr = jit_data->header; + proglen = jit_data->proglen; + alloclen = proglen + FUNCTION_DESCR_SIZE; + extra_pass = true; + goto skip_init_ctx; + } + + addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL); + if (addrs == NULL) { + fp = org_fp; + goto out_addrs; + } + + memset(&cgctx, 0, sizeof(struct codegen_context)); + + /* Make sure that the stack is quadword aligned. */ + cgctx.stack_size = round_up(fp->aux->stack_depth, 16); + + /* Scouting faux-generate pass 0 */ + if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { + /* We hit something illegal or unsupported. */ + fp = org_fp; + goto out_addrs; + } + + /* + * If we have seen a tail call, we need a second pass. + * This is because bpf_jit_emit_common_epilogue() is called + * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen. + */ + if (cgctx.seen & SEEN_TAILCALL) { + cgctx.idx = 0; + if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { + fp = org_fp; + goto out_addrs; + } + } + + /* + * Pretend to build prologue, given the features we've seen. This will + * update ctgtx.idx as it pretends to output instructions, then we can + * calculate total size from idx. + */ + bpf_jit_build_prologue(0, &cgctx); + bpf_jit_build_epilogue(0, &cgctx); + + proglen = cgctx.idx * 4; + alloclen = proglen + FUNCTION_DESCR_SIZE; + + bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, bpf_jit_fill_ill_insns); + if (!bpf_hdr) { + fp = org_fp; + goto out_addrs; + } + +skip_init_ctx: + code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); + + if (extra_pass) { + /* + * Do not touch the prologue and epilogue as they will remain + * unchanged. Only fix the branch target address for subprog + * calls in the body. + * + * This does not change the offsets and lengths of the subprog + * call instruction sequences and hence, the size of the JITed + * image as well. + */ + bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs); + + /* There is no need to perform the usual passes. */ + goto skip_codegen_passes; + } + + /* Code generation passes 1-2 */ + for (pass = 1; pass < 3; pass++) { + /* Now build the prologue, body code & epilogue for real. */ + cgctx.idx = 0; + bpf_jit_build_prologue(code_base, &cgctx); + bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass); + bpf_jit_build_epilogue(code_base, &cgctx); + + if (bpf_jit_enable > 1) + pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, + proglen - (cgctx.idx * 4), cgctx.seen); + } + +skip_codegen_passes: + if (bpf_jit_enable > 1) + /* + * Note that we output the base address of the code_base + * rather than image, since opcodes are in code_base. + */ + bpf_jit_dump(flen, proglen, pass, code_base); + +#ifdef PPC64_ELF_ABI_v1 + /* Function descriptor nastiness: Address + TOC */ + ((u64 *)image)[0] = (u64)code_base; + ((u64 *)image)[1] = local_paca->kernel_toc; +#endif + + fp->bpf_func = (void *)image; + fp->jited = 1; + fp->jited_len = alloclen; + + bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE)); + if (!fp->is_func || extra_pass) { + bpf_prog_fill_jited_linfo(fp, addrs); +out_addrs: + kfree(addrs); + kfree(jit_data); + fp->aux->jit_data = NULL; + } else { + jit_data->addrs = addrs; + jit_data->ctx = cgctx; + jit_data->proglen = proglen; + jit_data->image = image; + jit_data->header = bpf_hdr; + } + +out: + if (bpf_blinded) + bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp); + + return fp; +} + +/* Overriding bpf_jit_free() as we don't set images read-only. */ +void bpf_jit_free(struct bpf_prog *fp) +{ + unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; + struct bpf_binary_header *bpf_hdr = (void *)addr; + + if (fp->jited) + bpf_jit_binary_free(bpf_hdr); + + bpf_prog_unlock_free(fp); +} diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 111451bc5cc0..8a1f9fb00e78 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -18,11 +18,6 @@ #include "bpf_jit64.h" -static void bpf_jit_fill_ill_insns(void *area, unsigned int size) -{ - memset32(area, BREAKPOINT_INSTRUCTION, size/4); -} - static inline bool bpf_has_stack_frame(struct codegen_context *ctx) { /* @@ -69,7 +64,7 @@ static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg) BUG(); } -static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) +void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) { int i; @@ -136,7 +131,7 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx } } -static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) { bpf_jit_emit_common_epilogue(image, ctx); @@ -171,8 +166,7 @@ static void bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx, EMIT(PPC_RAW_BLRL()); } -static void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, - u64 func) +void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func) { unsigned int i, ctx_idx = ctx->idx; @@ -273,9 +267,8 @@ static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 } /* Assemble the body code between the prologue & epilogue */ -static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, - struct codegen_context *ctx, - u32 *addrs, bool extra_pass) +int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx, + u32 *addrs, bool extra_pass) { const struct bpf_insn *insn = fp->insnsi; int flen = fp->len; @@ -1010,249 +1003,3 @@ cond_branch: return 0; } - -/* Fix the branch target addresses for subprog calls */ -static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image, - struct codegen_context *ctx, u32 *addrs) -{ - const struct bpf_insn *insn = fp->insnsi; - bool func_addr_fixed; - u64 func_addr; - u32 tmp_idx; - int i, ret; - - for (i = 0; i < fp->len; i++) { - /* - * During the extra pass, only the branch target addresses for - * the subprog calls need to be fixed. All other instructions - * can left untouched. - * - * The JITed image length does not change because we already - * ensure that the JITed instruction sequence for these calls - * are of fixed length by padding them with NOPs. - */ - if (insn[i].code == (BPF_JMP | BPF_CALL) && - insn[i].src_reg == BPF_PSEUDO_CALL) { - ret = bpf_jit_get_func_addr(fp, &insn[i], true, - &func_addr, - &func_addr_fixed); - if (ret < 0) - return ret; - - /* - * Save ctx->idx as this would currently point to the - * end of the JITed image and set it to the offset of - * the instruction sequence corresponding to the - * subprog call temporarily. - */ - tmp_idx = ctx->idx; - ctx->idx = addrs[i] / 4; - bpf_jit_emit_func_call_rel(image, ctx, func_addr); - - /* - * Restore ctx->idx here. This is safe as the length - * of the JITed sequence remains unchanged. - */ - ctx->idx = tmp_idx; - } - } - - return 0; -} - -struct powerpc64_jit_data { - struct bpf_binary_header *header; - u32 *addrs; - u8 *image; - u32 proglen; - struct codegen_context ctx; -}; - -bool bpf_jit_needs_zext(void) -{ - return true; -} - -struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) -{ - u32 proglen; - u32 alloclen; - u8 *image = NULL; - u32 *code_base; - u32 *addrs; - struct powerpc64_jit_data *jit_data; - struct codegen_context cgctx; - int pass; - int flen; - struct bpf_binary_header *bpf_hdr; - struct bpf_prog *org_fp = fp; - struct bpf_prog *tmp_fp; - bool bpf_blinded = false; - bool extra_pass = false; - - if (!fp->jit_requested) - return org_fp; - - tmp_fp = bpf_jit_blind_constants(org_fp); - if (IS_ERR(tmp_fp)) - return org_fp; - - if (tmp_fp != org_fp) { - bpf_blinded = true; - fp = tmp_fp; - } - - jit_data = fp->aux->jit_data; - if (!jit_data) { - jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); - if (!jit_data) { - fp = org_fp; - goto out; - } - fp->aux->jit_data = jit_data; - } - - flen = fp->len; - addrs = jit_data->addrs; - if (addrs) { - cgctx = jit_data->ctx; - image = jit_data->image; - bpf_hdr = jit_data->header; - proglen = jit_data->proglen; - alloclen = proglen + FUNCTION_DESCR_SIZE; - extra_pass = true; - goto skip_init_ctx; - } - - addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL); - if (addrs == NULL) { - fp = org_fp; - goto out_addrs; - } - - memset(&cgctx, 0, sizeof(struct codegen_context)); - - /* Make sure that the stack is quadword aligned. */ - cgctx.stack_size = round_up(fp->aux->stack_depth, 16); - - /* Scouting faux-generate pass 0 */ - if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { - /* We hit something illegal or unsupported. */ - fp = org_fp; - goto out_addrs; - } - - /* - * If we have seen a tail call, we need a second pass. - * This is because bpf_jit_emit_common_epilogue() is called - * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen. - */ - if (cgctx.seen & SEEN_TAILCALL) { - cgctx.idx = 0; - if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) { - fp = org_fp; - goto out_addrs; - } - } - - /* - * Pretend to build prologue, given the features we've seen. This will - * update ctgtx.idx as it pretends to output instructions, then we can - * calculate total size from idx. - */ - bpf_jit_build_prologue(0, &cgctx); - bpf_jit_build_epilogue(0, &cgctx); - - proglen = cgctx.idx * 4; - alloclen = proglen + FUNCTION_DESCR_SIZE; - - bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, - bpf_jit_fill_ill_insns); - if (!bpf_hdr) { - fp = org_fp; - goto out_addrs; - } - -skip_init_ctx: - code_base = (u32 *)(image + FUNCTION_DESCR_SIZE); - - if (extra_pass) { - /* - * Do not touch the prologue and epilogue as they will remain - * unchanged. Only fix the branch target address for subprog - * calls in the body. - * - * This does not change the offsets and lengths of the subprog - * call instruction sequences and hence, the size of the JITed - * image as well. - */ - bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs); - - /* There is no need to perform the usual passes. */ - goto skip_codegen_passes; - } - - /* Code generation passes 1-2 */ - for (pass = 1; pass < 3; pass++) { - /* Now build the prologue, body code & epilogue for real. */ - cgctx.idx = 0; - bpf_jit_build_prologue(code_base, &cgctx); - bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass); - bpf_jit_build_epilogue(code_base, &cgctx); - - if (bpf_jit_enable > 1) - pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass, - proglen - (cgctx.idx * 4), cgctx.seen); - } - -skip_codegen_passes: - if (bpf_jit_enable > 1) - /* - * Note that we output the base address of the code_base - * rather than image, since opcodes are in code_base. - */ - bpf_jit_dump(flen, proglen, pass, code_base); - -#ifdef PPC64_ELF_ABI_v1 - /* Function descriptor nastiness: Address + TOC */ - ((u64 *)image)[0] = (u64)code_base; - ((u64 *)image)[1] = local_paca->kernel_toc; -#endif - - fp->bpf_func = (void *)image; - fp->jited = 1; - fp->jited_len = alloclen; - - bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE)); - if (!fp->is_func || extra_pass) { - bpf_prog_fill_jited_linfo(fp, addrs); -out_addrs: - kfree(addrs); - kfree(jit_data); - fp->aux->jit_data = NULL; - } else { - jit_data->addrs = addrs; - jit_data->ctx = cgctx; - jit_data->proglen = proglen; - jit_data->image = image; - jit_data->header = bpf_hdr; - } - -out: - if (bpf_blinded) - bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp); - - return fp; -} - -/* Overriding bpf_jit_free() as we don't set images read-only. */ -void bpf_jit_free(struct bpf_prog *fp) -{ - unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; - struct bpf_binary_header *bpf_hdr = (void *)addr; - - if (fp->jited) - bpf_jit_binary_free(bpf_hdr); - - bpf_prog_unlock_free(fp); -} |