diff options
Diffstat (limited to 'arch/riscv/net/bpf_jit_core.c')
| -rw-r--r-- | arch/riscv/net/bpf_jit_core.c | 118 |
1 files changed, 90 insertions, 28 deletions
diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c index 7a26a3e1c73c..f6ca5cfa6b2f 100644 --- a/arch/riscv/net/bpf_jit_core.c +++ b/arch/riscv/net/bpf_jit_core.c @@ -8,6 +8,9 @@ #include <linux/bpf.h> #include <linux/filter.h> +#include <linux/memory.h> +#include <asm/text-patching.h> +#include <asm/cfi.h> #include "bpf_jit.h" /* Number of iterations to try until offsets converge. */ @@ -23,9 +26,8 @@ static int build_body(struct rv_jit_context *ctx, bool extra_pass, int *offset) int ret; ret = bpf_jit_emit_insn(insn, ctx, extra_pass); - /* BPF_LD | BPF_IMM | BPF_DW: skip the next instruction. */ if (ret > 0) - i++; + i++; /* skip the next instruction */ if (offset) offset[i] = ctx->ninsns; if (ret < 0) @@ -77,6 +79,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) goto skip_init_ctx; } + ctx->arena_vm_start = bpf_arena_get_kern_vm_start(prog->aux->arena); + ctx->user_vm_start = bpf_arena_get_user_vm_start(prog->aux->arena); ctx->prog = prog; ctx->offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL); if (!ctx->offset) { @@ -98,7 +102,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) pass++; ctx->ninsns = 0; - bpf_jit_build_prologue(ctx); + bpf_jit_build_prologue(ctx, bpf_is_subprog(prog)); ctx->prologue_len = ctx->ninsns; if (build_body(ctx, extra_pass, ctx->offset)) { @@ -117,16 +121,24 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) sizeof(struct exception_table_entry); prog_size = sizeof(*ctx->insns) * ctx->ninsns; - jit_data->header = - bpf_jit_binary_alloc(prog_size + extable_size, - &jit_data->image, - sizeof(u32), - bpf_fill_ill_insns); - if (!jit_data->header) { + jit_data->ro_header = + bpf_jit_binary_pack_alloc(prog_size + extable_size, + &jit_data->ro_image, sizeof(u32), + &jit_data->header, &jit_data->image, + bpf_fill_ill_insns); + if (!jit_data->ro_header) { prog = orig_prog; goto out_offset; } + /* + * Use the image(RW) for writing the JITed instructions. But also save + * the ro_image(RX) for calculating the offsets in the image. The RW + * image will be later copied to the RX image from where the program + * will run. The bpf_jit_binary_pack_finalize() will do this copy in the + * final step. + */ + ctx->ro_insns = (u16 *)jit_data->ro_image; ctx->insns = (u16 *)jit_data->image; /* * Now, when the image is allocated, the image can @@ -138,39 +150,46 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) if (i == NR_JIT_ITERATIONS) { pr_err("bpf-jit: image did not converge in <%d passes!\n", i); - if (jit_data->header) - bpf_jit_binary_free(jit_data->header); prog = orig_prog; - goto out_offset; + goto out_free_hdr; } if (extable_size) - prog->aux->extable = (void *)ctx->insns + prog_size; + prog->aux->extable = (void *)ctx->ro_insns + prog_size; skip_init_ctx: pass++; ctx->ninsns = 0; ctx->nexentries = 0; - bpf_jit_build_prologue(ctx); + bpf_jit_build_prologue(ctx, bpf_is_subprog(prog)); if (build_body(ctx, extra_pass, NULL)) { - bpf_jit_binary_free(jit_data->header); prog = orig_prog; - goto out_offset; + goto out_free_hdr; } bpf_jit_build_epilogue(ctx); if (bpf_jit_enable > 1) bpf_jit_dump(prog->len, prog_size, pass, ctx->insns); - prog->bpf_func = (void *)ctx->insns; + prog->bpf_func = (void *)ctx->ro_insns + cfi_get_offset(); prog->jited = 1; - prog->jited_len = prog_size; - - bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns); + prog->jited_len = prog_size - cfi_get_offset(); if (!prog->is_func || extra_pass) { - bpf_jit_binary_lock_ro(jit_data->header); + if (WARN_ON(bpf_jit_binary_pack_finalize(jit_data->ro_header, jit_data->header))) { + /* ro_header has been freed */ + jit_data->ro_header = NULL; + prog = orig_prog; + goto out_offset; + } + /* + * The instructions have now been copied to the ROX region from + * where they will execute. + * Write any modified data cache blocks out to memory and + * invalidate the corresponding blocks in the instruction cache. + */ + bpf_flush_icache(jit_data->ro_header, ctx->ro_insns + ctx->ninsns); for (i = 0; i < prog->len; i++) ctx->offset[i] = ninsns_rvoff(ctx->offset[i]); bpf_prog_fill_jited_linfo(prog, ctx->offset); @@ -185,6 +204,14 @@ out: bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); return prog; + +out_free_hdr: + if (jit_data->header) { + bpf_arch_text_copy(&jit_data->ro_header->size, &jit_data->header->size, + sizeof(jit_data->header->size)); + bpf_jit_binary_pack_free(jit_data->ro_header, jit_data->header); + } + goto out_offset; } u64 bpf_jit_alloc_exec_limit(void) @@ -192,15 +219,50 @@ u64 bpf_jit_alloc_exec_limit(void) return BPF_JIT_REGION_SIZE; } -void *bpf_jit_alloc_exec(unsigned long size) +void *bpf_arch_text_copy(void *dst, void *src, size_t len) { - return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START, - BPF_JIT_REGION_END, GFP_KERNEL, - PAGE_KERNEL, 0, NUMA_NO_NODE, - __builtin_return_address(0)); + int ret; + + mutex_lock(&text_mutex); + ret = patch_text_nosync(dst, src, len); + mutex_unlock(&text_mutex); + + if (ret) + return ERR_PTR(-EINVAL); + + return dst; +} + +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + int ret; + + mutex_lock(&text_mutex); + ret = patch_text_set_nosync(dst, 0, len); + mutex_unlock(&text_mutex); + + return ret; } -void bpf_jit_free_exec(void *addr) +void bpf_jit_free(struct bpf_prog *prog) { - return vfree(addr); + if (prog->jited) { + struct rv_jit_data *jit_data = prog->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(jit_data->ro_header, jit_data->header); + kfree(jit_data); + } + hdr = bpf_jit_binary_pack_hdr(prog); + bpf_jit_binary_pack_free(hdr, NULL); + WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog)); + } + + bpf_prog_unlock_free(prog); } |